This is a model and attachment scheme for a rotary grinding tool (like a Dremel) that uses a small dc motor and two limit / lever micro switches.

I harvested some motors and a handful of limit switches from an off-brand roomba to incorporate into this simple rotary grinding tool that i use to post process printed models.

The attachment scheme here is a 'hat' that can be deformed to snap-fit into a matching slot on the tool head piece. I've used this to make various sanding and grinding heads that i can swap in and out as i need to.

If you have a spare motor and a switch this model may be a way to turn those items into a usable bench tool. More likely, however, you might find this model instructive for basing your own design on.

Rotary Grinding Tool features

• Removable / swappable tool heads
• Tool heads can be any shape
• Snap fit between tool head and motor mount

Creality

Ender 3

Yes

The only difficult to print piece is the Motor Cup mount, the cavity is meant to allow some space for the mount "hat" to deform into and this space requires a support to address the overhang, i've had success creating a cylindrical support that sits a couple millimeters inside the motor cup outer edge and then just prying it out.