simple brushless motor

a cheap (<£10) and simple educational brushless motor, allowing adjustment of:

• number of magnets
• coil size and clearance
• sensor phase angle
• coil power timing

BOM

electrical

• P channel mosfet - capable of switching at least 1A
• Hall effect sensor
• copper wire for the coil - I used about 8m of 0.224mm copper wire, with an overall resistance of 3.8 Ohms
• 2 1n4001 diodes. D2 is the flyback diode that protects the mosfet when it switches off.
• 5k resistor
• 10 uF cap
• 10k potentiometer

mechanical

• 10mm miniature bearing
• prototyping board
• [3d printed bobbin](4mm-bolt_motor2 v16_coil_1_Body1.stl)
• laser cut rotor, coil mount & base plate
• magnets - I used 5mm cylindrical

Links

• video, blog post
• fusion360 motor model
• Walter Lewin's physics lectures
• lt spice - get started

Todo

• put the pivot on the side of the breadboard for better hall effect alignment

License

• BY-SA Attribution-ShareAlike