Legal Eagle XL in Pennsylvania

[Kamcoman77]

Rudder looks great. After trimming all the rib ends it will be ready for gussets. When bending the gussets, use a piece of tubing one size smaller than the one the gusset goes on. For example: use a 1/2" tube to bend gussets that will go on a 5/8" tube and a 5/8" tube for 3/4" tube gussets. This allows for spring back so the gusset will fit the appropriate tube tightly.

[Pilotarix]

... When bending the gussets, use a piece of tubing one size smaller than the one the gusset goes on. ...

Thanks, I can see that this will help keep things nice and tight. I will definitely do that.

Here is an update on the recent activities.

I could not use the entire weekend to make progress since the family demanded two days without basement activities. 

My plywood arrived while we were not here. Faster than I thought. Even though nicely packed, the whole package was already warped, and the sheets are pretty bad. I think I let them rest on a flat surface and see what happens.

I still have a good amount of baltic birch plywood and also some 1/4". I made the test pieces from that. Today I tested if the glue is waterproof. It is definitely not. Only 2 min in boiling water were enough, and pieces started to separate without any force. So no way to use that.

Before I continue with the ruder fin, I have to make the hinges. That requires welding, as we all know. Hence today, I worked on my welding skills. They are still a big hurdle.
I welded 4130 5/8 tubing with 0.035 wall thickness and one pair of 7/8 tubing with 0.062 wall thickness.  First, I welded pairs, and then I welded all pairs into one big piece.  Lastly, I welded on the 7/8 to the 5/8 tubing. I used a 1/6 tungsten and 3/32 and 1/16 welding rod.
It looks pretty bad, mostly too hot, I guess. At least I made it from "only holes"  to "only some holes." 
To be continued.

[Vince Carucci]

Those welds look about normal when first getting started. Try to develop an understanding of what went wrong, then practice-practice-practice!

My wife bought me a Meco Midget for my birthday one year. It really increases your control. If you elect to use a standard torch, just make sure you have a nozzle small enough for thin wall steel tubes. [see the attachment for sizes]

The EAA has a BOOK and a DVD on gas welding of 4130 steel. The DVD is amazingly helpful. 

I've been tacking and welding up my frame this Summer and I can see an improvement every day. 

Good luck and hope to see it at AirVenture one year. 

Vince

[Vince Carucci]

One the second thought, I'm looking at your stack-of-dimes and the steel table. You're probably not using gas are you?

[Kamcoman77]

Lots of good areas on your test pieces. Looks like you are ready to weld the actual tubes.

[Pilotarix]

... Those welds look about normal when first getting started. ...

Sorry, I should have mentioned it. It's TIG welding. Since most of it will likely happen in my basement and Grage, I will not use gas welding. My wife is going to divorce me in no time when I do this. She was already scared about the Argon cylinder. Honestly, gas welding in the basement doesn't give me a warm and fuzzy feeling either.

This Meco Midget Torch is nice.

Lots of good areas on your test pieces. It looks like you are ready to weld the actual tubes.

Guys, thanks for the positive comments on my welds. I appreciate that.

I think it's still too hot. Once I have established a puddle, I can't really speed up because I will lose it, and if I try to reduce amperage with the foot pedal, I lose the puddle as well. So there is lots of room for improvement. Practice is what is needed.

Anyhow, I decided to give it a go. At least on a short piece. The result seem to be OK on the outside. The inside of the 7/8 tubing looks pretty rocky, that's not going to fit on the aluminum tubing anymore and will need some work. I will need a reamer to get this back to the desired diameter.

Side note. I used a circular saw for metal to cut off the pieces, not ideal, a metal band saw would probably be better but that is all I have.

[Kamcoman77]

Wish my welds looked that good! The roughness inside the larger tube just shows you got penetration. I had to smooth out the inner portion of my large tube before it would slide smoothly over the 3/4" aluminum spars. I used a small drum sander on my Dremel for that. I did have to use a reamer to make AN3 bolts fit the 5/16" tube.

[Pilotarix]

Thanks, good idea with the Dremel, unfortunately, I "smoked"  my Dremel tool recently... so I need a new one or something else.

Today, nothing exciting happened. I tested the fit of the K-block and gusset into one of the compression ribs and figured that the K-block needed to be changed to align with the K-block gusset perfectly.

[Chuck in Indiana]

I think it's still too hot. Once I have established a puddle, I can't really speed up because I will lose it, and if I try to reduce amperage with the foot pedal, I lose the puddle as well. So there is lots of room for improvement. Practice is what is needed.

Yes, it's too hot. You should be set at about 65 amps. I think some of your problem is too heavy of filler rod. When you dab, it chills the puddle, you need to up the heat, etc.
.035" filler is as big as you'll need.
Of course, your hinges are airworthy. Keep practicing. TIG has a *big* learning curve.

[Pilotarix]

Hi all,

I am pretty busy at work, so I had not had so much time to work on the eagle.

Yes, it's too hot. You should be set at about 65 amps. I think some of your problem is too heavy of filler rod. When you dab, it chills the puddle, you need to up the heat, etc.
.035" filler is as big as you'll need.
Of course, your hinges are airworthy. Keep practicing. TIG has a *big* learning curve.

Yep, TIG welding is an art, a little bit like Helicopter flying. You need to control a lot of things at once and keep them in balance.  I am working on it, but still not sure if I am going to make my own fuselage, we will see where I am in a couple of months.


So here is an update.

I stopped making ribs. Instead, I made a mock-up rear spar. I am currently sanding the ribs I have and then putting them on there to see what to do next and how it looks like. I make them specific for their location on the spar.
Rib #7 gives me some headaches currently, even though that should be straightforward. It looks like there are a couple of variations possible, and I just have to decide on one of them.
So I made all K-Blocks out of Hydrotec Meranti. I made the aileron stiffener of 0.125"/1/8 birch ply. Here, I am somewhat confused. The IronDesign supplemental plans show the aileron stiffener from 1/8" ply, and we should make 4 of them.  In the videos, it looks like there are two versions. One might be 0.125 or even 0.25 and one 0.8mm. However, the longer I stare at it, the more I get an idea of how to do it.

I continued working on the aluminum hinges. Still somewhat undecided if they are a good idea. They fit perfectly. I cannot make them like the ones in the video, but if I use 3 for one hinge, they come pretty close.

Lastly, I started making gussets for the rudder fin. The hint of bending the gusset around a tube one size smaller works great. That way, they fit really tight, and that's what we want.

I need to stop doing too many things at once. The shop gets messy doing that, and I cannot do a good job in a messy shop.

[Kamcoman77]

On your aileron stiffeners, if one of them is labeled A1, do not bother to make it. It does not go anywhere. I also added a 0.8mm ply piece on the opposite side of the 1/4" doubler for rib #7. Probably just added weight for no real benefit.

[Pilotarix]

Keith, thank you for making this picture. That is very helpful. It looks like you made a very big aileron stiffener on the root side. That seems to make sense because, with that, the support goes into the wing rather than stopping at the edge of the "aileron cut out." That is something I am going to copy.
A K-Block inside the rib. That is something I am going to do as well. If I understand that correctly, I would need an additional K-block on the wing tip side of this rib so that the aluminum sheet can rest against something in this area. I can put another K-block there, but I probably make a k-block gusset out of 0.25 plywood.

On your aileron stiffeners, if one of them is labeled A1, do not bother to make it. It does not go anywhere. ....

Very true, unfortunately, I did that already.

[Kamcoman77]

You are correct about the extra K-block on the aileron cove side of the ribs. The cove filler needs something to attach to. I did make my 1/4" doubler longer than the Iron Design drawing. Here is a link to three YouTube videos by Iron Design about the ailerons. Can be a little confusing.

[Chuck in Indiana]

That's a seriously sturdy hinge.. tabletop cnc mill? Your fabricated hinge would have been fine, though.
I see you are putting the hinge hole in the wing jig. Locating everything involved with a pin in the jig pays big dividends at assembly.
Nice work..

[Pilotarix]

...Here is a link to three YouTube videos by Iron Design about the ailerons. It can be a little confusing.

Thanks for sending the link, I have been through these videos quite a couple of times, and it can be somewhat confusing. I think I have an idea now about how I will do it. Getting the first-hand experience from somebody who has done it helped a lot.

That's a seriously sturdy hinge.. tabletop cnc mill? Your fabricated hinge would have been fine, though.
I see you are putting the hinge hole in the wing jig. Locating everything involved with a pin in the jig pays big dividends at assembly.
Nice work..

Thanks. I agree; both hinges will probably be fine. I am not an engineer by any means, so all I know is that I don't know what I don't know. That always comes into my mind when I deviate from plans. So I am still not sure what hinge I am finally going to use. For the steel ones, I will need an expensive reamer to make them fit nicely. The material for the other ones I have is still lying around.
I will make more of the steel ones and see if I can do a better job with welding: thinner welding rod and less heat.

Yes, the CNC is a half DIY tabletop CNC router with a working area of almost 2X4. It's pretty sturdy and does non-ferrous metals with very reasonable precision if certain parameters are met. 

I also made the rudder horn from 1/8 6061. Aluminum is always causing a big mess especially combined with mist cooling.
I made the CAD file for the rudder horn after a night shift and paid the price. So I had to make a second and piece.