JJ, glad to see someone finally started making the cutting torch roller guide. About 35years ago, I made a similar roller guide for an OA torch from a 3/4" 2H nut and 2 cutting wheels from a pipe cutter. I just tackwelded the axles to the nut, drilled and tapped the nut for in a set screw that tightened on the cutting tip. It worked like a charm and took all of 30 minutes to make.