Carbon falcon gets talons - RC Groups
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Oct 10, 2003, 03:04 PM
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Carbon falcon gets talons


Well I finally have a finished landing gear. After spending too much time making wire landing gear that failed every time I decided to try a Carbon fiber approach
Last edited by bat; Oct 10, 2003 at 03:32 PM.
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Oct 10, 2003, 03:26 PM
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All materials used in the landing gear construction can be purchased at air dynamics

Materials:
3 Dubro ultralite 1 wheels
1 .098 Carbon fiber rod
1 .05 carbonfiber rod
3 Large plastic t-connectors (.098)
1 package of wheel retainers

First you need to drill out the main part of two t-connectors from .098 to .125 unfortunately the plastic stretches out while drilling and then contracts after drilling so you end up with too small of a drill out I tried to work the connector on anyway and almost broke the main cf rod. My solution was to make a slit down the length of the back side of the connector. Then I put the t-connectors on the main tubes right in front of the motor mount. Then I glue them into place.
Last edited by bat; Oct 10, 2003 at 03:32 PM.
Oct 10, 2003, 03:27 PM
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Next I cut a small length of .098 cf to cross the main frame tubes to mount the front landing gear. I then cut the last t-conector to fit between the main rods. Slip the t conector over the .098 rod that was just cut and then tack into place as close to the nose as you can. Then use cotton thread and ca to bind the mounting rod to the main frame. If possible keep the t connector free of glue so that you can choose the angle for the front strut at a latter time.
Oct 10, 2003, 03:29 PM
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The front strut consists of a long piece of .98 cf rod with a 1 .05 rod mounted perpendicular at the bottom for the wheel. Drill out the wheels which are .046 in axle diameter to fit on the .05 cf rod then cram the wheel retainer on. The rear landing gear is two .098 rods about 6inches in length. The t-connectorson the back are angled to form about a 60 degree angle. The cf rods slip right on. Then a .05 rod is used as an axle between the two struts and I glued it with some flex to put pressure on the struts so that they stay in their t-connectors. Place the wheels and retainers on the axle and you are fnished.
Oct 10, 2003, 03:30 PM
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Mistakes:
1 forcing the drilled out t-connector on the main frame
2 glueing the t-connectors in place to the main frame with the cf laning struts in the conectors. THEY WILL BE PERMANATELY BONDED INTO PLACE.
3 finishing the project and realizing that all the gear had been mounted upside down. (this cost me an inch of height on my entire system since the rear cf struts were glued to the t-connectors which had to be stripped off.
Oct 10, 2003, 03:31 PM
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Further mods:
Re-do the cf struts so that I get my inch back. Tonight I will test fly this short gear and test the landing ability with motor off. but becausee prop clearance is so small I doubt it will ROG
Place small contact points on the cf struts so that ortho rubberbands can lock the struts into their conectors.

The beauty is that with the removable struts I can fly it with or without landing gear and it breaks down the same as always
Enjoy!
Last edited by bat; Oct 10, 2003 at 03:40 PM.
Oct 10, 2003, 04:19 PM
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Very Nice! More ground clearance will help for sure for ROG.

Using the same method but in reverse could make it a tail dragger also.
Oct 10, 2003, 04:50 PM
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To ROG with trike gear you need the mainwheels pretty close behind the CG - you will never raise the nose for liftoff otherwise (particularly with no propwash over the control surfaces).
Oct 10, 2003, 05:04 PM
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Bill - You are right about it not able to rotate - didn't think of that.

How about if the nose gear rod is extended longer so the A of A is high enough that once speed was obtained it would lift off straight up? If so then the rears could stay back as the plane could take off without rotation maybe?
Oct 10, 2003, 05:15 PM
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preliminary test run complete

I live in an apartment complex and though there is not much space there is enough to test rog and a landing from a toss

ROG = fail the nose never pulled up bill you were right
flight = floated just like before I was shocked (thought it would feel heavy)
landing = all held together ( even with fast impact with a steep speed bumb.


Bill if I lengthen the over all gear and set it so the nose points upward 10-15 degrees while level on the ground will it be able to rog?


hardlock as light as the gear is having a tail drager could work
would look goofy with two struts up by the nose

the flight balance was beautiful.
Oct 10, 2003, 05:16 PM
Why yes, I DO work for GP
Quote:
Originally posted by hardlock
Bill - You are right about it not able to rotate - didn't think of that.

How about if the nose gear rod is extended longer so the A of A is high enough that once speed was obtained it would lift off straight up? If so then the rears could stay back as the plane could take off without rotation maybe?
That kind of landing gear CAN work, but has some perils... FI, you might find yourself on the back side of the power curve once it lifts off and clears ground effect, since you will have no control over what speed the plane takes off at. Also, it will be very prone to beign picked up and carried away by gusts while not flying. Finally, landing a plane with that sort of gear can be very dicey - you have a very narrow speed range that you can set down in without getting MEAN bounces...
Last edited by FlightofSong; Oct 10, 2003 at 05:20 PM.
Oct 10, 2003, 05:28 PM
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admittedly I try to only fly in the very calm hours since it is so light, so that might make my chances better
but I am sure you are right in that it is not optimal with many complexities.

I am afraid to try and undo what I got can we say
new frame rods will be needed
Oct 10, 2003, 05:52 PM
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Bat, extend the nose rod and try it. What's the worst that can happen? Afterall, it is the nearly indestructable Carbon Falcon!

As goofy as a tail dragger would look, I see an advantage in that the tail can lift till airspeed is obtained and then rotation could occur easier since the CG is behind the mains then instead of in front of them.

That's always been the big debate over nose picker vs tail dragger. With tri-gear at rotation you are forcing a heavy load down on the mains which hinders takeoff unless as Bill said, you have the mains very close to the CG. Problem there is that you'll rotate right into the prop and still need a tail skid to prevent over-rotation.
Oct 10, 2003, 06:59 PM
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I agree, by lengthening the noseleg to put it into a reasonable "flight attitude" you may get it to ROG. Too nose-up though and it will stall straight off the ground, not enough and it will need excessive speed for liftoff (which may make it 'zoom' up and stall unless you get the nose down quickly). But with a lightweight and slow-flying plane like this it's definitely worth a try

Of course a fundamental problem is that with no rudder or nosewheel steering you won't be able to correct if it veers one way or another on the takeoff roll!
Oct 11, 2003, 07:52 AM
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Thank you all for all the great input
due to a busy schedule It might be another week before I can build and test new gear.

I am interested in trying the tail drag method. on my dad's plane at Christmas. are there rules regarding placement of the front gear and the rear wheel with regard to cg. or is the key only the angle of attack

Also When I get this bird working I can take and make video clips of the flight but have no way of hosting the footage if the clip is small enough can it be attached as a file to this thread?

have a good weekend fellows I am off.


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