Radio Control Slope Soaring

Author: Dave Garwood

Edition: Model Aviation - 2011/06
Page Numbers: 103,104,106

Winter building projects

While I write this column in early March, we are experiencing yet another of the many snowstorms that hit the Northeast during the winter of 2010–2011. So many of us Northeastern and Midwest modelers have been building more than flying so far this year.

One of the projects on my winter workbench is an MM Glider Tech Marauder. This is a 115-inch-span modern version of a classic stick-built, flat-bottom-airfoil polyhedral glider.

I first saw one fly at the Charles River Radio Controllers (CRRC) RES (Rudder, Elevator, Spoiler) contest, and I was there at Soar Utah 2008 when Clarence Ashcraft completed his League of Silent Flight eight-hour slope flight (covered in the December 2008 Radio Controlled Soaring Digest) with one. When I asked Clarence at Soar Utah 2010 if he still favored the Marauder for big-sky slope flying he replied, "I'm building my fifth one."

Why does a slope pilot need a 115-inch-span polyhedral model? To diversify or to branch out into other types of soaring flight.

I'd like to fly it in the CRRC RES Contest this summer and do some lazy-day lawn-chair flying on big hills in big-sky conditions, such as at the Capital Area Soaring Association's (near Washington, D.C.) 45th annual Soar for Fun event in the fall. I also want to fly the Marauder in the big air on the western side of the Appalachian Mountains, where some impressive full-scale soaring distance records have been set.

Pushing sticks together, I realized that I'd partially forgotten how absorbing and relaxing it is to build with wood. There is the joy of shaping and fitting the materials. Whenever I'm able to cut, fit, glue, and sand wood so that you can see the joint but cannot feel it, I feel like a craftsman. There is a connection with model builders throughout the decades, because that's what models were built from for many years.

In addition, there is the sheer magic of turning a pile of sticks and sheets into an actual flying machine. And these sailplanes do fly. On one of the RCGroups Marauder building threads, the modeler was amazed and pleased to find that his newly built aircraft flew 300 feet on the initial hand-toss test. That's a hand toss the length of a football field!

A second winter building project is my fifth Dave Sanders Schweizer 1-26. There's no shame in wearing out an airframe, and I needed another to have two at the ready for any soaring trip.

The EPP-foam kit is available from SkyKing RC Products, and the 2-meter version remains at the top of the must-have list for New York Slope Dogs. This sweet-flying semiscale sailplane easily handles a large variety of wind conditions, and the foam airframe will withstand more than its share of in-a-bush and on-the-rocks landings.

I built mine with split-wing and removable-stabilizer modifications so that it will fit neatly back into its kit-shipping box for compact storage and transport. These modifications are documented on the SkyKing website.

With each build I have used stronger and tougher aileron servos, because I encounter stripped aileron servo gears more often than I like. Of course it happens at inconvenient times and places.

Shop and Building Tips

Blade handling: Installing a new, sharp blade is a sure way to improve the quality of a cut and make your work go smoother and more easily. Why is working with a sharp knife blade safer than working with a dull blade? Because a sharp blade is less likely to slip.

Purchase your single-edge razor blades and hobby-knife blades in packs of 100 to lower their cost. Store them in baby-food jars, which are clear so you can see their contents, and use tight-fitting lids to keep out moisture to reduce rusting.

Plentiful glue wipes: Using any type of glue—CA, epoxy, Titebond, Gorilla Glue, etc.—will generate small blobs that need to be cleaned up. It is uneconomical to use a whole paper towel for a small drip or to wipe the nozzle of a CA bottle before replacing the lid. Keeping a paper towel on the bench that has been used to wipe up one spill is a sure way to make a mess on the next thing you wipe.

For little drips, spills, and ooze-outs, use small paper towel squares that you discard immediately after use. Make miniature glue wipes by cutting paper towels. You can quickly produce a stack of 64 by cutting a stack of four paper towels with five passes of the scissors.

Film covering hinges: My long-standing favorite control-surface hinging method is what we commonly call "MonoKote hinges." I use the "Film Covering Hinge Technique" that is on page 17 of the Carl Goldberg Products Gentle Lady glider kit instructions (downloadable from the website) on nearly all of my builds, including the Marauder and Schweizer 1-26 I mentioned and my Slope Scale and Leading Edge Gliders warbirds. It is an easy method that has proven to be durable and long lasting. Attaching ailerons, elevators, and rudders with the covering requires a bit of practice, but your careful work will be rewarded with a strong, long-lasting hinge that prevents airflow through the joint.

Installing small parts: Triangle reinforcements and other small wood parts can be awkward to install, especially if coated with glue. One way to handle them is by sticking your hobby knife into the part and then applying the epoxy or other adhesive. The knife acts as a temporary handle for accurately placing the piece.

Insert the part into position in the construction, press with a finger to hold it in place, and withdraw the knife. This way, you get accurate installation on a small piece with less glue on your fingers.

Old-towel covering aid: A great help when covering a sailplane is an old towel.

Ironing covering onto the wings, fuselage, or tail parts over a folded towel gives a soft base that you can press against without scratching the covering or damaging the part on the other side.

Electronics and instruments

Want to know how high your half-pipe jumps are in real time? Winged Shadow Systems has redesigned the How High altimeter, and now it features real-time output capability.

The new How High RT is plug-in-compatible with the HiTec Aurora 9 and Spektrum DX8 telemetry systems. Live in-flight altitude is displayed on the transmitter when the altimeter is used with these radios. If you don't use those transmitters, no worries. The How High RT plugs into any RC receiver and reports peak altitude after each flight using a series of light flashes. No computer or additional equipment is needed.

This device offers 1-foot resolution, automatically adjusts for field elevation, and can report in feet or meters.

Winged Shadow instruments are designed and manufactured in the U.S. Details, including instruction-sheet downloads, are available on the company website.

In the October 2007 column I reported success with the Winged Shadow How Fast onboard airspeed-measuring device, and I have used the earlier Winged Shadow How High onboard altitude-measuring device. I'll report on the How High RT after I get a chance to use it.

Memories

One of the most joyous and memorable flying days I ever had was with Rob and Katie Martin at Soar Utah 1995. Katie flew my Coyote at Point of the Mountain.

The Katie Martin I knew was full of energy and enthusiasm. She radiated a joyful view of life, painting smiles on the faces of those around her. Katie has passed on, but for me a very happy memory remains.

This from Bob Martin:

"Katie passed away at Cedars-Sinai Hospital in Beverly Hills on December 19, 2010. She died of pulmonary hypertension.

"As you remember, she could fly with the guys, she flew all of my aircraft, including the SR-7, of course the Katie II was designed for her, and she was the first woman to fly an RC aircraft in Costa Rica.

"We would have been celebrating our 47th anniversary this June 6th and her birthday is June 1st. Some friends and I are going to go on a sailplane safari the 3rd, 4th and 5th of June. I will be flying her original Hobie Hawk I bought for her in 1974 that got me interested in sailplanes and launched Bob Martin RC.

"I am going to put a pinch of her ashes in a small bag, put that in the nose of the Hobie Hawk and take her flying."

Early RC slope soaring

I'm wondering what is the earliest article in print specifically about RC slope soaring, and I hope that readers can help with the search.

Let's start with the cover photo on the May 1983 Model Builder magazine showing Eli Whitney, a Trans World Airlines pilot, launching a Carl Goldberg Gentle Lady from Grouse Ridge Lookout near Grass Valley, California. Sadly, both Model Builder and Trans World Airlines have gone out of business, but the venerable Gentle Lady kit is still available.

Who among us can dig up an earlier RC slope soaring article or cover photo? MA