Installing flaps/elevators on horn arms

I'm considering just filling the drilled holes with epoxy and sliding the flaps/elevators on the horn arms and letting it go at that. In the past have used hardwood clips, "lucky boxes", hardwood doublers or glass reinforcement. Is that overkill? If the holes were hardened with CA and then epoxy used to hold the arms in, it seems to me that would be plenty strong. Impact with piped .65.(Probably flown in lots of wind). Has anyone out there ever had a control arm break through and come out the top/bottom of the surface? Thanks in Advanced,

If it were a .35-sized ship, I think it would be adequate. But I don't think your previous approaches were overkill.

You didn't mention if you were using 1/8" or 3/32" control horns..

I'd make my Impact control system very robust.

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"Good generally conquers evil. Unless, of course, good is stupid."

you have to make some sort of transition from the metal of the horn to the soft wood in the flap. At least most people use soft light wood. Otherwise the horn will break loose from the wood. A really quick way to stiffen up the area around the hole for the horn is to poke lots of holes in the wood with the tip of an exacto knife. Then soak the wood with thin CA. that turns the wood into plastic and you can drill it for the horn. A patch of glass CA'd onto the top and bottom will spread the load even more. using a dab of RTV silicone instead of epoxy give the joint a little freedom to move and make up for any misalignment between the horn and hinges.

>I'm considering just filling the drilled holes with epoxy
>and sliding the flaps/elevators on the horn arms and letting
>it go at that. In the past have used hardwood clips, "lucky
>boxes", hardwood doublers or glass reinforcement. Is that
>overkill? If the holes were hardened with CA and then epoxy
>used to hold the arms in, it seems to me that would be
>plenty strong. Impact with piped .65.(Probably flown in lots
>of wind). Has anyone out there ever had a control arm break
>through and come out the top/bottom of the surface? Thanks
>in Advanced,

I cap the area with ply under the sheeting AND harden the area with CA. My concern has never been busting the area while flying, but instead busting the area while TWEAKING.

On the UHP IMpact it is very easy. Just plywood the 1/4" core over the area to be drilled. CA the heck out of the area and then sheet with the 1/16" sheeting and block sand. You will never see it.

On the Mr. Hyde I did something even more different. I laser cut the slot in the core and glued in a 1/8" ID tube, planked the area, and sheeted. Done. No drilling at all...

Nice CAD!

I like.

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"I still say a church steeple with a lightening rod on top shows a lack of confidence." -Doug McLeod

Thanks, everyone- I had planked the elev/flaps and not installed the hardened contact points as I have done in the past and was looking for an easy way out. So now I/ve gone in and done the needed surgery and have plated over the holes with plywood. Thanks for the input. best regards,