Discussion GMP GeeBee R3

[jhawk]

I am by no means an expert builder and hope all will chime in if things don't look right. That being said if anyone saw the Giant Scale Planes booth at the Toledo show you may have seen the 122" R3 sitting there. Well now it's in the shop and unpacked. At first glance it's a monster, wings as big as any 40%er. The build seem pretty stright forward except for the landing gear which I've been told Robart is working on a set of struts.

The hardware seem very complete with fiberglass horns like the pilot kits, control rods and ball links.

The fuel tanks and tires will most likly not be used...

Here are some shots...

[jhawk]

The canopy is like those on the comp arf aircraft installed from the inside, and the hatch only has 2 bolts per side with 24" between them its almost 40" long. I will most likely add another at or near the center of the two to reduce vibration and give it addtional structral strength.

Over the plane is strong beefy would be the correct word hope to be under 50lbs..

She has a really nice carbon tail wheel, wing tubes and spinner.

Planning on the following equipment:
Each Evevator Half JR8711
Rudder Pull Pull 2 JR8711
Alerion 2 Hitec 7954
Flap 1 Hitec 7955 Each
Figi Fuel tank with PSP fittings
Smark Fly ignition Kill
EP Buddy A123
DA170 exhaust TBD

[Wayne's World]

Looks good Jim, Cant wait to see it when your done. Those wheels look like they should be on a trainer.... Check out the Sullivan Sky-lite aluminum wheels, i have them on three planes now. Chief has them up to 5" thats what i put on the Sbach.

[jhawk]

Ok yesterday was spend scuffing and cleaning the phonic control horns in addtion to removing the plactic covering on some of them. I also rounded up al the hardware for Today.

So now both Elevators are done and ready to set aside, there are 2 servo holes in the evlevator haves. I chose the center, thinking best over all toeque from the middle...

I drilled and wicked thin CA in all the servo scew hole also...

Both wings are done and drying, I'm still a fan of gorilla glue for the hinges all linkage and extensions done. The landing gear will be the hang up on the wings, Wayne is right the wheels are lacking and the supplied axels are way to big for the wheel, I don't have a problem drilling a quality wheel but these will not work...

Adding wheels and axels to shopping list...

The struts are heavy duty and most likly up to the task, but the only shock absorbtion on landing will be the flex of the wheel. I might just get a set of Robart struts and make them work. The other challange will be mounting the struts with the Wheel fairing together. Will cross that bridge later..

Jim H

[BingWing]

I have an 60` electric version and its one hell of a good looking aircraft. Keen to see your build. Good luck

[jhawk]

Back at the build this week, have decided to go with the MOKI 215, thanks to John in MI got a great deal so will be back at it soon. I have dropped off a wing, landing gear and wheel pant to Sierra products for work on a set of struts for this beast..
Jim H

[vmceachern]

Just for S&G's I put together the 20cc version w/28cc 3w,flew it a couple times and had severe yaw instability,I figure thats the cheap servo I put on the rudder, also has the typical 432 point landing like most GB's do if you try and wheelie land it. Popped a couple wires, gonna make some changes and try her again. Gotta work on them 3 point landings or she won't survive long

[MODE 1]

A man with your talents should be able to harrier land it.

[vmceachern]

	Quote: Originally Posted by MODE 1
	A man with your talents should be able to harrier land it.

The problem with that is my talent and me sometimes are in different places LOL

[vmceachern]

Tried my 20 cc version again and still having yaw instability albeit not quite as bad with a stronger servo,133in/oz. Should be enough I thought. Gonna do away with the pull/pull and go with a direct drive rod next and try that. And the landings are getting better, you just gotta 3 point the thing or it will pogo.

[hrrcflyer]

vmceachern,

I have been following a couple of different threads on this plane on other forums and there have been a few people who are having the same problems you are. The almost unanimous solution was to make sure your wheel pants and fairings are absolutely straight. As large as they are, I can see where this would definitely be a problem. I was tempted to get the 50cc version myself, but I haven't got one yet.

Good luck with your plane. Let us know if you found the problem.......

David

[vmceachern]

	Quote: Originally Posted by hrrcflyer
	vmceachern, I have been following a couple of different threads on this plane on other forums and there have been a few people who are having the same problems you are. The almost unanimous solution was to make sure your wheel pants and fairings are absolutely straight. As large as they are, I can see where this would definitely be a problem. I was tempted to get the 50cc version myself, but I haven't got one yet. Good luck with your plane. Let us know if you found the problem....... David

Sounds very reasonable. That thought had crossed my mind. Thanks for the info. I will check that out for sure

[MODE 1]

Interesting. I never experienced any side effects from the large wheel pants on my version. Only thing I could say was a negative point would be the drag factor from a dead stick. It slows down very quickly. Much faster than any bipe. Other than that it flew much the same as any similar style model and much better than a war bird.


Butch, what about adding a small mix to help matters. I never did this myself for the reasons given above but it could help.

[vmceachern]

You'd figure the way it is now would be good and i'm pretty sure i lined them up best as I could.Still gonna do the straight push/pull cause I did see improvement when changing the servo. Reasoning be that I could finally get to full throttle with out too much trouble if started from a straight run. And man does it scoot!!!!

[vmceachern]

Not really sure that a mix would help, just won't find center in flight unless you slow down.Hit the power when straight and touch the right rudder and it would continue on right yaw, correct with left and center overshoots and continues to yaw left, slow down and it finally will find center