Luke11CNC Build Log ,I'm so naïve

[Swarfing]

Lengthen the screw is not that hard if you access to lathe. Dose the nut travel the whole length of the screw? I bought a shorter screw to save a few quid and did just that. So don't panic mister mannering.

[Jonathan]

I got mine all machined to 25mm.

Lengthen the screw is not that hard if you access to lathe.

That'll be my lathe then.

I've done that before to add a handle to lathe leadscrew - drilled & reamed a hole in the end then machined a bar to fit. Put a straight knurl on the bar to make it grip, loctite and big hammer to 'press fit' it. Start by machining the bar slightly oversize, then after put the ballscrew in lathe, get it on centre and skim the bar the right size so that it is on centre.

Can't the whole screw be moved along and the bearing mount on the non driven end be moved?

[Swarfing]

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.

[Jonathan]

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?