Miniature Brushless Electric Grinding Pen

For detailed installation instructions, please refer to the installation video

April 13th update: Added a detachable pen tail cap, compatible with GX12 female header. A new dinosaur head icon rotary cap has also been added

Connectors：Drive box screws: M2*14 self-tapping screws, pen tail fixing screws: M2*6 self-tapping screws. Motor fixing screws: M1.6*6 screws. Drive board fixing screws: M3*6 self-tapping screws

Parts List (Purchase screenshots are included in the assembly guide for reference):

Small Brushless Motor (refer to the image)

75W Brushless Motor Driver Board (Both green and orange versions are usable; the mounting screw positions differ, so select the drive box print that matches your chosen screws)

DC5521 High-Current Metal Female Header (power input)

Miniature Push Button Switch (forward/reverse switching)

3-pin 0.3mm Soft Silicone Wire

ER8 Drill Chuck

ER8 Collet 3MM (Choose according to your preferred grinding head; I use 3MM shank heads most often, so I purchased a 3MM collet)

KCD11 Rocker Switch (power switch)

GX12 3-pin Aviation Female Connector (connects the electric grinder pen and the drive box)

10K Potentiometer (three-pin) to replace the original circuit potentiometer

Installing the orange driver board requires removing the potentiometer. Forward/reverse switching can be achieved by connecting the two solder points next to the potentiometer to the two wires of the push-button switch

If using the green driver board, the potentiometer does not need to be removed. There are three solder points (5V, 0-5V, GND) where an external potentiometer can be connected for forward/reverse control, but the internal potentiometer needs to be set to maximum for the external one to function correctly. To save space, I removed the potentiometer in my own build. For the green driver board, forward/reverse switching is achieved by connecting a push-button switch to the CW/CCW solder points, with the other switch wire connected to the main ground.