Abstract
Ever since getting the chance to use, then learn, then design for the 5x10 foot CNC router at my old job, I wanted a CNC machine so bad. Since I learned on a 2D system, I was looking for a router, primarily for engraving and detailed wood routing. In terms of CNC this is relatively uncomplicated, and there are lots of fully DIY solutions out there I had been considering, when… Something listed as an “engraving machine” was listed on Govdeals.com for $20. There was almost no fight for it, I ended up with a CNC machine for $60. It had been sitting in the rain for a long time, it was massive, and required an ancient computer to work. Luckily, since it was so cheap, I could create a new control system for it relatively easily following those fully DIY guides. By the end of it, I had a relatively useful CNC machine that I use for small projects when I have the time to refine my CNC workflow, which is still a bit hard to pin down.
Fabrication
The machine is an Isel 3020, a bench top model of CNC made by Isel, who make large scale industrial machines. So the original control system for the CNC was very high quality, unfortunately though it would show activity lights, it was totally invisible to serial devices, so the rain had done its damage after all. I pulled the old control board and replaced it with three stepper drivers rated to handle to current of the motors in the machine, I was hoping these would be safe, since they were inside the plexiglass shielded work area of the CNC. The stepper drivers would be controlled by a 6 axis board designed to run fluidNC, this control board would take all the limit switches and contact a relay to engage the spindle motor, which after lots of cleaning did still work. All belts, slides and mechanical components of the mill were fine as they were, just needing a little bit of cleaning. This series of changes brought the machine up to modern day interactivity, and I could upload .nc files to the machine to test the machine profile before long.
Conclusions
Dialing in Z zeroing is tough, remaining a challenge until now. I hope to add a touch off plate to make that process a bit more consistent and repeatable. I can create some impressive contours, including the Muon logo and sphere recess in the example photo. I hope to have some larger work to show for the capabilities of the machine soon.
