My Dart Swinger Project!

Just from what I have read, you are set up for failure.

First is the 110 flux-core welder.
Second, I hope you are not even trying to run it on an extension cord.

What I would do is clean everything up for a clean weld, tack the pieces where you want them.

Talk to a local voc-tech school, every high school has one near-by.
Make a donation for school supply's, have the welding teacher, weld it the rest of the way together for you.
The welds will be nice and strong, plus you can learn some welding tricks for a small donation.

I agree, but will disagree. Flux welds a little hotter than mig. Just like running straight co, runs hotter than 75-25 gas on a mig. Now, I will say, it has to be Clean, he better have his A-game on, and he better have the right wire. As long as he stays away from the single pass wire, he should be ok. But that turns around and complicates the other passes. Hard to control warpage with 3-4 passes. Can I ask a question? What is with cutting the middle of the tube? Why not just the outside end, put in a new axle end, weld it in and call it a day?