Reply To: Myford ML4 Restoration: Headstock bearings and spindle removal

[Luke MitchellParticipant @lukemitchell30627]

Hello all.

Firstly, I am a first time poster here. I found the site after looking for other ML4 restorations (of which there seems to be precious little, at least not publicised on the internet).

I have recently inherited the lathe from my grandfather. It was his brothers and he doesn't have a great deal of information about it – save that it was often used and clearly loved. It has sat now for a long time, a decade or more, and is in need of some love.

I stripped down, cleaned and lubricated as much of the lathe as possible and I've managed to turn a few simple projects using it: a sink plug, made using brass; an arbor for an angle grinder; boring out a pulley wheel.

On aluminium and brass I can get a fairly good finish. When parting, or cutting steels, however there is a lot of vibration and chatter and a whirring sound from the headstock. There is also a little vertical play in the spindle (about 0.2mm, measured using my cheap DTI) and a little run-out (0.03mm).

I was told that the headstock bearings would need replacing and my experience turning seems to confirm this.

This evening I carefully adjusted the clamp bolts in the headstock, taking care not to over-tighten them as I've read this can split the casting. I then nipped up the grub screws until the spindle seized, then backed off 1/4 turn. This operation eliminated much of the vertical play (it was reduced to ~0.05mm). However, when I powered up the lathe and began turning it produced an awful chatter even during shallow cuts. Slackening the clamp bolts helped but brought back the play.

I believe the vertical play is making parting, in particular, very difficult. More than once the work has jumped onto the parting tool.

Some details about the lathe:

• 1.1/8" x 12 TPI thread on the spindle nose
• 3.1/2" height between center and ways
• MT2 in the spindle
• MT1 in the tailstock
• Tumbler reverse
• "Newer" tailstock casting with large dovetail gib
• Toolpost bolt has been re-tapped to M10 at some point

The spindle thread leads me to suspect it is a later ML4 as this is the same (I believe) as the ML7. The serial number has been painted over however and so I cannot use this to age the machine.

Some (slightly random) photos: