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Moly Disulfide on Machine Ways?

The Doctor

Cast Iron
Joined
Nov 9, 2003
Location
Lumberton, New Jersey USA
It seems to me like it would reduce wear and give you a much smoother feel, but I'm not 100% sure that would be the final result. I once asked Scott Logan if he thought that would be a good thing to use on my Logan lathe, he said he did not know if it would be beneficial or not, but he knew Vactra oil number two would be a good thing to use. Does anybody here have a good answer to this question?

Ed
 
I've used Mobil Vactra way lube and now use that and DTE 26 hydraulic oil on several smaller lathes.

It seems to me that how well the moly works would depend on the base that it is in. If it's an oil additive, then the oil, if light enough, can let chips drop out or get wiped away.

If it's in a grease base, it sounds like a disaster would be in the air as the grease holds both metal chips as well as more abrasive materials.

There are some very good old posts in the RCM (rec.crafts.metalworking) news group concerning way lubes with some pretty convincing reasons why they are questionable for HSMs whose machine do not have oiling systems to force materials out from under ways.

I think as long as you keep the ways regularly lubed and clean after each job, they will stay in good shape.

I've often wondered if too much lube is bad also as your tailstock may end up slipping no matter how tight the grip :eek:

Den
 
There are some very good old posts in the RCM (rec.crafts.metalworking) news group concerning way lubes with some pretty convincing reasons why they are questionable for HSMs whose machine do not have oiling systems to force materials out from under ways.
But you can easily add a simple waylube feed, I di on the Logan. A couple lube drillings and gits flip-tops, and you are in business with way lube fed under the saddle. And, yes, it does wash out an incredible amount of stuff, even after you swear you have wiped everything clean.

I can easily see it carrying crud under if that is the only way that lube can get under there.

Another idea is to feed it into the top of your wipers. That might work ok too, and due to the locatiion of the feed, might not carry stuff under as badly.

By the way, I second the Vactra. At least with feed from under the saddle, it makes the carriage move relatively effortlessly. It was a HUGE change from the 20wt that I started out using, even before doing the lube mod. The 20 wt would be better than nothing though.
 
JT, I try to hit the tops of the wipers and get them wet for this reason. Seems to work pretty well. On my new (to me) Harrison, there are oil grooves in the carriage ways but I haven't figured out where they are fed from yet.
 
Nothing sticky on the ways please.

It gathers chips and grit to make a sticky valve grinding compound that blows right past the felts of the way wipers.

Use a way oil.
 
Forrest, What are your thought on way lubes for home shop (or other smaller) machines? And while you're reading, any problem putting way lube in an apron? It seems as though it would stick just right to the gears in a splash lube apron and still give pressure protection to the gears and worm.

The reason I ask this is because my new machine has a single shot lube built into the apron and feeds the cross slide plus other parts unknown at this time.
Den
 
From some of the replies, it appears I did not make my intentions 100% clear. I am not thinking of using a molly disulfide grease on the ways, or using molly as my only lubricant. What I was thinking of doing is applying molly dry film lubricant to the ways on the carriage when it is off, and then keeping it very well lubed with Mobil's Vactra number two oil from that point on. I was just thinking that the molly may reduce the stiction of the carriage, and give it a smoother feel, as well as preserving its overall life. Oiling would be performed as normal.

As far as Vactra versus a motor oil or ATF, I used to use both of the former lubes on my old South Bend, and it started operating much smoother when I switched to Vactra. I would definitely recommend it highly, but I would still like to know what some of you think about adding so molly to it?

Ed
 
Ed, I think if adding moly disulfide was an advantage, the manufactures of machine tools would do it at initial build. I know back in the late 80's or early 90's some idiot marketed waylube with moly d mixed in with it. Several of my customers used it. I had to replace every metering unit on every machine. Moly d is a solid, clogged up all the metering units. Use a high quality way lube like Moble Vactra. If your machine has no lube distrubution system, look at adding one, will add many more years of life to the machine.
Bill
 
..........I'll bet you're talking about an atomized moly spray gib and way lube? I've bought a few cans of it, but for other applications. It was the hot thing and took the accuracy shooting (benchrest) world by storm several years ago, but has fallen on hard times of late. Apparently in that application it did what it was supposed to do but inconsistancy problems turned up in addition to difficult cleaning.

The stuff I've bought listed it's applications as being for extreme slidding pressures and usefull in tempurature extremes. Probably both attributes which endeared it to shooters. Then there is also an apparent ability to plate surfaces. I can see the attraction to use it under a lathe's saddle.

I think that it may be more at home in a dry lube type situation? I may be talking out of place as I'm neither a chemist, metalurgist nor experienced machinist but it may clog, clump or ball under an oiled relatively lightly loaded lathe saddle? Some oil additives for IC engines use moly with apparent success, but these oiling systems are in constant pressure flow situations of high volumn.

One reason I've not used it myself (and I'd lie is I'd said I hadn't been tempted) is that nothing I've read that had anything to do with lathe lubrication has ever mentioned moly or an oil with a moly additive. Like you I would have thought it's lubing ability under extreme pressure would be a benefit for metal-metal sliding surfaces. And I guess it is for some applications.

I've contented myself that engineers and designers of machines like my lathe have tried it and discarded it for some reason. I'd be interested in knowing what was found but I've lived to be as old as I am NOT knowing :).

Best,
Rick
 
Take this for whatever you think it's worth:

My employer (a US manufacturer of communications and weather satellites) generally does on-ground testing of Moly-Disulphide-lubricated spaceflight mechanisms in a pure nitrogen atmosphere because moisture in the air "contaminates" the lube and makes it abrasive.

Such "contamination" is not permanent, and is normally removed from piece-parts before assembly by heating ("baking out").

Interestingly, graphite works well wet but becomes abrasive in the absence of moisture.

John
 
what mr. bpt and those guys said. if it calls
for ways oil, use ways oil . if it calls for
spindle oil.........you guessed it. i don't
understand posts with arguments like " which
red chainsaw oil is the best for lathe ways"
and "can't i use synthetic motor oil instead"
what kind of retard question is that....i could
fathom vactra #2- vs.- GulfWay , or whatever.
REAL machine oil -velocite 10 (sb spindle)
(vactra #2,#4) doesn't cost that much . i would
bet dollars to donuts it's cheaper than the
freakin' red chainsaw oil somebody insists on
using!!!!arghhhh.....
unless someone is an amateur hydraulics
engineer, i would challenge them to surpass
the performance of what's been standard for
what?, 70 years? vactra 2- is 2.50/quart ,40.00
per 5 gallon pail where i live- i looked
in the phonebook under-Oil Companies ...
 
Oil acts with the large surface area of ways in a compliant hydrostatic manor to provide averaging over the entire way movement. Graphite or moly disulfide may not function in the same manor to provide the compliant hydrostatic averaging of the oil lubrication.

Don Clement
Running Springs, California
 
ED , I don't think you have been answered yet.
Most all of the statements made so far are correct and I agree with them...particularly with using way oil ..But !
Molydisulphide has some unique properties and can be used to get this advantage.
Forget all the sales hipe..lets look at its good points.
MDS will "plate " a surface and give extrodinary low friction results *.
Its anti-galling abilities are without question!
It will also "ball", "clog" and do other nasty things....caused by a loss of carrier (oil/solvent)
It is a mess to keep clean as well !
It is a dry or wet lube, depending on application.
For high temperature chain lube (400 to 500 F)it is superb..
But To The Point !!
To get the plated characteristics, the metal must be virgin and clean,clean,clean, so here is a course of action.
Freshly machined surfaces (without coolant/oils)are perfect. anything else must be spotlessly clean...I am talking about abrading the surface with Wet/Dry paper and lacquer thinner and removing ALL oil !
Now lube the mating surfaces with dry MDS and slid them together...almost like a lapping function for a period of time ( 5 to 10 min)
This allows the MDS to penetrate all pores of the surface.
Under an electron microscope, an actual plateing appears as the MDS adheres to the molicular stucture of the bearing surfaces.....this is what produces the lower friction characteristics!
Now you can either leave the residue or wipe it off,and apply a good way lube...
The company I worked for had over 100 high speed 40 ton punch presses( fine blanking) and cross head rebuilding became an art form with us.
We had Cast Iron crossheads with both Cast Iron and Bronze Gibs/Ways.
The above procedure I described almost tripled the life of a crosshead, while just adding MDS to an existing running "set" maybe added 15 % to the life...not a cost benefit ratio we wanted.
It took a little longer to rebuild, but we had cooler gibs and tighter tolerances.
Hope this helps Ed

Rich
 
Found this thread in a google search and thought I'd revive it rather than making a new thread.

I've got a large milltronics bridge mill that is used for primarily wood and plastic machining. It was converted to grease, with the consultation of the manufacturer, when we had excessive way lube running from the ways of the bridge onto the wood and plastic parts being machined. The manufacturer recommended a Mobil XHP 221 Lithium grease, but I feel like the grease recommendation they made was relatively arbitrary. I know that the grease setup we have on our machine is a bit obscure for them, so I don't feel like there's been a large amount of research that went into the selection of said grease.

I asked about switching back to a way lube to eliminate the need to manual greasing but was told that their engineers advised against it. I was told that given our applications he said that the blocks and ball nuts hold the grease better and that it would be better in the long run.

So with that being said, I was looking at moly greases because of their higher lubricity. Since we only cut wood and plastics on this machine, wear associated with chips sticking to the grease isn't a problem. I was just wondering if anyone here can think of any good reason as to not run moly grease and to stick with the grease the milltronics seemingly arbitrarily recommended. Aside from the moly grease being more expensive up front, I feel like it would be a much better lubricant for ways.

Any input helps.

Cheers,

Ray
 
I have never seen a grease for ball screws or linear rails and blocks with moly in it. These greases are very specialized and spendy. You want the best check out Kluber, I use Kyodo Yushi as that is what my MTB recommends. I prefer grease over oil for this application, but be REALLY careful not to over grease the blocks, you can easily blow the end caps/ball returns as a grease gun can generate a lot of pressure.
 
IMO Moly has no place on lathe ways. Vactra works and cleanliness is the best protection against damage.

I've used a small amount (2%) of Moly additive (Dow Corning Gear Guard) in splash lubed gearboxes for years. It cuts down on wear and can be used in almost anything as long as there are no materials that can be harmed by it.

I coated my table saw blade raising and tilting mechanisms with Moly (Dri Slide). It makes movement smoother and reduces sawdust sticking. I poured some in a cup and brushed it on. At first it was almost transparent but as the solvent evaporated I brushed on more coats and it started to build up.

I gave my fireplace damper the same treatment and it moves smooth as silk.

The warning given by others about clogging is for real. I have the accessory needle spout for the Dri Slide and unless you blow it out after every use it clogs solid.

Edit: Just noticed this was an old thread.
 
Ray,

The only reason I can think of not to use grease with Moly is if there is something that might react badly to it. At this time, other than something with chlorine in it I know of no such materials. It does have some health hazards in contact with skin or eyes so precautions should be taken. Grease that oozes out should not be touched with bare skin.
 
I have never seen a grease for ball screws or linear rails and blocks with moly in it. These greases are very specialized and spendy. You want the best check out Kluber, I use Kyodo Yushi as that is what my MTB recommends. I prefer grease over oil for this application, but be REALLY careful not to over grease the blocks, you can easily blow the end caps/ball returns as a grease gun can generate a lot of pressure.

I'm actually in the process of purchasing spindle bearing grease for another machine and am going with a Kluber grease. You're right about it being spendy! It mentions in the grease description that it's specially formulated for cnc components (ball screws, spindles, linear rails etc) It makes sense that a specialized grease would be used on precision components.

The fact that milltronics recommended a consumer grade lithium grease from Mobil was surprising and definitely suspect. I also asked the service tech regarding greasing limits and whether or not there was a risk of blowing seals. Oddly enough he assured me that there was nothing to be concerned about, but I question that statement as well. At this point I'm pretty unsure as to how I should proceed with things. I just recently took over this Milltronics bridge mill and up until now, the previous guy that ran it was using a cheap shitty generic tube of black grease. Cheap farm grade stuff.

It's not an old machine (Less than 3.5years old) so I'm really wanting to avoid any crib deaths here. I'll have to talk to the boss/owner and get his input on how to proceed. It's not my machine and not my money, but personally I'd be going with the specialty grease and not taking any chances. Whether or not hes willing to cough up the money on a $150 tube of grease will be up to him I guess.

Thanks a lot for the input!
 








 
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