gregoryshock

Ifinally got the retracts I want to use. I went with http://www.wingspanretracts.com/Rotating_Retracts However, We had to remove the main support to make them fit. Iwas wondering if or what I should put in to regain strength? The retracts say they are meant to fit my plane. But if you move it too far forward you won't be able to sheet the top the of the wing. You move it back and you have to cut out the main spar!

MinnFlyer

My Feedback: (4)

The trick is to remove as little of the spar as necessary. Looks like you've already removed it all

Edwin

My Feedback: (2)

That aint gonna work. Just my opinion.
Edwin

gregoryshock

We are trying to think of something to use in place of the spar. Like a metal piece epoxied in. But the thing is Lado never got their retracts in... So I bought these as soon as they become available. But they are a little too high. We think maybe we can epoxy part of the orgininal spar back in. I was just wondering if anyone else had this kind of trouble with electric retracts. Other than this, these retracts seem to run really good!

Edwin

My Feedback: (2)

Just my opinion, but I dont see anyway that wing can be salvaged. I would build another. A splice isnt gonna hold up. What should have been done is cut just enough to allow the strut to go through spar. If the electric are too long, then a different retract should be used. If thats a 60 sized, sierras would be a good choice.
I looked at the picture again and think (still need to build a new wing) but you might be able to get away with using ply on the leading and trailing edge of the wing. It would be an experiment. And I wouldnt fly it too hard in any yank and bank menuvers.
Edwin

MinnFlyer

My Feedback: (4)

I wouldn't call it a total write-off just yet.

How long is the spar from top to bottom?

Live Wire

A Ply wood bridge to go across the gap. You can remove a a portion of the rib,s to fit the bridge in and will work with very little extra weight.

gregoryshock

I think we have this issue solved!

MinnFlyer

My Feedback: (4)

I'm afraid not. Even with the bracing you have got two very vulnerable areas. It would have been much better to extend the new spar as far as possible and glue it directly to the original spar.

dasintex

My Feedback: (10)

I would even extend that brace to anchor to the adjacent ribs, and the brace should be glued, sandwiched to the original spar, perhaps a doubler on the brace so it can contact with the original spar; all this rework will add for some unacounted extra weight; but other than that it would think it may work and provide the strength needed.

Leroy Gardner

minnflyer is right, that is the highest stress point on the whole plane. A proper splice will make it as strong as it ever was and don't wory about the 3 or 4 oz. of weight, thats not the issue here. You can cut a 1" hole in a member like that and not even weeken it ,but don't cut a horse shoe out of either side ( top/bottom here) that will really weeken it. always leave a bridge. Leroy

larrysogla

I remember reading through one of this forums that "epoxy glue IS NOT STRUCTURAL MATERIAL". Before this I was not aware of that. Wood, metal and composites are structural material BUT GLUE IS NOT STRUCTURAL MATERIAL. Minnflyer correctly diagrammed that a proper structural bridge is to bond the reinforcing plywood side to side with the existing plywood spar and to extend it all the way to the other ribs as well. Bridging the gap with only the tip of the bridge plywood glued to the rib is a NO-No as you are making the glue the structural material by doing this. Remember that "tip joints" are the weakest joints, they will not hold up to "pulling apart" forces. A side to side glue bond will bring the proper structural strength. Oh well, I assume that the guy has already flown his airplane, but this might benefit somebody else. Larry.

bolar

My Feedback: (5)

That's how I did it. I'm currently building a .40 Midwest Messerschmidt and had a similar situation. The kit was not designed for retracts so I had to make it work. By the way, nice pic Minnflyer.