Jim's XL build D-25

[Sam Buchanan]

CAD, engineering analysis with angles and stuff, lasers.......man, the Eagle universe, it is a-changin'.....

Looks great, Jim!

[s johnson]

Congratulations Jim.. You will have a great time with the build.
I'll trade you shops. The set up looks good.

Scott J.

[Jlwright]

Thanks Scott. The big tools are not much help in building an Eagle but having a warm place to build is priceless.
Having a Bridgeport and small lathe is really nice. Being able to work and also build an airplane at the same time is like getting free time. The best tools I have are the people on this forum that have already solved a lot of the everyday issues that can come up in building an Eagle.

[Rich Snyder]

The best tools I have are the people on this forum that have already solved a lot of the everyday issues that can come up in building an Eagle.


Amen to that. Speaking of which: here is problem that a few of us are dealing with. The apparent unavailability of 7/8" x .062 tubing. I had a go at reaming the .065 out but I don't have a lathe and a drill and sandpaper is completely inefficient. Is it going to be a structural problem using 7/8" x .058? What did you do Jim?

[Jlwright]

Another thread said .058 would be fine. I bought .065 and will have to ream it to size. I didn't get the memo in time.

[rockiedog2]

say guys why the 058 even? 035 will be fine in fact in my early proof XL plans on page 5 is a drawing of the fuse and it says at the bottom "all tube .035 4130". that may have been changed in a later revision...i don't know but i would be surprised if a later revision required other than .035. it's plenty adequate and the heavy wall is...well, heavy for no gain.
if a later revision required something other than .035 then i stand corrected.
if it was mine i would cut that heavy wall out and put a piece of 035 in there.

[Sam Buchanan]

say guys why the 058 even? 035 will be fine in fact in my early proof XL plans on page 5 is a drawing of the fuse and it says at the bottom "all tube .035 4130". that may have been changed in a later revision...i don't know but i would be surprised if a later revision required other than .035. it's plenty adequate and the heavy wall is...well, heavy for no gain.
if a later revision required something other than .035 then i stand corrected.
if it was mine i would cut that heavy wall out and put a piece of 035 in there.

XL-58 plans have the same 0.035" callout. All you need is a socket for the trailing edge of the vertical stab to slip into.

[Jlwright]

Now I see where the confusion is. The drawing call out 3/4 or 7/8 as an option on DWG. 25. When I saw the short top 7/8 piece that is called out .062 i thought it meant the whole tail piece could be substituted with the 7/8 by .062.  I should have stayed with the 3/4-.035 and added the 7/8 tube to the top and ignored the option of using 7/8 tube.

[Jlwright]

 I decided to try bending the top longeron on the concrete floor and then adding it to the fuselage.

I heard through the grapevine that Leonard does not approve of bending the top longeron to make it a one piece part. I was told he said it is critical that the tubes terminate in a central location and on a Double Eagle it would not pass inspection. I plan on welding all the other tubes right in the bend area which to me makes it a central location. I will add gussets  to that area if there is a consensus it needs to be done. Maybe I screwed up.

[Sam Buchanan]

I decided to try bending the top longeron on the concrete floor and then adding it to the fuselage.

I heard through the grapevine that Leonard does not approve of bending the top longeron to make it a one piece part. I was told he said it is critical that the tubes terminate in a central location and on a Double Eagle it would not pass inspection. I plan on welding all the other tubes right in the bend area which to me makes it a central location. I will add gussets  to that area if there is a consensus it needs to be done. Maybe I screwed up.

Jim, you should be fine. Take a close look at this photo:



Notice how the bent top longeron is tied into the other members so no bends are left "hanging".

Also notice the bends in the cabin cabanes. This is what you need to avoid. I messed up when bending them and got the bend with too large a radius and above where the longerons tie in. I added gussets to strengthen this area. My thinking was driven by the idea that it was stronger to have a one-piece cabane vs a welded one. But bends like I did need to be avoided.

Builders shouldn't copy everything they see on the internet.  

[Jlwright]

Builders shouldn't copy everything they see on the internet.  

Now you tell me! :-)

I can tie everything together easily to make a strong cluster.  I was going to try to bend the cabanes but maybe I'll just go ahead and cut and weld. It's pretty hard to tell exactly where you are going to end up when you make a bend.

[rockiedog2]

Sam's right those cabanes need to be cut and then a finger patch welded over the joint

[Sam Buchanan]

Builders shouldn't copy everything they see on the internet.  

Now you tell me! :-)

I can tie everything together easily to make a strong cluster.  I was going to try to bend the cabanes but maybe I'll just go ahead and cut and weld. It's pretty hard to tell exactly where you are going to end up when you make a bend.

Jim, one more thing I would do differently next time is add a longeron on one side of the cabin (right side in my case). There is no need to have both sides of the cabin open and the additional longeron would stiffen the cabin area. It would also give you something to prop your elbow on while cruising over the countryside.  

[rockiedog2]

43.13 has a good section on tube structure repair approved methods. there are a lot of good illustrations. notice every illustration has a centerline axis drawn in on each tube and all those lines meet in the center of the cluster... i think it says in the text somewhere that all tubes should point at the center of the cluster. we can't bend the cabanes without violating that requirement.
that doesn't mean we can't get away with a little deviation. mine has a number of minor deviations and so far it's stayed together. but obviously when it's not in line it isn't a straight push/pull on the tube anymore and a bent tube wants to bend some more.
and that's all i know about that.

[Sam Buchanan]

43.13 has a good section on tube structure repair approved methods. there are a lot of good illustrations. notice every illustration has a centerline axis drawn in on each tube and all those lines meet in the center of the cluster... i think it says in the text somewhere that all tubes should point at the center of the cluster. we can't bend the cabanes without violating that requirement.
that doesn't mean we can't get away with a little deviation. mine has a number of minor deviations and so far it's stayed together. but obviously when it's not in line it isn't a straight push/pull on the tube anymore and a bent tube wants to bend some more.
and that's all i know about that.

Yep, that is the correct way to do it.

As the disclaimer states on my website (in so many words); a builder would be a fool to build their Eagle the same way I built mine.....the website is for entertainment purposes only......

But that doesn't seem to prevent people from cloning what they see on the internet....but this is a discussion for a different thread.