Aero Mail
Airtronics Phone Number
The wrong telephone number was listed in the “Manufacturer/Distributor” section at the end of the Airtronics RDS8000 product review in the July 2008 MA. For dealers to place an order with Global Hobby Distributors, the number is (800) 346-6543. The (800) 262-1178 number is strictly for technical assistance.
Our apologies for any inconvenience this may have caused.
—MA staff
That’s My KANDU!
I was quite surprised to see the picture of the KANDU airplane on page 156 of the July MA. I am still flying the original from the November 2001 feature article. I received e-mails from Greece, Australia and New Zealand as well as here in the U.S. when the article was printed. New Zealand modelers sent me a copy of their magazine with the same article.
One person asked me about adapting floats to the KANDU. Since I live in Phoenix with no lakes readily available I had not given it much consideration. However, I see no reason why it would not be successful. I have built and am flying two 60-size versions of the KANDU. They fly just like the 40.
Dale E. Singleton via E-mail
J-3 Cub
Great article (“Plane Talk: E-flite J-3 Cub 25 ARF on Floats”) in the July MA magazine; I have the float-equipped J-3 you reviewed and I agree with your conclusions in the article.
However, you stated at the end of the article to use two 2100 mAh wired in series to give the same output as the 3S 4200 mAh battery. I think you meant in parallel rather than series since the series wiring would give you 22.2 volts instead of the 11.7 you anticipate.
Thanks again for a good write up.
Kent Galbraith Orlando, Florida
Good catch, Kent! In parallel, two 2100 mAh 11.1-volt packs would yield the 4200 mAh. The Power 25 outrunner won’t handle 22.2 volts.
—Michael Ramsey MA Editor
Simple Sailplane Modification
I just finished re-reading your feature article on simple sailplanes in the Sept. 07 Model Aviation magazine.
I recently received an old Olympic II from my son who hasn’t flown it in 10 or 12 years. It’s in good condition and weighs 2.9 lbs RTF. The CG is at the rear edge of the spar. He said it didn’t fly very well; it tended to wander and had a high sink rate. He thought it might be caused by too much angle of attack on the wing, so he dropped the back edge of the stab about 1/8 of an inch. There is still a small positive incidence on the wing relative to the stab, 2 or 3 degrees, hard to measure. He never flew it after the mod. I would appreciate your thoughts on whether I should try to fly it like it is, or put the stab back where it was originally. Also, do I need washout in the tips? Any other hints would be helpful. Great article, Dave.
Gary Acord Ventura, California
The CG at the back of the spar sounds good. I’ll bet making sure the inner wing panels are flat, and the outer panels have 1/4 inch to 1/2 inch of washout (trailing edge tip up off the bench a little) will make your Olympic fly much better.
Fliton Edge Advice
I enjoyed Michael Ramsey’s review of the Edge 540 in the June issue. This ARF looks like a good match for my new Saito 82.
Two questions. (1) What prop—diameter and pitch—gave you the best results with the Saito 80? (2) How do you keep the muffler assembly from loosening up? I’m having a terrible time with vibration loosening the muffler assembly while breaking in my Saito despite having balanced the prop. Do you use threadlocker? Blue? Red? High-temp silicone?
Any suggestions would be appreciated.
Bob Levy via E-mail
You could turn a 14 x 6 propeller on the .82 since it has more torque than my .80. What I don’t like about the 14-inch propellers is that they are much heavier. If you don’t need the nose weight, go with a 13 x 7.
My mufflers always loosened until I put them together with Loctite 518 Gasket Eliminator. Clean everything beforehand to make sure the threads are oil free, and the muffler will stay on. I use it on every exhaust system I own.
—Michael Ramsey MA Editor
Corrosion Advice for Float-Fliers
I enjoyed Jim Feldmann’s article very much. I’ve been doing this for many years myself and have encouraged a lot of others to give it a try, too.
My first “floater” was a Four-Star 40 kit. Several clubs in the Dallas–Fort Worth area had started a club-racing event and were looking for a suitable plane. We chose that kit right after it was first announced, and got probably the first batch off of the line.
During that first year, we decided to try running one of the races as sort of a “Schneider Cup” reenactment, so we all set them up to accept floats for that event. This was back in the early ’90s (or maybe late ’80s). I’m still float-flying that same plane today—most recently about a month ago.
Anyway, the article talked about what to do if your radio gets dunked. Sealing the battery and receivers inside plastic wrap does help keep things drier longer, but water will still find its way in.
For years now the local float-fliers here have been using a product called CorrosionX in their receivers and any other electrical stuff that could get wet. It’s designed for marine use, especially around salt water, and both prevents and removes corrosion as well as repels moisture. It’s also a non-conductive product, so it’s suitable for use on electrical items.
At the first demonstration I saw, the representative had a portable TV halfway submerged in a clear tank of the stuff—plugged in and happily playing away!
I've dunked many a plane (what float-flier hasn't?), and have never had a problem with those mineral deposits you'd mentioned because of this stuff. You just open the receiver, servos, switch and anything else electronic that might get wet, spray the CorrosionX in it and just close it up again, leaving the product inside.
If you haven't pre-treated your equipment, you can treat it after you get it wet and the CorrosionX will force all of the water out. You can also spray it on your servo connectors to clear up that occasional problem you might see with dirty contacts (works for non-float planes, too).
About 10 years ago, I dunked my Shuttle (.32-size heli) at a float-fly; it was upside-down in the water hanging from the floats. I took everything apart, even the engine's pull-start and the mechanical gyro, and sprayed this stuff in them as well as all of the airframe bearings. It's all still working fine today.
The only caveat I have to add about that is that I did go ahead and clean out most of the CorrosionX from the gyro's sensor box after it had done its job, but only because I didn't want it to potentially slow down that spinning "dumbbell" in there. Other than that, I just left the product in place.
Have a look at www.corrosionx.com if you want to get some more info on it.
Alan Buckner via E-mail
Gets the Full-Scale Wet, Too
I just received my July 2008 issue where you featured “Try flying from water. You’ll like it.” I really enjoyed this issue. Keep up the good work on the waterbirds.
I’m into water flying. My interest started early when my Dad brought home from WWII a U-Control Tarpon model and rocket engine. I’ll have to admit flying off the water with RC models only told me I needed to get a seaplane rating and build a full size.
I bought the Progressive Aerodyne Searey kit in 1995 and flew it in 1996. The attached picture was made by a friend three months ago of me landing on Lake Gail in Florida (I’m 75). It’s a 40-knot boat and a 100-knot amphibious airplane.
Needless to say, if the Searey gets upgraded it’ll be a POC RC model first. I’m working on some modifications. I’m having great fun with RC models and the real thing.
By the way, I highly recommend flying the seaplanes on Great Planes’ RealFlight R/C Flight Simulator. I especially recommend the G-4 Expansion Pack 5 for the seaplanes. I found them very realistic.
Frank Gracy Bellingham, Massachusetts
Born to Make a Difference
Just a quick line to say thank you for the tribute you offered to LA Johnston in Jim T. Graham's "Born to Fly" column in the July issue of Model Aviation. He is indeed a special person and I also consider myself blessed for having received some of his expert assistance as well (even though I already know how to solder). Thanks again.
Tom Nelson Mount Juliet, Tennessee
I was pleasantly surprised to see and read Jim T. Graham's article in the July issue of MA about Mr. LA Johnston. I believe my first contact with Mr. Johnston was in 2005.
I purchased an Atlas outrunner and ESC. For some reason the Atlas would not start until about half throttle. I ran several tests thinking it was the ESC. Mr. Johnston told me to send it back; a new one was on the way.
The new one did the same thing. I decided to take an 18-amp unit I had in a plane and try it. It required about half throttle to start the Atlas to run. I should have thought to do this earlier.
In my conversation with Mr. Johnston, he told me to send the Atlas back; he had Hobby Lobby send me another Atlas. It has run fine for over two years. I expect it will for as long as I can fly.
I talked to him on the phone several times; all my questions were answered, as well as many suggestions, which I followed. Mr. Johnston's model plane experience started like mine. I was twelve years old.
At 86, it is still a fun thing for me to fly the model gliders, all of which I have built. He told me he was planning on retiring. I told him I have been retired for over 30 years. I am now thinking of buying an AVA RES Electric, or a Hyper 2.3-meter RES Electric, if they make it.
I am sure Mr. LA Johnston would have ready answers for me. Thank you again for the fine article in MA.
Donald Kellis via E-mail
Jim, thanks for two things!
First, thanks for being a friend to me.
Second, thanks for getting me such notoriety!
You would not believe the number of people who have dropped me notes telling me how much they enjoyed the article, and telling me how much I had helped them personally.
I guess that is one of the things I always enjoyed doing without even thinking of it—helping and teaching people!
Just wanted you to know I do appreciate all you have done for me!
MA
LA Johnston
Transcribed from original scans by AI. Minor OCR errors may remain.
