@phaedrux said in 3D scanning a $2 coin with 3D printer and DIY touch probe:
That's really cool. How does the touch probe work?
It's actually quite simple. 3 sets of switches that are wired in series. A spring pushes the contacts so that the current goes through when the probe does not touch anything. When the probe touches something, the current is interrupted.
Here's a touch probe I found on thingiverse: https://www.thingiverse.com/thing:721620 I am sure you can find many others.
Here's how I made mine:
Everything is from stuff I found around... washers for contacts (no clue what size, probably washers for M4 screws i think), PCB prototyping board (4 cm by 6 cm), 2mm and 3mm copper pipes (from local hobby shop), M2 screws, spring comes from BL-Touch kit, and finally a small sewing needle. I tried to find a small, but thick needle, because the longer it is (or thinner), the more will bend when it's touching. If you need to scan deep things, then make the pipe longer.
The sewing needle goes in the 2mm copper pipe, and with pliers I squished the pipe as hard as I could to grip the head of the needle.