If you’ve been following the blog, you’ll have seen that I recently replaced the pulleys with aluminium pulleys. I’ve also been having trouble with my shells not lining up. Until yesterday, I hadn’t put two and two together, and realise that one was causing the other.

I put a post on the Reprap Skeinforge forum, showing the shot glass, and asking what might the problem be. I thought it must have been an SF issue, but the forumer’s quickly suggested that the problem was probably with backlash.

Nophead then suggested that the problem was probably the aluminium pulleys. He stated that the teeth on the pulleys are too narrow, and cause the belt to slop around on the teeth. So I pulled the Aluminium pulleys off, and replaced them with the original RP pulleys.

What a difference. So, learn from my fail, the ebay Aluminium pulleys are worthless. Video of the shot glass being printed: