Made with things I had in stock the coil is .25mm wire and fills the spool this gives 63ohms. The PSU is a 20v laptop supply I have added a 500mA wire ended fuse on the board. The sphere is 18mm I have tried larger magnets and they sit lower, maybe need bigger balls did I say that ?
I intend to experiment with metal filled PLA and if things go well I will reprint this thing.
The regulator is a good old fashioned 78L05 and will work up to 35volts I note the surface mount divice is 15 volts max.
Many thanks for this fun project reparator !
.5 mm nozzle and .2mm layers