CrossFiles T
his column has hosted many ques- tions from modelers about building and flight trimming. Readers have always risen to the challenge and
helped others become better than average modelers. Now, I’m doing the asking and hoping for some bright answers. I have about a dozen .020 replica F/F mod-
els that I want to convert to electric R/C. They span 30–34 inches (150–170 square inches area) and weigh about 100–120 grams without motor. They flew well as freeflighters and now that I’m a bit slow at chasing, should morph into R/C (rudder, el- evator and motor speed). I have a Brooklyn Dodger, a Swami, a Fubar, a Buzzard Bombshell and several others. I have heard there is a web site that has a formula for conversions of this sort. I tried the various on-line vendors and had little success. All of their charts start with larger engines such as 0.10 and larger. What I want to do is plug in the span, weight, engine and prop and come out with the motor, battery, prop and trim. Any suggestions will be greatly appre- ciated, and I’m sure will help some other readers. Every year there is a great indoor contest
at the National Building Museum which is attended by some of the best builders on the East coast. Just to show you that Mike Moskow builds more than great big outdoor rubber models, here he is with a very unique pusher canard Bostonian designed by Barn- aby Wainfan. I have the same model and have logged well over 100 flights along with a lot of fun. I have shown (and built) two of Rune Jo- hansson’s whimsical kits and both flew quite well. I’m still working on converting his Wright Flyer to electric R/C. So far, the motors that are light enough aren’t power-
by don ross You can reach Don Rossat 8 Village Lane, Methuen, MA 01844, or via e-mail at
flywords@comcast.net
PHOTO: MARK FINEMAN
Mark Fineman’s Flying Yankeeis from an old Scientific kit and would be a good entry for anyone wanting to get into simple competition aircraft.
ful enough. I’m sure I’ll figure it out soon. Now, Rune shows us his Santos Dumont fly- er and it looks like lots of fun and an easy build. I’ll have more flight info soon. Mark Fineman is no newcomer to these
pages. I’ve shown many of his models and commented on his sterling contest perfor- mances at Barron Field and at Geneseo. This month I’m showing two of Mark’s mod- els to illustrate his broad interests. His Fly- ing Yankee is an old Scientific kit (I wish someone would resurrect those great kits) and as Mark says, “Is just right for a small field flying.” It flew right off the board and
regularly puts in times of 45 seconds to a minute. (Remember, a 1-minute flight in a 5 mph breeze will move your model 440 feet which is a long chase for some of us seniors.) Mark’s Zephyr, designed by Abe Bergman is “One of the best baby ROGs I have ever flown. This is my eighth one be- cause the others have flown away. This one won a S.A.M. 7 Baby ROG contest this summer.” We haven’t heard from Bruce Pike in a
while. Now he sends us the Aeronca C-3 Col- legiate that he built from a Dumas kit for a friend. The model is for display only so Bruce shortened the wing by two bays to make it easier to transport. The engine cylinders are from Williams Brothers and the prop is hand carved. The prop decals are from Northeast Screen Graphics and the ba- sic decals came with the kit. Bruce says the kit supplied tissue was very good. You have to admire a guy who is willing to carve a prop just for a display model. Next is another entry from down under in
South Africa. The Van Zyl family is very ac- tive in freeflight and Johann is a prolific builder. Our familiar friend, Jake Larson is in constant contact with the clan and he sends us a picture of Johann with part of his fleet. All are rubber powered and, as you can see, Johann builds both scale and en- durance. He also builds and flies many of his late father’s designs. Now, I will weigh in with a favorite of my
PHOTO: JOHANN VAN ZYL
Johann Van Zyl is a prolific builder and from what Jake Larson says, “Can make almost anything fly well.” Here is only a small part of his armada.
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own. This is the XB-70 Valkyrie built for .020 gas power as a freeflight. It performed well but was a bit too fast for my taste, and even- tually was relegated to a shelf in the base- ment. Now, I’m going to resurrect it as an electric R/C which brings us full circle to my first question. This one, I think will take a bit more power than my Brooklyn Dodger.
APRIL 2012
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