Parts (purchased at Lowes for about $3):

• 1/2" diameter, 12" section of threaded rod

• 1 regular hex nut (1/2" diameter)

• 1 nylon lock hex nut (1/2" diameter)

• 2 washers (1/2" hole, 2" diameter)

* Note: if your drill does not open to 1/2" then get 3/8" hardware instead.

Instructions

1. Cut the threaded rod to 7 inches long.  (Max spool width: 4 inches)

2. Put the spool on the rod

3. Thread the washers on to the rod against each side of the spool

4. Put the nuts on against the washers, the nylon nut goes on the side closest to the drill

5. Tighten up the bolts so that the washers form a friction clutch against the spool.

6. Chuck the machine into the drill and spin to wind the filament.

FYI, big hardware stores have a lot of cardboard tubes/spools that they'll give away for free, just take them from the aisle and show them to the cashier during checkout.