I used a 2 component epoxy glue, but if you have an other reasonably heat resistant glue able to bond metal and wood, by all means use that glue. The width of the bolt is determined by the ball bearing you have available, and the length by the total thickness of the piece of wood, the ball bearing and nut together. The cut 50 uses a slightly different bottom board, but middle and top boards look to be the same as cut 40. All the circuit boards are available for cut 40 models. Do a search on their site for 'plasma cutter pcb' or 'welder pcb'. If you, because of the stand-off distance, use a piece of wood thicker than the bolt head, use washers or nuts to get the bolt head flush with the bottom of your piece of wood. AliExpress has pcbs for China plasma cutters and China welders. The length of your piece of wood determines the maximum radius you will be able to cut. The width of the piece of wood should be wide enough to accommodate the ball bearing, and the holes for the nozzle. The thickness of the piece of wood you use is determined by the length of the nozzle of your plasma cutter, and if you're not using a drag tip, the stand-off distance has to be added to the length of the nozzle. The size drill bit you'll need to use is determined by the diameter of the nozzle of your plasma cutter, and for the central hole it's determined by the bolt head. optional, washers or extra nuts (stand-off distance).a pencil or other means of making markings.a measuring device, I used callipers, but a ruler will do.