I need help on a scratch wing I'm doing
 

As you can see, in order for my custom landing gear plate to span the spars, an edge of the wood is above the airfoil, do I just grind that side down? Or is there a better solution, maybe recess the plate further in the wing? The right side is level with where about the sheeting glass and paint will take it. There is a base plate, and then the breakaway plate has gear attached to it, and that break plate is screwed to the base plate which will stay mounted in the wing.

I'm open to all comments and or ideas here. The breakaway plate will eventually be carbon fiber plate.

RE: I need help on a scratch wing I'm doing
 

Do you have some plans of it so we can give you a better suggestion? usually the plates are attached somehow to the wing spar structure, or the wing tube box..

RE: I need help on a scratch wing I'm doing
 

The plates are going to be attached to the spar, but the spar height is giong to be machined based on teh depth of the plate in that area. It's a 1.5 inch spar and then at the plate it will be .380 cut out from the spare material as an example deep, so the top of the plate is flush with the top of the rest of the spar, something like that.

RE: I need help on a scratch wing I'm doing
 

There are probably many things you could do. Recessing the plate 1/8 to 3/16" might help as you say. If you don't have enough height for the retract unit, you could then shim between the retract unit and the plate to get back to your needed height.

You could also "chamfer" the LE of the flex plate, so it gets closer to being parallel with the foam LE. You could also move the fwd outboard screw (that holds the plate to the spar) inboard 1/2" or so.

And, if you could move the fwd spar aft some, that might allow you to shorten the flex plate.

Good Luck! [8D]

RE: I need help on a scratch wing I'm doing
 

I'd sand it to match the airfoil and be done with it.

kc

EDIT: I'd also use the router to mortise out so the retract was flush as well.

RE: I need help on a scratch wing I'm doing
 

The thickness of the retract is same as the break plate, so can't do that. But I can mount it from the bottom of the break plate, I have not made my mind up on that yet.

I'm just leary of sanding to match the airfoil cause I'm not sure all options have been exhausted. I've looked at it and can't come up with jack crap. The only good news is I won't have to sand it till the sheeting is on, so anything that can be made up anywhere there are still places to have a little hope. If that main 1/4" ply breaks ina hard landing, There is going to be a crap load of work to get the wing back functioning.

So if at all possible to keep it full, even if I need to take the gear lower into the wing, but then that's another problem cause the aft part of the plate will now be below grade, so do I put a piece of wood on top of that to make grade again?

I don't remember having this problem with the isobar because we set the spars further back on the airplane. Trouble is, these wings are being made for an airplane that already has the spar slots and spar receivers installed, so I'm matching up to them.

Guess I'll just sand it and move on now that I'm thinking about it.

Thanks guys.

RE: I need help on a scratch wing I'm doing
 

Shortening the plate a bit would help a lot, and will also help the spar be at the full depth of the wing improving its strenght. The plate could be hold in place by another piece of wood glued to the front spar, matching its depth with the wing skin.... guess that it would be a possible solution.

RE: I need help on a scratch wing I'm doing
 

Sean,

Shrink your plate down to bolt on to the right and left of where you have the bolts now. Mortise this plate into the main plates attached to the spars. Then glue ply blocking underneath the "edges" of the plate where the retracts bolt in. This will give you some thickness at that perimeter. Then mortise in the thickness of the retract flanges. Then sand the main plate flush with the sheating. This way you can also have a bigger area of consistent glassing/paint up to the break away plate.

RE: I need help on a scratch wing I'm doing
 

Sean,

I would just round the corners and be done with it. As long as you are installing spars they are going to distribute most of the force during a landing. If you're worry about the retract plate being too small, just add a layer of carbon fiber underneathe a bit. But I don't think it will be necessary.

What wing is this for? Megabar???

JR

RE: I need help on a scratch wing I'm doing
 

Ya, working full time on it. Spars are being machined right now, will pick up on Saturday. Wing sheeting and glass is here and to be done next week.

RE: I need help on a scratch wing I'm doing
 

You could also clip the front corner at about a 45 degree angle and move the front bolt back a little. Put a carbon doubler underneath in that corner should be plenty strong. If you have enough wheel spacing could even move gear in a half inch or so on each side would have to cut less off the corner.

RE: I need help on a scratch wing I'm doing
 

it looks like you've got room to add a doubler under the break plate between the spar and each side of the retract and around the back edge (a U shaped doubler), then mortise it down flush, the doubler would still be part of your break plate not attached to the spars, Hysol should secure it enough to do the job.

kc

RE: I need help on a scratch wing I'm doing
 

Recess the plate further into the wing, you are out at the end of the spars anyway. While you are at it make the plate just a little bit wider & try to pick up the leading edge as well. Once you are happy with the placement build it back up to the level of the cores with balsa prior to sheeting. - John.