Bearing Experts: Need Advice: SUCCESS!

[daddo]

Done a lot of restoring on old machines.

One thing I learned. If the bearing is smooth and can be lightly re-packed or cleaned and repacked- keep it the way it is.

I have run into bearings that no longer exist and I had to get a close metric and modify shafts or housings to accept the new bearings. A lot of work I do not suggest.
Some bearings are (deep) particularly for lateral stresses- be aware of these as some old bearings may have numbers hard to see.

Removing an old bearing may damage it permanently and make it useless, and if the new bearing is off by .001", it can ruin your day.

[Philip1231]

Sorry folks: offline for a while. Thanks everyone who responded. A few days ago I knew nothing about bearings. Now at least I can say I know next to nothing.

So it ends up that these bearings made by MRC are obsolete: this was indicated to me by the good folks at MRO supply. They did have a replacement at a very good price, but lead time and minimum order requirements did not work for me, so I opted for the NSK bearings from Amazon, which were delivered yesterday. Got the metric calipers out: yes they measure 17 x 40 x 12 just as the spec says they are. New ones look to be identical. These are apparently deep groove bearings, and the replacements are supposedly the same. The cross-reference book is apparently the answer to sourcing an equivalent bearing, and the one I came across was actually found on the MRO website.

Daddo makes an excellent point and that is my wheelhouse: leave it alone and don't look for (more) trouble. We shall see: I am already too far down the road on this project, as I have removed both bearings. The one bearing that was fit tight to the spindle required the use (and purchase) of a bearing puller. These things work, but they apply the force to the outer race for removal, I guess rendering the bearing useless, or at least suspect.  Unless I am missing something (do I have the bearing puller plate flipped upside down?) these bearing pullers work, but at a cost.

I ended up using copious amounts of PB Blaster to get things apart, and I assume that probably liquified any grease remaining in the original bearings. These bearings seem to spin effortlessly with not sign of anything being out of kilter. However, being sealed, I guess there is no way of repacking them with grease, the way they are apparently supposed to be lubricated. I wonder if using a spray lubricant like Triflow with Teflon, which makes them spin like a top, is an acceptable alternative? This is how I treated the FAFNIR bearings on the actual drill press. It is definitely a lot easier than going the replacement route.

I will be reassembling over the weekend, and if the bearing gods are with me, I should have a functional motor by Monday. At least the paint job on the motor is coming out first class, so even if it never runs again, it looks good

[Cian]

(04-09-2021, 07:16 AM)Philip1231 Wrote: The one bearing that was fit tight to the spindle required the use (and purchase) of a bearing puller. These things work, but they apply the force to the outer race for removal, I guess rendering the bearing useless, or at least suspect.  Unless I am missing something (do I have the bearing puller plate flipped upside down?) these bearing pullers work, but at a cost.I will be reassembling over the weekend, and if the bearing gods are with me, I should have a functional motor by Monday. At least the paint job on the motor is coming out first class, so even if it never runs again, it looks good

I'm not a machinist by any stretch, but those bearing pullers are a worthwhile investment. And, yes, they do pull on the outer race, and I wouldnt use the bearings after removal if I had a choice. The cost to replace is very minor compared to the labor.

Good luck.

[Philip1231]

Success!

It all went back together with nary an extra part. At the very last minute I figured out how to support the lower bearing inner race as I drove the spindle in from the top: put a socket in the opening that supported the bearing and smacked the other end with a hammer; beautiful! Cleaned the contacts on the centrifugal switch, wired it up, and it runs like a Rolex! You might be seeing this motor soon in another post