Only need to print one chuck. Put the chuck in the drill and attach the the loop jigs to the chuck you printed to spin them with the drill. Print as many of the LoopJig.stl's as you need. The jig was made so that you could leave the wire wrapped around the loop when you are done wrapping it. In my case, I used flex seal and hot glue to seal the wire off so the loop antennas could be used underwater.