Jim's XL build D-25

[grdev]

Yes, all of Leonard's drawings are center to center The forward wing mount would be 24" from the center top tube of station one

[Jlwright]

I'm going to tack weld the forward cabanes at the 24 inch dimension and hope for the best. I'll deal with the rear situation when the time comes. If the rear mount doesn't hit directly on top of the rear cabanes I'll just figure a way to brace it with gussets or whatever it takes.

[Sam Buchanan]

I am assuming then the 29 inch dimension is center to center of the cabanes.

Jim, I don't recall the exact mental process I used for these dimensions, but you take the 27.5" dimension on the rib plans, add the spars, figure out where the fittings will be, and make sure you have enough room on the top longeron to make everything work.

Simple. 

I kinda designed my own gussets for the fittings using the TLAR method (That Looks About Right). There is a piece of sheet stock that is welded to the cabanes, ties into the fittings and wraps over the "tee" of the attachment. Looked strong enough to me.

Every Eagle is unique!

[Jlwright]

After sleeping on this I can make this work but the rear mount make take a little engineering to make a good solid attachment to the cabanes.

[grdev]

I'm curious , what is your solution? I was going to work on mine today, but I'll wait until you do yours.

[Jlwright]

maybe you need to come down and look at this with me to make sure i am not screwing this up.:-[

[grdev]

maybe Tom H will check in here, he has been a great source of information on the cg for my DE.  
We hope to come down next weekend , will check in with you early next week. I have some ideas for the Ultra Vair/XL engine mount.

[grdev]

Jim, just thinking out loud, what if you were to take a short piece of 3/4 or 5/8", say maybe 4" long and split it in half.  You could weld the stock mount onto that and slide it back and forth until you have the right location. You could make it long enough to cover your bend in the longeron to strengthen your bend. Should only add a few oz to your build, and be a low profile fix.

[grdev]

After thought, if you did that for the front mount as well you would be able to adjust your cg when you do your wt/balance and when your happy with the location then weld your mounts. May it is a bad idea, but sounds like it would work to me. Maybe give you some leeway on where you place your fuel tank.

[Jlwright]

I finished the front cabanes today and only ended up 3/8 forward than the plans show. I think with the fuel tank forward it will work out to my advantage. Tomorrow I think I will jig up station 1. I just noticed my plans number is D-25 and not 15.

[Tom H]

Gil, per your suggestion I'm checking in, but have to say first that I don't have much knowledge and no experience with the XL model.  Regarding CG, you want to get the flying CG in the right range on any aircraft.  There has been a lot of discussion of LEU and DE flying CGs on the old Yahoo list, and essentially have concluded that on those aircraft, a flying CG in the 25 - 30% aft of wing leading edge is a good area.  I don't know if this applies to the LEXL.  Maybe someone with flying experience in the LEXL could chime in.

[grdev]

Thanks for checking in Tom, your work on the DE was most welcomed . Just off hand do you know the weight of your engine on your le, and are your actual  measurements the same as the drawings? I'm using a 1/3 Corvair and I need to figure out just how wide I need to build my engine mount. The engine should weigh 85 pounds. I don't have an actual weight yet for the engine and prop, but I'm hoping it is close to the 1/2 VW
Thanks Gil

[Jlwright]

I got a little more done today. I tacked in the firewall and tomorrow I'll add the diagonals and the seat frame.

[Tom H]

Gil, our LEU engine, half VW, 69 x 90.5, w/ prop, oil, distributor, ready to mount on the airplane, weighed 92.5 lbs. 

Our LEU airframe was built per plan's dimensions.

We had to push the engine more forward than we had planned to get the CG at 25% aft of wing leading edge.  It flew and landed great; just did not have enough hp for climb.

[Jlwright]

I have to admit I'm getting pretty tired of grinding and fitting weld joints. I can see the light at the end of the tunnel though.