[cameraman32]

Hello, I've got some stainless steel / brass worm gear sets that go into a project I'm machining and I need to find a good lubricant for them. I can't constantly oil them (they are locked inside the device which is not meant to be opened regularly) and am wondering what will work best. Oil? Grease? What kinds?

I've been thinking that a teflon type grease, or other "space age" type grease might work well. There is so much friction in worm gears that the lubricant is probably quite important.

Thanks!
Stewart

[Al_The_Man]

Nook Industries, which make acme and ballscrew jacks that use a worm gear, mention PAG-1 & PAG-45 grease for their units.
I have not personally sourced this type but a Google may unearth it.
Al.

[X2cnc]

I'd use ordinary 90wt hypoid gear oil from your favorite auto parts store.

[RICHARD ZASTROW]

Be sure whatever you use is formulated for use with copper alloys like brass and bronze etc. Many lubes will attack the copper alloys and pit them.

Dick Z

[cameraman32]

Thanks, i'll check out that Nook grease, and check if its approved for use with brass.

I was kind of hoping that someone would know of a perfect super low friction lube I'd never heard of.

[RICHARD ZASTROW]

You may consider the Royal Purple Synthetic mentioned in the Cone Drive list
www.conedrive.com/iandm/approvedlubrication.pdf
or check out http://www.machinerylubrication.com/...?articleid=169

Dick Z

[HuFlungDung]

Haas recommends Mobil SHC630 synthetic oil in their rotary indexers. Its not too viscous, but that suffices for worm gear drives that barely get warm while in operation.

Browning has a very heavy weight worm gear lubricant, IIRC, about 140 weight or more, pours like molasses at room temp. That would be for a really hardworking gearbox that gets hot.

It may be an interesting bit of trivia to know, but a single start worm has the highest coefficient of friction (resists backdriving), and more starts may prove to be better in some instances if speed reduction is the primary concern, where heat buildup may otherwise be considerable. Logically enough, a large diameter worm also has a higher circumferential velocity, so this may also generate more heat through both stirring action and worm velocity.

[Geof]

Is my suspicion that you are building something for moving an astronomical telescope at all valid?

If that is the case I think heat build up is the least of your worries, and I doubt you will be seeing very hig loads. Just about any general purpose lithium grease would probably be okay; even white petrolatum would probably be fine.

[highspeedmazak]

go to Napa and ask for the red grease I believe it is called #3 they will know exactly what you are looking for it is red grease that works great and can take just about anything. Check to make sure it is compatable with your metals but put it this way. It is the only grease that stands up to salt water for bearings. Not that you will ever have any water in it but just ask them they will explain how tough it is.

[RICHARD ZASTROW]

Stewart, I know this is off the subject. Just for your personal edification and possible application, You might want to look up "Gear Bearings" on NASA's available technology site.

John Vranich came up with a clever design for a combination of a gear and roller bearing. When used in a planetary gear set you can have near zero backlash, high torque multiplication, high efficiency in a small package.

OK, I'm guilty too. lol

Dick Z

[RICHARD ZASTROW]

Stewart, Try this http://techtransfer.gsfc.nasa.gov//f...-bearings.html

Dick Z

[L.C.]

might sound like b.s. but everthing your looking for is an oldtime secret . try it or at least try it after you've spent over 100. dollars and still nothing is worlking the way you want. MARVELES MYSTERY OIL .