STEM Prac Electric Motor Build

These 3D printed parts combine with magnets, enamelled wire and copper or brass sheet to build a basic electric motor from scratch.

Materials

• 2 stands (printed)
• 2 magnet stands (printed)
• 1 armature fram (printed)
• 1 commutator (printed)
• strong magnets
• copper or brass sheet
• enamelled wire
• 2-part epoxy glue
• solder
• sticky tape
• 12V battery pack

Tools

• tin snips to cut copper sheet
• soldering iron
• hammer

Instructions

1. Be sure you have all listed materials and tools
2. Print the STL files in PLA at a layer height of 0.1mm (because PLA doesn't warp)
3. Cut a length of enamelled wire (1m )
4. Wind it around the armature frame as many times as you can.
5. Scrape the enamel off both ends of the wire. Do this the same way as you would strip a little of the insulation from a wire to expose the copper. You should be able to see the copper which is a slightly different colour
6. Cut out some brass or copper rectangles 17mm by 9mm
7. Shape the rectangles to fit the round surface of the commutator. Do this by using a hammer to beat them against a pencil.
8. Test the fit before gluing. The two metal sheets should not overlap or touch anywhere.See picture for appropriate gap size.
9. Mix the two part epoxy and stick on the two metal sections of the commutator
10. Leave to cure overnight
11. Fit the finished commutator on the Armature frame (a tight fit)
12. Solder each end of the wire to a seperate metallic strip on the commutator.
13. Stick the stands onto the table at so they hold the armature and commutator and allow the whole thing to spin freely.
14. Stick the magnets to the magnet stands with sticky tape
15. Stick the magnet stand on either side of the armature, close but not preventing the body from spinning.
16. Apply one wire from the battery pack to each terminal of the commutator. The motor should spin if built correctly!