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Bridgeport bearing?

MGKELLY

Plastic
Joined
Jan 31, 2014
Location
NJ
Hello, I’m not a machinist by trade and looking for specs for bearings to rebuild my 2J head.

For example: Radial/Deep Groove Ball Bearing - Round Bore, 35 mm ID, 72 mm OD, 17 mm Width, Double Shielded, ABEC 3

I’m aware that I can purchase Bridgeport bearings online from multiple sites, but I would like the specs along with the part numbers.
I don't want to be a pain in the arse, but is there a sticky or would someone have specs for all the BP bearings?

Thanks, Joe
 
2 of : 6203-2RS Bearing 17x40x12 Si3N4 Ceramic Sealed ABEC-5 Bearings
2 of : 6908-2RS Ceramic Si3N4 ABEC 7 Sealed Ball Bearing 40x62x12
1 of : 7007C P5 ABEC-5 Quality High Precision Angular Contact Bearing 35x62x14
1 of : 7206C P5 High Precision Angular Contact Bearing 30x62x16 ABEC-5
1 set of : 7207CYDUP4 Nachi Angular Contact Bearing 35x72x17 Abec-7
 
These are the spindle bearings
This is kit SRK-00 from H+W
ac858973d5737cc1d0bbc657f122ef4c.jpg



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Hello, I’m not a machinist by trade and looking for specs for bearings to rebuild my 2J head.

For example: Radial/Deep Groove Ball Bearing - Round Bore, 35 mm ID, 72 mm OD, 17 mm Width, Double Shielded, ABEC 3

I’m aware that I can purchase Bridgeport bearings online from multiple sites, but I would like the specs along with the part numbers.
I don't want to be a pain in the arse, but is there a sticky or would someone have specs for all the BP bearings?

Thanks, Joe

Can I add a related question that I'd like to see as a sticky? If we change the spindle bearings, will we then HAVE to regrind the R8 taper? Did Bridgeport grind the tapers with the spindles insitu? Were the runouts on the original bearings worse than ours are now (such that the grinding process TYPICALLY resulted in a loss of concentricity with the quill (i.e. spindle OD)?

My spindle bearings seem ok. I would change them, but I'm worried I'll lose the runout of my spindle.
 
I just replaced the bearings on my Acer(BP Clone)
I did not regrind the taper.
I have just under .00015” runout. I figured good enough, some places only guarantee .0001 after a regrind, but that seems high to me if done with the new bearings on.


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If we change the spindle bearings, will we then HAVE to regrind the R8 taper? Did Bridgeport grind the tapers with the spindles insitu?

My spindle bearings seem ok. I would change them, but I'm worried I'll lose the runout of my spindle.

Adam,

As I recall the book mentions something about sending the spindle to be reground with the quill, insitu. But in terms of replacing spindle bearings, I doubt regrinding happens very often, unless the spindle taper is trashed.

jhruska here on the forum is a rebuilder and he never mentioned regrinding the spindle when he told me how to replace spindle bearings.

The H&W video doesn't mention any regrinding when they change the spindle bearings.

Imo, even if there was a very slight misalignment between the spindle and the quill after bearing replacement (I can't imagine it would be beyond a tenth) it wouldn't really affect anything.

Let's think about it, when milling, you tram to the spindle not the quill. So parallelism between the spindle and quill really doesn't matter when milling. It could make a difference when drilling, but the small potential difference in parallelism would be much less than typical runout of a drill chuck, or even a collet. So I can't imagine that would be noticeable either.

Either way, I can't see how replacing spindle bearings would increase runout, unless they were cheap bearings, or installed wrong or the spindle was somehow bent.
 








 
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