LSA140 Build

[lsa140]

Starting to really enjoy welding the fuselage. I highly recommend the XL tig finger. I had ordered the smaller tig finger as well, but have not ended up using it for the fuselage. The XL slides nicely past your four fingers and works well to rest against the hot tubing.

Yesterday I tried out this large gas lens set from weldcity. The #10 tapers down to a workable size, and you can get very long electrode extension if needed. I've had it out further than shown in the image. The big lens and tapered cup seem to funnel a nice stream of gas. I also really like the ergonomics of gripping the cup. This lens and torch combination seem to work well for this application. It really pushed the gas into the odd shapes, angles, and corners encountered on welding the fuselage.

I've found that feeding the puddle from the rear works well on the tight elbow joints.

[Bdflies]

Next time you order welding stuff, could I suggest you try a pair of Tillman 24C gloves. http://jtillman.com/products/gloves/tig/24c/
They come as 24CM (medium) and 24CL (large).
Get the size that's appropriate.
These are among the absolute best TIG gloves.

[lsa140]

Will do, I really like Tillman. I believe these are there 25B series, split deerskin.

[Patrol28]

I tried out a KMG at the trade show portion of the street rod nationals last year. Makes me want one. Burr Kings are nice too. I've been getting by for the last 25 years on a Jet 6x48 and a 12" disc.

[lsa140]

I almost picked one up last fall, but decided to invest the money into airplane parts. They have some interesting wheels/attachments for notching tubes.

[lsa140]

The large gas lens and long electrode extension came in very handy on this cluster... The top, right longeron (.028) at the rear of the baggage compartment has 7 tubes intersecting it. It took some body contorting, and patience to run all of the welds with the grain/fused nicely deep in the corners.

I'm seeing a small amount of contamination surface on the weld puddle on occasion, but haven't encountered anything disruptive. It's easy to end up with grinder crumbs and residue oil just inside the tubing fishmouth. Before assembly each tube end was dipped in acetone and wiped with a cloth, but a small amount held on in some tubes.

[lsa140]

The rotisserie lowered to allow welding the sides from a seated position.

[lsa140]

Reached the cockpit, welding the rear spar carry through area.

[Chris In Milwaukee]

I get all warm and fuzzy when I see those welds. Outstanding!

[lsa140]

Thanks Chris, I'm up where you will actually be able to see them when the plane is finished, trying to be on best behavior

[lsa140]

Another cluster with 7 tubes interstecting the longeron. (one tube more than plans - additional structure added to this area) This on sits left side, behind the pilot. (station D) This is where I will be adding some float fittings. I'm trying to decide between standard (similiar to the gear attach) or flush (external mount that bolts into some bushings welded on the fuselage) The airplane is so clean, I hate add extra fittings hanging out in the airstream, but that might be the easiest way to go.

[Bdflies]

Those are some great looking welds!
At the risk of sustaining heavy flack, I'm going to throw out another welding consideration. There are LOTS of fuselages flying, that are completely MIG welded. While I wouldn't necessarily recommend such, I would like to see a pulse-MIG system used. The process is very close to TIG, in control and appearance, but easier since you don't have to orchestrate the torch & filler rod. The equipment isn't cheap, but the results are amazing!
>>>>INCOMING<<<< 😳

[Chris In Milwaukee]

No fire fight from me! I imagine that there's a place for all welding technologies if everything is used within its designed limits. This coming from a guy who hasn't welded anything in his life except a few short pieces of mild steel plate and tubing in an EAA workshop. :-)

[lsa140]

I'm pretty sure the forum rules need to reed: No politics, religion, or debating/arguing weld methods for 4130... All of the mentioned topics get heated fast. Pun intended

[lsa140]

Worked on landing gear attach fittings this afternoon. Used a dead blow hammer and a 3/4 x 3/4 x 6 piece of hardwood to form the fittings over the 3/8 mild steel form. I'm stacking, tacking, drilling, cutting, and grinding them to shape. The last grinds take out the tacks, and seperate the parts. The front two fittings that are shaped differently due to the longeron upsweep to the firewall were cut together, then the other 3 bent fittings on that fuselage side were stacked and processed together. Gluing the paper templates to the top piece of steel works great.

[whee]

Looking good! You leaving the gear fittings a little oversized? I didn't and had to remake a few of mine.

[lsa140]

Slightly, are you talking about clearance for the bolt head/washer clearing the radius on the bends?

[Chris In Milwaukee]

Looks great! Great progress!

If they don't work out, you can always send them in to use on the set of the next Star Wars movie.

IMG_0335.jpg

[lsa140]

Funny you mention that! I was thinking the same thing when I snapped the photo. The new star wars has an updated version of that same design.

[whee]

No. Some of mine needed extra material to fit against the longeron tightly and a couple others needed the bolt holes further out so the gear leg didn't hit the strap that gets welded in there.

[lsa140]

Thanks for the heads up. Double checked and have adequate clearance. The LSA also uses smaller hardware in that area. What did you use to take the holes to the final diameter? I think I can get a piloted chucking reamer to the rear fittings by running a drill bit extension through the front gear mount holes.

[lsa140]

Finished up cutting out the gear attach fittings. I still have to make the pieces that wrap around the longeron and tie into the inner gear mount pieces. The rear fitting also incorperates the wing strut attach.

I added a top clamp to the fitting bend jig that did a great job of keeping the center fitting surface flat.

The flat, inner fitting piece were made all together in a stack. A couple TIG beads were run across an area that would eventually be trimmed. I left enough material to bore a 3/4" hole to form the inner radius than contacts the longeron. I used a scrap piece of 3/4" tubing to hold the stack while shaping it on the belt grinder. Hogged material with the 80 grit belt, and finished it off with 180. I really like the 180 grit belt for this type of work. It doesn't bite too much, and leaves a very nice edge.

[N942VT]

Really nice job, it's been good following your progress.

[lsa140]

Much appreciated, happy to share. That's a beautiful 4 place you have there.

[Patrol28]

Good show. Yes the dreaded fittings. lots of work. If you haven't already, check out rotabroaches. Amazon has 'em. The small kit goes to 3/4". They make nice round holes and stay sharp with proper use.

[lsa140]

I've had a set of those in my Amazon cart for a week now... I need to go ahead and hit order.

[lsa140]

Fabricated the brake mounts that weld on the 1-1/4" axle. Radius ground the outside, and used a 1-1/4" hole saw for the inside.

Matco apparently had more 8" wheel orders in the last couple months than they usually recieve all year. I'm guessing the introduction of the 27" Desser tundra tire is helping their 8" sales. I placed an order with them 3 weeks ago, and it sounds like my rims will be back from the anodizer/shipped end of this week.