Early Myford Super 7 (1953) Spindle lubrication

[Dave TParticipant @davet19446]

Hi All,

I own the above, which has an oil reservoir cast into the headstock. The sight glass/oil windows is irreparable, and significantly rarer than unicorn teeth, i.e completely unobtainable. Do you think it's feasible to add a drip oiler into the lid of the reservoir and control the lube feed from there? It would be easy to mill up a new lid and add an oiler, but I want to know that it has a reasonable chance of working!

Cheers

Dave

[Dave TParticipant @davet19446]

[Brian WoodParticipant @brianwood45127]

Hello Dave,

One thought—-are you able machine a replica window in perspex, plexiglass if from over the pond? It would look neat.

Failing that, your plan will work, I can see no reason why not

Regards Brian.

[TomfileryParticipant @tomfilery]

Dave,

I replaced mine with a watch glass (crystal for a wrist watch) bought from eBay. Sorry, I can’t remember what diameter I actually bought, but they were available in increments of 0.1mm and it wasn’t expensive.

Regards Tom

[Dave TParticipant @davet19446]

The watch glass and aluminium ring disappeared due to the white plastic body disintegrating – I either need the full assy. or an alternative such as I suggested – When I have a working lathe, I can spin up a plug (or 3D print one) to blank the orifice.

[noel shelleyParticipant @noelshelley55608]

I would be tempted to machine up one in perspex and after careful cleaning with a solvent stick it in place with CT1, abit like silicon but 10 times better. Noel.

[Simon Williams 3Participant @simonwilliams3]

As a fellow owner of a S7 of the same vintage, I gave up filling the reservoir with oil a long time ago. I never remembered to turn off the oil drip when locking up for the night, so the oil arrived in a puddle in the drip tray by the morning. I give mine an occasional squirt from the oil can when I remember.

I recently took the spindle out to rescue the back gear (yes, I've broken a tooth, on an interrupted cut). There is no evidence of wear or scoring or whatever evidence of oil starvation.

Still it could be premature over-confidence, I've only had the lathe since 1974, and it had a hard life in its previous incarnation in a boys technical school. I doubt it got oiled much there either.

If you want to use the lathe to make a new oiler window, a token drip or two of oil into the front bearing before you start should suffice.

Keep calm and carry on.

Simon

[DMRParticipant @dmr]

Hi Dave,

I am with Simon Williams 3 on this. You do not need a continuous oil feed and, above all your window arrangement is not irrepairable. I have an S7 of both designs. My early machine has no cone scoring whereas the later machine does, presumably from the felt pad running dry in the past.

What you do need to do is get the tap (as Myford called it) out upwards so that you can push your new white casing into place. That is a bit of a frightening exercise as it is a push-fit. Just oil the hole in the back of the sight glass and even put a spot on top of the cone where it sticks out at the front and you will be good to run for a few hours. You need a piece of nylon rod or similar to turn up a new white bit and put a fine thread on the front/outer end. Trickiest bit is the screw-on front with its short fine thread. The fibre washer is easy and I have spare glass as I made 3 from a microscope side when I broke mine.

See my PM and I can talk you through it if you are interested.

Dennis

[Dave TParticipant @davet19446]

Posted by DMR on 15/05/2022 22:09:22:

Hi Dave,

I am with Simon Williams 3 on this. You do not need a continuous oil feed and, above all your window arrangement is not irrepairable. I have an S7 of both designs. My early machine has no cone scoring whereas the later machine does, presumably from the felt pad running dry in the past.

What you do need to do is get the tap (as Myford called it) out upwards so that you can push your new white casing into place. That is a bit of a frightening exercise as it is a push-fit. Just oil the hole in the back of the sight glass and even put a spot on top of the cone where it sticks out at the front and you will be good to run for a few hours. You need a piece of nylon rod or similar to turn up a new white bit and put a fine thread on the front/outer end. Trickiest bit is the screw-on front with its short fine thread. The fibre washer is easy and I have spare glass as I made 3 from a microscope side when I broke mine.

See my PM and I can talk you through it if you are interested.

Dennis

Hi Dennis,

I extracted the tap a while ago, to remove the remains of the white casing. My problem is that new white casings are impossible to obtain – maybe if I had a lathe I could make one! I would probably make one out of brass if I had the talent and a lathe that worked

[thomas oliver 2Participant @thomasoliver2]

I once had a Myford ML7 and it used up the oil supply about every weekv. I changed to EP90 back axle oil and found that it only needed a drip every few weeks after that. I used the lathe for five years with no ill effects. T.O

[Simon Williams 3Participant @simonwilliams3]

Just a cautionary note with respect to using gear oil. For the purposes of this discussion there are two grades of EP90, differing only in the additives used in blending the oil. EP90/GL4 is compatible with bronze – as per the front tapered bearing – but EP90/GL5 is not. It rots the bronze. Or at least it can't be used in vintage gearboxes with bronze synchromesh rings, so its reasonable to suppose that it would do the same to the front spindle bearing on an S7.

No doubt the forum can explain further.

Rgds Simon

Edited for silly typo

Edited By Simon Williams 3 on 16/05/2022 23:33:37

[noel shelleyParticipant @noelshelley55608]

The ML 7 has a white metal front bearing so the EP90/ bronze issue does not apply ! Not only that but it is a completely different design/ type of bearing. To use an SAE 90 oil would be ask for trouble it is WAY to thick compared to the maker recommended SAE 10, 5L of SAE 10 about £20, new bronze headstock bearing in these troubled times, a small fortune ! Noel.

[SillyOldDufferModerator @sillyoldduffer]

The ML7 is fitted with plain bearings, which have advantages and disadvantages. They're cheap and easy to make, and they were a good way keeping vibration low compared with the inferior ball-bearings of the day, which tended to brinell due to the difficulty of making perfect spheres and rollers. The brinell problem was cracked during the 1930's but didn't become generally available due to trade secrets and patents until after WW2. The main disadvantages of plain bearings are all related to lubrication difficulties. When the bearing is stopped, there's metal to metal contact, which causes severe wear and high start friction until the oil pressure builds up enough for the bearing to float in it. It's essential to have enough oil in the system for the bearing to float, otherwise a bearing that should last 40 years has to be replaced prematurely.

How quickly wear kills a bearing depends on the load, speed, and number of stop-starts. It's not a fast process, making it easy for owners to assume their oil regime is OK, when it's not. Wear caused by previous neglect and/or hard work is probably the cause of high oil-consumption : the gap is big enough to leak when the lathe is stopped and a lot of oil is needed to pressurise the bearing when turning.

The most important goal is to ensure there's enough oil in the system. Any oil is better than nothing, but the manufacturers recommendation is best. The viscosity matters most – too thin will flow rapidly through the system and make it hard to reach operating pressure; too thick means not enough oil will be available to reach operating pressure. The feed system matters:

• Large plain bearings are pressure fed oil from a pump
• Small bearings can be drip fed, or filtered through a felt pad, or syphoned in.

For cheapness, Myford used a simple drip system – not scientifically accurate, but completely adequate provided the owner remembers to turn the tap on and off between sessions, and puts a reasonable type of oil in.

I don't see any point in using EP90 on a Myford. It's an 'Extreme Pressure' oil, formulated to survive the hot mincing action of a gear-box transmitting significant power. EP oil is modified and contains additives, one of which attacks Copper. Mustn't be used on Brass or Bronze. Not ideal for the slow, cool, plain bearing on a Myford lathe, and might be harmful in the long run.

Noel mentions SAE 10 which sounds right to me. And if the bearing is leaky due to wear, I think more oil is needed, not restricting the flow to save a few quid!

Owning an older lathe means it's going to need repairs; when a bearing is done for, don't fiddle with the oil, replace the bearing! I don't suppose Myford expected their lathes to still be in perfect running order 70 years after coming out of the factory.

Dave

Edited By SillyOldDuffer on 17/05/2022 11:14:49

[noel shelleyParticipant @noelshelley55608]

There is often cofusion about oil numbers, but in round figures SAE 10 is ISO 32, this is the number that Myford use NUTTO 32..Noel.

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