Cincinnati No.2 Tool and Cutter Grinder

[RayG]

Hi RC,

Still trying to understand the different grades, there doesn't seem to be any benefit in terms of eccentricity going past P4 (abec7) the eccentricity is still 2.5..

2 microns, is spot on nice work!..

Regards
Ray

[Machtool]

What's the precision of the RHP 7305 TADULEP7 bearings? P7 doesn't appear in the tables..

That’s an old RHP designation, probably 15 years. EP7 is the Accuracy. Meaning ABEC 7 / P4

(I'll send an email later with details, and grab a pair.)

To me or them? That don’t generally deal with the public, they barely tolerate me.

Do they make a 2305 in precision grades, or is it that the "self aligning" feature negates the precision anyway?

Not that I’m aware of, and Richard put plenty of work into it. I’d be putting a 6205 in there. Best quality we can find.

Lewis list a Fafnir 6205 – C2, being reduced (less than Normal) clearance. No other information But would surprise me if that was a reasonable precision. They used to claim they didn’t make anything less than ABEC 7

Preload being light wont worry you, its still a preload, and every thing you do on a tool and cutter ends up with wash out / spark out passes any way.

I looked up my tables, a shift of 18 microns moves that bearing from light to medium preload. So too small to shim, I can show you how to pop them apart without damage and grind / lap a ring, if you wanted to go that way.

Phil.

[.RC.]

I think Fafnir make plenty of standard grade bearings now, being part of Timken and all...

BTW that would be a 6305 not a 6205...

[RayG]

BTW that would be a 6305 not a 6205...

Thanks RC,

Here's a bit of a classic for you, paper shims to adjust preload...



I got one end off ok, that was the end where all the threads are right handed, but I can't seem to budge the other end, on yours was the outer bearing cap left handed at one end and right handed at the other?... All the other threads are left handed at one end and right handed at the other.. Doesn't want to move either way at the moment, and I'd like to know I'm going the right way before I start applying a bit more persuasion..

Regards
Ray

[.RC.]

The inner cone shaped retainer will have a left hand thread on the other end, but the outer retainer will be just a normal right hand thread as it is stationary..

[Bryan]

I can show you how to pop them apart without damage and grind / lap a ring, if you wanted to go that way.

Popping bearings apart without damage is something I wouldn't mind knowing too. Is that something you can share or a trade secret?

[RayG]

Hi .RC,

Yep right again, both the outer shells are right hand thread, much easier when you turn the right way..

Here, just for interest's sake is the 2305 from the other end, note that it has P6 etched after the number, so I'm guessing they (SKF that is) probably sorted through a batch of standard 2305's and picked the best..



GQ might recognize the background...

Hi Bryan, I've heard AC bearings can come apart, but I've never seen how it's done, I guess you just press the right way, because, when you look at it there is nothing much holding them together. (until they are installed that is..)

Regards
Ray

[harty69]

Popping bearings apart without damage is something I wouldn't mind knowing too. Is that something you can share or a trade secret?

me three

cheers
Harty

[.RC.]

P6 is not precision Ray.... Well I tell a lie... P6 is the first precision class up from P0 which is standard class...

Opposite to ABEC....

I have found some precision self aligning bearings though..... From a bearing company in Slovakia

http://www.zvlslovakia.sk/en/vyrobky8.php

Some good reading in their catalogue when it finally downloads http://www.zvlslovakia.sk/download/katalog-en.pdf

[Machtool]

BTW that would be a 6305 not a 6205...

Opps my bad. In that case they are showing a SKF 6305 P5. I'd have to look if that accuracy tightens up the internal clearance.

On the accuracy, much of what they have around there is old, old stock, going back to when Fafnir seemed to only do precision.

Phil.

[Log]

Thanks RC,

Here's a bit of a classic for you, paper shims to adjust preload...



I got one end off ok, that was the end where all the threads are right handed, but I can't seem to budge the other end, on yours was the outer bearing cap left handed at one end and right handed at the other?... All the other threads are left handed at one end and right handed at the other.. Doesn't want to move either way at the moment, and I'd like to know I'm going the right way before I start applying a bit more persuasion..

Regards
Ray

Nothing wrong with a quick paper shim to get ya out trouble when necessary, with precision bearings it's especially ok if you use paper from a bearing book or bearing instruction paper, as in the picture,,.
That is a bearing ball and races on the paper shim I can see in the pic, yes?

Good to see you are able to get bearings at a good price. Soldier on, and thanks for showing the project.

Cheers.

If I'm not right, then I'm wrong, I'll just go bend some more bananas.

[britannia]

Thanks for all the info on Cincinnati #2 T& C Grinders,one came up at a local (Darwin) auction last Saturday. I was able to see what the accessories were by your photos & went confidently to bid, no one else knew what it was & I won it for the opening bid of $200. now I have it at home I found it is in better condition than I thought, I did have a problem with the Wheel head being stuck as Ray did but I solved that today, My next problem is that The head will not come off ? I loosened the two nuts inside the head (photo attached) but even with enough weight to almost lift the machine no go?
I found a manual to download but it is for a 1975 & mine is 1935,
I dated it with a list I downloaded (attached) that dates by serial number prefix.
The machine is still on my truck as I had brake trouble on the way home & it is on stands in the shed where I would have set the grinder up to work on it. While I wait for brake parts I am climbing up to get to it.

[.RC.]

A manual for that grinder is here... -->> http://users.beagle.com.au/lathefan/...grinder001.pdf

I thought the wheel head was only held by gravity... My macson was...

[RayG]

Hi Barry,

Congratulations on a nice pick up, I haven't had the wheel head off mine, so I'm not sure I can help much in that regard.

Thanks for the build dates listing, mine is C3701/42 which would make it much earlier than I thought, C is 1935.... I was thinking it was 1950's era Birmingham, well there you go...

Back to the question, I've found parts manuals to be a bit unreliable, the operators manual that RC linked to is fine, but when it comes to dissassembly, there are so many different models made over a long period by different factories, that you need to take the parts manuals with a grain of salt.

I can scan the manual (such as it is) I have for the wheel head pages if you think that might help.

Has yours got rollers or balls for the table?

Regards
Ray

[britannia]

Thanks for the quick reply fella"s.
I already have that operators manual R.C but thanks.
The Service Manual I have shows a later (1975) model with motor on the head. If you have an exploded view of the head for the model we have I would much appreciate a look Ray.
My Serial number is C4103-35 made by Cincinnati Milling Machines limited Birmingham.
Before finding the date list I would have assumed the 35 was year of build?
I found the list on a forum while searching for manuals, so can't vouch for the accuracy.
It would seem our machines are closely related Ray but mine has balls, perhaps brother to your Miss?
I did not remove the slide for transport but fitted small wooden wedges to lift it & all seems well as it is still as smooth as.
I did however slide it along to look inside (curiosity) & there are no chains, maybe the patents are different?
There is a list of patents on mine so we could compare if you wish.

If the head is held on by gravity could our gravity be heavier than Birmingham's I missed that episode of Julius Summoner Miller.

Cheers
Barry.