Bearings

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IPD_Mrs

IPD_Mrs

Member
Joined
Jun 27, 2007
Messages
2,048
Location
Zionsville, Indiana
The head stock on my Jet is starting to get a little more than warm when on for any length of time. There is no noise or wabble and it is still in alignment, I am just a little concern with the transfer of heat from the head stock through the dead center and on to the blank. Not to mention it is too warm to rest my forearm on when sanding. [V] Anyway the bearings for the Jet are the 6004VV and the 6005VV. Does anyone know if one brand is better than another of bearings? I don't want to replace bearings every three months because I bought crappy bearings.

Mike
 
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Mike,
I just read a post about this where someone purchased thd 6004/6005 bearings from fastenal for $7, I am guessing apiece, which does not seem to high of a price. I hope that this helps.
 
Mike, we used to have 3 large pin routers that needed new bearings annually...they were used just about 24/7 with heavy pattern routing.

We very specifically required american made bearings and seals which we were able to get locally in Oregon from a local bearing house.

Doug
 
I think I may have not made myself very clear. I do not paying more for good quality. So if the bearings cost me $30 each then so be it, I just want good quality, not something that will wear out in 90 days. Also I think my heat problem is caused by the hand wheel being to sight up to the casting of of the head stock. I will turn it back about 1/4 turn tonight and see if that takes care of the heat problem.

Thanks for your replies and I am still looking for a good quality set of precision 6004 and 6005 bearings. :)

Mike
 
You should be able to get a good set of American-made bearings from your local bearing supply house for about $20, IIRC.

As I recall, there is a little shoulder on the spindle of the JET Mini so that you cannot over-tighten the handwheel. There is a little wave-washer that goes between the handwheel and the headstock casting to take up any slop. I don't think loosening your handwheel will help your problem.

Have you called the JET technicians to see what they have to say?? Your lathe may still be in warranty and they may send you a free replacement set??
 
Actually backing the hand wheel off 1/4 turn solved the heat build up problem. :)
The Jet bushings are like $20 each and I have heard of too many people replacing theirs in a short time which is why I was looking for a better bearing. I don't know enough about sizes to know what I can do. I see ZZ VV RD2 and so on and do not know what if any of these are compatible or if one company produces a truer bearing than another. Also I see things like load rating and don't want something that will not allow me to put a small block on and turn a bowl.

Mike
 
Mike: Glad to hear you solved your heating problem. Surprised.....but whatever works.

Your 6004/6005 bearings don't really come in different load ratings. The 6004 number means the bearing is of a specific size and load rating. There really isn't such a thing as a heavy duty 6004 bearing. If machine designers need a heavier load capacity, they just use a larger bearing. Any 6004/6005 bearing made by a good company should serve your needs just fine. The letters after the bearing number indicate whether the bearings are sealed or not and some other characteristics of the bearing. These codes are proprietary and are different for every manufacturer. The VV on the JET bearings mean that they are double shielded bearings.

Here is a short description of bearing basics. It was written for motorcycle enthusiasts; but applies to all bearing applications.

http://www.sportbikes.com/articles.aspx?id=28652
 
Timken and SKF to name a couple and you can also get sealed Radial ball bearings in different "grades" in the same size. You need to go to a real industrial supply company like Applied industrial Tech or MSC. Let me know if your extra side load has cause damage to your bearings that presents itself in the near future and you need help getting a good set. BTW I should add that sometimes options are limited but they almost always exist to some degree.
 
Can anyone tell me if these are ok to put on the Jet? I know the size is correct, one of the 6004 and one of the 6005, but just want to make sure these are good enough.

Mike
 
Originally posted by panini

I'm noticing I'm have the same heating problem in the headstock of my jet JWL-1220VS latel. Is it a problem with all mini jets of just a few?
Click to expand...

Based on what has been posted here and on other pencrafting sites, I would say it is not a common problem.
 
Originally posted by MLKWoodWorking

Can anyone tell me if these are ok to put on the Jet? I know the size is correct, one of the 6004 and one of the 6005, but just want to make sure these are good enough.
Click to expand...

Mike: Not quite sure what you mean by "these"?? Did you intend to post a picture or a link with your message?
 
I have had pretty good luck buying these bearings from McMaster Carr, for use in the machine I work for. The website is

http://www.mcmaster.com

and the P/N for the 6004 Double Sheilded bearing is 6661K17. They also have a good explination of the bearing coding system, and explain the basics.
 
Mike
vxb bearing
15000 rpm
11200n dynamic load
6550n static load


sfk
15000 rpm
2520 lbf dynamic load
1470 lbf static load

11200n = 2517.86016272 lbf (extra money gets you 2.14 "ish" lbf extra load dynamic)

6550n = 1472.498577305 lbf (extra money doesnt get you any extra static load.)

Hope this helps
 
Originally posted by MLKWoodWorking

http://www.vxb.com/page/bearings/PROD/6005ZZ10-1

Thanks Randy for showing my senile side! [:0]

EDIT: Corrected for the double shielded.
Click to expand...

Mike: I was just getting ready to tell you that you had the wrong bearing; but I see that you caught the mistake. The RS code on the bearing you originally mentioned is a "RUBBER SEALED" bearing and what is in the JET is a double metal shielded bearing.

I'm no expert in this area so the fact that I say I have never heard of the VXB brand doesn't mean a whole lot. It looks like they are made in the US which could be good and they are made out of SS which could also be good. They are quite a bit cheaper, price-wise, that what I thought good bearings should cost so that might be bad. VXB does not state what the ABEC rating is. You might want to call them and find out.

jwalt posted a link to McMaster and I have some concerns about what I see there as well. First off, they claim their bearings are ABEC class 1 which is the lowest class of five qualities available. ABEC classes are 1, 3, 5, 7, and 9. The MMC bearings are not made out of SS.....probably not a big deal; but may indicate a lesser quality and I did not see where MMC indicated if the bearings were made in the USA or foreign made. Finally, their price is about twice what I thought a quality bearing should cost. Heck, I don't think JET even charges that much for their OEM replacements.

Bottom line, I don't have a recommendation for you. One seems too cheap and the other seems too expensive. Still think your best bet would be to get out the yellow pages and see if you can find a local bearing supplier to talk to. I would try for Timken or SKF bearings unless a salesman could convince you that he has an equal product.

By gut feeling is that pretty much any bearing should work. There are not terribly large loads on the bearings of the mini lathes and most of them don't get run but a few hours a week so in most cases, when bearings fail, I think it is not due to wear so much as it it to the bearings not being quite right when manufactured.

I hope someone will drop in who has more experience in this area and can offer some good comments. that's part of the reason that I suggested calling a bearing supplier.

And one final question. You said your headstock heating heat problem had been solved by loosening the hand-wheel. So why are you still interested in buying bearings? Do you still have some reason ton suspect your bearings are bad??

Good luck!!
 
Originally posted by Randy_



The MMC bearings are not made out of SS.....probably not a big deal; but may indicate a lesser quality and I did not see where MMC indicated if the bearings were made in the USA or foreign made.
Click to expand...


The company that I work for is a certified relubrication facility so this is something that I know a bit about. An old saying in the bearing industry is "It's all in the balls".... Stainless steel is corrosion resistant but it is also relatively soft, therefore they would tend to wear out quicker. I would personally want a bearing that is much harder in my lathe.

Another sad fact is that a good bit of the high quality bearings are manufactured in China. You heard right China. They have factories that excel at producing extremely high quality miniature bearings. If you take a moment to think about the hard disk that's probably whizzing away in the computer that is very close to you there is a very high probability that the bearings that are in that hard drive were manufactured in China.


Randy is correct in regards to the bearings failing not so much by wear as by abuse. It's not a good idea to hammer anything into or out of your headstock because you can damage your bearings in a way that is referred to as brinelling.

http://en.wikipedia.org/wiki/False_brinelling

http://www.nationalprecision.com/c11basics.htm

http://www.precisionspindle.com/brinelling.htm

http://www.mrotoday.com/mro/archives/uptime/bearingsAM1999.htm

You can also brinell your bearings during installation if you do not support the bearing properly during assembly.


One last thought...... Make sure that the bearings that you are buying are lubricated with grease! A buddy of mine had to replace his bearings a second time because the ones that he purchased were only lubricated with oil. Each manufacturer has their own designation for a bearing lubricated with oil and one lubricated with grease.
 
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