Petoskey stones, found in the upper Great Lakes region, are fossilized coral that have a unique pattern when wet. While these stones can be polished to bring out the pattern, we’ve found an easier way by coating with Amazing Clear Cast by Alumilite. Once cured, you have a high gloss, highly durable coating that reveals each stones unique pattern.
Pulling an old HP printer to bits for parts, and it suddenly turned into a CNC machine conversion. Took me 4 days, but there were a few small hurdles to overcome. The brains of it is an Arduino Uno with a Protoneer CNC shield running GRBL. (Big shout out to https://info.protoneer.com/1)
The Z and X axis runs on ball bearing drawer slides, and they have absolutely no vertical or horizontal play.
The threaded rods run through MDF thread inserts and using a small piece of 6mm acrylic for a ‘nut’ to lock it into the mounts. The inserts don’t seem to have the same amount of backlash as a standard nut.
All electrics (incl a PSU) is at the end where the ink carts used to be.
The X axis is a bit noisy because it is mounted to the printers steel base plate, but some nylon washers should dull that down a bit.
The dremel flexi-shaft runs down the inside of the 1″ square tube (the bit the pen was zip tied to) on the Z axis.
PS…I’ve never attempted anything like this before, I’m still learning about the whole CNC thing (spot the sticky notes to remind me what axis I was moving!). The fact that I could use the original bodywork (panels) was more good luck than good design….except when it comes to drilling holes for USB cables. That was just crappy “eye-ometer”.
UPDATE: Here is a blog I wrote up about the build, including the first runs.
https://justcheckinm8.blogspot.co.nz/