Myford Split nut adjustment

[Clive HartlandParticipant @clivehartland94829]

I am starting to find my split nut on the lead screw is getting tight.

When I look at them and clean them I can see a grub screw which appears to hold them apart when closed on the lead screw.

How do I adjust this as it is under the apron?

Clive

[Clive HartlandParticipant @clivehartland94829]

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

Hi Clive ,

Which model lathe and what vintage ?

If ML7/ML7R/non cross feed S7 these usually have a hand operated twiddler sticking out under the apron on C/L of operating lever boss – looks like a watch winder .

Nuts getting tight is a bit odd – they usually wear loose . When I did a complete strip down of my ML7R I found that the whitemetal nuts had extruded lots of material around the threads and in other places and the effect of this had been erratic action . Easy enough to sort out .

If your machine is anything other than a power crossfeed S7 stripping down the apron is an easy and worthwhile task . If you mark apron and saddle before stripping they go together again with no loss of alignment .

MW

[Clive HartlandParticipant @clivehartland94829]

MW, its an ML10 so nothing to twiddle, the socket drive grub screw keeps the two nuts seperate when the lever is in the closed position and it seems is a, 'Hit and miss' affair for adjustment.

It is difficult to set the adjustment in the open, so it has to be re-assembled again to see if it is too loose or too tight.

Maybe it is full of crud as there is nothing to prevent entry of swarf etc.

I will rip it down again and reset it.

Clive

[KWILParticipant @kwil]

Clive, The S7 has a similar separatiion screw arrangement as MW says. Technique is to slacken off the separation screw, close the half nuts firmly and whilst holding them closed, screw in the adjuster until it stops turning. Remove closing force and then 1/5 -> 1/4 turn in so as to cause the half nuts just to not close tightly on the leadscrew.

K

[Clive HartlandParticipant @clivehartland94829]

Thank you Kwill, I will do that tomorrow and clean up the items at the same time.

Clive

[JOHN BRIDGE 1Participant @johnbridge1]

I have a ML7 and my adjuster is in the bottom half of the half nut it is a 4BA 1 3/4" cap head and it screws up though the center of the bottom half not and comes into contact with the top half nut to keep them apart.It has a small spring between the cap head and the half nut. Has the bottom half nut been fitted to the top and the top one fitted to the bottom which would put the adjuster at the top and inaccessible with the apron on.

John

Edited By JOHN BRIDGE 1 on 17/02/2012 23:41:49

Edited By JOHN BRIDGE 1 on 18/02/2012 00:00:32

[Clive HartlandParticipant @clivehartland94829]

John, My assembly is not like that. I have the shown half nuts but there is no adjusting screw with a spring!

Instead it has a fairly long skt. grub screw that controls the seperation of the half nuts when closed.

This is faily inaccessable when assembled and I need to take it down again and re-adjust and clean it all.

In fact I will look and see if I can modify it in some way to have external adjustment.

Thanks. Clive

[Sub MandrelParticipant @submandrel]

Ian Bradley once gave a mod for an ML7 to add a separation screw – it provide repeatability when engaging the half nuts -if they close completely any swarf in there will cause an error.

99.9% 0f mini lathe users don't realise there is a well-hidden separation screw fitted to them as well.

Neil

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