then just used an oldham coupling to connect screw to motor.

Does it not introduce backlash?

Dan

No, ballscrew is held between the two thrust bearings so it is held tight.
Hood

How is your ball screw supported at the tail stock end?
Mine is machined and simply sits/runs in what would be the hole for the original leadscrew. It doesn't look as though it's secured in anyway, but I guess I could drill/tap it and come up with some method of adding a thrust bearing to hold the entire screw under tension...

I made up a wee housing to accept the ball thrust bearing and it is simply held there against the end bracket by the ballscrew pusing against it, the other end is the same so the the ballscrew is kept captive. I just use the  half of the oldham coupling to keep the preload on the bearing, I nipped it up then lichtly tapped untill I was happy then tightened the capscrew fully. It should be good enogh to keep it from moving but if not I will drill the coupling and screw for a pin.
Hood

Got the lower cabinet wired up with the exception of the main power. Have the wires run up to the control and hope to get them connected soon.
I got some 2 pack paint that, although not a perfect match for this lathe (actually closer to the big lathe) it is good enough and came out relatively well. Need to redo the back panel as there are a few runs there as the paint was setting when I painted it so applied it too heavily, nothing a sand and re-coat wont solve I hope.

Hood

Edit, just looked at the pic and the paint looks a lot lighter than it is, if you look at the big lathes control panel in the background you will see the true colour as I gave that a coat with the paint that was left.

Got the spindle motor tested through the CSMIO today and it worked fine and was nice and quiet. Had to do a bit of jiggery pokery with the encoder output of the drive and what I told the CSMIO it was, seems like the ratio in Spindle Pulleys is not getting seen by the CSMIO.
 Tested the spindle up to the full 2500rpm (5000 motor) and again it was fine and quiet, tried at 10rpm and  a few others in between and all was well.
 I then thought I would do a bit of testing for Russ so went and got a brush and set the spindle to 500rpm (1000rpm motor) and shoved the shaft between the chuck and bed, took a fair amount of force to slow it down so I think it will be fine at the 2:1 gearing.
Problem now is the chuck has tightened up that much I cant get the bleeding thing off It is now also rubbing on the steel plate behind it so will have to remove the keyboard/switch panel so I can get a spanner on the spindle flats to get the chuck removed. I will then have to machine the back of the chuck a bit so that it cant rub on the steel. Dont think it would ever normally tighten up that much even under heavy cutting but might as well do it just in case.
I am actually thinking of making a new spindle as I am not a fan of the threaded spindle noses as if I ever want to use M4 then there is a chance it could undo.

Hope to get the axis moving this weekend but not sure if I will get the time.
Hood

Good news, the ol' Broom Handle Jam" method of torque verification.
(same as I use here btw)
Thanks for the test result Hood, anxious now to see a heavy cut vid.

Regards,
Russ

I too don't like the threaded spindle on my 9x20 and had the same problem with the chuck tightening up while I was tuning the servo. Took some serious effort and fair extension to the keys to unthread it. Have also been thinking of making a new spindle for it, but haven't yet decided how I want it. If you have ideas would be interesting.

Dan

Not going to be many heavy cuts on this lathe Russ Well certainly suppose things are relative, what would you call heavy cuts?

Dan
 was thinking of a D spindle nose at first but then thought an A or B would be better or rather easier, same taper but no cams to worry about.
Hood

Does your's have flats on the spindle?

Mine doesn't, and I was under the impression any flats would of been on the original pulley block/back gear.