Simon Hitchen

Simon Hitchen

Well Known Member
Looking out for a friend.

Hi Guys,

I need a little advice. A friend of mine is 90% of the way through an '6' and has filled the ends of all control surfaces with foam and fiberglass. I see no problem with doing the tail surfaces this way as you are able to counterbalance them before installation.

Ive read Bob Axsoms reports (very informative) and I just wondered if anyone else had any experience with filled aileron ends, good or bad. I brought the concern up with my friend, he claims that it is common practice and it shouldn't be a problem. The first flight is not the place to find out....

Any help appreciated. Thanx.
 
Last edited:
Why do they do that? Is it for appearance or aero? Seems like a lot of added weight to provide little benefit? I'd be afraid it would come dislodged and lock up the flight control.
 
Misunderstood?

I don't think they are filling the control rods. Just the sides of the control surfaces themselves. Sounds like you might be talking past each other. Just my 2 cents. :confused:
 
Last edited:
apkp777 said:
Why do they do that? Is it for appearance or aero? Seems like a lot of added weight to provide little benefit? I'd be afraid it would come dislodged and lock up the flight control.
Click to expand...
Both? I have seen a few planes that have this done and it looks great. Since the tail surfaces are counter-balanced, you aren't adding and weight there. Two pieces of foam per aileron and a little bit of fiberglass adds a negligible amount of weight. Worth doing, IMO.
 
I am not familiar with this mod. Let me make sure I understand what you are doing.

Make a piece of high density foam to fit in the outboard and inboard ribs. Epoxy it in place and "fit and fair" it?

Do this to the elevators, ailerons and flaps? Do you put any glass over any of it? Are you using micro balloons or equivalent? I can imagine it looks good. Probably wouldn't come loose if done right. I'd like to see some pictures if anyone has them. Might be something I want to do. I have an ugly spot on one of my elevators this would make disappear.
 
Not a problem

Simon,

I'm doing it on the new project. Working on the tips now and will be filling in the tips. Also, going to do the ends of the ailerons and flaps as well.

I'm going to take pictures and will present as a "Builders Tip." Weight gain is minimal. The foam will be glassed in with two layers of cloth.

Regarding the advantages, it will provide a cleaner airflow over and around the aileron, looks good and makes painting a little easier.

Get that thing done Simon!!!!

When you visiting again? Arriba's is calling.
 
No known safety problem

I filled all of the control surface end pockets and I got an increase in speed out of the work on the tail. there were no control differences noted but I got no speed gain out of the work on the flaps and ailerons. I think there is speed to be gained but two different approaches have proved unsuccessful. One approach was a cover plate over the aileron to tip gap - the speed was reduced. The second was to fill in the end pockets with balsa wood plugs - again the test flight indicated a reduction in speed. I think the problem is similar to holding a bottomless cup into the airstream then putting a bottom in it and observing the increase in force felt by your hand. I think in order to have a beneficial effect here you have to close the opening in the front of the aileron pivot point on the high pressure bottom of the wing. I'm considering riveting angle brackets containing platenuts for mounting fairings to the aileron mounting brackets. Then I would mold some clay in the shape of the fairings I would like to have around the mounts and layup the first layer of fiberglass right on the plane over mold release wax. The first layer would be removed and and built up on the bench to three layers. The idea would be to have the fairings removable. Trailing fairings would also have to be made aft of the aileron pivot point. I would reinstall the end plugs and the top covers from previous experiments and then I would expect some gain in speed but not much.

Bob Axsom
 
Many thanx Guys,

All good advice, thanx guys.

You do have to be a little careful with some of these mods but Im pleased that this particular mod is a safe one when done properly.

Thanx.
 
You must log in or register to reply here.