You wont know much performance youre missing until check out propellers pitch gaugeand fix necessary author tells build simple inexpen sive instrument CHALLENGE If think about propellers eventually will get around subjects pitch pitch distribution Pitch inches millimeters distance given point propeller will move forward revolution turning perfect slip-free medium Pitch distribution refers pitch various points along propeller radius type pitch distribution called helical Helical-pitch propellers have same pitch point along radius blade angle changes root tip point along blade moves forward same distance revolution Other pitch distribution designs deliberately change pitch root tip achieve designers objectives does average modeler care Its curiosity search whys improved performance made us think about propellers first place Most us go through period experimentation eventually settle prop works best someone shows up flying field new Airblaster Superprop blows everyone away run down favorite hobby store stock up Superblasters Sure enough really works U Don Hughes £ Fscu LcflxF7 WOrn Ld2 L1G first works great did well break Superblaster replace another doesnt work well original Perhaps engine vibrates Did wonder Its because propellers arent created equal Though props supposed same can irregularities propeller blades different pitch can cause vibration can weight imbalance Performance suffers pitch distribution may same original Again performance suffers pitch gauge needed detect subtle differences experimenter looking perfect prop cant get along pitch gauge Commercial pitch gauges work great However might want first try described just get used concept see can justify cost professional unit Take look photo left What see propeller fastened slotted base plate cardboard triangle under near prop blade base plate something found surplus metals store Its section aluminum heat-sink extrusion material piece flat warpfree hardwood plywood saw kerfs half-inch will just well Continued page 80 June 1992 63 Left The Poor Mans prop itcn uauge CNCCKIfl9 ryosno prop yor Iectrics ins near waae EflUWS piivn UT UIfl wflhle oppuamie 01U05 measures 81/2 Fix bevel shim prop hub both blades have pitch 81/4 RIght Typical measuring templates made stiff cardboard found back writing tablets template should labeled show inches pitch radius location ELDON J LIND CO #401 UIUUH Easiest hinge tool available $325 Finest Building Tools Available w SEND SELFADORESSED STAMPED EN VELOPE FOR CATALOG #101 EXTRA HANDS Makes covering easy $1775 3151 CARAVELLE HAVASU CITY AZ 86403 602 4537970 happen live near Ocala Florida consider paying visit Ray Parker fine craftsman gentleman version Stephens Akro would exist Contact Ray Leeward Air Ranch Ocala like enjoy crafting balsa-and-plywood models love aerobatic flying building Stephens Akro will time well spent bench model does Acknowledgements Bud Davisson Emily Zimmerman Ray Parker contributed some information article want publicly thank helping project come alive * Poor Mans Prop/Hughes Continued Page 63 Note small block prop hub raises prop off base allow insertion triangle prop held place conical nut prop balancer prop pitch gauge simple inexpensive construct Pitch measured slipping various triangles under prop until find bottoms base plate slot matches propeller angle will have construct triangles pitches wish measure Fortunately geometric basis pitch calculation pretty simple Ive reduced triangle dimensions rather using trigonometry angles Just plug numbers equation triangle base always has length 100 millimeters pitch 314 x dia x 100 ngle height mm example wish make triangle representing 7 pitch 4-in radius must multiply 2 get diameter use formula formula yields 28 millimeters height base always 100 millimeters Just construct 900 right triangle dimensions cardboard such found back paper tablets triangle 6-in pitch 3-in radius multiply 2 use formula would 32 millimeters 100 millimeters photos shows templates some pitch angles commonly use will want check least two points probably blade radius Make templates COMPOSITE SOLUTIONS--PO Ito 252 Haclet NJ 07730 CARBON FIBRE Tuned Exhaust Systems LOW RPM Pipes below 11000 STANDARD engines 40 90 size OSRossi Pico Webra Sc per Tigre others Performance Pipes LONG STROKE ENGINES 60 size OS OSHanno Special Webra YS YS-120 4 cycle Custom Pipes UC Speed Aerobatics other applications carrying Free Flight Competition Timers br Info call s 908 264-6693 till 10PM 1ST OUR PRODUCTS ARE OMPETITIVELY PRICED AGAINST ALUMINUM INPORTS Satcsfaction guaranteed money back need sure dont cost much dont take much time Some typical templates shown photos Shallow angles may require constructing triangle rectangle done 5 lh-in-pitch 3Ii 6-in-radius template template will come up bottom blade propeller being measured another photos Kyosho Electrics blade 8-in pitch other 81/2 easiest way correct unbalance make pitch both blades 81/4 splitting difference between 8 81/2 shimming back hub masking tape easier alternative beveling prop made wood Wood props can sanded filed proper hub angle Just sure keep hub surface flat want know whats going propellers youd best make purchase prop pitch gauge odel Aviation WiLire assembly before yuu bUllO rM tAY M Stephens Akro/Shepherd Continued Page 48 $lAiNrJG Nay SpecialGT GENERIXExpiresjune7 Foorrerly DOCS GENERIX FLY-ROD UlIro-Hi-Tec Fon Fly Special Airfoil Technology & Nerd Nodriog Bar Tiere Build 0-Tube Wiog Keeglas Soon & Geon Inclodeus Whnol Conloor Germ Balno &- Plysoood Skid Horderoro & Supor Lire Coveong Conrporirioo Arofrarne Kir ConporerRadionfMionoo$59 Fogine 34040 Full Sire Plan TAn OATOR2 Km rho Prier Ore holh Tnil Galonni Bror Oral Aroundt No Micro Nredndt NOT rho Paid Heaor Ornigord Cornhor-Srraronr & Elecronic Aoo Spor-r Plooo Will Pack Arnybadyr Lonoh SFuN 38 uREA 3ff \ -Z7SFEOAL PRICE 2 Flarernl $2995Z2Z~ABF CI4EAF SENSATIONSul Jr Soredy Likic Per Ho Fun-Flynn, Foon Wing Kovglo Boon Sapro Lilo __________________ Door Broovo Whool Hordonore & Oreor lorocrions Build 12 BR Doer Lor Ore Peico Fool 111 Blow 262035 Off 90% rho Cowynorior Huge Ainfoil-Plirs So Slow Toenpa FL 33615 Coo Walk Nrc er Irnocro FOeHiogrd Try 11813-854-lOTS SF424 4e ARE 770 SFOAL PRICE COO pEgro SC Ooroe S7000er ji3995 Write foe PSEE Calairg
Edition: Model Aviation - 1992/06
Page Numbers: 63, 80
You wont know much performance youre missing until check out propellers pitch gaugeand fix necessary author tells build simple inexpen sive instrument CHALLENGE If think about propellers eventually will get around subjects pitch pitch distribution Pitch inches millimeters distance given point propeller will move forward revolution turning perfect slip-free medium Pitch distribution refers pitch various points along propeller radius type pitch distribution called helical Helical-pitch propellers have same pitch point along radius blade angle changes root tip point along blade moves forward same distance revolution Other pitch distribution designs deliberately change pitch root tip achieve designers objectives does average modeler care Its curiosity search whys improved performance made us think about propellers first place Most us go through period experimentation eventually settle prop works best someone shows up flying field new Airblaster Superprop blows everyone away run down favorite hobby store stock up Superblasters Sure enough really works U Don Hughes £ Fscu LcflxF7 WOrn Ld2 L1G first works great did well break Superblaster replace another doesnt work well original Perhaps engine vibrates Did wonder Its because propellers arent created equal Though props supposed same can irregularities propeller blades different pitch can cause vibration can weight imbalance Performance suffers pitch distribution may same original Again performance suffers pitch gauge needed detect subtle differences experimenter looking perfect prop cant get along pitch gauge Commercial pitch gauges work great However might want first try described just get used concept see can justify cost professional unit Take look photo left What see propeller fastened slotted base plate cardboard triangle under near prop blade base plate something found surplus metals store Its section aluminum heat-sink extrusion material piece flat warpfree hardwood plywood saw kerfs half-inch will just well Continued page 80 June 1992 63 Left The Poor Mans prop itcn uauge CNCCKIfl9 ryosno prop yor Iectrics ins near waae EflUWS piivn UT UIfl wflhle oppuamie 01U05 measures 81/2 Fix bevel shim prop hub both blades have pitch 81/4 RIght Typical measuring templates made stiff cardboard found back writing tablets template should labeled show inches pitch radius location ELDON J LIND CO #401 UIUUH Easiest hinge tool available $325 Finest Building Tools Available w SEND SELFADORESSED STAMPED EN VELOPE FOR CATALOG #101 EXTRA HANDS Makes covering easy $1775 3151 CARAVELLE HAVASU CITY AZ 86403 602 4537970 happen live near Ocala Florida consider paying visit Ray Parker fine craftsman gentleman version Stephens Akro would exist Contact Ray Leeward Air Ranch Ocala like enjoy crafting balsa-and-plywood models love aerobatic flying building Stephens Akro will time well spent bench model does Acknowledgements Bud Davisson Emily Zimmerman Ray Parker contributed some information article want publicly thank helping project come alive * Poor Mans Prop/Hughes Continued Page 63 Note small block prop hub raises prop off base allow insertion triangle prop held place conical nut prop balancer prop pitch gauge simple inexpensive construct Pitch measured slipping various triangles under prop until find bottoms base plate slot matches propeller angle will have construct triangles pitches wish measure Fortunately geometric basis pitch calculation pretty simple Ive reduced triangle dimensions rather using trigonometry angles Just plug numbers equation triangle base always has length 100 millimeters pitch 314 x dia x 100 ngle height mm example wish make triangle representing 7 pitch 4-in radius must multiply 2 get diameter use formula formula yields 28 millimeters height base always 100 millimeters Just construct 900 right triangle dimensions cardboard such found back paper tablets triangle 6-in pitch 3-in radius multiply 2 use formula would 32 millimeters 100 millimeters photos shows templates some pitch angles commonly use will want check least two points probably blade radius Make templates COMPOSITE SOLUTIONS--PO Ito 252 Haclet NJ 07730 CARBON FIBRE Tuned Exhaust Systems LOW RPM Pipes below 11000 STANDARD engines 40 90 size OSRossi Pico Webra Sc per Tigre others Performance Pipes LONG STROKE ENGINES 60 size OS OSHanno Special Webra YS YS-120 4 cycle Custom Pipes UC Speed Aerobatics other applications carrying Free Flight Competition Timers br Info call s 908 264-6693 till 10PM 1ST OUR PRODUCTS ARE OMPETITIVELY PRICED AGAINST ALUMINUM INPORTS Satcsfaction guaranteed money back need sure dont cost much dont take much time Some typical templates shown photos Shallow angles may require constructing triangle rectangle done 5 lh-in-pitch 3Ii 6-in-radius template template will come up bottom blade propeller being measured another photos Kyosho Electrics blade 8-in pitch other 81/2 easiest way correct unbalance make pitch both blades 81/4 splitting difference between 8 81/2 shimming back hub masking tape easier alternative beveling prop made wood Wood props can sanded filed proper hub angle Just sure keep hub surface flat want know whats going propellers youd best make purchase prop pitch gauge odel Aviation WiLire assembly before yuu bUllO rM tAY M Stephens Akro/Shepherd Continued Page 48 $lAiNrJG Nay SpecialGT GENERIXExpiresjune7 Foorrerly DOCS GENERIX FLY-ROD UlIro-Hi-Tec Fon Fly Special Airfoil Technology & Nerd Nodriog Bar Tiere Build 0-Tube Wiog Keeglas Soon & Geon Inclodeus Whnol Conloor Germ Balno &- Plysoood Skid Horderoro & Supor Lire Coveong Conrporirioo Arofrarne Kir ConporerRadionfMionoo$59 Fogine 34040 Full Sire Plan TAn OATOR2 Km rho Prier Ore holh Tnil Galonni Bror Oral Aroundt No Micro Nredndt NOT rho Paid Heaor Ornigord Cornhor-Srraronr & Elecronic Aoo Spor-r Plooo Will Pack Arnybadyr Lonoh SFuN 38 uREA 3ff \ -Z7SFEOAL PRICE 2 Flarernl $2995Z2Z~ABF CI4EAF SENSATIONSul Jr Soredy Likic Per Ho Fun-Flynn, Foon Wing Kovglo Boon Sapro Lilo __________________ Door Broovo Whool Hordonore & Oreor lorocrions Build 12 BR Doer Lor Ore Peico Fool 111 Blow 262035 Off 90% rho Cowynorior Huge Ainfoil-Plirs So Slow Toenpa FL 33615 Coo Walk Nrc er Irnocro FOeHiogrd Try 11813-854-lOTS SF424 4e ARE 770 SFOAL PRICE COO pEgro SC Ooroe S7000er ji3995 Write foe PSEE Calairg