What grease to avoid?
Posted 16 January 2013 - 12:22 AM
Sometimes you would find really good lubricants, but the dealer would only sell in commercial quantities, never got any inquiries from individuals since he opened the business and he has no idea how to handle payment without a local purchase order.
Posted 16 January 2013 - 06:54 PM
This type of grease can go up near 500F, but more importantly, can go quite a bit colder than the data sheet indicates.
Posted 17 January 2013 - 12:03 AM
I am here again just to clarify that I assumed Hilmi was talking about motor bearings for his observatory, so I made suggestions based on that assumption. (My suggestions were in general for motor (open) bearings with grease fittings on them)
To those who still like to read further on, Attached here is a pdf link from EASA.
http://www.electromo...cation of Ro...
It includes grease compatibility chart which explains itself why two greases must not be mixed (point 10¼.).
Summary of Pdf:
Greases are composed of base oil (mineral or synthetic) AND a thickener (usually lithium, calcium, polyurea etc). Greases are then classified according to the types of thickener used. Almost all bearing manufacturers assign grease codes. when assigning their own code numbers to the different kinds of greases, often relate these numbers to the trade name of the lubrication products...
Also with reference to sealed and shielded bearings, Washing/cleaning and repacking is never recommended. They are supposed to run/have grease for their lifetime. If they become sloppy/noisy, best solution is to replace them. but, as mentioned above, keep in mind that there are bearing manufacturer's grease codes numbers (which will vary from one manufacturer to another), do identify the grease with which bearing was packed at the factory. (unfortunately those bearing code numbers are not always indicated on the bearing or the package), Therefore, only OPEN bearings, which are in good condition, could be cleaned/repacked with same type of grease again.......
Synthetic greases are used in applications where mineral grease can not provide satisfactory results. typical applications include extremely low or high temperatures and very high speed operations. It should be interesting to point out that one bearing manufacture (McGill) do not recommend using synthetic base grease for its spherical roller bearings because it is not capable of providing adequate film....
You will also notice superLube/Synco appears nowhere in any of bearing manufacturer's list. So, I would not use superLube PTFE in any Ball/Roller bearings because it is possibly designed for reducing the friction beween two coarse surfaces. e.g It would be great to use under CG-5 ' s DEC axle (which is actually a load carrying thrust face and has no bearing(s) at all (No anti-friction or friction bearing, thrust or radial bearing).
Here is another interesting link about PTFE. It is not known as worlds' lowest in coefficient of friction (0.05-0.10) as calimed by the "man" on super-lube's website, rather number one is BAM (0.02) and 2nd one is DLC (0.05). PTFE ranks third in the lowest in co-efficient of friction.Btw, PTFE is the same stuff used in non-stick fry pans which are known to giving off toxic vapors even at 163ºC killing pet birds... (I would use superLube only if I buy CG5 or perhaps VX who knows)
Posted 17 January 2013 - 12:31 AM
I also never recommend opening, cleaning and relubing sealed bearings in mounts. It's cheaper, easier and better to simply replace them if they are damaged or defective or you need better quality. The grease that is in there is fine for these applications and with the bearings "sealed" it stays good for a long time. The real challenge comes with the crud inside the housings on the contact surfaces and in the taper, roller or needle bearings. There I find that a thin coating of SuperLube works quite well. However, there is another important reason that I use SuperLube and that is that it is readily available and reasonably priced. I know that there are other lubes out there and some that are probably even better, but it gets to be like replacing all the axis bearings in a mount with full ceramic ball bearings, you can do it but it is not worth the cost for the slight improvement. I also like the fact that I can get SuperLube all over my hands, etc. and not be poisoned by it. Since I frequently have the stuff all over my hands I consider that an important benefit for me and those I recommend it to.
Interestingly, the railroad industry is one of the places where SuperLube gets some use. The supplier that I use is actually a supplier to the railroad industry.
I don't argue that there are better (and worse) lubes out there, but in the searching I did when starting out in this business, it was my conclusion that SuperLube is a good fit for what we need when it comes to lubricating mounts.
Crossing my fingers that the elbow surgery won't be any worse that my numerous shoulder and knee surgeries. I'm too busy for that kind of problem. That elbow grease is great stuff but it's hard to fit the elbow inside the axis housings. Maybe that's why I'm ending up with surgery. Got to get my hands on some of that "Khalfan Aziz's miraculous slippery stuff" sometime though.
Posted 17 January 2013 - 01:15 AM
Posted 17 January 2013 - 02:02 AM
Hilmi, I'm sure there are high-end bike shops in Oman. A good high-end teflon grease like "Finish Line Teflon Grease" is probably identical or very similar to SuperLube.
Your local high-end bike shop would know what this is, and if they don't have it they would be able to recommend something similar.
Posted 17 January 2013 - 12:07 PM
Posted 17 January 2013 - 12:46 PM
SuperLube is nice however its not available and its a scope mount with motors that will not be running hour after hour at high speeds and loads, any good quality automotive chassis and wheel bearing grease from a reputable manufacturer will just be fine, I,ve spent decades lubing cars, aircraft and industrial equipment, in one place I worked at for 15yrs had several high speed pick and place robots running 15hrs a day non stop, for 6 days a week, the worm was steel, the wormwheel was bronze both supported by regular grade ball bearings, they got relubed about twice a year with regular automotive grease and we never had any problems,DA.
The problem with the automotive lubes that you refer to is that they are petroleum based. They tend to be too stiff at low temperatures (the work fine in a car once it gets going) and they tend to separate leaving the heavy gunky portions behind with the light oil portions leaking out the seams. In addition, most people do not want to have to strip down, clean out and relube their mounts that frequently. In the days of fully exposed worms and wheels, not such a big deal, but most mounts are not built that way anymore.
I have seen and cleaned out the insides of many telescope mounts where a lot of different stuff, including plain old automotive lubes have been used. Will and auto lube work? Sure it will but so would good old vasoline or Crisco or just about anything else you have laying around. Will it make a mess of things? Yes. Will it be the best thing to use in a low rpm telescope mount? Not by a long shot. SuperLube and other similar synthetic greases are readily available in most of the world and worth the few extra bucks they cost and a little will go a long ways.
Telescope mounts are not automobiles and if you want them to work well with minimal maintenance, you should not treat them like one.
Posted 17 January 2013 - 07:10 PM
Posted 17 January 2013 - 07:52 PM
finaly an intelligent responce
Hey Hilmi, Couldn't one of us just squeeze some Superlube into a small bag and send it to you? My tube is more than I'll ever use in three lifetimes. How much could a small envelope/package cost to mail from the USA to Oman? Will it trigger any weird anti terrorism scanners? PM me if you think there's any merit to this.
Posted 17 January 2013 - 07:55 PM
Posted 17 January 2013 - 09:34 PM
I think it's against the postal service policy to ship flammable products. Only authorized people can ship them. Ask the shipping company first.
SuperLube is not flamable and would probably be fine to send to him and I would be happy to do so, but then he could probably buy it on line just as easy. Hilmi was looking for something that he could get locally.
Hilmi, if you want some sent to you, PM me.
Posted 18 January 2013 - 02:02 PM
Posted 18 January 2013 - 06:08 PM
I never said that a scope mount was like a car Ed, however the O.P. has stated that Superlube isn,t available in his country so a good quality auto grease would do the job just fine IMHO, in fact before Superlube came on the market most people including myself used just that, regular auto grade lithium grease from a reputable manufacturer, you may have had problems with auto grease? I have not, to me lubing a scope mount should be a simple process not rocket science which seems to be where this thread is going,I can,t see the point of makeing a mountain out of a mole hill?, however each to his own,DA.
Like I said, just about anything will work, including auto grease. But I have cleaned enough gunk out of mounts at this point to have a good idea of what works better and what just makes an awful mess. There is one thing I do stress though and that is to not pack mount bearings like you do a car's bearings (that's more what I was referring to car wise). Some people advocate doing that and it the best and quickest way to stiffen up your mount out there. I have encounted taper bearings jammed with what use to be lithium grease. What a mess.
I think for a potentially local solution that is similar to SuperLube, some of the bike greases will work best. I think what we were looking for was the "best" locally-available solution.
Posted 18 January 2013 - 11:30 PM
Since superlube sells and ships internationally online I'll just get a tube of that stuff. I also appreciate all the offers of help I got from people offering to send me a bit of the stuff.
Posted 19 January 2013 - 12:11 AM
...... I think what we were looking for was the "best" locally-available solution.
That's great, but the thread title would indicate that the OP was looking for pointers as to what would be the "worst" options..... .
Posted 22 February 2013 - 11:35 PM
Avoid "Grease 2". It's a shoddy production in comparison to the original movie "Grease".