Simple Mini Rotary Tool

I wanted to buy a mini rotary device that could be used for my DIY projects. Using regular drilling machine was too much hassle.

Dremel is good but out of my budget ..

So I built a simple mini rotary tool for
1. Pcb drilling
2. Glass etching - Lite work
3. drilling holes in PVC needs etc

Remember this tool can cause injury.

Not recommend to cut glass or metal or wood....


always safety first !!! where eye protection and gloves

What do we need?
- a 12v DC motor
- 104 or 0.1uf capacitor
- push button switch
- few wires
- 9v battery and holder
- Chuck for 0.7 to 1.5 mm and for 2.3 mm bits, ordered from Aliexpress

Most of the dremel bits are 2.3mm diameter on Aliexpress...

Assembly is simple

Connect a capacitor to both ends of the motor. And one end to battery holder and other to push button.

Connect other end of push button to remaining end of battery holder.

I tried to put 1k variable resistor. but to much current. Even an NpN transistor did not help. May be in future I will have variable speed

I used a diamond coated bur to etch my initials on a glass bottle and drilled holes on pcb. worked good.

Needs high torque fit cutting glass or wood.... may be for version 2