A-10 Fixed Landing Gear. A solution

by Eyedoc | July 11, 2019 | (9) Posted in How To

PFT A-10 FIXED LANDING GEAR. MY SOLUTION. 

I prefer to take off and land rather than hand launch and belly-skid for landing.  It looked like the belly landing thing could goof up some props so I tinkered with some gear designs. I talked this over with Josh Bixler at Flite Fest Ohio 2019 and he asked me to post an article on the subject. This is my first article so please bear with me. 

MAIN GEAR.  The gear legs exit the bottom of the engine nacelles 1/2 inch behind the existing wheel cut-outs. I found it necessary to use 1/8 inch ( .125 ) music wire for the main gear. The supplied .100 music wire was a little “floppy” for my taste. I bent a coil into the gear and it is just outside of the nacelle. The gear legs are bent rearward near the bottom ( like military Trailing - Link gear ) to put the wheels a little further aft of the CG.

I put a thin plywood plate ( same thickness as the engine mount ) on the inside top of the nacelle butted against the engine mount. There is also a plate glued to the bottom of the nacelle just behind the existing wheel opening. I then drilled a 1/8 inch hole through both plates trying to stay 90 degrees from the bottom wing surface. I’ll try to add a picture.  

Note the SECRET SAUCE to this lite-weight installation. The gear is inserted through the bottom of the nacelle THEN THROUGH A STEERING ARM and then through the top plywood plate. Note that the end of the steering arm is screwed to the plywood plate to keep it from rotating. HOW DO YOU TIGHTEN THE STEERING ARM COLLAR you might ask. You put a HOLE IN THE SIDE OF THE NACELLE for the wrench !!

This installation is as light as I could come up with and the gear is removable by simply loosening the collar and pulling the gear out of the hole. The steering arm will remain in place because it is screwed into the plywood plate. 

If there is any interest in this I can describe the nosewheel setup too. It is nearly identical except that the steering arm is actually used for steering so you must add a collar just inside the fuselage to keep the gear from falling out !  See pic below ( nose gear ...... steerable).  


Submitted respectfully,  Gary Contner

These 3 pix are in response to bird2jump. Gary

COMMENTS

bird2jump on July 15, 2019
Eyedoc, nice design work for adding in the LG. Please add a photo of the entire LG and of the A10 with the LG at different locations, back, front etc. Thanks.
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Eyedoc on July 16, 2019
Hi bird2jump! You are my 1st ever commenter. I took some photos which may help. I’ll try to post them here. If not I’ll try to add them to the article. Let me know if you need further info. If you come with a better way PLEASE
LET ME KNOW. Gary.



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bird2jump on July 16, 2019
Gary, great photos. It was just what I was looking for. Your photos show the distance between fuselage, wings and the ground. As well as approximate angle of attack of the entire plane at take off. How far does your A10 go on the runway before it’s airborne? How does the plane then land on the runway with your LG? Thanks, Bert.
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Eyedoc on July 16, 2019
It’s a virgin. I was waiting for Flite fest to buy the upgraded power pack which I did. Should have it installed this weekend. It won’t be on the ground long. I expect 40 feet or less. I’ll let you know. The current nose gear is made of the supplied .100 wire and may have a bit too much sideplay. I’ll keep you posted. Are you thinking about a similar installation? Gary
Talked
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Eyedoc on July 16, 2019
BTW. Keep your eyes out for other A-10 related articles. I’ve got another trick up my sleeve for ESC cooling. Gary
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njacobs on July 16, 2019
What a great little article. Nice ideas and great pics. Sorry I missed FliteTest 2019, our club had our own Warbirds Over the Bay weekend so I had to support my local club. See you next year !!
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Eyedoc on July 16, 2019
Thanks for the kind words. Gary
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bird2jump on July 17, 2019
Gary, I was planning on ordering the A10 based on the use of your LG. What is the name of the upgraded flight pack that you’ve ordered? Good luck on your maiden flight,. Looking forward to your experience in writing. Please take a video. Thanks, Bert
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bird2jump on July 17, 2019
Gary, in your first photo where did you get the nylon coupling apparatus that fixed the 0.100 wire inside the nacelle with a set screw? What is the diameter of your foam wheels! Thanks, Bert.
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Eyedoc on July 17, 2019
Hi Bert. The device (nylon) that holds the gear is called a STEERING ARM. They are common RC hardware and are made for different wire diameters. The A-10 is recommended to use power pack C twin. In the build video Josh shows installation of new FT RADIAL motors which are capable of using 4-cell batteries. He claims 20% more power. Yet they supplied the standard power pack C. So I upgraded. They call it POWER PACK C TWIN “RADIAL EDITION”. I just looked at Flite test store and it is listed as PREORDER. They are close because they had many at Flite fest. Gary
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Eyedoc on July 17, 2019
Also...The wheels came with the kit. Gary
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bird2jump on July 20, 2019
Gary, what did you wrap the 0.125" wire around to produce the coiled spring? How did you do it? Wrap the wire around a screwdriver shaft? It looks so professional that it doesn't look easy to manually to manufacture.. I found 3.2 mm diameter steering arms, 5 pack for $3.20 on HobbyKing.com that fits the 0.125 wire you're using. Thanks for your previous responses to my questions, Bert.
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Eyedoc on July 21, 2019
Hi Bert. Thought you gave up on me! The set screws on most steering arms are 6-32 machine screws. I replaced them with 6-32 Allen head machine screws so you can use a 7/64 Allen wrench to stick thru the nacelle. You must shorten the screws of course. Use a Dremel tool with a cutoff wheel for that. Next I’ll have to learn to post videos to show everyone how to bend the coils. We did that routinely back in the 1970’s when I was doing RC before. Gary
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bird2jump on July 22, 2019
Gary, thanks for your insightful answers. I’m looking forward to your how to video on coil bending. Nice to see that what’s important in the 70s is making its way back in the 21st century! Can you give me the approximate length of the 0.125 wire from the bottom of the fuselage to the center of the wheels? Thanks, Bert.
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Eyedoc on July 22, 2019
Bert..... All measurements are from the bottom of the nacelle/fuselage to the center of the wheel ( axle). Main gear is 5 5/8 inches. Nose gear is 6 3/16 inches. Gary
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Eyedoc on July 22, 2019
P.S. The wheels supplied in the kit measure roughly 2 3/4 inch diameter. Gary
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Mr. E on July 27, 2019
I have wanted to do myself ever since I started building.
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Eyedoc on July 27, 2019
Hopefully this article can help. Eyedoc
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A-10 Fixed Landing Gear. A solution