Making the ballscrew yoke and bearing retainer, machining the ballscrew pulley.

Ballnut yoke:

Having machined up the block, time to drill and tap some holes, starting with the M3 fixings for the ballnut. 

Manual tapping - not worth messing with CNC.

Finally, machine off the top of the lump. The top surface should be tangent to the internal bore.

Then finally, slot the end, to give a clean edge. There's a 0.5mm gap beneath the cutter.

Finished - looking good.

Time to remove the ballnut from the ballscrew. A piece of 10mm pushfit hose is just the right size to act as a keep for the ballnut.

Ballscrew pulley:

Next - machine the pulley for the ballscrew. Needs a 10mm bore, a counterbore for the M10 nut and a couple of grubscrews. It's not completely conventional but I'll be tightening the pulley against the bearing with the M10 nut and locking the pulley to the ballscrew with the grub screws.

This is a 32t pulley, so 4 slugs and a 4-jaw chuck come to mind.

There - held in place with electrical tape.

Done

Fits togetehr as planned - no cockups.

Bearing retainer plate:

Progress so far:

Next 

• Make the M10 retainer nut and spacer for the ballscrew. 
• Chop off the ballscrew to the right length and machine both ends. 
• Make the limit switch brackets and drill out the encoder head fixing holes (M3 clear)
• Move on the the cross slide body.