Anyone familiar with Myford 254s ?

[Bob Unitt 1Participant @bobunitt1]

[Bob Unitt 1Participant @bobunitt1]

I'm servicing my Myford 254s and I've found an adjuster which isn't described in the service manual, and the guy at Myford doesn't know what it is either. Is there anyone on this forum who might be able to help ?

[Nick_GParticipant @nick_g]

Posted by Bob Unitt 1 on 26/11/2014 17:34:37:

Is there anyone on this forum who might be able to help ?

A picture of the item and it's location would assist greatly I would imagine.

Nick

[Bob Unitt 1Participant @bobunitt1]

This is all I have – I know it's a stop-crew, but not what it stops (Excuseme if I get it wrong, this is the first time I've posted an image here) :-

[Neil WyattModerator @neilwyatt]

As a guess, it may adjust the degree of engagement of the half nut.

Neil

[Swarf, Mostly!Participant @swarfmostly]

Hi there, Bob,

You've cropped your third photo. What's on the lower end of the leader line whose upper end is at the bottom left-hand corner of the front of the gearbox?

Best regards,

Swarf, Mostly!

[Nick_GParticipant @nick_g]

.

I cannot assist you in it's purpose.

But I can say that some of the brethren here will be mortified to the degree of having to go to see their doctor tomorrow due to seeing a Myford so oily and dirty. —

Nick

[Bob Unitt 1Participant @bobunitt1]

Posted by Swarf, Mostly! on 27/11/2014 20:11:39:

You've cropped your third photo. What's on the lower end of the leader line whose upper end is at the bottom left-hand corner of the front of the gearbox?

Oil drain plug.

[Bob Unitt 1Participant @bobunitt1]

Posted by Nick_G on 27/11/2014 20:15:01:I cannot assist you in it's purpose.

But I can say that some of the brethren here will be mortified to the degree of having to go to see their doctor tomorrow due to seeing a Myford so oily and dirty.

A clean lathe is the sign of a sick mind…

[Nick_GParticipant @nick_g]

Posted by Bob Unitt 1 on 27/11/2014 20:17:55:

A clean lathe is the sign of a sick mind…

Nick

[JasonBModerator @jasonb]

Full drawing and parts list

[Neil WyattModerator @neilwyatt]

Yep, it has to be the halfnut engagement stop.

Neil

[Bob Unitt 1Participant @bobunitt1]

Posted by JasonB on 27/11/2014 20:56:34:

Full drawing and parts list

I have those thanks, I didn't want to reproduce them in full in case there was a copyright issue.

[Bob Unitt 1Participant @bobunitt1]

Posted by Neil Wyatt on 27/11/2014 21:04:16:

Yep, it has to be the halfnut engagement stop.

Neil

Thanks. I wonder how it's supposed to be set …

[John Stevenson 1Participant @johnstevenson1]

Slack it off, close 1/2 nuts and keep pressure on to keep closed.

Then tighten the screw until it just takes over from the hand pressure. This means that it has the slightest clearance.

Job done, off down the pub.

[Bob Unitt 1Participant @bobunitt1]

Posted by John Stevenson on 27/11/2014 22:39:51:

Slack it off, close 1/2 nuts and keep pressure on to keep closed.

Then tighten the screw until it just takes over from the hand pressure. This means that it has the slightest clearance.

Thanks John, enjoy your pint.

[Bob Unitt 1Participant @bobunitt1]

As suggested it controls the clearance on the engaged half-nuts. Someone on another list dug out the S7 manual page for me, and based on John's post and on that page I :-

Unscrewed the Stop-screw.
Engaged the leadscrew nuts.
Put a DTI probe on the Engagement lever.
Wound the Stop-screw up until the DTI indicated movement.
Removed the DTI.
Wound the Stop-screw up a further 1/4-turn.

Thank you all for your replies.

I'll now print this sequence off, along with my pictures, and put it in the manual – for the next time I can't remember what that screw does…

[David JuppParticipant @davidjupp51506]

The drawing for the 254R on Myford site matches the equipment shown better than the 254S drawing.

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