I haven’t finished my LR2 build yet; in fact my shop still has no power, lights, insulation etc so this is all academic for now, but among other things, I will want to use a CNC system like the LR2 to cut 2D plywood parts that will fit together to create a 3D body buck from which I can create fiberglass car body panels.
The car chassis will be a 4130 alloy tube space frame, which will involve a lot of tube notching/coping/fishmouthing. I also intend to use the LR2 MPCNC router to cut plywood sheets precisely with perforations and register tabs that will puzzle together to locate 4130 chromoly tubes (and other things) in space relative to each other precisely for welding. With as many tubes as I will need to cut, I would like to automate the process because I am a disaster with either a grinder or a hole saw, and a CNC can be more accurate than me using my harbor freight plasma cutter. Every little pause, shake, tremble etc when I am plasma cutting, seems to telegraph through into the cut quality.
I am still thinking through the work flow, but until I am really in the shop trying it, I won’t really have that nailed down. I intend to use an SSR to start and stop the plasma torch, triggered via one of the hot end outputs (in Marlin I put the hot ends in “bang bang” mode for this). However, the part of this that I have become obsessed with, is the feed mechanism that will feed and rotate the tube relative to the plasma torch. I wanted to describe to everyone what I am trying, in case anyone is thinking of going down the same path. This could either be useful to someone, or simply a cautionary tale, so here goes!