A hand-held plasma cutter is an excellent tool to have if you are working with sheet metal, but its not particularly well suited to making long or repetitive cuts. Which is why [workshop from scratch] worked his usual scrapheap magic and built his own motorized track for making perfectly straight cuts.
Most of the frame, and even the small truck that rides on it, is made out of square stock in various sizes. A couple of bearings are enough to make sure the movement is smooth and doesnt have too much slop. Motion is provided by a long threaded rod and two nuts, which are welded to the side of the truck.
If you had the patience (and forearm strength) you could just put a crank on the rod and be done with it, but in this case [workshop from scratch] used the motor, gearbox, and chuck from an old electric drill to grab onto the threaded rod and do the spinning for him. He rigged up an enclosure for the side of the rack that holds the motor, DC power supply, and motor controller, along with a couple of switches and a knob to control the speed.
A modification allows him to enable the plasma cutter with one of the switches on the panel, which gives the setup a much more complete feel than just putting a zip tie on the trigger. With this design, the plasma cutter itself can still be removed from the mount and used normally. You can even remove the motorized component with a few bolts if you just wanted to do manual cuts on the bed.
In the video after the break, the keen-eyed viewer may notice a few familiar pieces of gear in the background, such as the hydraulic bench vise we covered earlier in the year. As the name of the channel implies, [workshop from scratch] is all about building the workshop tools that many take for granted, and theyve all been phenomenally fascinating projects. While we admire the gumption it takes to try and build a lathe out of scrap granite slabs, theres something to be said for DIY tools that end up looking nearly as good as commercial offerings.