To stop me doing very simple tasks on my Sherline CNC that were frankly outsized and just abusive on the Sherline. That was about 5 years ago.

The time has come for this lathe become NC :-) It was always on the cards, but this is it's year :-)

I am looking for suggestions with respect to upgrading the spindle, the bearings are somewhat simple, crude and a bit rough. Also I would like to increase the power and speed available - the max is um 1,400RPM as standard.

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Currently the spindle is driven within the gearbox, but I think this is going to be problematic as I want to dump the gearbox contents entirely, I have been thinking about a cartridge style spindle with perhaps 5 bearings, so not sure where I am actually going to drive this yet.

I am envisaging a couple of plates at each end of the gearbox to enable me to align the spindle.

I am thinking about a servo to drive the spindle, but a VFD may have to suffice for phase 1.

Whilst trying to only ask one question at a time....... I am also thinking about putting the ball screw down between the rails, space is tight, but possible, however I am concerned about keeping chips away from the ball screw and if it is just going to be easier to put the ballscrew where the leadscrew was on the front face.. I am stuggling to envisage a way of really keep chips away from the ballscrew, even with a spiral wrap the incumbent leadscrew still got chips on it :-( Is this a valid concern or should I just re-use the spiral wrap and ignore it?

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Ignore the second saddle - that is the one I will make if my current scraping activities write off the existing :-) Or more likely I ruin it by milling out the web that limits it to 7 inch travel currently and likely 6 unless I am vicious or cunning.

It is early days and I have a lot of issues to resolve, so please go easy on me!

cheers,

Jon