Author Topic: Isotopes LEXL build in MO (Read 7062 times)

Isotope · « **Reply #75 on:** January 23, 2026, 01:40:31 PM »

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 · « **Reply #76 on:** January 23, 2026, 02:03:10 PM »

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 · « **Reply #77 on:** January 25, 2026, 08:09:54 PM »

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 · « **Reply #78 on:** January 25, 2026, 09:49:27 PM »

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 · « **Reply #79 on:** **Today** at 05:55:09 PM »

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 · « **Reply #80 on:** **Today** at 06:08:04 PM »

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.