Summary

An attempt at a pre-assembled casting.

Instructions

This aluminum swivel pulley was cast in an ABS mold. One inch wheel diameter, and should accommodate 1/4 inch rope.

[ Update: An Alternate swivel style was uploaded by mistake. I left that one here (pulley_alternate.stl) and added the one used in this project (pulley.stl). Either one can be printed if someone wants a plastic pulley, and the wheel and axle fits either one.]

Since pre-assembled parts are commonly 3D printed, I thought perhaps a mold could be printed where the cast metal parts would already be assembled.

This pulley was a simple test. The swivel ring is cast within the pulley. When the mold is stripped off, the ring is (hopefully) free to swivel.

I haven't bothered to cast the wheel yet since I'd probably redesign the whole thing if I actually intend to use it. It could have thicker sections for more strength.

I suppose the pulley's wheel could be cast pre-assembled, but there has to be adequate space between the parts. Clearances around the axle should be minimal, so there's a conflict.

An integrated wheel / axle could probably be cast, if it were worth the effort, but a nut and bolt is just so easy.

,,,,,,,,,

There have been lots of failures while experimenting lately. The timing pulley (see last 2 photos) was one of them. I just can't get it right despite a dozen attempts.

A spectacular ball of flame erupted when I first tried casting the timing pulley by a different method. The aluminum was poured way too hot, while the mold was spinning at 2000 RPM. The smoke reached its ignition point, and went poof.

That's when I considered abandoning this whole aluminum casting thing. But the feeling went away after a couple hours, when the shakes wore off. It was just a wake-up call... Don't get cocky.

Aluminum swivel pulley cast in ABS mold