Simple wrench to hold the Craftbot hotend when replacing the nozzle.

Fits very snugly around the silicone sleeve on the hotend (at least on my machine), so if you want a slightly looser fit, just print at a slightly larger scale (say 102% or something).

Probably a good idea to print with 5 perimeters, but infill doesn't need to be very high. Layer height can be anything, really. I used 0.3 mm to save time.