Built a mobile spit 20 years ago from a haywagon. Cut a propane tank in half lengthwise, welded it together into a long pit, added legs and bolted to the haywagon. Welded angle iron on each end vertically, cut slots in it for the rod. Got a 16' Stainless Steel 1Â¼" diameter rod and welded gear on one end, then hooked with small chain to a gear reduction motor that we vise-gripped to the angle iron to turn the rod, had bearings that fit into the slots we cut in the angle iron for the rod to turn on. We made two SS forks, 3 tong, welded to 1Â½" long pipe with wingbolt threads fitted to them to pull back and move forward, plus extention bars that went thru nuts welded to the tongs so we could do 4 or 5 top rounds at a time and keep them all turning at once. We did several pigs the same way, driving the extensions thru the hog which held it together while turning. We used slabwood from the local mill for fire/coals. We'd drive it to the site and start the fire and toss on the meat, then watch as everyone would stand around and drink beer, their heads turning with the spit constantly!