Summary Yet another spool holder! No need for a filament guide!!! Can be used on top of Bot or benchtop. Instructions Print. Parts are pre-mirrored. Cut 3/8" dia. dowels (2)@112 mm, (2)@134 mm, (1)@114 mm. Drill out dowel holes if need be and assemble as shown. If dowels are a loose fit, install screws in pilot holes to secure. Trim or sand for a snug fit onto bot as shown. Drill and install small bolts or rods in 114 mm axle ends to keep top brackets in position and stop axle from spinning. This should be a loose fit so that it can be lifted out for easy color change. Drill out upper bracket as needed. Drill out or trim bushings for a very sug fit on axle. Position bushings on axle as shown. Small inner ones (use 2 or 4) provide a small amount of friction to keep spool from unwinding, and outer ones keep spool centered. (Note that MakerBot brand spools have asymetric spindle holes)