Revision as of 15:53, 23 August 2020

Fidget Spinner Bearings (22mm total diameter, 8mm bore and 7mm width)
- Amazon Source ~10 USD for 20; ~0.50 USD per bearing

8 Disc magnets per rotor (8 mm thickness, 20mm diameter) 26.42 USD for 20. Much more for USA source - $3 each - so $24/motor. [2]
Copper wire (0,2 mm diameter max. definitely not more because you will get eddy current issues) [3] (Enameled copper wire ie Magnet Wire )
- Cost of $1-2 per motor using the $7 spools.
Bit of brass tubing (4 mm outer diameter) to connect the coil endings in. [4]
Solder
Glue (the type that sticks)
8 mm metal rod for an axle (offcuts from universal axis are great for this)
3d printing filament (kg estimate, also infill needed)
a little bit of epoxy to glue the magnets in place [5]

Links

@@ Line 4: / Line 4: @@
 **[https://www.amazon.com/Pack-608-2RS-Ball-Bearing-Skateboards/dp/B07C6FL8TW/ref=lp_16411051_1_3?s=industrial&ie=UTF8&qid=1596637217&sr=1-3 Amazon Source ~10 USD for 20; ~0.50 USD per bearing]
-* 8 Disc magnets per rotor (8 mm thickness, 20mm diameter) [https://www.aliexpress.com/item/32797367574.html?spm=a2g0s.12269583.0.0.23ca74d74jPZDB 26.42 USD for 20]. Much more for USA source - $5 each - so $40/motor.
+* 8 Disc magnets per rotor (8 mm thickness, 20mm diameter) [https://www.aliexpress.com/item/32797367574.html?spm=a2g0s.12269583.0.0.23ca74d74jPZDB 26.42 USD for 20]. Much more for USA source - $3 each - so $24/motor. [https://appliedmagnets.com/neodymium-magnets-3-4-in-x-3-8-in-rare-earth-disc-p-689.html]
 * Copper wire (0,2 mm diameter max. definitely not more because you will get eddy current issues) [https://www.koper-draad.nl/product/koperlakdraad-02-mm-awg-32-lengte-1730-meter/] (Enameled copper wire ie [[Magnet Wire]] )
 **Cost of $1-2 per motor using the $7 spools.