A sample coil master spool which easily splits in half to allow for loading of sample coils.

The master spool uses 6mm x 3mm magnets (actual depth sized for 2.75mm magnets). Generally, when you purchase 6x3 magnets they are closer in size to 6x2.75, so please adjust the holes to 3mm if your magnets are true to dimension.

Source files included in case you need to modify for your own purposes. 

Cheers!