I modeled up a frame in Sketch-up based on the 3" tubing I have in the scrap pile, and picked up some cold roll for the rest (I ordered the spear online). If anyone wants the sketchup file I can post it.
I started having porosity issues and discovered the mig torch had worked its way out of the front of the machine and all my gas was leaking out. I'm new to gas, so this was a head scratcher for a minute.
Here's the frame built up. The hay spear comes with a tapered, weld-in sleeve. The spear has threads on the back and you just stick it in the hole and run the nut down to ~500 ft-lbs. You can make it out in the background of this pic - red with a blue nut on the end:
Here's the back set up with a skid steer style hookup. I bought a new tractor this summer and having that quick-attach feature on the loader has been amazing. I caught a lot of crap from my family for buying new, but I reminded everyone that my wife's grandfather bought an Allis Chalmers Model C brand new in 1941 and we still use it. Yeah, that didn't help.
I like spending money on dumb stuff, so...
I did a lot of experimenting on scrap to dial in a setting that would give me a small, flat bead profile, but still penetrate.
Since this is going on a new tractor, I decided to have it powder coated instead of just brushing Rustoleum on it. Time to blast it:
All that pitting is a good thing,right? Helps, uh, give the powder something to grab onto!
Nicer than I could do with a paint brush!
I fed the cows their first couple of round bales with it last night and everything worked as it should. I doubt I saved much money building this myself (after buying the letters and getting it powder coated), but it was a fun project.
Mig is way more fun than I expected. I definitely see the limitations, though. I still struggle with getting my welds to flatten out on T joints. I set the machine as recommended and then end up adding a half to one volt to try and spread the bead out a bit more. I can hear the sound change from a nice even bacon frying sound to a rougher, less even sound and it just doesn't feel right. If anyone has any tips I'm all ears. Thanks!
However skid steer and loader attachments are crazily overpriced. I’ve built a couple that were actually money savers. My latest was a custom pusher/rake for scraping out and cleaning underneath some conveyors. 
one week later and she was bent like a banana. I was almost impressed that they managed to bend it 
