lubricating lathes

Despite using Castrol GTX for 20 years without changing it in my lathe headstock (it did go black though), it is said that engine oils contain a detergent that hold particles in suspension, so they can be dumped at the next oil change. Which most of us do not do.

When you look at the power density of a modern gear box, many push 100 HP + through lathe headstock sized gears and that the fluid last for 10 years + and multiple materials used in a gear box, these would seem to be a good candidate for use in lathes. Or just stick to a ISO 68 straight oil.

And stick a magnet in the bottom of your head stock, it might attract iron particles.

Frank

I fail to understand why people use engine oil for general lubrication of a lathe when they can buy iso 32 hydraulic oil instead. Personally though I find the best thing for slide ways is slide way oil. Little is needed and it hangs around for some time and doesn't absorbing moisture from the air or gum up like most automotive oils do. In fact I wish I could get the next grade up in small quantaties which is suitable for vertical surfaces. Automotive oils are designed to run hot for long periods. They also have all sorts of additives in them. It's also well know in some circles that if these oils are changed at say twice the recommended interval things might never wear out. They aren't as great as some might think. They did get well ahead of engine etc technology for a while but those days have gone.

Real gearhead lathes generally use hardened and ground gears. It's easy to see when a lathe has these or even by ear. I'm not at all sure what I would use to lubricate typical Chinese use of gears in small lathes and millers but I would like the sludge worn from the gears to settle at the bottom rather than circulate and grind the gears down further. I'm inclined to use grease on the back gears of my boxford and oil on change wheels and gearbox etc. I have been a bit naughty on change wheels I should use ISO 32 but use a GP oil.

I've not looked at Chinese lathe ball/roller bearings but suspect just as when the Koreans were the source of smaller lathes that some wont be hardened. From memory ArcEuro have some pages on changing NVG bearings. I've used molyslip grease on bearings for some time. My lathes have been relatively low speed in terms of what typical greases can handle. Of late because it's available I use a high speed one that ArcEuro sell. Believe it or not it will extend life. It's important to not add too much grease of any sort to bearings of this type.

Plain bearings - Myford etc really do need to use the right lubricant if they are to last. I'd hazard a guess that ISO 32 hydraulic oil meets the spec for these as well - a highly refined mineral oil.

John

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Looking at the original post - it's a Chester Conquest.. Although there are no holes the headstock is not sealed to the bed, so the gears inside should be greased not oiled, same for the spindle bearings, apron gears, halfnut slides (as inaccessible for oiling). On my similar machine I use Finish Line Teflon Grease for all except the bearings which get moly-grease in modest amounts. Layshaft bearings are sealed for life units.

For everything else (leadscrew bearings, leadscrew, slides, bed, gears), I'm afraid I use a surplus of neat cutting oil, brushed on if things start to look dry, although a bit of teflon grease works wonders on nylon gears (e.g. the change gears). I can't detect any wear after 16/17 years of moderate (ab)use.

Neil

I don't think I would use my cutting oil Neil. It tends to collapse bottles it's left in and go down all on it's own. I just smear some on work at times. I cured the disappearing oil by putting in a sealed jam jar with a test tube strapped to the side. I just take a few gollops out of the bottle and drip it into the test tube. The test tube also serves to hold the brush I use.

The cutting oil came mail order from Morris Lubricants. 5lt which should last me for ever. Good but not as good as the thicker stuff that used to be used on auto's where splash got on peoples overalls and gave the testicle cancer and dermatitis elsewhere - there is a message there about using oils intended for other purposes. The stink of some automotive stuff is enough to put me off anyway..

I'm afraid I usually run the change wheels to the gearbox dry. I have been meaning to take the cover of the gearbox and use moly grease on the gears for about 13 odd years since I bough the lathe. I have put a touch of cycle oil on them at times - all wrong and have wondered about using chain lubricants maybe waxy types on the change wheels. Boxfords have a separate feed drive so the lead screw doesn't receive much attention or need it really as I don't screw cut all that often. I just make sure it's clean. Rags usually have some oil or the other on them.

John

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When the RNZAF had Hastings C Mk3 aircraft they found out what happens if you mix oils, The Mk3 used detergent oil, but when passing through Singapore, stopped at RAF Changi, where the RAF ground crew topped up the engines with the same non-detergent oil as used on the RAF Mk1 & 2. On take off the oil foamed, and blew out of the engines, one Hastings stops flying Ooops.

I use plain 30 grade, it's sold here mainly for 4st lawn mowers etc.

Ian S C

A couple of years ago I checked my trailer hubs,similar size to mini hubs, and the bearings looked a bit dry i had been using Castrol moly grease, had look on the tub and it states that moly grease should not be used for auto wheel bearings. I do not remember this warning when Castrol used tins before the plastic tubs. I had a think about my previous comment on straight thirty making the slides stiffer,I suppose its because the multigrade iI normally use is lower viscosity. I use 32 hydraulic oil on both my Colchesters,as thats the specified oil and is in use for a long time in the gearboxes/headstock. I cannot why there is objection to using good multigrade oil for Myford bearings, the lubrication system is total loss so the bearing gets a constant feed of fresh oil,if there is any debris in the oil it goes to waste and does not recirculate.Automotive and motorcycle gearboxes of the 1960s tended to use motor grade oils,and minis and others used the engine oil to lubricate the gearbox,our lathe headstocks are a similar technology to those days so multigrades should be ok,there used to be a saying any oil (except EP) is better than no oil. There has been a trend to using thinner oils in gearboxes as speeds increased. From 1950 to 1960 the gear box oil on villiers motor cycle engines changed from sae 140 Castrol D ,to 90 and then to 30 ,

I read recently that Moly grease doesn't create enough friction to make the rollers roll in taper bearings so they wear prematurely.

Steve

There is a lot of anti on moly grease and oil additives from the motor industry in particular. This didn't stop Ford from using the grease when they noticed parts were not getting through warantee. There has also been claims about poisoning engine sensors when a typical engine hardly had any at all. Could be true these days but some how I doubt it. I will always remember a test the AA did on a mini a long time ago. Treated engine so emptied the oil out and then drove it a considerable distance considering that it was like that. Stripped the lot and only found signs of slight overheating. Might be folk law but I doubt it. I stripped an engine that had done over 100,000 miles that had always used it on every oil change - no signs at all of any wear on any crankshaft associated bearings and sub 0.002in on the bores. 6 cylinders and it ran fairly well for 2 days with with one cylinder not firing - bang and a hole in the piston which blew all of the oil out of the exhaust. I didn't realise until I checked and filled it up - the lot came out in a few minutes just ticking over. I did one trip home from work, around 10 miles and a further 25 miles at high speed that night before I found this was happening.

Lathe head stock bearings of the rolling kind should be preloaded so I don't see how they can stop rolling, balls or rollers. it seems the stuff works by changing the surfaces of the metal it's in contact with - a sort of boundary lubricant effect. Can't say I would use it in the engine of a modern car. I probably would if I could on wheel bearings or anything else suitable. These days some one else services my car. I do ask them to put copper slip on the correct part of single pot sliding callipers and hope they do and that's about it.

John

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Plastic is tricky. I have microscopes and a common problem on a Nikon type is plastic gears shrinking, breaking etc because some one has used the usual microscope grease on them or something out of the cupboard. Nye lubricants springs to mind but might prove expensive. They also do a huge range. There is an ebay.de seller that sells suitable grease. It's used in optical stuff so mustn't fume at all. Not sure if this would be suitable for your use but what parts are you lubricating that are made of plastic?

John

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If you want to use silicone grease the best source is probably a dive shop (scuba etc). It has to be the pure real thing just like grease used in air rifles, in the later case some greases explode. In the other it's probably more related to fuming but on the other hand some one who fills tanks for them told me he had to use a very similar oil to the one F1 use in his compressor - complaining about the cost.

I wouldn't use silicone oil. It migrates and gets all over the place.

I'm still curious about what part on a lathe is made of plastic and needs lubrication?

John

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Edited By John W1 on 10/06/2015 18:29:49

Silicone is rarely used in Dive Regulators and indeed diving equipment generally nowadays. Commonly used is ChristoLube which is really good but I personally prefer to use Tribolube 71, you can use it in any pre-charged air rifle or pistol secure that it won't cause you any problems. Never had an airgun explode because of the wrong grease though. Now, mixing Oxygen and Grease, that would cause some pyrotechnics!

Not cheap though.
graham.

I understand air guns have exploded due to hydrocarbon type problems. I have even seen photo's where the air reservoir on a gun had exploded. This was some time ago when my son was younger so must be 14-15 years ago and most people were using silicon grease from dive shops where any was needed. I'd guess some places still offer silicon grease.

John

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Edited By John W1 on 10/06/2015 21:24:34

I recently bought some special,grease for the high pressure pump for filling the air bottle on my PCP airgun. I had to import it from the USA and the postage was 3 x the cost of the grease. It is synthetic and loaded with PTFE. You can guess what would happen if straight oils were used at 200 plus Bar.

I am happy to use any oil that hs PTFE in it on the slideways of my machines, There are several types used on bicycles now. The PTFE searches out dirt and when you look the next day you will see a black line at the edge of the carriage as the PTFE replaces dirt. I find it is not any use for drilling etc and if heated can be dangerous to health.

Clive

I didn't have much of a problem finding the silcon grease I mentioned

**LINK**

John

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"if heated can be dangerous to health"

Clive , I think the term "life extinct" is the one the HSE use! PTFE breaks down and can form a close relative of phosgene gas and some other significantly more toxic products when exposed to incandescent heat so you should take care on a cutting tool which might well get very hot. The assumption was that smokers might get the stuff on their hands and then inhale it when they lit up. Not a such a problem for any non smokers like me though!

Mark

Hi All,

Some advice please.

I read David Haythornthwaite's post on lubricating a Myford Super 7with interest.

https://docplayer.net/42226569-Care-and-lubrication-of-myford-series-7-lathes.html

The one thing I am unable to get clarity on, is how do I oil the "right" side bearing (just before chuck)?

If you look at the above link - photo 7 shows how to oil the "left main bearing" (sorry not sure of official name); but how do I do the right side (top right hand corner of photo 8)

I added a red arrow in this image to show which bearing I mean:

how do I oil the right bearing, wouldn't this be the single most important bearing to oil? I would expect this bearing to be under the greatest load?

Wayne