ML7 Leadscrews/nuts Still Available?

[Dr_GMJNParticipant @dr_gmjn]

All, I’ve been looking to improve the overall ‘feel’ of my ML7. there’s a fair amount of backlash in my top and cross slide lead screws.

Are they available anywhere at present?

Revently fitted the Arc thrust bearings and some re-settable dials; they need to be imperial.

Thanks.

[Dr_GMJNParticipant @dr_gmjn]

[Michael GilliganParticipant @michaelgilligan61133]

This might help you identify the specific parts that you are seeking: **LINK**

https://www.myford.co.uk/acatalog/info%2d3556%2ehtml

Note: I was more than a little surprised to see that ‘Myford’ is now offering certain unfinished castings for sale:

**LINK** : https://www.myford.co.uk/acatalog/Shop-Soiled-Items.html

MichaelG.

[Oily RagParticipant @oilyrag]

Posted by Michael Gilligan on 13/02/2021 11:12:40:

Note: I was more than a little surprised to see that ‘Myford’ is now offering certain unfinished castings for sale:

**LINK** : https://www.myford.co.uk/acatalog/Shop-Soiled-Items.html

 

MichaelG.

 

HaHaHa … latest method of competing with the Charlees!

Edited By Oily Rag on 13/02/2021 11:27:28

[Dr_GMJNParticipant @dr_gmjn]

Parts 10, 25 and 16 – Leadscrews and Nuts.

[Dr_GMJNParticipant @dr_gmjn]

Is there a method of slitting the nuts and loading them with a screw (like on the SX2P Mill)?

[BazyleParticipant @bazyle]

The link to parts could be useful. I have a non-Myford lathe topslide retrofitted at some time with the Myford feednut and dial.

The extended cross slide endplates could be an interesting upgrade for other lathes. But no drawings or dimensions provided. I wonder if owners of both ML7 and ML10 could oblige with dimensions of the mounting hole spacing and relative position of the feedscrew hole.

[Michael GilliganParticipant @michaelgilligan61133]

Those of an inquisitive nature might be interested to know that there are NSNs for some Myford parts:

… and these can be located by searching for the Myford part number

Example: **LINK**

https://www.nsncenter.com/NSN/3416-99-445-1924

… It might be amusing [or even useful] to compile a list for forthcoming MOD auctions

MichaelG.

[SteviegtrParticipant @steviegtr]

Ebay No 143946170355 says more than 10 available.

Steve.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Steviegtr on 13/02/2021 17:53:43:

Ebay No 143946170355 says more than 10 available.

Steve.

.

Interesting … it’s ‘unbranded’ and ‘made from brass’ but listed with a Myford part number

MichaelG.

[Ex contributorParticipant @mgnbuk]

Interesting … it’s ‘unbranded’ and ‘made from brass’ but listed with a Myford part number

Struck me as a bit odd as well, Michael – the new cross slide nut I bought from the spares counter at Beeston for my Super 7 was a Mazak die casting, same as the worn one that I took out.

And "Myford" show that part number for the Super 7 in their listing – no mention of it being applicable to the ML 7 as well.

Nigel B.

[SteviegtrParticipant @steviegtr]

Just had another look Only has feedback points as a buyer but zero as a seller. Maybe home made items.

Steve.

[noel shelleyParticipant @noelshelley55608]

Are they mazak or could they be white metal? Noel.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by noel shelley on 13/02/2021 18:56:31:

Are they mazak or could they be white metal? Noel.

.

To the best of my knowledge, Noel … the originals are mazak [or zamak] die castings.

Happy to be proved wrong if anyone can provide evidence.

MichaelG.

.

Ref. https://en.wikipedia.org/wiki/Zamak

Edited By Michael Gilligan on 13/02/2021 19:37:38

[A SmithParticipant @asmith78105]

The originals are of a hard whitemetal, a fair bit of zinc, at a guess. ML7 lead screws come in two diameters, 5/8" & 3/4". Best to get the right ones…………..

Andy

[Dr_GMJNParticipant @dr_gmjn]

Someone on the Myford FB page has offered to send me a pair from the next batch he makes out of Phosphor bronze, silver soldered to a brass flange. Worth a try.

[noel shelleyParticipant @noelshelley55608]

The OP says topslide and crossslide screws – I think. PB may be rather hard.

[HopperParticipant @hopper]

Posted by noel shelley on 13/02/2021 23:19:25:

The OP says topslide and crossslide screws – I think. PB may be rather hard.

Yes indeed. Phosphor bronze will prematurely wear the non-hardened feedscrew. That is why Myford and many other lathe manufacturers used brass or Mazak (zinc-aluminium alloy) for half nuts and feedscrew nuts. The nuts are sacrificial: they wear out but do not wear the feed screw as much as a harder material would. I make my own halfnuts and feed nuts/inserts from brass. They will outlast me at this stage of the game.

Myford and some private sellers still sell the brass feedscrew nuts on their site and on eBay. Search for "Myford feed nut" and "Myford feedscrew" to find them. Leadscrew generally refers to the big 'un along the bed only. EG: FEED NUT

You should be able to measure the amount of wear on the screw's thread itself with a dial indicator showing the slice movement back and forth at different points on the screw engagment with the nut. Usually the ends are pretty much unworn so compare that reading with the area engages in the common operating position. Myford still sells the complete feedscrew with nut kits if needed.

Not sure about Myford's stock/availability in time of plague though. But at the end of the day, unless the nuts are totally worn out, they will not affect the performance of your lathe. The slack is taken up by cutting forces as soon as the tool engages. You just have to remember to turn the dial past the point of backlash if resetting a cut etc. Standard turning procedure anyway.

Or you could buy a length of Acme threaded rod of suitable size and machine the ends to suit. UK suppliers have been mentioned in previous threads on here.

 

 

 

Edited By Hopper on 14/02/2021 09:02:07

Edited By Hopper on 14/02/2021 09:13:54

[Dr_GMJNParticipant @dr_gmjn]

Thanks Hopper – I’ll pass on your comments and see if they can be made in brass instead.

Its not that I’m particularly worried about It wobbling about during cutting, more that I want it to ‘feel’ better when turning the screws.

[HopperParticipant @hopper]

LOL. You might end up arguing religion with the nut maker on that one.

[Dr_GMJNParticipant @dr_gmjn]

Posted by Hopper on 14/02/2021 09:32:42:

LOL. You might end up arguing religion with the nut maker on that one.

Ha ha correct! starter for 10: which composition of brass do you mean?

Anyway, excessive wear caused by whatever material I end up with will probably be someone else’s problem by the time it becomes an issue!

Cheers!

[Peter Low 4Participant @peterlow4]

As my cross slide nut has some play in it, i've been following this thread. Unfortunately nobody seems to be selling these to suit an ML7 with imperial thread. (except Myford listing nut & screw sets at fairy tale prices).

So the brass nut listed on ebay mentioned above (143946170355) seemed my only option, though I also noted the lack of feedback on it etc. Reckoning that if its an obviously bad fit, I can send it back, and if it wears prematurely, well it will have been nicer to work with for a while, than the present set up.

So I ordered one and it arrived today and it fits and seems Ok. The scew action is a little stiff but I'm hoping this will be as i, running in a stiff engine. I will post again if it wears too quicly, though I'm not using the lathe every day, it may take a while.

[Ex contributorParticipant @mgnbuk]

(except Myford listing nut & screw sets at fairy tale prices).

Myford's "fairy tale prices" are Ebay placeholders for items that they don't currently have in stock – apparently it is preferable to keep a listing showing when you don't have stock but place a price on the item that disuades orders being placed than remove the listing. When the item becomes available agin, the price is changed to suit.

I sent a message to Myford asking when the ML7 screws & nuts would be available again & got the following reply :

"Unfortunately we have no confirmed date at the moment. I'd suggest trying us in 6-8 weeks time if you still want one."

So it would appear that replacement stock of these items is in hand, just have to be patient.

Nigel B.

[Martin DowingParticipant @martindowing58466]

Leadscrew you can buy from McMaster Carr (LH, 5/8 inch).

You can buy 3 feet section.

Feedscrews you can turn yourself. Do it from 40-45 HRc rod and they can work with phosphor bronze.

ACME taps Chinese are selling cheap so nut is not a problem.

ACME nuts together with section of screw they also sell. They are cheaper than p&p alone from most of Western dealers.

You may adapt Chinese ACME screw by turning and threading ends and brazing thrust collar.

Leadscrew half nuts are best poured out of white metal.. Use secttion of leadsrcew as a form.

You will need to process ends though albeit it gives you good opportunity o install shear pins as gearbox protection.

Martin

[HopperParticipant @hopper]

Posted by Peter Low 4 on 19/02/2021 16:16:34:

As my cross slide nut has some play in it, i've been following this thread. Unfortunately nobody seems to be selling these to suit an ML7 with imperial thread. (except Myford listing nut & screw sets at fairy tale prices).

So the brass nut listed on ebay mentioned above (143946170355) seemed my only option, though I also noted the lack of feedback on it etc. Reckoning that if its an obviously bad fit, I can send it back, and if it wears prematurely, well it will have been nicer to work with for a while, than the present set up.

So I ordered one and it arrived today and it fits and seems Ok. The scew action is a little stiff but I'm hoping this will be as i, running in a stiff engine. I will post again if it wears too quicly, though I'm not using the lathe every day, it may take a while.

Probably 20 years or so. Most original half and feed nuts were brass or even the softer Mazak zinc-aluminium alloy for a reason. So they don't wear the non-hardened feed screw.

This gives greater accuracy as the parts wear. A worn nut will still track accurately, just with a bit more slop which is not particularly important. As long as it engages with the screw, it will follow the screw thread faithfully.

But a worn feed screw or lead screw has a slightly varying pitch between the worn section and the unworn section. So turning the cross slide dial say 100 thou on the graduations could result in only 90-something thou of movement of the cross slide.

So better to use brass nuts and preserve that feedscrew thread for best accuracy.

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