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DennisNYS
07-08-2009, 06:44 PM
Does anyone have a favorite on-line source, for Bridgeport bearings ?
H&W seems very high for these particular bearings.
I currently have my mill COMPLETELY disassembled, for a thorough cleaning.
The bearings located inside the knee (Z ?), and the X, and Y handles, just do not
feel smooth, at all !
Thank You,
Dennis.

lane
07-08-2009, 06:47 PM
Any bearing supply house can match all the bearings , except the spindle bearings. They can be gotten easy enough . just takes $$$$$$

Rookie machinist
07-08-2009, 07:08 PM
Let the bearing replacement debate begin!!! The corrcet bearings are not cheap, I believe about 500 a pair. Search the forum for bridgeport bearings and you will find lots of posts and the correct part numbers.

lazlo
07-08-2009, 07:13 PM
The spindle bearings are Fafnir 2MM207WI DUL. That's a standard 7207 angular contact bearing pair, light preload, ABEC-7 tolerance.
The spindle pulley bearings are specials: ABEC-3 6207's (radial bearings) that are match-ground for light axial preload, IIRC.

The knee bearing is a 5306 non precision double-row angular contact bearing.

I'll have to check the manual when I get home for the table bearings, I think they're 7204's.

oldtiffie
07-08-2009, 07:52 PM
Wow Lazlo.

That's about as good and as accurate and concise as it gets.

Do you or anyone else have a comprehensive cross-indexed/referenced listing of bearing numbers, cost and manufacturers - preferably world-wide? It will give many people the options of types, classes, source of manufacturer, countries of source and performance criteria as well as cost.

A good bearing manual and similar reference material/s would be pretty well essential reading I would think or else the "numbers" and "grades" may mean little or nothing at all. This particularly applies to installing the bearings - especially the spindle cartridge.

lakeside53
07-08-2009, 10:01 PM
Ebay is my favorite source - if you know the cross reference numbers, there are some killer deals! I troll ebay for spindle and other bearings every day...

In addition to Fafnir/timken, the other common spindle bearing manfs are Barden and RHP. Be sure you are getting 15 degree angular contact when looking at Barden - many on ebay are 40.

You can use "non-precision" 7207 SU DB ground bearings for the pulley. Harder to find with seals though. I found some magneto bearings -JM207K PP DUL that worked perfectly...

H&W will sell you standard 6207 bearings for the pulley. IMO.. they suck in that application.

wierdscience
07-08-2009, 10:13 PM
Anybody try these spindle kits from H&W?RHP bearings,can't be too bad.

http://cgi.ebay.com/SPINDLE-REBUILD-KIT-BRIDGEPORT-MILL-ABEC7-INSTRUCTIONS_W0QQitemZ130257621546QQcmdZViewItemQQ ptZLH_DefaultDomain_0?hash=item1e53f5922a&_trksid=p3286.c0.m14&_trkparms=65%3A12%7C66%3A2%7C39%3A1%7C72%3A1205%7C 293%3A1%7C294%3A50

lakeside53
07-08-2009, 11:43 PM
The RHP 7207 (as pictured) are good lower spindle bearings, but on a step pulley head, I don't agree with the shielded 6206 bearing for the top. Oil will build up on it (if from no other source on a step pulley head - from the bull gear dripping down the worm) and flush out the grease, so why bother with grease in the lower? The BP system is designed to be "full loss" and relies on continuous clean oil available. If you can find them a decent price, Use an unshielded 6206, preferably a C2 of abec 3 precision class. I've used a top quality unsheilded 6206 (or a sealed version with the seals removed..).. seemed o.k...


Sometimes Ebay sellers supply sealed "spindle bearings". These may be listed as abec 7 but they are not internally the same as a BP spindle bearing. The seal will eventually result in a lot of "dirty" oil (it accumulates slowly and the junk settles onto the bearings) on top of them ultimately flushing out the the grease...

Yes, it's possible to design a sealed system (BP did supply sealed heads to the woodworking industry), but not just by putting sealed bearings in the spindle.

tattoomike68
07-09-2009, 12:08 AM
Iv put 80mm semi truck bearing into a 2.5" 6 spindle wickman screw machine. it was a $110 , i could have waited and spend big bucks and not had much better results. The machine was holding less than .0005 again afterwards.

You can get $40 bearings and put them in an old bridgport mill spindle and run them for years. the same bearing you would use on your snowmobile/ 4 wheeler trailer.

Was it the right way to fix the machines? Hell no! Did it get them back in service in short order? Hell yes it did.

just dont let the bearing salesman screw you, he can take a cheap bearing and put stars on it and charge you 5 times the price. Tell me how would you ever know?

lakeside53
07-09-2009, 12:26 AM
Unless he has a laser engraving machine... I can tell:D and in any case, the construction of precision spindle bearings is quite different to typical wheel bearings (Duplex ground?). Spindle bearings are matched pairs in sealed pouches of lubricant. I buy sealed NOS - never been "had" yet.


I'm betting these will go for less than $100, maybe as low as $60.

http://cgi.ebay.com/1-SET-FAFNIR-2MM207WI-DUL-SUPER-PRECISION-BALL-BEARINGS_W0QQitemZ370225786924QQcmdZViewItemQQptZL H_DefaultDomain_0?hash=item56332d302c&_trksid=p3286.c0.m14&_trkparms=65%3A1%7C66%3A2%7C39%3A1%7C293%3A1%7C294 %3A50

bborr01
07-09-2009, 12:33 AM
Hi Dennis,
I see this is your first post. Welcome to the site. I have seen a few threads about this subject and you will probably find additional information by using the search function, although I already have seen some good new posts.
Regarding the spindle bearings, I have to agree with lane from a provious thread that spindle bearings don't go bad that often. For the rest of the bearings, I cant see spending a lot of extra money on some high grade bearings for low rpm and low stress bearings.
Brian

tattoomike68
07-09-2009, 12:41 AM
Unless he has a laser engraving machine... I can tell:D and in any case, the construction of precision spindle bearings is quite different to typical wheel bearings. Spindle bearing are matched pairs in sealed pouches of lubricant. I buy sealed NOS - never been "had" yet.

yea he can lazer some stars in and pack them in greased pairs. I just dont trust them guys. Does that mean they are true to a butthair? I think not, few shops have a swedish guage and a man to scrape the bearing true so what happens is they slap it in the machine and run the hell out of it.

When the boss is bitching,, GET THAT MACHINE RUNNING RIGHT NOW you just get er done.. no time to inspect the bearing down to the millionth of an inch.

lakeside53
07-09-2009, 02:22 AM
Back to the original post - if all you are needing is x/y handle bearings and knee - those are available everywhere, any are not precision. It's also rare for the handle/screw bearings to ever fail; the knee lift support bearing is another story. Earlier BPs had a "custom" bearing for the knee - a W306PP3 (NOT W306PP)- a flanged bearing with a combination shield/seal. Later knees had the sealed 5306 with a spacer washer.

pcarpenter
07-09-2009, 11:26 AM
Geesh-- talk about a post going off topic. The OP was asking about the knee bearings and the table thrust bearings...both of which are not standard items either.

The table thrust bearings are a back to back pair with indicators etched on them. They bear all load axially and need to provide zero runout in that axis. They are not a standard thickness. I cleaned the hard grease out of mine (mine were grease sealed) and repacked and all was well but for one....where I dinged a shield enough that it drags. I went in search of a replacement to find that a standard bearing of that diameter is not as thick as the original....and likely will have more axial runout. I may try shimming one to proper pre-load to make this work as the proprietary item is pretty expensive and its' a *very* low speed application. All that matters is that it be able to provide zero runout.

The knee bearing as mentioned is a proprietary variation on a 306PP. Mine had 306pp seals in it, sending me in an odd search for the right item. As mentioned, it would be easy to take a standard 306PP and use a shop-made washer on top to make up for the raised center race which appears to be the only difference. I found a 306PP and intended to do this...may still some day. However, again, pulling the rubber seals and cleaning and re-packing really solved my problem with hardened grease.

Edit-- by the way, I have purchased a few things from H&W and dealing with real people who are in the machine tool rebuilding business is really handy. My only disappointment was in ordering a head mounting washer to replace one that was missing. Instead of a washer with a radiused edge like the original, I got a standard black oxided washer....which I could have gotten locally, or made myself.

good luck to you....especially with reading through the off-topic spindle bearing information:D

Paul

lazlo
07-09-2009, 12:07 PM
The spindle bearings are Fafnir 2MM207WI DUL. That's a standard 7207 angular contact bearing pair, light preload, ABEC-7 tolerance.
The spindle pulley bearings are specials: ABEC-3 6207's (radial bearings) that are match-ground for light axial preload, IIRC.

The knee bearing is a 5306 non precision double-row angular contact bearing.

I'll have to check the manual when I get home for the table bearings, I think they're 7204's.

I checked my 1966 manual this morning, and those part numbers I listed are correct.

The table bearings are "Norma XF-12": 20 mm ID x 47 mm OD x 15.4 mm width.

That's an oddball felt-sealed angular contact bearing that's no longer made, but a standard 7204 angular contact bearing is slightly thinner (20 mm ID x 47mm OD x 14 mm width). So you can just replace the stock Norma's with a pair of 7204's (cheap at any bearing store) and shim the 2.8mm difference.