Isotopes LEXL build in MO

[Isotope]

Ok. So i made my 4 root ribs to allow for the ply doubler and wing attach brackets. What i did not do is allow for the extra 1/8 ply on the opposite side of web.. So in turn my root ribs will set 1/8" back so i will have to shave an 1/8" off the front cap strip of the rib? Also where the rib slides over the rear spar root it will also not fit for the same reason. See pics. Obvious i need to trim 1/8" off the rib cap strips to allow for the ply? And perhaps add some "doubler" 1/4" cap strip to beef up where i shaved off? Anyone else ran into this. Paps i know you glued the doublers on the rear spar befor the ribs but i did not account for the ply on the opposite side of the web. Also used Les's wing build assist drawing and it dosnt mention this.
PS. How wide are we to make the U shaped wing attached doublers that go on the root? If im reading the drawings right it looks like 2" but i wanted to make sure i wasnt suppose to make them 2.5" like the strut block ply doublers.

[Kamcoman77]

I added and notched all my extra 1/4" pieces before I assembled my wings. I used 3/16" thick 6061 for wing attach fittings, so my notches are slightly different from plans. I probably added more verticals than some other builders, but my ribs look pretty good epoxied to my spars. The diagonal in the 3rd photo is a brace for my fuel tank, so it is not shown in the plans. The U-shaped 1/8" thick ply doublers are 2" x 4-3/4"

[Isotope]

Im concerned and confused about the "grain direction" on the 3/4x5/8" cap strip on lower rear spar. The grain on these cap strips do not match the plans where it says "grain on spars horizontal" they run vertical in relation to the spar.. I can not find a good explanation on this. Some info i read states that the grain direction needs to run parallel with the widest dimension of the strip witch would contradict the plans. Another source i read says if you built your "box spars" with vertical grain to limit G's to 2.5 to 3 G's. Do i need to build two new rear spares?  How do i control the orientation of grain aircraft spruce sends me? See pics.

[Kamcoman77]

The spars in the lower photo should be just fine. The lower caps are loaded in tension, so the grain direction is not that critical. In my opinion, the Legal Eagles are overbuilt enough that strength is not an issue as long as the members have the correct sizes and the glue joints are strong.

[leshoman]

The spar is 3/4" plus 1/8" so min gap should be 15/16"  7/8 is better and easier to slip over rear spar.   Only glue bottom and back of fear spar to rear spar so it does need to fit tight on all sides

[Kamcoman77]

Just noticed you have all the root end plywood doublers epoxied on the rear spar. To slide the ribs in place from the root to the strut ply doubler you will probably have to chisel off some of the root end ply doublers. I have had good luck using a heat gun to get the ply very hot and sliding a chisel under the ply. It came off with very little damage to the spar. If you have not added the strut block ply doubler you can slide all the ribs on from the tip end. If the strut block ply is already on it will probably be easiest to remove it and leave all your root end ply doublers in place.

[Isotope]

I do not have the strut ply doublers glued on the rear spar yet.
 Started back to work working alot of over time after a vacation so not making alot of progress at the moment. Next step is still to cut the bevel in the front spar with a table saw which i am nervous about doing.

[Kamcoman77]

That's good news about the strut doublers. You can just slide the ribs over the rear spar from the tip, starting with rib #3. Cutting the bevel with your table saw should be very easy, and no cause for concern. Just set the blade at 10° or whatever angle you decide on, set your fence so pushing the spar through will just skim off the tiny edge of the ply web & remove mostly the sliver of spruce off the spar cap. The thing that helped me was setting up supports at both ends of the spar, so I did not need another person helping.

[Isotope]

I made way too big a deal worrying about cutting the bevel in the front spar. It was very easy to do by myself with a table saw and two milk crates. Turns out my table saw is exactly the same hight as a milk crate.. hum.
 I have the ribs modified around the root wing attach ply and slid over the rear spare and have decided to take a break from the build for a while and admire this beautiful wing on display in my den. I think i have made pretty good progress in a short time. Stay tuned

[Kamcoman77]

Looks very nice. Now comes all the modifications to the ribs for aileron hinge blocks & compression ribs. Please don't glue the ribs to the rear spar until you get those modifications made.

[Brock]

Few questions about the 2 1/2" ply strips that go over the strut braces and wing mounting filler block. See pics. On the 2 1/2" strut brace ply does it go on both sides. On plans it says ply on both sides but does that mean double ply on one side (2 1/2" ply ontop of the web)? Also where it butts up against the rib does it stop there? If not the rib would have to me modified for the ply to continue. I assume that would be stronger. And then on wing brace U shape ply does it go on both sides as well or just the side opposite of the web?

Reviewing some posts as I continue to build I realize I had skipped over this detail above.  So on p35 is says 1/8" on both sides I had figured the the spar-web was one of the 1/8" then the 2-1/2 strip was just added to the other side.  Or do the plans really mean two 1/8" ply on the web side and one 1/8" on the other side?

[Shay King]

Both sides I reckon. I don’t have a great picture, but you can just see the strip on the front as well.

[pappyadkins]

I've seen it both ways... Page 35 (XL version) is confusing he uses terms like "1/8 ply top to bottom over both sides" (And we don't do that for sure... but on the same page he says "ply over filler"... On page 36 if you look closely he only draws the ply dubbler on the filler side...  I can't remember where I heard him say that it only needs to be on the one side, but it was ok if you do it on both... Maybe at his hanger or Osh...  Anyways, both ways have successfully flown!!!  you'll need longer bolts than came in the 'original John's kit' --- lol

[Brock]

Shay, I believe my question was not clear, or somt'n.  My question is not about the ply on the wing root (I did the same way as you pictured) but rather at the lift strut atach point.  The short diagonal between the upper and lower spar-caps.  Does it get a 2-1/2" ply on top of the spar-web or is the spar-web the 1/8" ply on that side and it gets the 2-1/2 ply other side covering the diagonal/filler-block?

I've a mental dislike for the non-symetrical.  On the root there are two plies on each side.  So likewise I want to have either one ply per side on the lift-strut attach or two on each side.  Ha, if I use two then the spacing between the aluminum attach points will be the same as the root.  I like that but that is clearly not in the plans.

Clear as mud?

[Kamcoman77]

I put 1/8" ply on both sides of my strut blocks.