Gears - Oil - Grease ?

[graham-xrf]

Watching Stefan Gotteswinter describe his recently acquired Weiler Primus lathe, he gets to a point where he shows the feed gearbox opened up (about 17:38), and he mentions that the gearbox is not oil filled, but instead uses a greased gears scheme rather than the gears running in an oil bath. The same machine does stay with full oil bath for the spindle drive, up to the point it uses a dual belt final drive to the spindle.

So for my old South Bends, they rely on the "total loss" oiling, as did many wartime era machines. Keep all the moving bits nicely oiled, then you know that all the oil you put in at the upper regions eventually ends up "down there " somewhere, and the arrangements to collect it up are kinda "non-existent". It relies on one being daily diligent, and looking after the cleaning and oiling with every use.

So to grease. We know hard chips and grindings and general dirt can stick in it, and not get carried away by moving oil, but if one could effectively "cover up and seal off" the routes where junk can get in onto the gears, is there any much downside to adopting grease as the gear lubricant?

 

[markba633csi]

There are a few other choices- one is molybdenum sulfide spray as used on motorcycle drive chains.
I've also tried chainsaw bar oil as it has a sticky additive and tends to stay put, if used in small amounts

 

[Downunder Bob]

If you are referring to, the open change gears for screw cutting and feeds, and not a QCGB, norton or other style.

For the open change gears I have found that chain saw bar oil is a good lubricant here, it resists flinging off when running at high speed, yet is still an oil, and does not carry chips and grit around as much as grease and gives good lubrication. Most QCGB that I have seen have some kind of drip feed, some rather crude and others pretty good, but mostly total loss, so it might be a good idea to make up a drip tray to prevent the mess.

 

[graham-xrf]

If you are referring to, the open change gears for screw cutting and feeds, and not a QCGB, norton or other style.

For the open change gears I have found that chain saw bar oil is a good lubricant here, it resists flinging off when running at high speed, yet is still an oil, and does not carry chips and grit around as much as grease and gives good lubrication. Most QCGB that I have seen have some kind of drip feed, some rather crude and others pretty good, but mostly total loss, so it might be a good idea to make up a drip tray to prevent the mess.

I had pipe-dreamed a scheme where I added a synthetic rubber (silicone?) arrangement with holes that would stretch over the gear change levers, sealed onto them, and then, in other ways, making the open underside closed off. This would be awkward or impossible to make leakproof, but if the gears then relied on grease, or maybe high tech dry lube as suggested by @markba633csi, it could be an improvement. Feed gearbox stuff does not rotate at the speeds needed for spindle gearing, and some does not get used very much.

Re: the change gear train. Mine have a simple metal cover that just rotates away to open, is fully open to the world from the underside. There must be some good to be had by arranging that to be closed off somewhat, if not fully sealed to the environment outside.

 

[benmychree]

Solutions in search of a real problem --- my vote is simply a clingy oil, like Vactra #2, absolutely not grease nor Moly dry or greasy especially if gears need to be handled/changed.

 

[graham-xrf]

Solutions in search of a real problem --- my vote is simply a clingy oil, like Vactra #2, absolutely not grease nor Moly dry or greasy especially if gears need to be handled/changed.

I do understand the sentiment, but it is contrary to my nature.
There is absolutely zero that I am ever completely OK with, even in brand new kit.
At least in the mind, I will play through any ideas, notions, speculations, whatever. Most recognize the lack of significant upside if the thing is just what it always was supposed to be, and does one thing reasonably well. If there is any scope for an improvement, this is where the new notion gets hatched!

 

[David2011]

My first lathe called for using something like motorcycle chain grease on the spindle and back gears. Just had to refresh it once in a while.

 

[GrifterGuru]

I've also tried chainsaw bar oil as it has a sticky additive and tends to stay put, if used in small amounts

Correct me if I am wrong, but as chainsaw bar-oil has a tackifier in it, would it not be in the same bracket as Vactra 4 (ISO 220) way oil since way-oil has a tackifier in it? (Yes, I have used a smidge of Vactra 4 on the metal gears on my SC3 and it stayed put.)

 

[graham-xrf]

Correct me if I am wrong, but as chainsaw bar-oil has a tackifier in it, would it not be in the same bracket as Vactra 4 (ISO 220) way oil since way-oil has a tackifier in it? (Yes, I have used a smidge of Vactra 4 on the metal gears on my SC3 and it stayed put.)

Indeed chainsaw oil does have sticky tackifier in it, designed to stop oil flinging off the end of the chain saw guide. That said, I am not sure how good are any other chainsaw oil qualities when used in a engineering lubrication role between surfaces that have some load force between them. The stuff is cheap! For me, if it works on the gears just fine, I am OK with it.

Vactra 2 is the one I got for way oil, because that was the one I saw recommended in the Tubalcain (Mr Pete) video for South Bends. I guess Vactra 4 is thicker, and maybe even more sticky tacky.

 

[GrifterGuru]

I guess Vactra 4 is thicker, and maybe even more sticky tacky.

Yes, quite a bit heavier in terms of viscocity and also tackier, hence my preferred way oil for my 7x.

Vactra 2 is ISO 68, Vactra 4 is ISO 220, thus ISO 220 is a smidge under three and a quarter times thicker than ISO 68.

In short, the ISO grade is the viscocity, therefore the higher the ISO number, the thicker (heavier) the oil is.

See HERE (<< link) for a brief explanation of ISO VG (VG = Viscocity Grade).