GW-inactive

My Feedback: (4)

Here is the problem i have. Too light a balsa. Good problem ehh??
Well not with ailerons its not. On the menace ailerons i just built last night they seem very flexible. I was wondering if adding a strip of 1/4" of Carbon fiber on the TE would stiffen them up?
If so, should i put it on the top of the TE or on the edge of the TE(facing the stab) ?

I know covering will help strengthen them up, but i want to make sure i get true responce on the surface deflections.

Never used CFiber before. How does it install? I have ordered some .007 from Lonestar and will use it if its deemed needed.

thanks
gw

PaulSwany

My Feedback: (45)

My Menace aileron's were pretty flexible on the TE, but very stiff on the LE..... the plans call for 3/16 sq stock which is pretty slim stuff to start with and if you ended up with light stock, it's a double wammy....

I don't see anything wrong with using a little carbon fiber on the TE... Just cut it to size with a VERY sharp exacto blade and lay it on the wood and soak it with thin CA... smooth it out a little with a piece of wax paper and you're done!

The plans call for CF on the spars and TE of the wing... did you omit that?

GW-inactive

My Feedback: (4)

Paul
i am planning on CF on the spars on TE of wing. Waiting on Lonestar for parts. Although i think the CF may be overkill on the spars as long as you use stiff 1/4". But i will use it anyway. The ailerons seem very flexible at this time though. Where would you locate it for maximum strength on aileron ( top of TE or outside edge of TE full length)? I dont know if carbon is stonger in tension or compression. I would think probably tension is its best suite.
As for applying it, do i use a thick ca? Apply it liberally to the CF and then press it to the balsa spars, and wipe away excess?

Glad to hear your Menace has turned out so well. Hope to have mine done by Next Weekend. Still have not decided on the covering. I know it will be transparent, but the Nelson might be a little more trouble than i want. Foamguy also said it was not very durable to tears. That will not work well when flatspinning it to the ground and missing the edge of the runway. : )

I have my 605BB's on the way for it. got the kevlar for the pull-pull. On your pull pulls did you run both rudder and elevator in tubes to the rear of the fuse? I looked over your pics, and could not quite see what you did for the rudder. I was just planning on tube for the elev and a quick passs through the fuse for the rudder just to get it on the oposite side.

Later
GW

PaulSwany

My Feedback: (45)

I think that if you want to stiffen up your ailerons, you would use the CF on the outside edge of the TE.... although you'd only get a piece 3/16" wide that way... You could also do the face at 1/4" wide for extra stiffness. I used THIN and MEDIUM ca for my CF. Just tacked it down with some medium, then soak it with the thin. Rub it down with a piece of wax paper.

I liked the Nelson's film for it's significant weight advantage... it was worth the trouble.... but be forwarned, it is a pain in the ***** to cover with !!

I did pull-pull for both rudder and elevator. I used little pieces of inner nyrod as wire guides. For the rudder, I just drilled a 1/8" hole at an angle, then put a piece of tube thru it. I started out with kevlar thread, but it started to fray where it went into the tube... So I went with a Du-bro setup.

Here's a pic:

bugsiegel

My Feedback: (2)

I would think a good place for CF on the aileron would be the bottom end of the trailing edge. It's the down deflection that will put the most strain on the aileron. With the CF the TE will be strong. I believe the true strength of the aileron comes from the covering. Such a large control surface and just a small area of control.. There just has to be some give.
You want them to flex a little anyway. Mine scrape and hit on the black top all the time, so a little give helps them last longer. I always have to repair the ends……..I like to practice the spot landings on the black top… I use marine non-slip tape on the bottom to save the covering.
With the CF I lay it in place and then soak it with thin CA
There are a lot of events coming this year I may have to build a back up.
Maybe I’ll try the Minus.. see what that plane is all about.

PaulSwany

My Feedback: (45)

You might want to reinforce the control horn mount area with some 1/32" birtch ply. Really strengthens the area and the weight gain is insignificant.

Kevins_RC

My Feedback: (1)

I suggest that you use a giant scale CA hinge to strengthen the area for the control horn mounting. I cut a giant scale CA hinge in half. Align the CA hinge where the control horn is to be mounted. Then apply thin CA glue it in place. I use the other half of the CA hinge on the opposite side of the control surface. The CA hinge strengthens the area where the control horn is mounted and strengthens the balsa between the CA hinges. Its easy and fast.

GW-inactive

My Feedback: (4)

thanks bugs,paul,and kevin. All great ideas. Back to work on it . Lone star made a stellar delivery to me this time. Ordered from them Friday afternoon. Got the goods in alabama today. Good job Lonestar.
I think you are right bugs, bottom of TE will be best, plus it will be hid from view.

Paul, thanks for the heads up on strengthening the control area. I had almost forgot about the problems i had with my WaspPlus in that area.

Kevin. That is a quick fix , and one great idea. Cheap,quick, and easy. My way of doing things!!

Later Guys, Back to work on the Menace. Gonna see if I can do a complete frameup in one day. I believe it can be done by 10 pm.

GW

airjeffro

The menace kits come with iron on carbon fiber, it sounds like you have CF laminate. If you have CF laminate, I would suggest roughing up the side to be glued then laying a thin bead of medium cya on the CF then very carefully laying it onto the rear face of the aileron. The CF is very strong in tension and pretty strong in compression, if you put it on the top or bottom of your aileron te, the other side will be very likely to fail in compression. Apply the CF to the spars and wing te as shown on the plans.

dyerstown

I agree that making a CF/balsa/CF sandwich is a great way to gain significant stiffness. Composite panels are made like this (actually, the balsa is end grain.) It acts like an I-beam. My experience is that CF stays bonded well when used in tension, but can delaminate when used in compression. Putting CF on both top and bottom insures that the bending in compression is negligible. Good luck!

PilotFrog

To expand upon the I beam idea. I am thinking of using carbon tow on the spars and TE of my Menace rather than laminate. This stuff is unbelievably strong in tension. By just adding some thin balsa pillars between the spars sandwich glued cross-grain to the ribs you add a tremendous amount of strength with almost no weight. This is how it is done on the Morris Fun Design....there is no shear webbing between the spars.
A few lightening holes could be cut in the ribs with little loss in overall strength to more than make up for the added weight.
My only concern is that the tow is directional along the axis of the spar and gives no strength or rigidity increase front to back.
PilotFrog