Originally Posted by
veecee
Interesting idea on offsetting the diff balls. Would be nice to see what the improvements are. Pretty sure the 416 pulleys are moulded in one piece.
Nope. You can't mould something with internal angles in one piece and then take it off the mould. It just doesn't happen. The pulleys you talk about have a side ring welded with ultrasound I suppose (it's a very neat way to weld plastics, but there are other ways) which is why it seems seamless. Take a closer look and you'll find one side of the pulley has a smaller internal diameter (measure the recessed part where you have the ball holes). That's because
that is a ring attached there as I explained. There are plenty of pulleys that look like they are one piece (check out a Corally diff pulley) but none is.
That's why my idea is to machine it. It's more work, but better quality.
Offsetting the balls will save wear. Running nine/ten/twelve/sixteen balls in the same groove wears it down sooner. And you only need to offset the balls a fraction of a milimetre not any more.