THE PURPOSE article pro vide basic information will allow make own Giant Scale props mathematical formulas theory intentionally omitted Tools props shaped band saw 12-in disc sander 3-in drum sander mounted drill press will have access tools have some alternatives suggest cant yourself find some cut prop blanks straight-grained hard maple can use 5/16-in drill bit preferably mounted drill press youll need have some method removing wood prop blankand High Point balancer equal Alternatives disc drum sanders include belt sander draw knife spoke shave block plane surform file drum roto rasp possible variety prop shapes well diameter pitch limitless carve own few examples Carving model props almost lost art what wonderful varieties fered modeling industry Still may able buy exactly what looking Carv ing own may best choice doesnt take long might think U Wendell Hostetler Carve Props etc band saw almost necessity although might able get jigsaw saber saw important use coarse abrasive paper initial shaping no finer 50-grit final hand sanding done 80 220-grit garnet alu minum oxide paper Example propeller words pic tures going show steps 1 Prop profile layout face prop blank2 Layout leading edge prop blank Giant Scale - 7 Th-r7f77ThThZ2Iz VTh2fl - - . p-4 k -~-- - -A - ------ --- Il /1 I/I 89/O////3/4/6/B2O2 a68oz i36IMI - 1 1.J.i...L.1... 20 22 24 Y8#O making 18-in-diameter prop pitch approximately 9 type prop has very good 24 Kioritz engine flying 22 28-lb bi planes should turn close 8000 rpm static ground unload air close peak en gines horsepower curve Step 1 Cut blank straight grained kiln-dried hard maple size x 1-5/8 x 18 Keep angles 90 degrees Step 2 Lay out center lines circle hub prop design profile face blank Photo 1 Mark lines leading edge prop represent face back surfaces prop Photo 2 Lay out 1 /8-in-wide lines end blank Photo 3 Drawings Al A2 used example layout Its important use centerline refer encing pattern blank Step 3 Drill 5/16-in hole hole size engines shaft center prop blank Use center punch drilling guideand use drill press Step 4 Cut out prop blank per layout Photos 5 6 Step 5 Remove wood back surface amount shown Photos 9 10 Note Photo 10 area removed comes within 1/8 top leading edge near hub tapers thinner toward tip allows shaping leading edge obtain approximately Clark Y air foil blade Step 6 Shape wood face prop Photo 14 shows area removed first Step 7 Roughly check horizontal balance should done major wood removals made Yoi se Te surface Stan surfw iside aft rop rotates theairi 3p both sides major imbalance likely due unequal shaping Step 8 Hand-sand prop abrasive wrapped around wood block starting 80-grit progressing 220-grit sanding should remove irregularities left drum sander Step 9 Carefully check horizontal balance Sand off lumps heavy side until both sides same weight June 1984 55 J 0 nI$id LA 0 4 0 2468 /0 /2 4 /6 /8 NO OCR TEXT Left 6 Cut being made line representing leading edge cut off wedge tip will tack-glued blank final cuts Right 7 blank ready shaping Above 10 view Ot leading edge showing same shaded area Photo 9 material needs removed Right 11 rough cut being made disc sander back side blank 9 shaded area represents wood needs removed shape beck Step 10 Check vertical balance Photo 17 prop falls off right left vertical position re move some material heavy side area hub prop re fuses balance vertically sanding place small pan head sheet metal screw light side center hub area Photo 18 Step 11 Final-sand prop 220-grit paper block Check final balance sanding heavy blade until balance perfect Photo 19 Step 12 Drill remaining holes prop hub required en gine Finishing prop may used running flight after Step 12 usually finish prop several ways simple finish consists coat auto body primer followed coat acrylic enamel natural clear finish use two coats Zip Guard followed Verathane polyure thane finish sanding between coats recommended deluxe finish obtained following manner Spray two three coats Super Poxy Primer Sand between coat 220-grit abrasive 2 Spray desired color wet-sand 400 600-grit 3 Mask contrasting color tips stripes desired 4 Wet-sand 600-grit paper 5 Insert shaft High Point balancer through prop spray coat clear Super Poxy 5 Balance prop spraying lighter blade until weight equal ized Sometimes just use Super Poxy June 1984 57 wont learn dont try array its apparent author has learned plenty probably wont visible magazine reproduction diameter pitch tip thickness recorded prop together kind performance gave Primer balance prop go flying Using Pitch Chart pitch prop can determined follows Cut about six wedge-shaped pieces filecard stock equal varying slope 9 14 degrees wedges serted under prop blade threequarters 7 5% distance center prop hub its tipuntil wedge matches blade gle point determined information chart will note 75% point 18-in prop 675 6 prop pitch chart excellent given us good friend Don Chapman got Capt Ralph Kanko USAF originated chart based sound theory saves mathematical calculations will measure pitch props 8 38 diameter 2 30 pitch 18-in prop wedge matches blade angle pitch degrees point 6/4 center 12 degrees pitch can determined chart locating 12 vertical line pitch degrees moving right chart until horizontal line intersects 18 diagonal line prop diameter intersection follow line vertically downward read figure pitch inches example figure 9 9-in pitch prop chart possible de termine pitch prop dis tance its center will explain procedure further Variations As prop diameter increased prop width should also increased Try following widths starters 20 dia l/4 wide 22 dia 1-7/8 wide 23 & 24 dia 2 wide widths absolute experiment several ways change prop pitch may increase decrease pitch increasing decreasing thickness prop blank Pitch will increase approximately 1 1/16 increase thicknessfor props 20-24 range Pitch may also increased de creased increasing decreasing distance center prop point begins taper wards tip farther point center prop greater pitch closer point center prop hub less pitch Pitch may also varied narrowing width prop blank increasing width will decrease pitch ever prefer increase pitch creasing thickness prop blank like decrease pitch prop following way Mark leading edge prop blank shown B2 sketch Decreasing thick ness distance approx 3 center hub will result less pitch decrease thickness 1/8 1/16 side will lower pitch 1 2 though will vary size prop impor tant understand angle lines edge hub out 3-in mark no significance will vary different size props example just happen almost same angle lines repre senting back face prop extend out tip sure sloped lines extend hub area X area side view prop blank hub area must kept flat parallel prop example has constant pitch pitch same points along blade hub tip about 3 center hub pitch degree approx 25 tip pitch degree 9 58 Model Aviation Left 12 finish cut drum sander back side prop Above 13 Corn pleted back surface bottom blank ready hand sanding Check angles pitch degrees same points both blades sure equal see Photo 23 Right 14 Shaded area wood removed face blank trail ing edge right leading edge left Measuring pitch other stations 15 A very rough check horizontal balance 16 Final check horizontal balanceI want find pitch prop tip first measure pitch degree tip example measured 9 center hub 18-india prop angle 9 deg As go prop chart answer must remember chart de signed measure prop pitch threequarters point 6 cen 9-in pitch may want reread above until can fully comprehend simple very important concept variations area experiment profile face prop viewed top leading edge prop blank slightly curved line used represent face prop view A2 drawing Make few props line straight observe results could shift 1/8-in tip thick ness off center either toward front face back surface prop offset tip toward face prop takes different appearance blades look swept-forward offset tip toward back prop blades swept-back performance prop will appreciably af fected slight changes offsetting tip has found rpm may creased several hundred cutting off approximately e tip Remember rebalance prop after tip trim very important keep props thin tips maximum performance Also keep thin reasonably possible cross section throughout Continued page 157 20 Typical leading edge view layout prop blank 21 Various sections tip left hub area right showing approximate Clark V airfoil photos author ter hub example three-quarters point also equals three-quarters point prop diame ter prop rotates Therefore measure pitch degree 9 tip prop must make believe prop has 24-in diameter get correct pitch chart tip Consult numbers inside rectang ular box chart confirm follow 9 pitch degrees legend move over 24-in diameter line down pitch inches answer 9-in pitch Lets try another example measur ing pitch degree 3 hub center prop example measures 25 deg pitch degrees 3-in point Consult chart remem bering now must make believe prop has 8-in diameter get correct pitch reading Follow pitch degrees 8-in diameter down pitch answers answer 9 22 Card stock being used guide datermine thickness prop duplicated 23 Angle wedges cut card stock mea sure pitch degrees Theyre used conjunc tion chart check inches pitch June 1984 59 Len 17 Final check vertical balance Above 18 pan head sheet metal screw serted hub aid vertical balanc ing Right 19 multiple exposure shows properly balanced prop will hold position around 360 degrees rotation flair correctly autorotate safely As far reliability concerned Su perior really holds up blades tend stay track after hardest pullouts would recommend machine anyone looking high-quality general sportcompetition Helicopter careful atten tion should give hours flight before parts start wear As final comment disap pointed aerobatic qualities Superior find ironic machine has done well several contests around world Although Ewald Heim wins Helicopter competitions Europe Star-Ranger common see Superiors finishing close tail second third positions possible am doing something wrong Superioror maybe FAI judges looking something fast-flying acrobats Next month will review Futaba 7GH Helicopter radio discuss van ous features make Helicopter radio what Until next monthBCNU Larry Jolly 5501 W Como Santa Ana CA 92703 RC Giant Scale/Beckman Continued page 53 aircraft lots wings wires Construction basic rugged good selections readily-available spruce pine replacing balsa needed strength arent really beginners models experienced modeler beginner some experienced help will have no trouble some ways building models now will easier first designed days didnt have Giant Scale accessories hinges horns wheels etc avail able now Jerry shows two different airfoils plans semi-symmetrical sport wing obviously scale other undercambered scale air foil latter looks little thick havent researched Im probably wrong sport wing required good flying Most aircraft designs onequarter scale will fly much like real ones have scale outlines airfoils would expect sport wing fly little faster little less floaty big gest advantage sport wing will little easier build has room mounting servos like WW designs wings things two hard beat Im trying find time build Triplane Plans $20 includes shipping plans rolled tube Par tial kits available $130 Pup $140 Triplane Send Behrens Plan Ser vice 3 1-27 Healy Ave Far Rockaway NY 11619 Bryon Fun-Fly Festival Byron Originals hosting Giant Scale Fun-Fly Festival r mmmmmm~rn1 IMode~ Catalog I II II Hundreds unusual tools borrowed Jewelr UGunsmilhing Clock Making professional IModel Making trades NOW AVAiLABLE TO YOU BY MAIL guaranteedI 6II ~thisorsendur couponname address MICROMARK Box 5112 LX ast Main St Clinton NJ 08809 NAME EADDRESS CITY __________________________________________________________ STATE ______ ZIP mJ b third year row annual IMAA Fun-Fly Festival 1984 will held Los Angeles August 16-19 Byron event will same week end three days August 17-19 Anyone attended first two Ida Grove events knows kind facilities provided year Byron nouncement talks about paved runway scale hanger scale tower radar checking flight speed Christen Eagles will hand again last year event provides nice alternative modelers Midwest cannot make trek Los Angeles plan go make motel reservations early few accommodations Ida Grove itself expect up 60 miles away Campers motor homes can probably get space Ida Grove dont crash plane week before Without plane fly part show will just another duespaying spectator behind ropes Bob Beckman 8248 Holly Grove Ct Manassas VA 22110 Props/Hostetler Continued ae 59 length blade Photo 21 shows cross section prop blade sev eral pointsfrom near hub within 3/8 tip sections similar Clark Y airfoil Note back side prop flat leading edge trailing edge point though appears curved finished propeller appearance curve due changing pitch degrees different sta tions about 25 deg near hub 9 deg tip Duplicating other props Directly meas ure diameter blade width thickness hub Set prop its trailing edge flat surface Photo 22 Use two pieces stiff paper card stock equal square 90-deg corners guides measure dimen sions measuring distance between cards various points along prop blade record re sults Transfer information leading edge prop blank A2 B2 sketches Trace profile prop transfer prop blank proceed Step 3 want emphasize con struction information means introduce very interesting area Giant Scale modeling Actually mak ing prop much easier explain ing reading little practice wrn able com plete prop less 45 mm hope enjoy fascinating area modeling much FF Old-Timers/Haught Continued page 61 Mills PA 16875 Martin tells miniature lightweight ignition coils have well-received has encouraged him expand line latest additions metal AAA battery boxes recharga ble AAA batteries firm also has charger AAA batteries pro vides longer battery service money well keeping all-up flying weight minimum system has differ ence between competitive model dog Snuffy Other users Gettig system have reported good results meContinued page 160 June 1984 157 ROM M icro Mark Small Tool Specialists
Edition: Model Aviation - 1984/06
Page Numbers: 54, 55, 56, 57, 58, 59, 157
THE PURPOSE article pro vide basic information will allow make own Giant Scale props mathematical formulas theory intentionally omitted Tools props shaped band saw 12-in disc sander 3-in drum sander mounted drill press will have access tools have some alternatives suggest cant yourself find some cut prop blanks straight-grained hard maple can use 5/16-in drill bit preferably mounted drill press youll need have some method removing wood prop blankand High Point balancer equal Alternatives disc drum sanders include belt sander draw knife spoke shave block plane surform file drum roto rasp possible variety prop shapes well diameter pitch limitless carve own few examples Carving model props almost lost art what wonderful varieties fered modeling industry Still may able buy exactly what looking Carv ing own may best choice doesnt take long might think U Wendell Hostetler Carve Props etc band saw almost necessity although might able get jigsaw saber saw important use coarse abrasive paper initial shaping no finer 50-grit final hand sanding done 80 220-grit garnet alu minum oxide paper Example propeller words pic tures going show steps 1 Prop profile layout face prop blank2 Layout leading edge prop blank Giant Scale - 7 Th-r7f77ThThZ2Iz VTh2fl - - . p-4 k -~-- - -A - ------ --- Il /1 I/I 89/O////3/4/6/B2O2 a68oz i36IMI - 1 1.J.i...L.1... 20 22 24 Y8#O making 18-in-diameter prop pitch approximately 9 type prop has very good 24 Kioritz engine flying 22 28-lb bi planes should turn close 8000 rpm static ground unload air close peak en gines horsepower curve Step 1 Cut blank straight grained kiln-dried hard maple size x 1-5/8 x 18 Keep angles 90 degrees Step 2 Lay out center lines circle hub prop design profile face blank Photo 1 Mark lines leading edge prop represent face back surfaces prop Photo 2 Lay out 1 /8-in-wide lines end blank Photo 3 Drawings Al A2 used example layout Its important use centerline refer encing pattern blank Step 3 Drill 5/16-in hole hole size engines shaft center prop blank Use center punch drilling guideand use drill press Step 4 Cut out prop blank per layout Photos 5 6 Step 5 Remove wood back surface amount shown Photos 9 10 Note Photo 10 area removed comes within 1/8 top leading edge near hub tapers thinner toward tip allows shaping leading edge obtain approximately Clark Y air foil blade Step 6 Shape wood face prop Photo 14 shows area removed first Step 7 Roughly check horizontal balance should done major wood removals made Yoi se Te surface Stan surfw iside aft rop rotates theairi 3p both sides major imbalance likely due unequal shaping Step 8 Hand-sand prop abrasive wrapped around wood block starting 80-grit progressing 220-grit sanding should remove irregularities left drum sander Step 9 Carefully check horizontal balance Sand off lumps heavy side until both sides same weight June 1984 55 J 0 nI$id LA 0 4 0 2468 /0 /2 4 /6 /8 NO OCR TEXT Left 6 Cut being made line representing leading edge cut off wedge tip will tack-glued blank final cuts Right 7 blank ready shaping Above 10 view Ot leading edge showing same shaded area Photo 9 material needs removed Right 11 rough cut being made disc sander back side blank 9 shaded area represents wood needs removed shape beck Step 10 Check vertical balance Photo 17 prop falls off right left vertical position re move some material heavy side area hub prop re fuses balance vertically sanding place small pan head sheet metal screw light side center hub area Photo 18 Step 11 Final-sand prop 220-grit paper block Check final balance sanding heavy blade until balance perfect Photo 19 Step 12 Drill remaining holes prop hub required en gine Finishing prop may used running flight after Step 12 usually finish prop several ways simple finish consists coat auto body primer followed coat acrylic enamel natural clear finish use two coats Zip Guard followed Verathane polyure thane finish sanding between coats recommended deluxe finish obtained following manner Spray two three coats Super Poxy Primer Sand between coat 220-grit abrasive 2 Spray desired color wet-sand 400 600-grit 3 Mask contrasting color tips stripes desired 4 Wet-sand 600-grit paper 5 Insert shaft High Point balancer through prop spray coat clear Super Poxy 5 Balance prop spraying lighter blade until weight equal ized Sometimes just use Super Poxy June 1984 57 wont learn dont try array its apparent author has learned plenty probably wont visible magazine reproduction diameter pitch tip thickness recorded prop together kind performance gave Primer balance prop go flying Using Pitch Chart pitch prop can determined follows Cut about six wedge-shaped pieces filecard stock equal varying slope 9 14 degrees wedges serted under prop blade threequarters 7 5% distance center prop hub its tipuntil wedge matches blade gle point determined information chart will note 75% point 18-in prop 675 6 prop pitch chart excellent given us good friend Don Chapman got Capt Ralph Kanko USAF originated chart based sound theory saves mathematical calculations will measure pitch props 8 38 diameter 2 30 pitch 18-in prop wedge matches blade angle pitch degrees point 6/4 center 12 degrees pitch can determined chart locating 12 vertical line pitch degrees moving right chart until horizontal line intersects 18 diagonal line prop diameter intersection follow line vertically downward read figure pitch inches example figure 9 9-in pitch prop chart possible de termine pitch prop dis tance its center will explain procedure further Variations As prop diameter increased prop width should also increased Try following widths starters 20 dia l/4 wide 22 dia 1-7/8 wide 23 & 24 dia 2 wide widths absolute experiment several ways change prop pitch may increase decrease pitch increasing decreasing thickness prop blank Pitch will increase approximately 1 1/16 increase thicknessfor props 20-24 range Pitch may also increased de creased increasing decreasing distance center prop point begins taper wards tip farther point center prop greater pitch closer point center prop hub less pitch Pitch may also varied narrowing width prop blank increasing width will decrease pitch ever prefer increase pitch creasing thickness prop blank like decrease pitch prop following way Mark leading edge prop blank shown B2 sketch Decreasing thick ness distance approx 3 center hub will result less pitch decrease thickness 1/8 1/16 side will lower pitch 1 2 though will vary size prop impor tant understand angle lines edge hub out 3-in mark no significance will vary different size props example just happen almost same angle lines repre senting back face prop extend out tip sure sloped lines extend hub area X area side view prop blank hub area must kept flat parallel prop example has constant pitch pitch same points along blade hub tip about 3 center hub pitch degree approx 25 tip pitch degree 9 58 Model Aviation Left 12 finish cut drum sander back side prop Above 13 Corn pleted back surface bottom blank ready hand sanding Check angles pitch degrees same points both blades sure equal see Photo 23 Right 14 Shaded area wood removed face blank trail ing edge right leading edge left Measuring pitch other stations 15 A very rough check horizontal balance 16 Final check horizontal balanceI want find pitch prop tip first measure pitch degree tip example measured 9 center hub 18-india prop angle 9 deg As go prop chart answer must remember chart de signed measure prop pitch threequarters point 6 cen 9-in pitch may want reread above until can fully comprehend simple very important concept variations area experiment profile face prop viewed top leading edge prop blank slightly curved line used represent face prop view A2 drawing Make few props line straight observe results could shift 1/8-in tip thick ness off center either toward front face back surface prop offset tip toward face prop takes different appearance blades look swept-forward offset tip toward back prop blades swept-back performance prop will appreciably af fected slight changes offsetting tip has found rpm may creased several hundred cutting off approximately e tip Remember rebalance prop after tip trim very important keep props thin tips maximum performance Also keep thin reasonably possible cross section throughout Continued page 157 20 Typical leading edge view layout prop blank 21 Various sections tip left hub area right showing approximate Clark V airfoil photos author ter hub example three-quarters point also equals three-quarters point prop diame ter prop rotates Therefore measure pitch degree 9 tip prop must make believe prop has 24-in diameter get correct pitch chart tip Consult numbers inside rectang ular box chart confirm follow 9 pitch degrees legend move over 24-in diameter line down pitch inches answer 9-in pitch Lets try another example measur ing pitch degree 3 hub center prop example measures 25 deg pitch degrees 3-in point Consult chart remem bering now must make believe prop has 8-in diameter get correct pitch reading Follow pitch degrees 8-in diameter down pitch answers answer 9 22 Card stock being used guide datermine thickness prop duplicated 23 Angle wedges cut card stock mea sure pitch degrees Theyre used conjunc tion chart check inches pitch June 1984 59 Len 17 Final check vertical balance Above 18 pan head sheet metal screw serted hub aid vertical balanc ing Right 19 multiple exposure shows properly balanced prop will hold position around 360 degrees rotation flair correctly autorotate safely As far reliability concerned Su perior really holds up blades tend stay track after hardest pullouts would recommend machine anyone looking high-quality general sportcompetition Helicopter careful atten tion should give hours flight before parts start wear As final comment disap pointed aerobatic qualities Superior find ironic machine has done well several contests around world Although Ewald Heim wins Helicopter competitions Europe Star-Ranger common see Superiors finishing close tail second third positions possible am doing something wrong Superioror maybe FAI judges looking something fast-flying acrobats Next month will review Futaba 7GH Helicopter radio discuss van ous features make Helicopter radio what Until next monthBCNU Larry Jolly 5501 W Como Santa Ana CA 92703 RC Giant Scale/Beckman Continued page 53 aircraft lots wings wires Construction basic rugged good selections readily-available spruce pine replacing balsa needed strength arent really beginners models experienced modeler beginner some experienced help will have no trouble some ways building models now will easier first designed days didnt have Giant Scale accessories hinges horns wheels etc avail able now Jerry shows two different airfoils plans semi-symmetrical sport wing obviously scale other undercambered scale air foil latter looks little thick havent researched Im probably wrong sport wing required good flying Most aircraft designs onequarter scale will fly much like real ones have scale outlines airfoils would expect sport wing fly little faster little less floaty big gest advantage sport wing will little easier build has room mounting servos like WW designs wings things two hard beat Im trying find time build Triplane Plans $20 includes shipping plans rolled tube Par tial kits available $130 Pup $140 Triplane Send Behrens Plan Ser vice 3 1-27 Healy Ave Far Rockaway NY 11619 Bryon Fun-Fly Festival Byron Originals hosting Giant Scale Fun-Fly Festival r mmmmmm~rn1 IMode~ Catalog I II II Hundreds unusual tools borrowed Jewelr UGunsmilhing Clock Making professional IModel Making trades NOW AVAiLABLE TO YOU BY MAIL guaranteedI 6II ~thisorsendur couponname address MICROMARK Box 5112 LX ast Main St Clinton NJ 08809 NAME EADDRESS CITY __________________________________________________________ STATE ______ ZIP mJ b third year row annual IMAA Fun-Fly Festival 1984 will held Los Angeles August 16-19 Byron event will same week end three days August 17-19 Anyone attended first two Ida Grove events knows kind facilities provided year Byron nouncement talks about paved runway scale hanger scale tower radar checking flight speed Christen Eagles will hand again last year event provides nice alternative modelers Midwest cannot make trek Los Angeles plan go make motel reservations early few accommodations Ida Grove itself expect up 60 miles away Campers motor homes can probably get space Ida Grove dont crash plane week before Without plane fly part show will just another duespaying spectator behind ropes Bob Beckman 8248 Holly Grove Ct Manassas VA 22110 Props/Hostetler Continued ae 59 length blade Photo 21 shows cross section prop blade sev eral pointsfrom near hub within 3/8 tip sections similar Clark Y airfoil Note back side prop flat leading edge trailing edge point though appears curved finished propeller appearance curve due changing pitch degrees different sta tions about 25 deg near hub 9 deg tip Duplicating other props Directly meas ure diameter blade width thickness hub Set prop its trailing edge flat surface Photo 22 Use two pieces stiff paper card stock equal square 90-deg corners guides measure dimen sions measuring distance between cards various points along prop blade record re sults Transfer information leading edge prop blank A2 B2 sketches Trace profile prop transfer prop blank proceed Step 3 want emphasize con struction information means introduce very interesting area Giant Scale modeling Actually mak ing prop much easier explain ing reading little practice wrn able com plete prop less 45 mm hope enjoy fascinating area modeling much FF Old-Timers/Haught Continued page 61 Mills PA 16875 Martin tells miniature lightweight ignition coils have well-received has encouraged him expand line latest additions metal AAA battery boxes recharga ble AAA batteries firm also has charger AAA batteries pro vides longer battery service money well keeping all-up flying weight minimum system has differ ence between competitive model dog Snuffy Other users Gettig system have reported good results meContinued page 160 June 1984 157 ROM M icro Mark Small Tool Specialists
Edition: Model Aviation - 1984/06
Page Numbers: 54, 55, 56, 57, 58, 59, 157
THE PURPOSE article pro vide basic information will allow make own Giant Scale props mathematical formulas theory intentionally omitted Tools props shaped band saw 12-in disc sander 3-in drum sander mounted drill press will have access tools have some alternatives suggest cant yourself find some cut prop blanks straight-grained hard maple can use 5/16-in drill bit preferably mounted drill press youll need have some method removing wood prop blankand High Point balancer equal Alternatives disc drum sanders include belt sander draw knife spoke shave block plane surform file drum roto rasp possible variety prop shapes well diameter pitch limitless carve own few examples Carving model props almost lost art what wonderful varieties fered modeling industry Still may able buy exactly what looking Carv ing own may best choice doesnt take long might think U Wendell Hostetler Carve Props etc band saw almost necessity although might able get jigsaw saber saw important use coarse abrasive paper initial shaping no finer 50-grit final hand sanding done 80 220-grit garnet alu minum oxide paper Example propeller words pic tures going show steps 1 Prop profile layout face prop blank2 Layout leading edge prop blank Giant Scale - 7 Th-r7f77ThThZ2Iz VTh2fl - - . p-4 k -~-- - -A - ------ --- Il /1 I/I 89/O////3/4/6/B2O2 a68oz i36IMI - 1 1.J.i...L.1... 20 22 24 Y8#O making 18-in-diameter prop pitch approximately 9 type prop has very good 24 Kioritz engine flying 22 28-lb bi planes should turn close 8000 rpm static ground unload air close peak en gines horsepower curve Step 1 Cut blank straight grained kiln-dried hard maple size x 1-5/8 x 18 Keep angles 90 degrees Step 2 Lay out center lines circle hub prop design profile face blank Photo 1 Mark lines leading edge prop represent face back surfaces prop Photo 2 Lay out 1 /8-in-wide lines end blank Photo 3 Drawings Al A2 used example layout Its important use centerline refer encing pattern blank Step 3 Drill 5/16-in hole hole size engines shaft center prop blank Use center punch drilling guideand use drill press Step 4 Cut out prop blank per layout Photos 5 6 Step 5 Remove wood back surface amount shown Photos 9 10 Note Photo 10 area removed comes within 1/8 top leading edge near hub tapers thinner toward tip allows shaping leading edge obtain approximately Clark Y air foil blade Step 6 Shape wood face prop Photo 14 shows area removed first Step 7 Roughly check horizontal balance should done major wood removals made Yoi se Te surface Stan surfw iside aft rop rotates theairi 3p both sides major imbalance likely due unequal shaping Step 8 Hand-sand prop abrasive wrapped around wood block starting 80-grit progressing 220-grit sanding should remove irregularities left drum sander Step 9 Carefully check horizontal balance Sand off lumps heavy side until both sides same weight June 1984 55 J 0 nI$id LA 0 4 0 2468 /0 /2 4 /6 /8 NO OCR TEXT Left 6 Cut being made line representing leading edge cut off wedge tip will tack-glued blank final cuts Right 7 blank ready shaping Above 10 view Ot leading edge showing same shaded area Photo 9 material needs removed Right 11 rough cut being made disc sander back side blank 9 shaded area represents wood needs removed shape beck Step 10 Check vertical balance Photo 17 prop falls off right left vertical position re move some material heavy side area hub prop re fuses balance vertically sanding place small pan head sheet metal screw light side center hub area Photo 18 Step 11 Final-sand prop 220-grit paper block Check final balance sanding heavy blade until balance perfect Photo 19 Step 12 Drill remaining holes prop hub required en gine Finishing prop may used running flight after Step 12 usually finish prop several ways simple finish consists coat auto body primer followed coat acrylic enamel natural clear finish use two coats Zip Guard followed Verathane polyure thane finish sanding between coats recommended deluxe finish obtained following manner Spray two three coats Super Poxy Primer Sand between coat 220-grit abrasive 2 Spray desired color wet-sand 400 600-grit 3 Mask contrasting color tips stripes desired 4 Wet-sand 600-grit paper 5 Insert shaft High Point balancer through prop spray coat clear Super Poxy 5 Balance prop spraying lighter blade until weight equal ized Sometimes just use Super Poxy June 1984 57 wont learn dont try array its apparent author has learned plenty probably wont visible magazine reproduction diameter pitch tip thickness recorded prop together kind performance gave Primer balance prop go flying Using Pitch Chart pitch prop can determined follows Cut about six wedge-shaped pieces filecard stock equal varying slope 9 14 degrees wedges serted under prop blade threequarters 7 5% distance center prop hub its tipuntil wedge matches blade gle point determined information chart will note 75% point 18-in prop 675 6 prop pitch chart excellent given us good friend Don Chapman got Capt Ralph Kanko USAF originated chart based sound theory saves mathematical calculations will measure pitch props 8 38 diameter 2 30 pitch 18-in prop wedge matches blade angle pitch degrees point 6/4 center 12 degrees pitch can determined chart locating 12 vertical line pitch degrees moving right chart until horizontal line intersects 18 diagonal line prop diameter intersection follow line vertically downward read figure pitch inches example figure 9 9-in pitch prop chart possible de termine pitch prop dis tance its center will explain procedure further Variations As prop diameter increased prop width should also increased Try following widths starters 20 dia l/4 wide 22 dia 1-7/8 wide 23 & 24 dia 2 wide widths absolute experiment several ways change prop pitch may increase decrease pitch increasing decreasing thickness prop blank Pitch will increase approximately 1 1/16 increase thicknessfor props 20-24 range Pitch may also increased de creased increasing decreasing distance center prop point begins taper wards tip farther point center prop greater pitch closer point center prop hub less pitch Pitch may also varied narrowing width prop blank increasing width will decrease pitch ever prefer increase pitch creasing thickness prop blank like decrease pitch prop following way Mark leading edge prop blank shown B2 sketch Decreasing thick ness distance approx 3 center hub will result less pitch decrease thickness 1/8 1/16 side will lower pitch 1 2 though will vary size prop impor tant understand angle lines edge hub out 3-in mark no significance will vary different size props example just happen almost same angle lines repre senting back face prop extend out tip sure sloped lines extend hub area X area side view prop blank hub area must kept flat parallel prop example has constant pitch pitch same points along blade hub tip about 3 center hub pitch degree approx 25 tip pitch degree 9 58 Model Aviation Left 12 finish cut drum sander back side prop Above 13 Corn pleted back surface bottom blank ready hand sanding Check angles pitch degrees same points both blades sure equal see Photo 23 Right 14 Shaded area wood removed face blank trail ing edge right leading edge left Measuring pitch other stations 15 A very rough check horizontal balance 16 Final check horizontal balanceI want find pitch prop tip first measure pitch degree tip example measured 9 center hub 18-india prop angle 9 deg As go prop chart answer must remember chart de signed measure prop pitch threequarters point 6 cen 9-in pitch may want reread above until can fully comprehend simple very important concept variations area experiment profile face prop viewed top leading edge prop blank slightly curved line used represent face prop view A2 drawing Make few props line straight observe results could shift 1/8-in tip thick ness off center either toward front face back surface prop offset tip toward face prop takes different appearance blades look swept-forward offset tip toward back prop blades swept-back performance prop will appreciably af fected slight changes offsetting tip has found rpm may creased several hundred cutting off approximately e tip Remember rebalance prop after tip trim very important keep props thin tips maximum performance Also keep thin reasonably possible cross section throughout Continued page 157 20 Typical leading edge view layout prop blank 21 Various sections tip left hub area right showing approximate Clark V airfoil photos author ter hub example three-quarters point also equals three-quarters point prop diame ter prop rotates Therefore measure pitch degree 9 tip prop must make believe prop has 24-in diameter get correct pitch chart tip Consult numbers inside rectang ular box chart confirm follow 9 pitch degrees legend move over 24-in diameter line down pitch inches answer 9-in pitch Lets try another example measur ing pitch degree 3 hub center prop example measures 25 deg pitch degrees 3-in point Consult chart remem bering now must make believe prop has 8-in diameter get correct pitch reading Follow pitch degrees 8-in diameter down pitch answers answer 9 22 Card stock being used guide datermine thickness prop duplicated 23 Angle wedges cut card stock mea sure pitch degrees Theyre used conjunc tion chart check inches pitch June 1984 59 Len 17 Final check vertical balance Above 18 pan head sheet metal screw serted hub aid vertical balanc ing Right 19 multiple exposure shows properly balanced prop will hold position around 360 degrees rotation flair correctly autorotate safely As far reliability concerned Su perior really holds up blades tend stay track after hardest pullouts would recommend machine anyone looking high-quality general sportcompetition Helicopter careful atten tion should give hours flight before parts start wear As final comment disap pointed aerobatic qualities Superior find ironic machine has done well several contests around world Although Ewald Heim wins Helicopter competitions Europe Star-Ranger common see Superiors finishing close tail second third positions possible am doing something wrong Superioror maybe FAI judges looking something fast-flying acrobats Next month will review Futaba 7GH Helicopter radio discuss van ous features make Helicopter radio what Until next monthBCNU Larry Jolly 5501 W Como Santa Ana CA 92703 RC Giant Scale/Beckman Continued page 53 aircraft lots wings wires Construction basic rugged good selections readily-available spruce pine replacing balsa needed strength arent really beginners models experienced modeler beginner some experienced help will have no trouble some ways building models now will easier first designed days didnt have Giant Scale accessories hinges horns wheels etc avail able now Jerry shows two different airfoils plans semi-symmetrical sport wing obviously scale other undercambered scale air foil latter looks little thick havent researched Im probably wrong sport wing required good flying Most aircraft designs onequarter scale will fly much like real ones have scale outlines airfoils would expect sport wing fly little faster little less floaty big gest advantage sport wing will little easier build has room mounting servos like WW designs wings things two hard beat Im trying find time build Triplane Plans $20 includes shipping plans rolled tube Par tial kits available $130 Pup $140 Triplane Send Behrens Plan Ser vice 3 1-27 Healy Ave Far Rockaway NY 11619 Bryon Fun-Fly Festival Byron Originals hosting Giant Scale Fun-Fly Festival r mmmmmm~rn1 IMode~ Catalog I II II Hundreds unusual tools borrowed Jewelr UGunsmilhing Clock Making professional IModel Making trades NOW AVAiLABLE TO YOU BY MAIL guaranteedI 6II ~thisorsendur couponname address MICROMARK Box 5112 LX ast Main St Clinton NJ 08809 NAME EADDRESS CITY __________________________________________________________ STATE ______ ZIP mJ b third year row annual IMAA Fun-Fly Festival 1984 will held Los Angeles August 16-19 Byron event will same week end three days August 17-19 Anyone attended first two Ida Grove events knows kind facilities provided year Byron nouncement talks about paved runway scale hanger scale tower radar checking flight speed Christen Eagles will hand again last year event provides nice alternative modelers Midwest cannot make trek Los Angeles plan go make motel reservations early few accommodations Ida Grove itself expect up 60 miles away Campers motor homes can probably get space Ida Grove dont crash plane week before Without plane fly part show will just another duespaying spectator behind ropes Bob Beckman 8248 Holly Grove Ct Manassas VA 22110 Props/Hostetler Continued ae 59 length blade Photo 21 shows cross section prop blade sev eral pointsfrom near hub within 3/8 tip sections similar Clark Y airfoil Note back side prop flat leading edge trailing edge point though appears curved finished propeller appearance curve due changing pitch degrees different sta tions about 25 deg near hub 9 deg tip Duplicating other props Directly meas ure diameter blade width thickness hub Set prop its trailing edge flat surface Photo 22 Use two pieces stiff paper card stock equal square 90-deg corners guides measure dimen sions measuring distance between cards various points along prop blade record re sults Transfer information leading edge prop blank A2 B2 sketches Trace profile prop transfer prop blank proceed Step 3 want emphasize con struction information means introduce very interesting area Giant Scale modeling Actually mak ing prop much easier explain ing reading little practice wrn able com plete prop less 45 mm hope enjoy fascinating area modeling much FF Old-Timers/Haught Continued page 61 Mills PA 16875 Martin tells miniature lightweight ignition coils have well-received has encouraged him expand line latest additions metal AAA battery boxes recharga ble AAA batteries firm also has charger AAA batteries pro vides longer battery service money well keeping all-up flying weight minimum system has differ ence between competitive model dog Snuffy Other users Gettig system have reported good results meContinued page 160 June 1984 157 ROM M icro Mark Small Tool Specialists
Edition: Model Aviation - 1984/06
Page Numbers: 54, 55, 56, 57, 58, 59, 157
THE PURPOSE article pro vide basic information will allow make own Giant Scale props mathematical formulas theory intentionally omitted Tools props shaped band saw 12-in disc sander 3-in drum sander mounted drill press will have access tools have some alternatives suggest cant yourself find some cut prop blanks straight-grained hard maple can use 5/16-in drill bit preferably mounted drill press youll need have some method removing wood prop blankand High Point balancer equal Alternatives disc drum sanders include belt sander draw knife spoke shave block plane surform file drum roto rasp possible variety prop shapes well diameter pitch limitless carve own few examples Carving model props almost lost art what wonderful varieties fered modeling industry Still may able buy exactly what looking Carv ing own may best choice doesnt take long might think U Wendell Hostetler Carve Props etc band saw almost necessity although might able get jigsaw saber saw important use coarse abrasive paper initial shaping no finer 50-grit final hand sanding done 80 220-grit garnet alu minum oxide paper Example propeller words pic tures going show steps 1 Prop profile layout face prop blank2 Layout leading edge prop blank Giant Scale - 7 Th-r7f77ThThZ2Iz VTh2fl - - . p-4 k -~-- - -A - ------ --- Il /1 I/I 89/O////3/4/6/B2O2 a68oz i36IMI - 1 1.J.i...L.1... 20 22 24 Y8#O making 18-in-diameter prop pitch approximately 9 type prop has very good 24 Kioritz engine flying 22 28-lb bi planes should turn close 8000 rpm static ground unload air close peak en gines horsepower curve Step 1 Cut blank straight grained kiln-dried hard maple size x 1-5/8 x 18 Keep angles 90 degrees Step 2 Lay out center lines circle hub prop design profile face blank Photo 1 Mark lines leading edge prop represent face back surfaces prop Photo 2 Lay out 1 /8-in-wide lines end blank Photo 3 Drawings Al A2 used example layout Its important use centerline refer encing pattern blank Step 3 Drill 5/16-in hole hole size engines shaft center prop blank Use center punch drilling guideand use drill press Step 4 Cut out prop blank per layout Photos 5 6 Step 5 Remove wood back surface amount shown Photos 9 10 Note Photo 10 area removed comes within 1/8 top leading edge near hub tapers thinner toward tip allows shaping leading edge obtain approximately Clark Y air foil blade Step 6 Shape wood face prop Photo 14 shows area removed first Step 7 Roughly check horizontal balance should done major wood removals made Yoi se Te surface Stan surfw iside aft rop rotates theairi 3p both sides major imbalance likely due unequal shaping Step 8 Hand-sand prop abrasive wrapped around wood block starting 80-grit progressing 220-grit sanding should remove irregularities left drum sander Step 9 Carefully check horizontal balance Sand off lumps heavy side until both sides same weight June 1984 55 J 0 nI$id LA 0 4 0 2468 /0 /2 4 /6 /8 NO OCR TEXT Left 6 Cut being made line representing leading edge cut off wedge tip will tack-glued blank final cuts Right 7 blank ready shaping Above 10 view Ot leading edge showing same shaded area Photo 9 material needs removed Right 11 rough cut being made disc sander back side blank 9 shaded area represents wood needs removed shape beck Step 10 Check vertical balance Photo 17 prop falls off right left vertical position re move some material heavy side area hub prop re fuses balance vertically sanding place small pan head sheet metal screw light side center hub area Photo 18 Step 11 Final-sand prop 220-grit paper block Check final balance sanding heavy blade until balance perfect Photo 19 Step 12 Drill remaining holes prop hub required en gine Finishing prop may used running flight after Step 12 usually finish prop several ways simple finish consists coat auto body primer followed coat acrylic enamel natural clear finish use two coats Zip Guard followed Verathane polyure thane finish sanding between coats recommended deluxe finish obtained following manner Spray two three coats Super Poxy Primer Sand between coat 220-grit abrasive 2 Spray desired color wet-sand 400 600-grit 3 Mask contrasting color tips stripes desired 4 Wet-sand 600-grit paper 5 Insert shaft High Point balancer through prop spray coat clear Super Poxy 5 Balance prop spraying lighter blade until weight equal ized Sometimes just use Super Poxy June 1984 57 wont learn dont try array its apparent author has learned plenty probably wont visible magazine reproduction diameter pitch tip thickness recorded prop together kind performance gave Primer balance prop go flying Using Pitch Chart pitch prop can determined follows Cut about six wedge-shaped pieces filecard stock equal varying slope 9 14 degrees wedges serted under prop blade threequarters 7 5% distance center prop hub its tipuntil wedge matches blade gle point determined information chart will note 75% point 18-in prop 675 6 prop pitch chart excellent given us good friend Don Chapman got Capt Ralph Kanko USAF originated chart based sound theory saves mathematical calculations will measure pitch props 8 38 diameter 2 30 pitch 18-in prop wedge matches blade angle pitch degrees point 6/4 center 12 degrees pitch can determined chart locating 12 vertical line pitch degrees moving right chart until horizontal line intersects 18 diagonal line prop diameter intersection follow line vertically downward read figure pitch inches example figure 9 9-in pitch prop chart possible de termine pitch prop dis tance its center will explain procedure further Variations As prop diameter increased prop width should also increased Try following widths starters 20 dia l/4 wide 22 dia 1-7/8 wide 23 & 24 dia 2 wide widths absolute experiment several ways change prop pitch may increase decrease pitch increasing decreasing thickness prop blank Pitch will increase approximately 1 1/16 increase thicknessfor props 20-24 range Pitch may also increased de creased increasing decreasing distance center prop point begins taper wards tip farther point center prop greater pitch closer point center prop hub less pitch Pitch may also varied narrowing width prop blank increasing width will decrease pitch ever prefer increase pitch creasing thickness prop blank like decrease pitch prop following way Mark leading edge prop blank shown B2 sketch Decreasing thick ness distance approx 3 center hub will result less pitch decrease thickness 1/8 1/16 side will lower pitch 1 2 though will vary size prop impor tant understand angle lines edge hub out 3-in mark no significance will vary different size props example just happen almost same angle lines repre senting back face prop extend out tip sure sloped lines extend hub area X area side view prop blank hub area must kept flat parallel prop example has constant pitch pitch same points along blade hub tip about 3 center hub pitch degree approx 25 tip pitch degree 9 58 Model Aviation Left 12 finish cut drum sander back side prop Above 13 Corn pleted back surface bottom blank ready hand sanding Check angles pitch degrees same points both blades sure equal see Photo 23 Right 14 Shaded area wood removed face blank trail ing edge right leading edge left Measuring pitch other stations 15 A very rough check horizontal balance 16 Final check horizontal balanceI want find pitch prop tip first measure pitch degree tip example measured 9 center hub 18-india prop angle 9 deg As go prop chart answer must remember chart de signed measure prop pitch threequarters point 6 cen 9-in pitch may want reread above until can fully comprehend simple very important concept variations area experiment profile face prop viewed top leading edge prop blank slightly curved line used represent face prop view A2 drawing Make few props line straight observe results could shift 1/8-in tip thick ness off center either toward front face back surface prop offset tip toward face prop takes different appearance blades look swept-forward offset tip toward back prop blades swept-back performance prop will appreciably af fected slight changes offsetting tip has found rpm may creased several hundred cutting off approximately e tip Remember rebalance prop after tip trim very important keep props thin tips maximum performance Also keep thin reasonably possible cross section throughout Continued page 157 20 Typical leading edge view layout prop blank 21 Various sections tip left hub area right showing approximate Clark V airfoil photos author ter hub example three-quarters point also equals three-quarters point prop diame ter prop rotates Therefore measure pitch degree 9 tip prop must make believe prop has 24-in diameter get correct pitch chart tip Consult numbers inside rectang ular box chart confirm follow 9 pitch degrees legend move over 24-in diameter line down pitch inches answer 9-in pitch Lets try another example measur ing pitch degree 3 hub center prop example measures 25 deg pitch degrees 3-in point Consult chart remem bering now must make believe prop has 8-in diameter get correct pitch reading Follow pitch degrees 8-in diameter down pitch answers answer 9 22 Card stock being used guide datermine thickness prop duplicated 23 Angle wedges cut card stock mea sure pitch degrees Theyre used conjunc tion chart check inches pitch June 1984 59 Len 17 Final check vertical balance Above 18 pan head sheet metal screw serted hub aid vertical balanc ing Right 19 multiple exposure shows properly balanced prop will hold position around 360 degrees rotation flair correctly autorotate safely As far reliability concerned Su perior really holds up blades tend stay track after hardest pullouts would recommend machine anyone looking high-quality general sportcompetition Helicopter careful atten tion should give hours flight before parts start wear As final comment disap pointed aerobatic qualities Superior find ironic machine has done well several contests around world Although Ewald Heim wins Helicopter competitions Europe Star-Ranger common see Superiors finishing close tail second third positions possible am doing something wrong Superioror maybe FAI judges looking something fast-flying acrobats Next month will review Futaba 7GH Helicopter radio discuss van ous features make Helicopter radio what Until next monthBCNU Larry Jolly 5501 W Como Santa Ana CA 92703 RC Giant Scale/Beckman Continued page 53 aircraft lots wings wires Construction basic rugged good selections readily-available spruce pine replacing balsa needed strength arent really beginners models experienced modeler beginner some experienced help will have no trouble some ways building models now will easier first designed days didnt have Giant Scale accessories hinges horns wheels etc avail able now Jerry shows two different airfoils plans semi-symmetrical sport wing obviously scale other undercambered scale air foil latter looks little thick havent researched Im probably wrong sport wing required good flying Most aircraft designs onequarter scale will fly much like real ones have scale outlines airfoils would expect sport wing fly little faster little less floaty big gest advantage sport wing will little easier build has room mounting servos like WW designs wings things two hard beat Im trying find time build Triplane Plans $20 includes shipping plans rolled tube Par tial kits available $130 Pup $140 Triplane Send Behrens Plan Ser vice 3 1-27 Healy Ave Far Rockaway NY 11619 Bryon Fun-Fly Festival Byron Originals hosting Giant Scale Fun-Fly Festival r mmmmmm~rn1 IMode~ Catalog I II II Hundreds unusual tools borrowed Jewelr UGunsmilhing Clock Making professional IModel Making trades NOW AVAiLABLE TO YOU BY MAIL guaranteedI 6II ~thisorsendur couponname address MICROMARK Box 5112 LX ast Main St Clinton NJ 08809 NAME EADDRESS CITY __________________________________________________________ STATE ______ ZIP mJ b third year row annual IMAA Fun-Fly Festival 1984 will held Los Angeles August 16-19 Byron event will same week end three days August 17-19 Anyone attended first two Ida Grove events knows kind facilities provided year Byron nouncement talks about paved runway scale hanger scale tower radar checking flight speed Christen Eagles will hand again last year event provides nice alternative modelers Midwest cannot make trek Los Angeles plan go make motel reservations early few accommodations Ida Grove itself expect up 60 miles away Campers motor homes can probably get space Ida Grove dont crash plane week before Without plane fly part show will just another duespaying spectator behind ropes Bob Beckman 8248 Holly Grove Ct Manassas VA 22110 Props/Hostetler Continued ae 59 length blade Photo 21 shows cross section prop blade sev eral pointsfrom near hub within 3/8 tip sections similar Clark Y airfoil Note back side prop flat leading edge trailing edge point though appears curved finished propeller appearance curve due changing pitch degrees different sta tions about 25 deg near hub 9 deg tip Duplicating other props Directly meas ure diameter blade width thickness hub Set prop its trailing edge flat surface Photo 22 Use two pieces stiff paper card stock equal square 90-deg corners guides measure dimen sions measuring distance between cards various points along prop blade record re sults Transfer information leading edge prop blank A2 B2 sketches Trace profile prop transfer prop blank proceed Step 3 want emphasize con struction information means introduce very interesting area Giant Scale modeling Actually mak ing prop much easier explain ing reading little practice wrn able com plete prop less 45 mm hope enjoy fascinating area modeling much FF Old-Timers/Haught Continued page 61 Mills PA 16875 Martin tells miniature lightweight ignition coils have well-received has encouraged him expand line latest additions metal AAA battery boxes recharga ble AAA batteries firm also has charger AAA batteries pro vides longer battery service money well keeping all-up flying weight minimum system has differ ence between competitive model dog Snuffy Other users Gettig system have reported good results meContinued page 160 June 1984 157 ROM M icro Mark Small Tool Specialists
Edition: Model Aviation - 1984/06
Page Numbers: 54, 55, 56, 57, 58, 59, 157
THE PURPOSE article pro vide basic information will allow make own Giant Scale props mathematical formulas theory intentionally omitted Tools props shaped band saw 12-in disc sander 3-in drum sander mounted drill press will have access tools have some alternatives suggest cant yourself find some cut prop blanks straight-grained hard maple can use 5/16-in drill bit preferably mounted drill press youll need have some method removing wood prop blankand High Point balancer equal Alternatives disc drum sanders include belt sander draw knife spoke shave block plane surform file drum roto rasp possible variety prop shapes well diameter pitch limitless carve own few examples Carving model props almost lost art what wonderful varieties fered modeling industry Still may able buy exactly what looking Carv ing own may best choice doesnt take long might think U Wendell Hostetler Carve Props etc band saw almost necessity although might able get jigsaw saber saw important use coarse abrasive paper initial shaping no finer 50-grit final hand sanding done 80 220-grit garnet alu minum oxide paper Example propeller words pic tures going show steps 1 Prop profile layout face prop blank2 Layout leading edge prop blank Giant Scale - 7 Th-r7f77ThThZ2Iz VTh2fl - - . p-4 k -~-- - -A - ------ --- Il /1 I/I 89/O////3/4/6/B2O2 a68oz i36IMI - 1 1.J.i...L.1... 20 22 24 Y8#O making 18-in-diameter prop pitch approximately 9 type prop has very good 24 Kioritz engine flying 22 28-lb bi planes should turn close 8000 rpm static ground unload air close peak en gines horsepower curve Step 1 Cut blank straight grained kiln-dried hard maple size x 1-5/8 x 18 Keep angles 90 degrees Step 2 Lay out center lines circle hub prop design profile face blank Photo 1 Mark lines leading edge prop represent face back surfaces prop Photo 2 Lay out 1 /8-in-wide lines end blank Photo 3 Drawings Al A2 used example layout Its important use centerline refer encing pattern blank Step 3 Drill 5/16-in hole hole size engines shaft center prop blank Use center punch drilling guideand use drill press Step 4 Cut out prop blank per layout Photos 5 6 Step 5 Remove wood back surface amount shown Photos 9 10 Note Photo 10 area removed comes within 1/8 top leading edge near hub tapers thinner toward tip allows shaping leading edge obtain approximately Clark Y air foil blade Step 6 Shape wood face prop Photo 14 shows area removed first Step 7 Roughly check horizontal balance should done major wood removals made Yoi se Te surface Stan surfw iside aft rop rotates theairi 3p both sides major imbalance likely due unequal shaping Step 8 Hand-sand prop abrasive wrapped around wood block starting 80-grit progressing 220-grit sanding should remove irregularities left drum sander Step 9 Carefully check horizontal balance Sand off lumps heavy side until both sides same weight June 1984 55 J 0 nI$id LA 0 4 0 2468 /0 /2 4 /6 /8 NO OCR TEXT Left 6 Cut being made line representing leading edge cut off wedge tip will tack-glued blank final cuts Right 7 blank ready shaping Above 10 view Ot leading edge showing same shaded area Photo 9 material needs removed Right 11 rough cut being made disc sander back side blank 9 shaded area represents wood needs removed shape beck Step 10 Check vertical balance Photo 17 prop falls off right left vertical position re move some material heavy side area hub prop re fuses balance vertically sanding place small pan head sheet metal screw light side center hub area Photo 18 Step 11 Final-sand prop 220-grit paper block Check final balance sanding heavy blade until balance perfect Photo 19 Step 12 Drill remaining holes prop hub required en gine Finishing prop may used running flight after Step 12 usually finish prop several ways simple finish consists coat auto body primer followed coat acrylic enamel natural clear finish use two coats Zip Guard followed Verathane polyure thane finish sanding between coats recommended deluxe finish obtained following manner Spray two three coats Super Poxy Primer Sand between coat 220-grit abrasive 2 Spray desired color wet-sand 400 600-grit 3 Mask contrasting color tips stripes desired 4 Wet-sand 600-grit paper 5 Insert shaft High Point balancer through prop spray coat clear Super Poxy 5 Balance prop spraying lighter blade until weight equal ized Sometimes just use Super Poxy June 1984 57 wont learn dont try array its apparent author has learned plenty probably wont visible magazine reproduction diameter pitch tip thickness recorded prop together kind performance gave Primer balance prop go flying Using Pitch Chart pitch prop can determined follows Cut about six wedge-shaped pieces filecard stock equal varying slope 9 14 degrees wedges serted under prop blade threequarters 7 5% distance center prop hub its tipuntil wedge matches blade gle point determined information chart will note 75% point 18-in prop 675 6 prop pitch chart excellent given us good friend Don Chapman got Capt Ralph Kanko USAF originated chart based sound theory saves mathematical calculations will measure pitch props 8 38 diameter 2 30 pitch 18-in prop wedge matches blade angle pitch degrees point 6/4 center 12 degrees pitch can determined chart locating 12 vertical line pitch degrees moving right chart until horizontal line intersects 18 diagonal line prop diameter intersection follow line vertically downward read figure pitch inches example figure 9 9-in pitch prop chart possible de termine pitch prop dis tance its center will explain procedure further Variations As prop diameter increased prop width should also increased Try following widths starters 20 dia l/4 wide 22 dia 1-7/8 wide 23 & 24 dia 2 wide widths absolute experiment several ways change prop pitch may increase decrease pitch increasing decreasing thickness prop blank Pitch will increase approximately 1 1/16 increase thicknessfor props 20-24 range Pitch may also increased de creased increasing decreasing distance center prop point begins taper wards tip farther point center prop greater pitch closer point center prop hub less pitch Pitch may also varied narrowing width prop blank increasing width will decrease pitch ever prefer increase pitch creasing thickness prop blank like decrease pitch prop following way Mark leading edge prop blank shown B2 sketch Decreasing thick ness distance approx 3 center hub will result less pitch decrease thickness 1/8 1/16 side will lower pitch 1 2 though will vary size prop impor tant understand angle lines edge hub out 3-in mark no significance will vary different size props example just happen almost same angle lines repre senting back face prop extend out tip sure sloped lines extend hub area X area side view prop blank hub area must kept flat parallel prop example has constant pitch pitch same points along blade hub tip about 3 center hub pitch degree approx 25 tip pitch degree 9 58 Model Aviation Left 12 finish cut drum sander back side prop Above 13 Corn pleted back surface bottom blank ready hand sanding Check angles pitch degrees same points both blades sure equal see Photo 23 Right 14 Shaded area wood removed face blank trail ing edge right leading edge left Measuring pitch other stations 15 A very rough check horizontal balance 16 Final check horizontal balanceI want find pitch prop tip first measure pitch degree tip example measured 9 center hub 18-india prop angle 9 deg As go prop chart answer must remember chart de signed measure prop pitch threequarters point 6 cen 9-in pitch may want reread above until can fully comprehend simple very important concept variations area experiment profile face prop viewed top leading edge prop blank slightly curved line used represent face prop view A2 drawing Make few props line straight observe results could shift 1/8-in tip thick ness off center either toward front face back surface prop offset tip toward face prop takes different appearance blades look swept-forward offset tip toward back prop blades swept-back performance prop will appreciably af fected slight changes offsetting tip has found rpm may creased several hundred cutting off approximately e tip Remember rebalance prop after tip trim very important keep props thin tips maximum performance Also keep thin reasonably possible cross section throughout Continued page 157 20 Typical leading edge view layout prop blank 21 Various sections tip left hub area right showing approximate Clark V airfoil photos author ter hub example three-quarters point also equals three-quarters point prop diame ter prop rotates Therefore measure pitch degree 9 tip prop must make believe prop has 24-in diameter get correct pitch chart tip Consult numbers inside rectang ular box chart confirm follow 9 pitch degrees legend move over 24-in diameter line down pitch inches answer 9-in pitch Lets try another example measur ing pitch degree 3 hub center prop example measures 25 deg pitch degrees 3-in point Consult chart remem bering now must make believe prop has 8-in diameter get correct pitch reading Follow pitch degrees 8-in diameter down pitch answers answer 9 22 Card stock being used guide datermine thickness prop duplicated 23 Angle wedges cut card stock mea sure pitch degrees Theyre used conjunc tion chart check inches pitch June 1984 59 Len 17 Final check vertical balance Above 18 pan head sheet metal screw serted hub aid vertical balanc ing Right 19 multiple exposure shows properly balanced prop will hold position around 360 degrees rotation flair correctly autorotate safely As far reliability concerned Su perior really holds up blades tend stay track after hardest pullouts would recommend machine anyone looking high-quality general sportcompetition Helicopter careful atten tion should give hours flight before parts start wear As final comment disap pointed aerobatic qualities Superior find ironic machine has done well several contests around world Although Ewald Heim wins Helicopter competitions Europe Star-Ranger common see Superiors finishing close tail second third positions possible am doing something wrong Superioror maybe FAI judges looking something fast-flying acrobats Next month will review Futaba 7GH Helicopter radio discuss van ous features make Helicopter radio what Until next monthBCNU Larry Jolly 5501 W Como Santa Ana CA 92703 RC Giant Scale/Beckman Continued page 53 aircraft lots wings wires Construction basic rugged good selections readily-available spruce pine replacing balsa needed strength arent really beginners models experienced modeler beginner some experienced help will have no trouble some ways building models now will easier first designed days didnt have Giant Scale accessories hinges horns wheels etc avail able now Jerry shows two different airfoils plans semi-symmetrical sport wing obviously scale other undercambered scale air foil latter looks little thick havent researched Im probably wrong sport wing required good flying Most aircraft designs onequarter scale will fly much like real ones have scale outlines airfoils would expect sport wing fly little faster little less floaty big gest advantage sport wing will little easier build has room mounting servos like WW designs wings things two hard beat Im trying find time build Triplane Plans $20 includes shipping plans rolled tube Par tial kits available $130 Pup $140 Triplane Send Behrens Plan Ser vice 3 1-27 Healy Ave Far Rockaway NY 11619 Bryon Fun-Fly Festival Byron Originals hosting Giant Scale Fun-Fly Festival r mmmmmm~rn1 IMode~ Catalog I II II Hundreds unusual tools borrowed Jewelr UGunsmilhing Clock Making professional IModel Making trades NOW AVAiLABLE TO YOU BY MAIL guaranteedI 6II ~thisorsendur couponname address MICROMARK Box 5112 LX ast Main St Clinton NJ 08809 NAME EADDRESS CITY __________________________________________________________ STATE ______ ZIP mJ b third year row annual IMAA Fun-Fly Festival 1984 will held Los Angeles August 16-19 Byron event will same week end three days August 17-19 Anyone attended first two Ida Grove events knows kind facilities provided year Byron nouncement talks about paved runway scale hanger scale tower radar checking flight speed Christen Eagles will hand again last year event provides nice alternative modelers Midwest cannot make trek Los Angeles plan go make motel reservations early few accommodations Ida Grove itself expect up 60 miles away Campers motor homes can probably get space Ida Grove dont crash plane week before Without plane fly part show will just another duespaying spectator behind ropes Bob Beckman 8248 Holly Grove Ct Manassas VA 22110 Props/Hostetler Continued ae 59 length blade Photo 21 shows cross section prop blade sev eral pointsfrom near hub within 3/8 tip sections similar Clark Y airfoil Note back side prop flat leading edge trailing edge point though appears curved finished propeller appearance curve due changing pitch degrees different sta tions about 25 deg near hub 9 deg tip Duplicating other props Directly meas ure diameter blade width thickness hub Set prop its trailing edge flat surface Photo 22 Use two pieces stiff paper card stock equal square 90-deg corners guides measure dimen sions measuring distance between cards various points along prop blade record re sults Transfer information leading edge prop blank A2 B2 sketches Trace profile prop transfer prop blank proceed Step 3 want emphasize con struction information means introduce very interesting area Giant Scale modeling Actually mak ing prop much easier explain ing reading little practice wrn able com plete prop less 45 mm hope enjoy fascinating area modeling much FF Old-Timers/Haught Continued page 61 Mills PA 16875 Martin tells miniature lightweight ignition coils have well-received has encouraged him expand line latest additions metal AAA battery boxes recharga ble AAA batteries firm also has charger AAA batteries pro vides longer battery service money well keeping all-up flying weight minimum system has differ ence between competitive model dog Snuffy Other users Gettig system have reported good results meContinued page 160 June 1984 157 ROM M icro Mark Small Tool Specialists
Edition: Model Aviation - 1984/06
Page Numbers: 54, 55, 56, 57, 58, 59, 157
THE PURPOSE article pro vide basic information will allow make own Giant Scale props mathematical formulas theory intentionally omitted Tools props shaped band saw 12-in disc sander 3-in drum sander mounted drill press will have access tools have some alternatives suggest cant yourself find some cut prop blanks straight-grained hard maple can use 5/16-in drill bit preferably mounted drill press youll need have some method removing wood prop blankand High Point balancer equal Alternatives disc drum sanders include belt sander draw knife spoke shave block plane surform file drum roto rasp possible variety prop shapes well diameter pitch limitless carve own few examples Carving model props almost lost art what wonderful varieties fered modeling industry Still may able buy exactly what looking Carv ing own may best choice doesnt take long might think U Wendell Hostetler Carve Props etc band saw almost necessity although might able get jigsaw saber saw important use coarse abrasive paper initial shaping no finer 50-grit final hand sanding done 80 220-grit garnet alu minum oxide paper Example propeller words pic tures going show steps 1 Prop profile layout face prop blank2 Layout leading edge prop blank Giant Scale - 7 Th-r7f77ThThZ2Iz VTh2fl - - . p-4 k -~-- - -A - ------ --- Il /1 I/I 89/O////3/4/6/B2O2 a68oz i36IMI - 1 1.J.i...L.1... 20 22 24 Y8#O making 18-in-diameter prop pitch approximately 9 type prop has very good 24 Kioritz engine flying 22 28-lb bi planes should turn close 8000 rpm static ground unload air close peak en gines horsepower curve Step 1 Cut blank straight grained kiln-dried hard maple size x 1-5/8 x 18 Keep angles 90 degrees Step 2 Lay out center lines circle hub prop design profile face blank Photo 1 Mark lines leading edge prop represent face back surfaces prop Photo 2 Lay out 1 /8-in-wide lines end blank Photo 3 Drawings Al A2 used example layout Its important use centerline refer encing pattern blank Step 3 Drill 5/16-in hole hole size engines shaft center prop blank Use center punch drilling guideand use drill press Step 4 Cut out prop blank per layout Photos 5 6 Step 5 Remove wood back surface amount shown Photos 9 10 Note Photo 10 area removed comes within 1/8 top leading edge near hub tapers thinner toward tip allows shaping leading edge obtain approximately Clark Y air foil blade Step 6 Shape wood face prop Photo 14 shows area removed first Step 7 Roughly check horizontal balance should done major wood removals made Yoi se Te surface Stan surfw iside aft rop rotates theairi 3p both sides major imbalance likely due unequal shaping Step 8 Hand-sand prop abrasive wrapped around wood block starting 80-grit progressing 220-grit sanding should remove irregularities left drum sander Step 9 Carefully check horizontal balance Sand off lumps heavy side until both sides same weight June 1984 55 J 0 nI$id LA 0 4 0 2468 /0 /2 4 /6 /8 NO OCR TEXT Left 6 Cut being made line representing leading edge cut off wedge tip will tack-glued blank final cuts Right 7 blank ready shaping Above 10 view Ot leading edge showing same shaded area Photo 9 material needs removed Right 11 rough cut being made disc sander back side blank 9 shaded area represents wood needs removed shape beck Step 10 Check vertical balance Photo 17 prop falls off right left vertical position re move some material heavy side area hub prop re fuses balance vertically sanding place small pan head sheet metal screw light side center hub area Photo 18 Step 11 Final-sand prop 220-grit paper block Check final balance sanding heavy blade until balance perfect Photo 19 Step 12 Drill remaining holes prop hub required en gine Finishing prop may used running flight after Step 12 usually finish prop several ways simple finish consists coat auto body primer followed coat acrylic enamel natural clear finish use two coats Zip Guard followed Verathane polyure thane finish sanding between coats recommended deluxe finish obtained following manner Spray two three coats Super Poxy Primer Sand between coat 220-grit abrasive 2 Spray desired color wet-sand 400 600-grit 3 Mask contrasting color tips stripes desired 4 Wet-sand 600-grit paper 5 Insert shaft High Point balancer through prop spray coat clear Super Poxy 5 Balance prop spraying lighter blade until weight equal ized Sometimes just use Super Poxy June 1984 57 wont learn dont try array its apparent author has learned plenty probably wont visible magazine reproduction diameter pitch tip thickness recorded prop together kind performance gave Primer balance prop go flying Using Pitch Chart pitch prop can determined follows Cut about six wedge-shaped pieces filecard stock equal varying slope 9 14 degrees wedges serted under prop blade threequarters 7 5% distance center prop hub its tipuntil wedge matches blade gle point determined information chart will note 75% point 18-in prop 675 6 prop pitch chart excellent given us good friend Don Chapman got Capt Ralph Kanko USAF originated chart based sound theory saves mathematical calculations will measure pitch props 8 38 diameter 2 30 pitch 18-in prop wedge matches blade angle pitch degrees point 6/4 center 12 degrees pitch can determined chart locating 12 vertical line pitch degrees moving right chart until horizontal line intersects 18 diagonal line prop diameter intersection follow line vertically downward read figure pitch inches example figure 9 9-in pitch prop chart possible de termine pitch prop dis tance its center will explain procedure further Variations As prop diameter increased prop width should also increased Try following widths starters 20 dia l/4 wide 22 dia 1-7/8 wide 23 & 24 dia 2 wide widths absolute experiment several ways change prop pitch may increase decrease pitch increasing decreasing thickness prop blank Pitch will increase approximately 1 1/16 increase thicknessfor props 20-24 range Pitch may also increased de creased increasing decreasing distance center prop point begins taper wards tip farther point center prop greater pitch closer point center prop hub less pitch Pitch may also varied narrowing width prop blank increasing width will decrease pitch ever prefer increase pitch creasing thickness prop blank like decrease pitch prop following way Mark leading edge prop blank shown B2 sketch Decreasing thick ness distance approx 3 center hub will result less pitch decrease thickness 1/8 1/16 side will lower pitch 1 2 though will vary size prop impor tant understand angle lines edge hub out 3-in mark no significance will vary different size props example just happen almost same angle lines repre senting back face prop extend out tip sure sloped lines extend hub area X area side view prop blank hub area must kept flat parallel prop example has constant pitch pitch same points along blade hub tip about 3 center hub pitch degree approx 25 tip pitch degree 9 58 Model Aviation Left 12 finish cut drum sander back side prop Above 13 Corn pleted back surface bottom blank ready hand sanding Check angles pitch degrees same points both blades sure equal see Photo 23 Right 14 Shaded area wood removed face blank trail ing edge right leading edge left Measuring pitch other stations 15 A very rough check horizontal balance 16 Final check horizontal balanceI want find pitch prop tip first measure pitch degree tip example measured 9 center hub 18-india prop angle 9 deg As go prop chart answer must remember chart de signed measure prop pitch threequarters point 6 cen 9-in pitch may want reread above until can fully comprehend simple very important concept variations area experiment profile face prop viewed top leading edge prop blank slightly curved line used represent face prop view A2 drawing Make few props line straight observe results could shift 1/8-in tip thick ness off center either toward front face back surface prop offset tip toward face prop takes different appearance blades look swept-forward offset tip toward back prop blades swept-back performance prop will appreciably af fected slight changes offsetting tip has found rpm may creased several hundred cutting off approximately e tip Remember rebalance prop after tip trim very important keep props thin tips maximum performance Also keep thin reasonably possible cross section throughout Continued page 157 20 Typical leading edge view layout prop blank 21 Various sections tip left hub area right showing approximate Clark V airfoil photos author ter hub example three-quarters point also equals three-quarters point prop diame ter prop rotates Therefore measure pitch degree 9 tip prop must make believe prop has 24-in diameter get correct pitch chart tip Consult numbers inside rectang ular box chart confirm follow 9 pitch degrees legend move over 24-in diameter line down pitch inches answer 9-in pitch Lets try another example measur ing pitch degree 3 hub center prop example measures 25 deg pitch degrees 3-in point Consult chart remem bering now must make believe prop has 8-in diameter get correct pitch reading Follow pitch degrees 8-in diameter down pitch answers answer 9 22 Card stock being used guide datermine thickness prop duplicated 23 Angle wedges cut card stock mea sure pitch degrees Theyre used conjunc tion chart check inches pitch June 1984 59 Len 17 Final check vertical balance Above 18 pan head sheet metal screw serted hub aid vertical balanc ing Right 19 multiple exposure shows properly balanced prop will hold position around 360 degrees rotation flair correctly autorotate safely As far reliability concerned Su perior really holds up blades tend stay track after hardest pullouts would recommend machine anyone looking high-quality general sportcompetition Helicopter careful atten tion should give hours flight before parts start wear As final comment disap pointed aerobatic qualities Superior find ironic machine has done well several contests around world Although Ewald Heim wins Helicopter competitions Europe Star-Ranger common see Superiors finishing close tail second third positions possible am doing something wrong Superioror maybe FAI judges looking something fast-flying acrobats Next month will review Futaba 7GH Helicopter radio discuss van ous features make Helicopter radio what Until next monthBCNU Larry Jolly 5501 W Como Santa Ana CA 92703 RC Giant Scale/Beckman Continued page 53 aircraft lots wings wires Construction basic rugged good selections readily-available spruce pine replacing balsa needed strength arent really beginners models experienced modeler beginner some experienced help will have no trouble some ways building models now will easier first designed days didnt have Giant Scale accessories hinges horns wheels etc avail able now Jerry shows two different airfoils plans semi-symmetrical sport wing obviously scale other undercambered scale air foil latter looks little thick havent researched Im probably wrong sport wing required good flying Most aircraft designs onequarter scale will fly much like real ones have scale outlines airfoils would expect sport wing fly little faster little less floaty big gest advantage sport wing will little easier build has room mounting servos like WW designs wings things two hard beat Im trying find time build Triplane Plans $20 includes shipping plans rolled tube Par tial kits available $130 Pup $140 Triplane Send Behrens Plan Ser vice 3 1-27 Healy Ave Far Rockaway NY 11619 Bryon Fun-Fly Festival Byron Originals hosting Giant Scale Fun-Fly Festival r mmmmmm~rn1 IMode~ Catalog I II II Hundreds unusual tools borrowed Jewelr UGunsmilhing Clock Making professional IModel Making trades NOW AVAiLABLE TO YOU BY MAIL guaranteedI 6II ~thisorsendur couponname address MICROMARK Box 5112 LX ast Main St Clinton NJ 08809 NAME EADDRESS CITY __________________________________________________________ STATE ______ ZIP mJ b third year row annual IMAA Fun-Fly Festival 1984 will held Los Angeles August 16-19 Byron event will same week end three days August 17-19 Anyone attended first two Ida Grove events knows kind facilities provided year Byron nouncement talks about paved runway scale hanger scale tower radar checking flight speed Christen Eagles will hand again last year event provides nice alternative modelers Midwest cannot make trek Los Angeles plan go make motel reservations early few accommodations Ida Grove itself expect up 60 miles away Campers motor homes can probably get space Ida Grove dont crash plane week before Without plane fly part show will just another duespaying spectator behind ropes Bob Beckman 8248 Holly Grove Ct Manassas VA 22110 Props/Hostetler Continued ae 59 length blade Photo 21 shows cross section prop blade sev eral pointsfrom near hub within 3/8 tip sections similar Clark Y airfoil Note back side prop flat leading edge trailing edge point though appears curved finished propeller appearance curve due changing pitch degrees different sta tions about 25 deg near hub 9 deg tip Duplicating other props Directly meas ure diameter blade width thickness hub Set prop its trailing edge flat surface Photo 22 Use two pieces stiff paper card stock equal square 90-deg corners guides measure dimen sions measuring distance between cards various points along prop blade record re sults Transfer information leading edge prop blank A2 B2 sketches Trace profile prop transfer prop blank proceed Step 3 want emphasize con struction information means introduce very interesting area Giant Scale modeling Actually mak ing prop much easier explain ing reading little practice wrn able com plete prop less 45 mm hope enjoy fascinating area modeling much FF Old-Timers/Haught Continued page 61 Mills PA 16875 Martin tells miniature lightweight ignition coils have well-received has encouraged him expand line latest additions metal AAA battery boxes recharga ble AAA batteries firm also has charger AAA batteries pro vides longer battery service money well keeping all-up flying weight minimum system has differ ence between competitive model dog Snuffy Other users Gettig system have reported good results meContinued page 160 June 1984 157 ROM M icro Mark Small Tool Specialists
Edition: Model Aviation - 1984/06
Page Numbers: 54, 55, 56, 57, 58, 59, 157
THE PURPOSE article pro vide basic information will allow make own Giant Scale props mathematical formulas theory intentionally omitted Tools props shaped band saw 12-in disc sander 3-in drum sander mounted drill press will have access tools have some alternatives suggest cant yourself find some cut prop blanks straight-grained hard maple can use 5/16-in drill bit preferably mounted drill press youll need have some method removing wood prop blankand High Point balancer equal Alternatives disc drum sanders include belt sander draw knife spoke shave block plane surform file drum roto rasp possible variety prop shapes well diameter pitch limitless carve own few examples Carving model props almost lost art what wonderful varieties fered modeling industry Still may able buy exactly what looking Carv ing own may best choice doesnt take long might think U Wendell Hostetler Carve Props etc band saw almost necessity although might able get jigsaw saber saw important use coarse abrasive paper initial shaping no finer 50-grit final hand sanding done 80 220-grit garnet alu minum oxide paper Example propeller words pic tures going show steps 1 Prop profile layout face prop blank2 Layout leading edge prop blank Giant Scale - 7 Th-r7f77ThThZ2Iz VTh2fl - - . p-4 k -~-- - -A - ------ --- Il /1 I/I 89/O////3/4/6/B2O2 a68oz i36IMI - 1 1.J.i...L.1... 20 22 24 Y8#O making 18-in-diameter prop pitch approximately 9 type prop has very good 24 Kioritz engine flying 22 28-lb bi planes should turn close 8000 rpm static ground unload air close peak en gines horsepower curve Step 1 Cut blank straight grained kiln-dried hard maple size x 1-5/8 x 18 Keep angles 90 degrees Step 2 Lay out center lines circle hub prop design profile face blank Photo 1 Mark lines leading edge prop represent face back surfaces prop Photo 2 Lay out 1 /8-in-wide lines end blank Photo 3 Drawings Al A2 used example layout Its important use centerline refer encing pattern blank Step 3 Drill 5/16-in hole hole size engines shaft center prop blank Use center punch drilling guideand use drill press Step 4 Cut out prop blank per layout Photos 5 6 Step 5 Remove wood back surface amount shown Photos 9 10 Note Photo 10 area removed comes within 1/8 top leading edge near hub tapers thinner toward tip allows shaping leading edge obtain approximately Clark Y air foil blade Step 6 Shape wood face prop Photo 14 shows area removed first Step 7 Roughly check horizontal balance should done major wood removals made Yoi se Te surface Stan surfw iside aft rop rotates theairi 3p both sides major imbalance likely due unequal shaping Step 8 Hand-sand prop abrasive wrapped around wood block starting 80-grit progressing 220-grit sanding should remove irregularities left drum sander Step 9 Carefully check horizontal balance Sand off lumps heavy side until both sides same weight June 1984 55 J 0 nI$id LA 0 4 0 2468 /0 /2 4 /6 /8 NO OCR TEXT Left 6 Cut being made line representing leading edge cut off wedge tip will tack-glued blank final cuts Right 7 blank ready shaping Above 10 view Ot leading edge showing same shaded area Photo 9 material needs removed Right 11 rough cut being made disc sander back side blank 9 shaded area represents wood needs removed shape beck Step 10 Check vertical balance Photo 17 prop falls off right left vertical position re move some material heavy side area hub prop re fuses balance vertically sanding place small pan head sheet metal screw light side center hub area Photo 18 Step 11 Final-sand prop 220-grit paper block Check final balance sanding heavy blade until balance perfect Photo 19 Step 12 Drill remaining holes prop hub required en gine Finishing prop may used running flight after Step 12 usually finish prop several ways simple finish consists coat auto body primer followed coat acrylic enamel natural clear finish use two coats Zip Guard followed Verathane polyure thane finish sanding between coats recommended deluxe finish obtained following manner Spray two three coats Super Poxy Primer Sand between coat 220-grit abrasive 2 Spray desired color wet-sand 400 600-grit 3 Mask contrasting color tips stripes desired 4 Wet-sand 600-grit paper 5 Insert shaft High Point balancer through prop spray coat clear Super Poxy 5 Balance prop spraying lighter blade until weight equal ized Sometimes just use Super Poxy June 1984 57 wont learn dont try array its apparent author has learned plenty probably wont visible magazine reproduction diameter pitch tip thickness recorded prop together kind performance gave Primer balance prop go flying Using Pitch Chart pitch prop can determined follows Cut about six wedge-shaped pieces filecard stock equal varying slope 9 14 degrees wedges serted under prop blade threequarters 7 5% distance center prop hub its tipuntil wedge matches blade gle point determined information chart will note 75% point 18-in prop 675 6 prop pitch chart excellent given us good friend Don Chapman got Capt Ralph Kanko USAF originated chart based sound theory saves mathematical calculations will measure pitch props 8 38 diameter 2 30 pitch 18-in prop wedge matches blade angle pitch degrees point 6/4 center 12 degrees pitch can determined chart locating 12 vertical line pitch degrees moving right chart until horizontal line intersects 18 diagonal line prop diameter intersection follow line vertically downward read figure pitch inches example figure 9 9-in pitch prop chart possible de termine pitch prop dis tance its center will explain procedure further Variations As prop diameter increased prop width should also increased Try following widths starters 20 dia l/4 wide 22 dia 1-7/8 wide 23 & 24 dia 2 wide widths absolute experiment several ways change prop pitch may increase decrease pitch increasing decreasing thickness prop blank Pitch will increase approximately 1 1/16 increase thicknessfor props 20-24 range Pitch may also increased de creased increasing decreasing distance center prop point begins taper wards tip farther point center prop greater pitch closer point center prop hub less pitch Pitch may also varied narrowing width prop blank increasing width will decrease pitch ever prefer increase pitch creasing thickness prop blank like decrease pitch prop following way Mark leading edge prop blank shown B2 sketch Decreasing thick ness distance approx 3 center hub will result less pitch decrease thickness 1/8 1/16 side will lower pitch 1 2 though will vary size prop impor tant understand angle lines edge hub out 3-in mark no significance will vary different size props example just happen almost same angle lines repre senting back face prop extend out tip sure sloped lines extend hub area X area side view prop blank hub area must kept flat parallel prop example has constant pitch pitch same points along blade hub tip about 3 center hub pitch degree approx 25 tip pitch degree 9 58 Model Aviation Left 12 finish cut drum sander back side prop Above 13 Corn pleted back surface bottom blank ready hand sanding Check angles pitch degrees same points both blades sure equal see Photo 23 Right 14 Shaded area wood removed face blank trail ing edge right leading edge left Measuring pitch other stations 15 A very rough check horizontal balance 16 Final check horizontal balanceI want find pitch prop tip first measure pitch degree tip example measured 9 center hub 18-india prop angle 9 deg As go prop chart answer must remember chart de signed measure prop pitch threequarters point 6 cen 9-in pitch may want reread above until can fully comprehend simple very important concept variations area experiment profile face prop viewed top leading edge prop blank slightly curved line used represent face prop view A2 drawing Make few props line straight observe results could shift 1/8-in tip thick ness off center either toward front face back surface prop offset tip toward face prop takes different appearance blades look swept-forward offset tip toward back prop blades swept-back performance prop will appreciably af fected slight changes offsetting tip has found rpm may creased several hundred cutting off approximately e tip Remember rebalance prop after tip trim very important keep props thin tips maximum performance Also keep thin reasonably possible cross section throughout Continued page 157 20 Typical leading edge view layout prop blank 21 Various sections tip left hub area right showing approximate Clark V airfoil photos author ter hub example three-quarters point also equals three-quarters point prop diame ter prop rotates Therefore measure pitch degree 9 tip prop must make believe prop has 24-in diameter get correct pitch chart tip Consult numbers inside rectang ular box chart confirm follow 9 pitch degrees legend move over 24-in diameter line down pitch inches answer 9-in pitch Lets try another example measur ing pitch degree 3 hub center prop example measures 25 deg pitch degrees 3-in point Consult chart remem bering now must make believe prop has 8-in diameter get correct pitch reading Follow pitch degrees 8-in diameter down pitch answers answer 9 22 Card stock being used guide datermine thickness prop duplicated 23 Angle wedges cut card stock mea sure pitch degrees Theyre used conjunc tion chart check inches pitch June 1984 59 Len 17 Final check vertical balance Above 18 pan head sheet metal screw serted hub aid vertical balanc ing Right 19 multiple exposure shows properly balanced prop will hold position around 360 degrees rotation flair correctly autorotate safely As far reliability concerned Su perior really holds up blades tend stay track after hardest pullouts would recommend machine anyone looking high-quality general sportcompetition Helicopter careful atten tion should give hours flight before parts start wear As final comment disap pointed aerobatic qualities Superior find ironic machine has done well several contests around world Although Ewald Heim wins Helicopter competitions Europe Star-Ranger common see Superiors finishing close tail second third positions possible am doing something wrong Superioror maybe FAI judges looking something fast-flying acrobats Next month will review Futaba 7GH Helicopter radio discuss van ous features make Helicopter radio what Until next monthBCNU Larry Jolly 5501 W Como Santa Ana CA 92703 RC Giant Scale/Beckman Continued page 53 aircraft lots wings wires Construction basic rugged good selections readily-available spruce pine replacing balsa needed strength arent really beginners models experienced modeler beginner some experienced help will have no trouble some ways building models now will easier first designed days didnt have Giant Scale accessories hinges horns wheels etc avail able now Jerry shows two different airfoils plans semi-symmetrical sport wing obviously scale other undercambered scale air foil latter looks little thick havent researched Im probably wrong sport wing required good flying Most aircraft designs onequarter scale will fly much like real ones have scale outlines airfoils would expect sport wing fly little faster little less floaty big gest advantage sport wing will little easier build has room mounting servos like WW designs wings things two hard beat Im trying find time build Triplane Plans $20 includes shipping plans rolled tube Par tial kits available $130 Pup $140 Triplane Send Behrens Plan Ser vice 3 1-27 Healy Ave Far Rockaway NY 11619 Bryon Fun-Fly Festival Byron Originals hosting Giant Scale Fun-Fly Festival r mmmmmm~rn1 IMode~ Catalog I II II Hundreds unusual tools borrowed Jewelr UGunsmilhing Clock Making professional IModel Making trades NOW AVAiLABLE TO YOU BY MAIL guaranteedI 6II ~thisorsendur couponname address MICROMARK Box 5112 LX ast Main St Clinton NJ 08809 NAME EADDRESS CITY __________________________________________________________ STATE ______ ZIP mJ b third year row annual IMAA Fun-Fly Festival 1984 will held Los Angeles August 16-19 Byron event will same week end three days August 17-19 Anyone attended first two Ida Grove events knows kind facilities provided year Byron nouncement talks about paved runway scale hanger scale tower radar checking flight speed Christen Eagles will hand again last year event provides nice alternative modelers Midwest cannot make trek Los Angeles plan go make motel reservations early few accommodations Ida Grove itself expect up 60 miles away Campers motor homes can probably get space Ida Grove dont crash plane week before Without plane fly part show will just another duespaying spectator behind ropes Bob Beckman 8248 Holly Grove Ct Manassas VA 22110 Props/Hostetler Continued ae 59 length blade Photo 21 shows cross section prop blade sev eral pointsfrom near hub within 3/8 tip sections similar Clark Y airfoil Note back side prop flat leading edge trailing edge point though appears curved finished propeller appearance curve due changing pitch degrees different sta tions about 25 deg near hub 9 deg tip Duplicating other props Directly meas ure diameter blade width thickness hub Set prop its trailing edge flat surface Photo 22 Use two pieces stiff paper card stock equal square 90-deg corners guides measure dimen sions measuring distance between cards various points along prop blade record re sults Transfer information leading edge prop blank A2 B2 sketches Trace profile prop transfer prop blank proceed Step 3 want emphasize con struction information means introduce very interesting area Giant Scale modeling Actually mak ing prop much easier explain ing reading little practice wrn able com plete prop less 45 mm hope enjoy fascinating area modeling much FF Old-Timers/Haught Continued page 61 Mills PA 16875 Martin tells miniature lightweight ignition coils have well-received has encouraged him expand line latest additions metal AAA battery boxes recharga ble AAA batteries firm also has charger AAA batteries pro vides longer battery service money well keeping all-up flying weight minimum system has differ ence between competitive model dog Snuffy Other users Gettig system have reported good results meContinued page 160 June 1984 157 ROM M icro Mark Small Tool Specialists