I am building my new spacewalker. Almost done, but I am having trouble installing the control horns for the ailerons.

I can't find a solid surface to secure the backplate of the horn. Do I open the covering and glue a piece of wood? or don't use large scale horns.

Is flaperon OK for this model? I have never used flaperon before?

I'm half way through mine right now. I was also surprised that GP went through the troubles of gluing a piece of wood for the aileron control horn, but they didn't do anything for the backplate. I plan to cut open the covering like you said. I already have a roll of cub yellow monocote from another project, so I've got plenty to recover these and other places, like the wing center, where I cut open to fiberglass the wing joint.

BTW, flaperon is not a good idea for planes with barn door ailerons. when you drop both barn doors, what you have created, in effect, is a wing with wash-in. This is very bad, because the wing tips will be at a higher angle of attack and so will stall first before the wing center.

Flaperons are okay for strip ailerons that run the whole length of the wing. Even then, I would be very judicious with its use.

I thought about adding flaps to this plane, but the wing loading is so light, even with a 1.20 4stroke, that I doubt flaps are really necessary.

Volfy,
Thank you for your input. I will purchase covering and add a piece of plywood to complete the control.
I was planning on using flaperon for fun only since I have this feature in my new Futaba. With this wing size I new flaps are not necessary.
I did not add anything to the wing joint. Do you really think it needs to be made stronger? what other modifications you suggest?

I think you'll be fine with your wing joint, as long as you made sure the plywood joiners fit well and use plenty of 30min epoxy for the joint.

I did fiberglass the wing center joint. Whether this is necessary seems to be a matter of religion for some people, so I will just say that I personally prefer to do it. It can add a lot of strength to the wing with only a negligible amount of weight gain. Plus it really isn't too much work. Mine will be moderately overpowered with a Magnum 1.20FS, so it's better to be on the safe side.

The GP instructions does state that if you plan to put the plane through some serious aerobatics, you might want to reinforce the important areas. They, of course, expect you to know what and how to reinforce. Good thing is, you can always go back and do it later if you so choose.

As for other mods, here is one that I just worked on today. I cut a recessed platform on the chin block to receive a set of 1/4scale Giles gears. I capped it with a layer of thin ply (1/64"?) and FG'ed over the area.

I'm not a big fan of wing mounted gears: harder to fix when broken and typically likes to nose over, especially when flown off grass. I don't much care for scale appearance for this aircraft, so I opted for better ground handling, and taller gear to clear the 16x6 prop I plan to use.

Here it is with one gear half. I cut the recess at a flatter angle than that of the chin block, which would have kicked the gears too far forward. This way, the wheels should be rright underneadth the LE when the wings are level.

As for other mods, well, the sky's the limit. I'm trying not to go nuts on this one like I did with my WM Super Stunt 60. So Iwill limit myself to the main gear mod and other prudent reinforcements.

Here's a look at the back of the firewall, with some tri-stock and the usually fiberglass complement.

I'll probably ditch the stock tail wheel - I don't like permanently mounted ones. I have a couple of Klett .60 size tailwheels that might do the trick.

I'm not gonna put the, IMHO cheesy, ABS wingtips on. The wingtips will be left squared off and covered over. Besides, 76" wing fits in my pickup bed better.

A 16 Oz. tank will fit no problem. The stock tank is a little small for a 1.20FS.

That's all I can think of. This is a well thought out and designed model and, as such, don't need much builder's embelishment to be an excellent flyer.

volfy
I think you'll like this one, I tried to install to control horns after installing the pieces of wood on ailerons. however the screws will not go through the leading edge. It's too thick.
I got frustrated so I called Great Planes trying to find out why didn't send the control horns with the plane or why there is no piece of wood on the other side.
the person who answered doesn't know why they don't have control horns. He doesn't know what piece of wood I'm talking about. However he found a note (on his computer I guess) that says backplate is not needed just put screws from the front side. They don't need to be supported with a black plate.
I will probably go and purchase longer screws to use the backplate. I'm not comfortable using the control horns without backplate. I'll make it work somehow.
I'm not very brave at this stage to modify the plane like you did I do have enough experience to do that. It is my first one in ten years.
Again, thanks for your input and hopefully I will e-mail you when it is completed (and tested).

Happy flying

A nice plane, but not acrobatic in my opinion. It is a floater and high speed flight is not its forte. I like to fly it scale like and do touch and goes. Leave the wild stunts to a wing with less dihedral (sp). The stock control horns work ok for this, I strenthened the wood with ca wicked into pin holes thruout the area and have had no problems for 4 years and many flights with YS 91. You will enjoy this fine plane I think but again its not that areobatic.. Cuda

Yep, I agree with Cuda. I didn't use the large scale horns on the ailerons as GP suggests, I used smaller nylon horns with four #2 screws in each and just wicked in some thin CA. Just be sure to let the CA cure completely before you put the screws back in. I've had no problems with mine. I'll also agree with Cuda that this is a great scale flying plane, it's not designed for speed or wild arobatics. I have an OS 61FX in mine and it flys very scale, even at half throttle, a 1.20 is gonna be a bit much.
You also don't need flaps on this bird, it's got so much wing that it doesn't want to come down as it is. When I'm flying mine in calm or very light winds I chop the throttle to idle on the down wind leg. The supplied gear works very well, just be sure to hold full up elevator when taxiing on grass and at the start of takeoff.

I, too, will use longer screws for the control horn backplates for the ailerons. Like many of the mods I do, I look at them as insurance: it probably doesn't need it, but if and when it does, I'll be very glad I paid the insurance.

I've seen several GP Spacewalkers built completely stock fly and handle very well. One has an OS 61FX, the other an OS 91 4stroke - both plenty power. However, every one I saw came out tail heavy and required quite a bit of nose weight. Many owners in these forums also have similar experience. So I figure if I have to add noseweight, it might as well be more engine.

Flyseven, I'll post more pics here as I go along. Hopefully I've finish it up in a couple of weeks.

This plane actually flies better a little tail heavy, with an OS 61FX I only added an ounce of lead inside the cowl. The CG on mine is about 1/2" back from the recommended setting and it lands much easier that way. If this plane is too nose heavy it's very hard to slow it down for landing, when you try to get it in a nose up attitude it just wants to keep flying.