Hey kind folks,
I thought I’d share a quick video showing the status of our Linux CNC foam-cutter project. I’m brand new to LinuxCNC and basically just took this on as a fun project to learn a bit.
photos.app.goo.gl/ksw5mnEoJEibSiqs5
The drive drums are custom designed 3D printed hypocycloidal drives running a pair of cables to a hot wire knife. The 3D printed drives are a bit janky but actually work surprisingly well. Not sure how durable they’d be in the long term.
While this test-bed is quite small, the objective is to be able to mount the drum modules on a wall some 12 feet apart and in doing so be able to cut shapes out of large foam sheets. The objective is to be able to build an ultra-low cost CNC foam cutter for less than $200. I could then manually stack the cut sheets together like a loaf of bread and build very large 3D printed objects ala a huge FDM (albiet with 2” thick layers).
Given the lower speed we’re running the unit on a Raspberry Pi. I’m sure the latency is a mess but it appears to be tracking. The forward and inverse kinematics functions were the majority of the challenge - I made life much more difficult by running the cables tangential to the drums instead of through a fixed ferrule but I was eventually able to solve the kinematics. The inverse kinematics were just trig but the forward kinematics required numerical methods (Newton-Raphson) which I only sort of understand but seem to work.
More to come to make this more useful. If there is any interest I’ll likely open-source the whole thing when it’s a bit more stable and refined.
Thanks to all of you who helped on here through my rough patches.
