12V Handheld Dremel-Style Rotary Tool (Custom Design)

This is my custom-designed handheld dremel-style rotary tool that I use in my workshop and have grown to love. It’s built around a 12V brushed DC motor, a 688AZ ball bearing, and a large on/off switch integrated into the handle. I power it directly from my lab power supply, which lets me control the speed easily and makes it perfect for light milling, cleaning, deburring, and general workshop tasks.

When printed in PETG, the housing holds up extremely well—even when exposed to Aceton, which makes cleaning quick and worry-free.

Features

Smooth, low-vibration operation
The motor shaft runs through a single 688AZ ball bearing seated at the top of the housing. This greatly reduces vibrations, keeps the tool well-centered, and results in a surprisingly quiet rotary tool.

Easy maintenance
The top section can be unscrewed, giving access to the PTFE tube used for tool holding. If it ever wears out, you can simply swap the tube without dismantling the entire tool.

Secure cable plug system
The cable plug (Fig. 5) not only guides the wire but also presses the motor firmly into place, preventing movement and ensuring excellent structural rigidity.

Large on/off switch
A big, easy-to-reach switch (Fig. 3) is embedded in the handle for quick activation or shutdown—super convenient when working with both hands.

Print Instructions

Material: PETG recommended (for chemical resistance)

Orientation: Print the casing standing upright (Fig. 1)

Assembly:

Slide in the 688AZ bearing

Insert the 12V motor

Add the mechanical adapter

Close everything with the top screw-on section

Install the switch and cable plug

Once assembled, you get a compact, sturdy, and reliable rotary tool that performs exceptionally well for its simplicity. I’ve been using mine daily—milling, cleaning parts, and doing fine work—and it continues to impress me.