cincinnatti no 1 T&C grinder spindle rebuild

Yesterday I discovered my bearings were shot in the no1 cin so pulled out the spindle and disassembled it the bearings are 35x62x14 6007 sized the bearing #'s don't come up in any searches .
Wondering what class bearings would be best for this application

Deep groove ball bearings - 67-2RS1

Although, the ones in my spindle are marked as matched (smallish dot on side of bearing). Mine are a bit noisy but was advised that changing them is major $ if keeping with matched pair. There was a thread on MadModder where someone did a lot of work to align bearings without buying matched ones.

Mine are kaput they are rough and one feels like it has an indent when I tuned the spindle so reusing isn't an option for me.

I'm thinking bearings made today are of better accuracy then when this machine was built so your probably right that a good quality bearing could be fit and still give descent results .

But then again maybe not hoping someone has done something similar and could chime in

I'm sure that authentic bearings would be better than in the past, the risk is higher though for fake ones :-(
This thread shows one person's approach on a Cincinnati No2 T&C: Spindle problem with cincinnati tool and cutter grinder 2 spindle

My grinder is from 1920's I think but it was converted with a spindle cartridge to replace the overhead line shaft.

at the big shop our Cinci #1 spindle was going bad so our bearing man just made a new spindle shaft sized for a set of beraings he had on hand form a never done job ,it was good again.
#1 is a very handy machine for the small foot print it takes.

eBay - Page Not Found

Mine is still running on the old tapered bronze bearings. I think it's 1900's vintage; not sure when they switched to cartridge ball bearings.

I say if your a mechanically inclined and you got the spindle out with-out dinging it up then congratulations for getting it apart. One important thing you hopefully followed is you marked the shaft when the inner TIR mark that looks like a o or * that was engraved in the inner race of the bearing location. On precision bearings the manufacturer marks the TIR (total indicator run-out) of the bearings path. The shaft is tested on a Centering machine or in V blocks at the factory and they mark the spindle and then mount the bearing inner race at 180 degrees from that spot.


If you didn't mark the spindle shaft where they were mounted you need to measure it before assembly. If you do not have a centering machine that looks like a lathe bed with 2 tailstocks that have been scraped to be in exact axis alignment. Then you mount then spindle shaft between centers and rotate the spindle by hand indicating with a .00005" or .0001" indicator on the bearing mount surfaces. Then use a scribe and hand mark that spot on bothe ends. If you do not have a centering machine set the spindle in 2 ground precision V blocks and indicate the lands.

Taft-Peirce Bench Centers by Suburban Tool - YouTube


Many times I used to get in a spindle Primitive Pete had taken apart and the star bearing retainer nuts were destroyed because they used a punch instead of a spanner to remove the nut (s). Another thing is when you assemble the bearings you will need to lubricate the new bearings. I would use Mobil grease 28 or 32 and pack it at 30% full or Kluber grease and pack the bearings at 25%. I would bet you could Google Greasing precision bearings or mounting them and see how it is done.

One more thing do nut use a brass or hardened punch to drive on the bearings and small flakes of metal flake off and contaminate the bearings. Clean is also key to a successful install, so clean the table spotless before the job. Assemble will be so much easier if you have a bearing heater so you heat the inner races and it expands a couple of thousands and it falls on.

In some cases if I wanted super dupper smooth running spindles I would send the spindle out after assembly and have it balanced. Rich

PS: Buy # 7 precision bearing, preferably a matched set...Buy from a known bearing house so you don't get a fake Chineese ones.

Original bearings are Hoffmann and contacted them a few days ago , they replied to my email asking how many bearings I need so it appears they are available but the pricing is making me nervous I'm sure they are pricey but should have news in the morning.

I looked on ebay and seams to be lots of 7007 type P4 P5

well I ended up installing a set of deep groove ball bearings for now until I get the correct bearings , it runs smoother and quieter than it ever did so don't think the bearings were ever good since I owned it.

I ran it a few hours tonight and kept going back and forth to the surface grinder to fine tune the shim I had to make to preload the bearings .
It runs quiet without any vibrations or heating up, preload remained the same as it warmed so it appears to be running right and tomorrow I will try it to see what kind of accuracy it gives .

Hoping it will be good enough to put a sharp edge on the tooling it was used for

I've been using this grinder all week with the new bearings and it's giving a much better finish than the old ones were giving and it's quiet .

It's hard to say if these ********* 6007 bearings will last but for $19.50 per bearing it won't break the bank even if they don't .

Check RPM to know you are not over speeding a wheel as it is marked for speed. know what grit and hardness is good for he work you wish to do. likely 3800 and perhaps 5500 would be good speeds

#1 is a very nice machine.

We had one with the motor set above the spindle. that made it easy to spin the wheel head to use the other end of spindle. Good also to be able to reverse the direction.

Ours was quite wore out so we greased the long travel ways and still it did very good accuracy..

Much sharpening is just a short travel so a machine need not be perfect to do good work.

Even long travel jobs with such as a reamer having back taper, that back taper can reduce the effect of long travel not being perfect.