Hi holt50. Mine is the standard tube roller from Harbor freight with the square tube dies that I machined larger for 1.5" square tube.
I'm not sure about your description but to me using I beam for the frame of the roller seems like total overkill and would take a big old arc welder for me to feel like I've penetrated enough to make a weld stick. If you look close at the HFT roller the heaviest plate is on the top where the adjuster is. The shafts are all 1" and the frame is mostly maybe 3/16" and because it's a box shape it's plenty strong for the stuff I've done with it. Maybe you could post a pic of what you've made?