earthsciteach's STOL Build for the "Contest"

Ak Flyer

Fly the wings off
Mentor
Have a throttle cut, come in slow, throttle back to land, start applying the brakes and then hit throttle cut and roll the brakes on and off as needed. Or, just have your brakes apply a bit lower than your minimum throttle setting. You could have them come on only at zero stick as well so you wouldn't be fighting it. I think I might have to try this on my nitro.
 

CrashRecovery

I'm a care bear...Really?
Mentor
I'd think you'd want to be able to deactivate the brake when landing so as to not nose over. This is getting into that programming stuff that makes my head hurt!

I actually was thinking about the brake thing. It would be easy to use a servo to actuate a band brake attached to the axle. The hard part would be operating it. A slider or knob would be a must so you can feather the brake. But, I don't think my fingers are that talented!
I think teach has it. A solid axel attached to a set of struts. Put some type of a pulley wheel with a large prop saver and the servo could pull on the rubber band to slow things down
 

Ak Flyer

Fly the wings off
Mentor
If you do, please post the results along with details of how you execute it!

Well, I just found damage to the wing of my nitro and I'm pretty focused on helis these days but maybe by the end of the summer. Hopefully someone will put up pics and video of the build and show how to land with it.
 

FlyingMonkey

Bought Another Trailer
Staff member
Admin
I think teach has it. A solid axel attached to a set of struts. Put some type of a pulley wheel with a large prop saver and the servo could pull on the rubber band to slow things down


Maybe you could do some programming so that you can do it as a throttle mix.

Brake is on when throttle is off, as throttle increases, brake decreases. The only time this would matter, would be on the ground, so it wouldn't effect anything in flight.
 

earthsciteach

Moderator
Moderator
Wing templates are cut, sanded and ready for the hot wire!
 

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earthsciteach

Moderator
Moderator
Figured I'd post up a couple of pics of my hot wire rigs. I use a car battery charger. I set the voltage at 12 v for the horizontal cutter and 6 V for the smaller vertical cutter. At 12 V, the guitar string burns through on the smaller one. They both work great!
 

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CrashRecovery

I'm a care bear...Really?
Mentor
Maybe you could do some programming so that you can do it as a throttle mix.

Brake is on when throttle is off, as throttle increases, brake decreases. The only time this would matter, would be on the ground, so it wouldn't effect anything in flight.

Is there an echo in here? lol That's definitely the way to go. Throttle mix.

The only thing I see would be a problem is if you have cut your throttle to glide in and you touch down your going to flip over because the brakes are locked. With a servo you could activate that channel and use a knob to control the pressure
 

earthsciteach

Moderator
Moderator
Well, totally screwed up my first wing cut. I set the long cutter to 6v because it was flying through the foam at 12v. Didn't work out so well for me. Wing attempt #2 coming up shortly!
 

earthsciteach

Moderator
Moderator
The left wing came out MUCH better. I need to trim the trailing edge and do some light filling and sanding in spots, but I'm happy with the result. I'm debating if I want to glass the wing. It is pretty thin and could definitely benefit from some fiberglass. I was planning on simply covering it with monokote (or similar), but not sure what to do at this point. I'll definitely be putting a spar in it. I guess I'll make my decision once that is done.
 

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CrashRecovery

I'm a care bear...Really?
Mentor
How you going to insert the the spar? I think with a carbon spar or two the mono coat should be enough.
 

earthsciteach

Moderator
Moderator
Since the wing is so thin, I'm going to route out the bottom and glue in place. I'll be using 4.8 mm OD carbon fiber rod as the spar.
 

earthsciteach

Moderator
Moderator
Looking for some thoughts on flaperon setup

The most complicated part of this whole build is going to be the flaperon setup that the Kitfox utilizes. These hang below and behind the wing. Here's a pic.
kitfox flaperon.jpg

I've been doing some reading about these. According to some they cause adverse yaw and it takes a lot of leading rudder to turn. So, I'm debating whether to go through the trouble of building these or going with conventional ailerons and flaps or flaperons. Any thoughts on the matter would be appreciated!
 

earthsciteach

Moderator
Moderator
I made a stop in at the LHS this morning and picked up the covering for the plane, balsa for the flaperons and a couple more lengths of carbon fiber. I've decided to build it with the Kitfox flaperons for scale experience (its just something different about this plane). I've worked the mounting of the flaperons in my head, so I'm good to go!
 

earthsciteach

Moderator
Moderator
Those won't quite do it. The flaperons are attached to brackets that extend out from the trailing edge of the wing. I'm going to make those brackets from balsa which will be terminate with a rod (pin) recessed in the flaperons to allow them to rotate.(see pic of the Kitfox wing above).