Myford ML7 questions

[drnewcombParticipant @drnewcomb]

Hello, all. I volunteer in the workshop at a large museum here in the US. In the shop we have several lathes, one of which is a nice little Myford ML7, well kitted out with many accessories. It has 3 and 6 jaw chucks, steady rest, collets, live centers, drill chucks and a milling attachment. One thing it does not seem to have is an appropriate oiler for the Lumatic HDFV4/45 fittings. I found that someone had attempted to use a grease gun on these fittings, as if they were Zerk grease nipples. (RTFM!). Can anyone provide some pointers on how to find/make an oiler for this lathe, particularly here in the US, where the ML7 is not all that common.

Also, one accessory this lathe does not have is a quick-change gearbox. I find the instructions in the manual for changing the gears for the lead screw to match a thread pitch to be cryptic at best. Are the gears marked or do you have to count the teeth? I’ve been reluctant to take it apart until I understood the instructions a little better.

Thanks in advance! And please forgive me if this is not the correct forum.

v/r Don Newcomb

P.S. I’m attaching photos of the ML7 and a strange oiler that seems to not quite work for the oil fitting but seems to have come with the ML7.

 

P.

[Robert Atkinson 2Participant @robertatkinson2]

Hi,

Welcome to the forum. If you search on here for myford oiler or oil gun you fill find plenty of information and opinions. The oller you have is typical of those intended for the Myford fittings. IMHO these never worked well. A thin piece of rubber sheet with a small hole in it placed between the gun and fitting helps.

I have a ML7 withou a gearbox and decided to fit an electronic leadscrew instead, Basically a stepper motor, spindle sensor and electronic ratio between them. I chose this one:

Presentation

but there are other product and diy designs.

Robert.

[Nigel Graham 2Participant @nigelgraham2]

Hello and welcome. Yes this the appropriiate place to ask!

 

Your lathe does have proper oilers for the headstock bearings so that is a blessing!

I lubricate the ways on my ML7 by cleaning them thoroughly with paper towels (kitchen wipes), puddling oil on the flat surfaces them winding the slides back over that. Not ideal but it seems to work.

 

I agree the diagram in the handbook is not ever so clear, but you should never need count wheel teeth because the proper change-wheels are marked with their tooth-counts. (As for any lathe with change-wheels rather than gearbox.)

When setting up a compound change-wheel train the two middle gears are connected by the keyed sleeve on the peg on which they revolve together.

The basic principle is [Driven/Driver = TPI/LS]

where the –

Driver and Driven are the tooth-counts of the gearing you need set up,

LS the Leadscrew (8TPI on the Myford)

TPI the turns count of the intended thread. That should never be coarser than the leadscrew, when driven conventionally, to avoid excess stress on the lathe. Even an 8tpi thread is quite heavy work for it.

Some sources quote the algebra the other way round: Driver/Driven, etc..

 

E.g. 60T wheel on the leadscrew / 30T driven by the tumbler gear, with an intervening idler of any convenient size to connect them and maintain the same direction, will give a 2:1 ratio so we now cut a thread of (2 X 8) = 16TPI (Which I see from my tables, is 3/4″ UNF and 3/8″ UNC.)

When you can’t obtain a direct single-stage ratio like that, the idler is replaced by a pair of wheels keyed together, and smaller wheel or a sleeve placed on the leadscrew end to put its wheel into mesh with the output wheel of that intervening pair.

There is, or should be, a table on the inside wall of the change-wheel guard to give the change-wheels for a very wide range of inch, and some metric, pitches with the standard change-wheel set. The latter might be approximations that become difficult over more than perhaps 10 or 20 turns.

 

A tip when setting the change-wheels in mesh. To avoid undue stress and wear they should not be tight together. Put a strip of ordinary, thin printing paper between them as a spacer; hold the assembly together while tightening the banjo screws then manually rotate the lathe to wind the paper out. This gives a clearance of typically 0.003″.

I see your lathe does have its thread dial indicator. That should be put into mesh with the leadscrew only for screw-cutting. Otherwise swing it back a little clear of the screw.

I have a note pinned up behind the lathe to remind me how to use that indicator for given TPI multiples!

….

There may be plenty who will come here advocating replacing change-wheels or gearboxes on even the simplest lathes with electronic leadscrews, but unless your lathe has neither of these it would seem a drastic solution to a simple problem. Unless you spend every day cutting umpteen screws of all sorts of different pitches – or are converting the lathe to CNC operation anyway!

A friend told me he reverted his gearbox-fitted Myford ML7 to change-wheels because it gives him wider range of pitches, particularly allowing metric as well as inch-based ones. He said he does not find it any less convenient to use change-wheels instead of gear-box.

 

 

 

 

[noel shelleyParticipant @noelshelley55608]

Welcome to the party, and yes this is a good place to ask your question. Nigel and Robert have answered well, I have both a gearbox on one machine and change wheels on the other, I have no preference as to which I use. Unless you want to screwcut, all the gears or box do is give a feed rate, which I seldom change. For what even a second hand gearbox costs, unless I was doing a lot of screw cutting I would stick with the change wheels. The wheels are all numbered with their tooth count. The oil gun was notorious for spreading oil everywhere except where you wanted it, I tend to use an ordinary pump feed can and apply oil then work it into where I want it, I bought my machine in 1971 and it’s still working well. Good luck. Noel.

[John HaineParticipant @johnhaine32865]

If you can find Guy Lautard’s Machinists Bedside Reader one of the volumes has  a design for a better oiler IIRC.

[peak4Participant @peak4]

Hello and welcome; I don’t have an ML7, but do use a Super 7 without gearbox and a Warco Super 7B clone with a gearbox.
Note that the US and UK versions of the gearbox are different; can’t remember exactly how now, without looking it up, but it’s related to different pipe threads; ours has a 19tpi option, which I think is different on the US version. The colour of the label on top of the box gives it away.
N.B. There is an earlier version of the box with different drive ratios, as well as after market items, so be sure what you’re viewing.
This site doesn’t easily have a facility for hosting files, but there is an excellent and helpful Facebook group with a fairly comprehensive files section, where you will find several versions of the manual(s), as well as lubrication guides.
There’s also an io group, which is a bit less user friendly, but works well enough, and is effectively a replacement for the now defunct Yahoo group.

Stay around here too as there’s a very broad and friendly knowledge base.

I don’t know how readily available the book is your side of the pond, but Ian Bradley’s book is worth reading (UK Amazon Link)

Re the oil gun, I still use two of the old fashioned push grease/oil guns; mine are Tecalemit, but I’ve replaced the end nozzle on the one I use for oil nipples.
In your case you have the proper ML7 oilers for the 32 weight hydraulic oil for the headstock; I use 68 slideway oil elsewhere.
One dodge is to use a layer of paper towel between the gun and the nipple, which act as a single use gasket.
Replacing the hard nozzle with a nylon one self seals fine without leaking in use.

For the time being, I’d just get used to using the change gears, each of which should be stamped with the number of teeth.

Bill

[Nigel Graham 2Participant @nigelgraham2]

Pipe threads: yes, according to my Tracy Tools chart:

British Standard Pipe has 2 19TPI sizes (1/4 and 3/8″). Why they didn’t use 18 or 20, I can’t imagine!

None of the American thread series use 19TPI; but the smallest NS pipe threads (1/16″ and 1/8″) are of 27TPI. Those are so small that taps and dies are more appropriate than trying to screw-cut them, anyway.

 

[cedric 1Participant @cedric]

You can buy a good oil gun that works and does not leak from pressparts.com

Used on printing presses apparently. Not cheap, but good.

Or you can machine down the tapered brass nozzle on a common flexible spouted oil can so it fits into the tiny hole in the oil fitting . Pump pressure will push oil in past the ball.

 

[peak4Participant @peak4]

Not necessarily off topic for Don, since he lives in the US; The two versions of the later gearbox are shown next to each other in this thread.
UK/EU label red & USA blue.

Myford gearbox confusion

Bill

[John Haine]

On John Haine Said:

If you can find Guy Lautard’s Machinists Bedside Reader one of the volumes has  a design for a better

On John Haine Said:

If you can find Guy Lautard’s Machinists Bedside Reader one of the volumes has  a design for a better oiler IIRC.

You can get the drawings and decription in his $10 pamphlet here http://lautard.com/oiling.htm

On John Haine Said:

If you can find Guy Lautard’s Machinists Bedside Reader one of the volumes has  a design for a better oiler IIRC.

You can still get the drawings and description in his $10 pamphlet here http://lautard.com/oiling.htm

I see on his website that Machinists Bedside Reader Vols 1 and 2 are back in print at $44 each. Get ’em while they last. They were out of print for years and listed used at stupid prices. I’ve never read them but they seem to draw universal praise.

[cedric 1]

On cedric 1 Said:

You can buy a good oil gun that works and does not leak from pressparts.com

Used on printing presses apparently. Not cheap, but good.

Or you can machine down the tapered brass nozzle on a common flexible spouted oil can so it fits into the tiny hole in the oil fitting . Pump pressure will push oil in past the ball.

 

pressparts.co.uk   At £24 presumably plus VAT and postage its pricey but where else will you get a good one?

[Howard LewisParticipant @howardlewis46836]

The objective with screwcutting is to have the correct ratio between the chuck and the Leadscrew.

The Leadscrew usually found on an Imperial 7 Series Myford will be 8 tpi. So factor of, or multiples of, 8 should be easy to set up with changewheels.

Arranging Metric pitches, 19 or 28 tpi may be more difficult and require setting up more complicated compound trains. There will usually be a plate showing the majority of gear trains for a given pitch (TPI)t.

Failing this If it is possible to find them outside UK, books such as “Screwcutting in the Lathe” by Ivan law – No 3 in the Workshop Practice Series, or “Gearing of Lathes for Screwcutting” by Brian Wood will be helpful.

To obtain a fine finish, it is merely necessary to arrange for the Leadscrew to rotate as slowly as possible, relative to the chuck. Extra 20T gears can be useful for this. A ratio of 31.25:1 should result in a feed rate of 0.004″ per rev. (A 20:80/20:80/20:40 train would give 0.00039 per rev, but need and extra stud, if there is enough room on the banjo.)  But a multi stage train may well need the tumbler reverse to be used to ensure that the Saddle moves towards the chuck, if that is a requirement.

The standard Myford oil gun lubricated me, and everything else! So I bought a Reilang, which fitted the ball oilers perfectly.

There are probably others which are as effective in sealing to the oilers.

Howard

[BazyleParticipant @bazyle]

With regards to screwcutting the Myford is a near as anything to a small Atlas or probably Craftsman lathe without a gearbox so any of your fellow volunteers with experience or books etc for these lathes will be applicable. As well as this forum check out the HSM magazine forum and you may find some local contacts.

[drnewcombParticipant @drnewcomb]

My thanks to everyone who replied. Your knowledge is greatly appreciated.

1. I made a mistake in my posting. It’s a 4-jaw chick, not a 6. I could not edit the post before the editing window expired.

2. I was thinking about the Lumatic oil fittings. Has anyone tried fitting a short (e.g. 5 mm) bit of plastic tubing to a 5 or 10 ml plastic syringe? The tubing sized to create a snug fit with the Lumatic nipple.

3. 99% of the work we do is on WWII US equipment. There’s not a lot of Axis (metric) gear to be repaired. The two other functioning lathes are South Bends, larger than the ML7, so it’s good to have a way to cut metric threads, if needed. Altho, I have not made a full inventory of the change gears to see what’s available. The current set up is a very slow lead screw rotation for automatic tool feed.

4. For the life of my I can’t seem to find the search function for this forum.

Thanks again to one and all.

[cedric 1Participant @cedric]

The tooth count of the gears is usually stamped on the side of the gear, near the centre hole. It often gets painted over and hidden.

 

[peak4Participant @peak4]

The search on this site isn’t the best really.
For many purposes it’s best to use an external search engine such as Google, and specify the site within that.
Shown here as a screenshot to save the site resolving the URL and confusing things

There is a site search built in, available in a couple of different places;

Or you can click on a member’s name and have a look at their profile; you may recognise this one.

Bill

[howardbParticipant @howardb]

This is a link to amazon.com for the type of oil gun I use on My Super 7 and ML7.

https://shorturl.at/aImYI

[bernard towersParticipant @bernardtowers37738]

My wanner has a concave hemisphere on the end so it still operates if off at a slight angle.

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