Quote Originally Posted by 2e0poz View Post
Your almost right Jonathan? The screw is very hard and can easily crack (only the centre is soft). If this is added to the floating end then no need to knurl it, just go for a nice tight slide fit and let the loctite do it's job.
The reason I knurled it is because that's what John S does. Well, says he does at least. Could anneal the very end of the screw to stop the risk of cracking, but that's probably taking it too far.

Putting the extension on the 'floating' end sounds good to me as all it's doing is stopping the screw whipping, not transmitting torque. The other end is probably easier though as the tolerances to fit the pulley are not tight as for a bearing. It depends how much we need to add?