Magnetic Carriage V0.3

Magnetic Carriage for StrongPrint http://www.thingiverse.com/thing:329498

Based on Supermagnete 15 mm donut magnet
http://www.supermagnete.fr/eng/R-15-06-06-N

The use of magnetic bearings (steel ball over a donut magnet or vice versa) allows 3 key advantages:
- Strictly no play
- Rapid assembly disassembly & therefore part exchange
- Dismantles in case of clash or out of range movement preventing damages to the machine & particularely the print head

These could be fitte