Troy, a.k.a tmbarbour has put out some really cool instructables on adding some new functionality to the Mill One! You might know him from his Add Homing Switches to a Sienci Mill One CNC project, and he’s made some other cool changes to his machine.
This instructable walks you through adding a Z axis probe to the Mill One using the built in pins on the CNC V3 Shield. This makes it a lot easier to automate the process of finding the Z height of your workpiece.
Knowing the RPM of your spindle can help you get more consistent results out of your Mill One. Not only that, it’s a cool little add on that’s fairly inexpensive and fun to make. Troy’s instructable covers everything you need to know to make your own.