Shopbot lubrication?

[billp]

I am constantly asked by other 'Botters as to what kind of lubrication I use on the rack/pinion gear of my machines.My usual response is that to my knowledge there has never been a "recommended" product, and everyone seems to have different ideas on the topic. I've heard of people using "Dri-cote', on the X & Y axes, but NOT the Z.. While others say to use "moly" or lithium.When we set up my PRT we used 30 weight motor oil, so I'm sure there is a wide range of possibilities here.The question I'm trying to ask is; what is working for other people? OR maybe I've missed it, has Shopbot ever "sanctioned"one type of lube over others?

[Jccwrks@aol.com]

I hate to say it, but the ONLY thing I've ever lubed was the z axis, and I do that on a daily basis with WD-40. I cut acrylic and sign foam and if not lubed daily, the partially sealed z axis will jamb within 3 days. I suppose the right thing to do would be to take the thing apart and clean it, but thanks to this forum, I hear that's a nasty job. The WD-40 seems to rinse debris out of the assembly and lightly lube it at the same time. As for the pinion gears, even without a lubricant, foam dust compresses into the teeth and acutally works the motor out of position creating play in the carraige. I'm afraid lubricating the pinion gears woud create dust magnets on my machine that would end up being more trouble than they're worth. Any better ideas?

[fuzzygrub@sinclair.net]

I've never used any lubrication on the x-y axis's but once my z-axis was missing steps so I used some cam break-in prelube and then wiped it down to slow dust accumalation. Probably the worst thing to do but it was handy. I would like to know what the proper lubes are myself because I'm definatly not a rocket scientist. ko

[cbradshaw]

I sent shopbot an email last weeking asking them that very question. They told me that they are now starting to recommend lubrication like the white lithium grease. The say that it will not collect as much dust as you would think.

[jorgy.tucson@worldnet.att.net]

I occassionally wipe down the ways and screws on my larger CNC with Marvel Mystery Oil. I'm sure any other light weight, high detergent oil will work (ATF). The idea is to remove the dirt and grime and provide a slippery surface. A little pm is good, things work much smoother. My experience with WD-40 is that it becomes sticky unless used on a daily basis.

[edcoleman]

Like John Henderson, the only axis I have lubricated was "Z". I've also had good sucess with WD-40, although I use it on a weekly basis, apparently I'm not as busy as John


I've never done anything with the X or Y

-Ed

[birdsofplay]

To Chime in regarding the Z axis ...

I too have only ever lubed the Z with Wd-40.

My HomeBrew Gear reduced Chain drive has a
brass pinion and a stainless drive gear and
they see quite a bit of dust buildup.
So lube would only make it harder to clean up IMHO

I am considering Rack Upgrade and intend to NOT
lube them either as most of you have stated here.

Just thinking "out loud", however, the Racks are kind-of hidden from the cutting area.
and therefore, less apt to collect dust.
So they shouldnt need too much cleaning or lube.
Kudos to SB for that subtle but effective design.

[rgengrave@aol.com]

It seems that if metal touches metal it will wear in time and might end up not cutting the right distance? for me to be on the safe side I use Molly spray when I start to see shinny spots in the tracks and the gear.

It might not need it? but why take the chance, I have only sprayed it 2 times in the last 1 1/2 years and still get the right distance.

Ron

[danhamm@abccom.bc.ca]

The thing about tapered teeth is they can wear "in" , the speed they move at is so slow, and the amount of pressure applied is not much..in my "opinion"
the slight bit of wood dust is probably all the lube mine will ever get. " I have used WD 40 on the Z a couple of times..

[bitbreaker]

To sum up all these confessions ...

It appears that we need an R&P Z axis too.

[bwclark@centurytel.net]

Here is a suggestion.

How about sealing wax (parrafin wax) used in canning. It is "dry" so not too much will stick to it, yet it is pretty good as a "simple" lubricant. Also, it will not "stain" your wood work should it "flake" off the rack.

Best way to apply is to take a bar and rub it against the rack and then have the carriage "run over" the freshly waxed areas. Remember, you do not need to apply too much, just enough to lubricate.

Now, I have to confess, that I never lubricated my rack and pinion or my Z axis (ballscrews) but I religiously clean (with a brush and airhose) my ballscrew/nut before each job and the rack when it starts looking "full".

Bruce Clark
bwclark@centurytel.net (mailto:bwclark@centurytel.net)

[cwho]

We always lube the z axis with a spray teflon and also wipe it after each cut. (3D cuts of about 4- 5 hours!) I also installed compressed air dusters on each rack, two per. Since I put the air on I have totally eliminated any gum up problems. The compressed air was really easy with a kit of sort of articulated air/oil delivery tips that I found online. If anyone wants me to post links and pics I will.

Charles

[rjguinn@optonline.net]

Charles,
Your method sounds very interesting.Please post some links & pics.Also,what teflon spray are you using & does it leave any residue to collect dust? Do you think this would be adequate lube for the x&y racks?It should be less messy than the moly lubes. Thanks

[ron_cleaver]

I just assembled a R&P ShopBot. It comes with a black grease (lithium if I remember correctly). Here's a relevant excerpt from the assembly manual:

"We recommend applying grease to the rack and pinions. A good quality bearing, lithium, or Teflon grease will work well. The grease will keep the rack motion smooth and reduce gear wear. (Surprising little debris actually collects in the grease.) Apply it by squeezing a little into the rack every few inches. It will then spread around and you can wipe off any excess."

[Mayo]

If you don't wipe off the excess, you can be sure that your shirt will do so each time you lean against the machine.
Just ask me how I know this :-)

[jkforney]

Mayo
The problem isn't my shirt, it was my wife's. And it happened at the Las Vegas show. She wasn't too happy. Of course, she too loves shopbot and has forgiven them.

John Forney

[christopher@crasshomestead]

I have noticed that the rails for my X and Y axis are beggining to get cut really bad by the rollers. They are litterally cutting the railing and leaving a groove in the rails. This also produces splinters of metal shavings on the rail which I have caught my hand ans clothing on several times. Is this normal? What can I do to prevent this? Am I going to have to replace the rails? Please help!
Chris

[jkforney]

Crass
The rails are a mild steel and the bearings are hardened. The accepted remedy is to run a routine that runs the x and y the full length in a loop to make sure that you are wearing the rails evenly. I normally run mine every month for an hour or so. In between times, I use a file to remove the burr that builds up.

Bishop-Wisecarver (the bearing suppliers) has sent me a hardened steel track which bolts on to the existing rails. It has the same profile as the bearing and should resist the wear. I am now trying to figure out how to attach it with the minimum amount of rework. Since it bolts on it requires moving the bearings either in or out 1/8 inch on both rails.

This is a test to see if the rails can be retrofited to shopbots. I hope to have it on and running at the Midwest Camp Shopbot and will post pictures with a report. I also have no idea how much the tracks will cost.


John Forney