Myford ML7

[25.4_mechanic]

While we are on the subject of Myford:
I am currently looking for a small lathe with a draw and lead spindle, as I want to be able to cut threads in metric and imperial, the more the better.

I can now buy a Myford ML7 with change gears.
I'm sure these things are a dime a dozen with you guys, but they're rarities with us.

I wouldn't mind fixing up a machine myself and making it beautiful again, this one is already pretty nice.

It's a "metric machine", whatever that means, at least adapted for the German-speaking market.

I haven't been to the machine yet, but I don't see any obvious traces of lacquer application in the pictures - apart from the signature, of course: A survivor?

Some accessories are included, as well as operating and set-up instructions ....

Question:
- How many change wheels must be in the accessories for the set to be complete?
I count 15 different gears in the thread table and see nine or ten gears in the picture of the accessories ... but there must also be some in the machine ...

- How much can one spend on this machine?
I know, everything is worth exactly as much as someone is willing to pay for it.
But what is realistic?
I don't think this violates any forum rules, it's not about a trade between participants here, but just estimations.

Thank you in advance for any advice,
Have a nice Sunday all,

Carsten

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[Agroshield]

To the best of my knowledge, Myford never made a true metric machine (i.e. one with topslide, cross-slide and leadscrew in metric). I think the one you show has a standard 8tpi leadscrew - look at the right hand screwcutting chart for 8tpi - it uses 20-anything-20 for a 1:1 ratio.

On the metric chart, it uses 21t for the metric translation gear (it appears in all the threads). This is 1/3 of the commonly-used 63t so the maths should work out.

What it does mean is that if you are cutting metric threads, you will need to keep the half nuts engaged and reverse the machine. Having a three-phase motor makes that easy. Having a screw-on chuck means you need to exercise caution.

Standard Myford change wheels were in multiples of five teeth, from 20 up to either 75 or 80. As they are hugely popular over here, there is a vast amount of information, including handbooks, available online for them. Start at lathes.co.uk Look on vintagemachinery.org Look on the passion-usinages forum. Look on the internet archive for 'Screwcutting in the lathe' by Martin Cleeve.

Random observations: it has no clutch. The spindle bore is tiny on a Myford. It appears to be a model in between an ML7 and a Super 7 - Super 7 halfnut lever, ML7 tailstock, Super 7 dials on slides, ML7 to-slide.

 

[25.4_mechanic]

To the best of my knowledge,

That sounded like a lot of knowledge on the subject. Thanks!

Yes, I can see in some of the pictures of the manual that it is still an 8TPI leadscrew - hence my

"metric machine", whatever that means

The different model characteristics would otherwise worry me, but maybe they put it together like that for export - that it could have been assembled from different scrap machines can be ruled out I think, where should mainland hobbyists have turned?

I can say goodbye to the nice but unimportant circumstance of finding a machine from one's own birth year, it would have had the more open tailstock. (I had already found lathes.co.uk)

Hmmm, threading without a clutch, I'll have to think about that first - sounds like a lot of failed attempts and headaches ....

Hope to hear some more on value finding, now I'm off to follow the links I didn't know about - maybe something will turn up ...

Many thanks for now!

Carsten

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[25.4_mechanic]

What it does mean is that if you are cutting metric threads, you will need to keep the half nuts engaged and reverse the machine. Having a three-phase motor makes that easy. Having a screw-on chuck means you need to exercise caution.

What does that mean exactly?
Low rotation speed? Sure, I'll do it that way.

Low cutting feed? Okay, be patient.
How else should I be careful?

Surely the chuck or flange has an anti-rotation lock?!?? (Don't know the correct term in English).

Can you please describe in more detail the caution needed when reversing direction under that specific circumistance? Thank you very much!

Carsten

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[Screwdriver]

What does that mean exactly?
Low rotation speed? Sure, I'll do it that way.

Low cutting feed? Okay, be patient.
How else should I be careful?

Surely the chuck or flange has an anti-rotation lock?!?? (Don't know the correct term in English).

Can you please describe in more detail the caution needed when reversing direction under that specific circumistance? Thank you very much!

Carsten

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I think the idea is not to slam it into reverse while the chuck is still spinning forwards. Just wait for it to slow to a stop.
NB it is perfectly ok to do that with a 3ph motor, just not with a screw on chuck. It won't have a lock.

 

[Pete.]

Graham Meek has designed a single tooth dog clutch for the Myford 7 which would allow cutting any pitch thread by disngaging the leadscrew and no need for any kind of threading dial.

 

[25.4_mechanic]

It appears to be a model in between an ML7 and a Super 7 - Super 7 halfnut lever, ML7 tailstock, Super 7 dials on slides, ML7 to-slide.

I have just received the serial number >K122119M< - according to it, it belongs to the younger listed here http://www.lathes.co.uk/myford-ml7/page2.html from 1974 to 77.

Could this explain that the factory had collected parts for machines for export - and even more for the Krauts - whatever was lying around and which they did not want to offer to the domestic public in this combination?

I think the idea is not to slam it into reverse while the chuck is still spinning forwards. Just wait for it to slow to a stop.
NB it is perfectly ok to do that with a 3ph motor, just not with a screw on chuck. It won't have a lock.

Ok, so you just have to have your brain with you and switch it on occasionally?
That should be possible, it doesn't take that long ...
Thanks, had me worried already.

Graham Meek has designed a single tooth dog clutch for the Myford 7 which would allow cutting any pitch thread by disngaging the leadscrew and no need for any kind of threading dial.

Will have a look for it. Thanks


Carsten

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[minimutly]

The ml7 I sold with a 3 phase motor and inverter did this beautifully, just flick the switch - it slowed, stopped, reversed - would have been nice to cut a thread with it. I guess, if you were creative, you could put a momentary switch on the bed - auto reverse at the end of the cut...

 

[Agroshield]

Could this explain that the factory had collected parts for machines for export...

Maybe. You can think of it as an ML7 with go-faster stripes on it (like the coloured grille bars in your cars). The one I was trying to describe earlier was the ML7-R (I had forgotten the model name at that point), but it is not that, as the photos from the lathes site show.

Manual here: http://www.small-lathes.co.uk/Files/1.388149MyfordML7Manual.pdf says 2x20t gears and one each 'by fives' to 75. Confirm it has the necessary 21t gear for your metric threads (and paint it so you do not confuse it with the 20t gears). Keep an eye out for a 12t/25t double gear. That is for the fine (turning) feeds and is useful to have.

If you do buy it, a useful book is this one: https://www.amazon.co.uk/Myford-Lathe-Manual-ML7-R-Super/dp/0852427751/

 

[25.4_mechanic]

Manual here: http://www.small-lathes.co.uk/Files/1.388149MyfordML7Manual.pdf says 2x20t gears and one each 'by fives' to 75.

Great to have the instructions in advance. Thanks for that, I hadn't found it yet.

Confirm it has the necessary 21t gear for your metric threads (and paint it so you do not confuse it with the 20t gears). Keep an eye out for a 12t/25t double gear. That is for the fine (turning) feeds and is useful to have.

I pulled up the pictures of the machine large, marked a tooth number 1 and counted what the pixels allowed:

I did the same with the "gear side" and am now a bit confused (the recognizability was also a bit worse here):

The unoccupied No2Stud may simply mean that the lead screw should not be driven the last time this machine ran, but in the wheel set I see only the 20t/55t wheel fit ...

I haven't quite figured out the two 65t wheels in the accessory kit either.


What are we dealing with here?

Thank you very much,

Carsten

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[25.4_mechanic]

The ml7 I sold with a 3 phase motor and inverter did this beautifully, just flick the switch - it slowed, stopped, reversed - would have been nice to cut a thread with it. I guess, if you were creative, you could put a momentary switch on the bed - auto reverse at the end of the cut...

That's good to read. Thank you!

Carsten

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[gaz1]

you would be lost with my gearbox

myford ml7 homemade gearbox

this is the gearbox to the lathe photos only and diagram to it in a seperate forum post

www.mig-welding.co.uk

 

[25.4_mechanic]

you would be lost with my gearbox

myford ml7 homemade gearbox

this is the gearbox to the lathe photos only and diagram to it in a seperate forum post

www.mig-welding.co.uk

Oh why, it's all logical and clearly laid out. By the way, congratulations on the project!


My problem is rather that I do not know the story behind the machine and will not get it out ("... also do not know what my father did at that time ..."), the composition of the existing gears seems unusual and this against the background that here was already stated, the machine seems to have been assembled from components of different development stages / models ...


Carsten

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[Agroshield]

Everything above what you have marked as 45t on the machine is fixed (cannot be altered). Behind the 45t one is a 25t one, which meshes with the tumbler gears. You do not (it is not necessary to) count this as part of the screwcutting setup. The 25t on the spindle drives it at 1:1 ratio via either one or both of the tumbler gears - all they do is reverse the direction depending on whether one or both are used (and the tumbler gears can be set in the middle to neutral for no drive to the geartrain - this is how it is set in the photo). To set it for fine feeds, you pull off the 45/25 and put on the 12/25 mentioned above so the 12t is the first driver in the train (so you would get feeds 60% of those shown bottom right on the screwcutting plate).

The 46 can be useful for cutting US pipe threads, which are 11 1/2 tpi. For standard UK and Europe pipe threads, where 19tpi is used, you would need a 38t gear. It looks like you are missing 25, 40 and 60. The 60 is sometimes misplaced as it makes a good gear for an indexer. Myford gears are easy to find over here, either new or used.

I would not read too much into how it is currently set up. Even if we assume the 55/20 goes on the empty stud, that gives a ratio of 27/253 from spindle to leadscrew, approx. 75tpi or 0.013" 0.34mm pitch

I would not fret too much about the parts it is made of. What you have is an improvement over standard. The later dials were resettable, whereas the earlier ones were not.

 

[25.4_mechanic]

I would not read too much into how it is currently set up. Even if we assume the 55/20 goes on the empty stud, that gives a ratio of 27/253 from spindle to leadscrew, approx. 75tpi or 0.013" 0.34mm pitch

I would not fret too much about the parts it is made of. What you have is an improvement over standard. The later dials were resettable, whereas the earlier ones were not.

Thank you, you give me courage.

Everything above what you have marked as 45t on the machine

I'm a little unsure about the gear on the TumblerClusterGear, you can't see it very well, but I think it's 45t.
However, the gear on the 1stStud is definitely a 46t - that seemed so strange to me that I recounted it x times and you can actually see it quite well.

I don't know if I'm misunderstanding the instructions from your link, but the gear on the TumblerClusterGear seems to belong to the so-called setup, see (the instructions are no longer subject to copyright, as far as I understand it):

2ndSpindleGear and TumblerReverseGears are certainly not touched unless absolutely necessary, but what follows seems to become configurable ...

So the 45t on the TumblerClusterGear could be called Setup_1 and the following 46t on 1stStud speaks for - and only for - the use for cutting a metric thread with a pitch of 0.45mm, which is actually needed exclusively for M2.5 - However, the rest of the setting does not quite match this..

Here I assume that TumblerClusterGear is what is called Driver in the tables ... any other ideas here?

Thank you,

Carsten

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[25.4_mechanic]

I had told the seller - in whose former parents' house the machine is located - that I would of course still try out the machine and that he should therefore not dismantle it.
What just came back is pretty much the biggest poppycock I've heard in a long time:

"The machine is still assembled in the basement, but the house where the machine is located has changed hands. This would actually be unproblematic, unfortunately, the new owner has changed the electrical installation so three-phase current is no longer available. At the beginning of the year when I still had three-phase current, it was still running. "

I think that the machine is dead to me, also because it would have meant a 550km drive ... And then not been able to try it out ...

Or what do you think?

Carsten

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[Pete.]

I had told the seller - in whose former parents' house the machine is located - that I would of course still try out the machine and that he should therefore not dismantle it.
What just came back is pretty much the biggest poppycock I've heard in a long time:

"The machine is still assembled in the basement, but the house where the machine is located has changed hands. This would actually be unproblematic, unfortunately, the new owner has changed the electrical installation so three-phase current is no longer available. At the beginning of the year when I still had three-phase current, it was still running. "

I think that the machine is dead to me, also because it would have meant a 550km drive ... And then not been able to try it out ...

Or what do you think?

Carsten

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That just means you MAY need another motor. No big deal it's the easiest thing to fix on a lathe.

Get some photos in good lighting. A good front-on pic showing it nd to end and close up of the slides and bedway, and all the loose bits like chucks. The condition will soon become apparent.

 

[Screwdriver]

I think that sounds plausible.

Take a little 3ph inverter with you?

Or maybe just threaten to do that and see what he says...

 

[Agroshield]

OK. Where to start? In Fig. 35 above, the gear labelled 4 is the same one you have identified higher up as 45t. In Fig. 35, you can see the 25t gear behind the smaller gear that is labelled 4. The gear labelled 4 can be removed from the holder it has in common with the 25t one behind it. You are correct that it is always called 'driver' in all the tables.

The three diagrams to the right of Fig. 35. are showing:

(1) A driver 2 (call it A) with an idler gear 7 and a leadscrew gear 4 (call it B). So the gear ratio in (1) is A/B. What is labelled 2 in diagram 1 is labelled 4 in Fig 35. For homework, work out what pitch would be cut if A=40 and B=127.

(2) The way the diagram is numbered is not great. The same driver- not labelled, so we can stick with (A) - drives what is labelled as 3 (let's call it B). B is fixed to gear 5 (call it C). C drives an idler (8) which drives the leadscrew (not labelled, call it D). So the gear ratio is A/B x C/D. Gear 1 is a spacer, behind gear 8 and does not mesh with anything.

(3) This is the same set-up as Fig. 35. Starting at the top, we can go A, B, C, D (D is labelled 3). 2 is behind 3 and we can call it E. The gear on the leadscrew is F. So the overall ratio is A/B x C/D x E/F.

Notice with all three set ups the relative position of the gears with respect to the body of the lathe. In 1 and 3, the leadscrew gear is tight to the body of the machine. In 2, it has moved to the left and has a spacer to its right.

46t is NOT used for 0.45mm. That is just a poorly scanned diagram. You can prove this to yourself if you look at the gears for 0.9mm and 1.8mm. The three pitches are multiples of each other so the gears used have to bear the same relationships to each other. Alternatively, if the 46t was needed for 0.45mm pitch, it would also be needed for 0.9mm and 1.8mm.

 

[Maker]

I had told the seller - in whose former parents' house the machine is located - that I would of course still try out the machine and that he should therefore not dismantle it.
What just came back is pretty much the biggest poppycock I've heard in a long time:

"The machine is still assembled in the basement, but the house where the machine is located has changed hands. This would actually be unproblematic, unfortunately, the new owner has changed the electrical installation so three-phase current is no longer available. At the beginning of the year when I still had three-phase current, it was still running. "

I think that the machine is dead to me, also because it would have meant a 550km drive ... And then not been able to try it out ...

Or what do you think?

Carsten

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It doesn't sound unreasonable that new owners would have three phase disconnected, there's probably three times the standing charge on a three phase meter, there might be an inflated rate on an imbalanced load on a three phase supply compared to single phase too.

The bigger red flag in my eyes is the house has changed hands, what's to stop the new owners saying "No that's my lathe it came with the house". I certainly wouldn't want a stranger in steel toes dragging machine tools through my house.