Covel Tool and cutter Grinder No. 6 followed me home. Lovely little grinder!

This last weekend I got a good deal on a little Covel No.6 that will be able to do what I need. It seems to be capable of doing basic OD/ID grinding and also light surface grinding. I have a Precise 30 spindle and a adapter that will bolt right on to the face of the main spindle so it should work great.

Great little machine and i'm all exited over it!!

I found a good description of its various accessories in http://www.iamachinery.com/brochures/scans/0013.pdf and I got the parts manual from Clausing.

I tore it down yesterday to clean it up, possibly repaint it. The slide ways are great, all the flaking is intact.

I need to replace the main bearings since they are filled with totally gonked up grease but it uses regular 6206 ABEC 5, deep groove ball bearings so the cost is reasonable, I plan to find some shielded or sealed 2Z or 2RZ bearings to make it easier to keep them clean when assembling. (Clean ABEC-3 bearings are way better running that a ABEC 9 bearings with particles in them...)

The only real problem I found so far is that there is some damage on the taper for the main grinding wheel and I did not get any wheel adapters. The PO had made a extension on it that threaded on to the spindle (that has 0.007" runout..). I will most likely have to re-grind the taper but I would need to know the angle (and find someone with a grinder, I might be able to go to the buyer of my previously owned Covel 512 and ask him for help but I'm not sure if he can set the table that much. That machine did not have the universal work head.

The gentleman I talked with a Clausing did not know the specification on the adapter.

Any chance someone here knows? Anyone with an adapter for sale?

I also need to find a suitable work head, ideally one with 5C or MT2 taper since I have plenty of collets in those sizes.


Any help is appreciated.

Ulf

Congrats on that nice find. I just brought home a T&C grinder; a KO Lee B600. The ways on this one are worn, but nothing that seems to contribute to inaccuracy in table movement. Spindle has less than 0.001" runout. I've gotten about as far as taking it all apart, cleaning the dried dirty grease off the screws and ways, and getting everything moving smoothly with a film of fresh oil. It's heavily used and the paint is ugly. But I don't think I will invest the time to repaint it. I liked this KO Lee because it's small and seems pretty versatile. Once I get some projects going I will know for sure.

Sorry I didn't answer any of your questions.

-Justin

As for wheel adapters, check out Sopko. William Sopko and Sons Co. - Precision Wheel Grinding Adapters and Spindle Accessories Manufacturer.

Thaks Boano,

I need to check the taper but the short cylindrical portion before the taper start is .875 so theese might work. I plan to use it as surface grinder also so the extended ones looks great.

Standard Taper Balancing Wheel Adapters for Small Surface Grinders


Cincinnati Taper Long Extended Wheel Adapters.
4.500" TPF WITH .87" DIAMETER AT LARGE END OF TAPER. FOR 1.250" ID WHEELS. USED ON ALL CINCINNATI NO. 1 OR NO. 2 SPINDLES, COVEL, AND GALLMEYER & LIVINGSTON CUTTER GRINDERS; OR ANY SPINDLES WITH .87" DIAMETER AT LARGE END OF TAPER AND 4.500" TPF.

This is great! I am so glad you posted the link to the brochure. I just inherited one of these. It was my grandfather's. My father inherited it, but then after a move didn't have room for it anymore and passed it to my brother. He decided he doesn't use or need it so he passed it to me. But he kept the mill and lathe. The jerk.

Anyway, I get it home and start looking into it. I couldn't figure out why a surface grinder, which is what I was told to come pick up and what I had seen used before, would have a rotating head. I couldn't think of a reason to surface grind with the wheel spinning any way but parallel with the primary movement of the table. I googled all over the place trying to find information on this Covel Type 6 surface grinder and couldn't find anything about it. It seemed like mine was the only one in the world.

And then a moderator at hobby-machinist.com realized and pointed out to me that it's not a surface grinder, it's a T&C grinder that doubles nicely as a surface grinder. A "universal grinder." As soon as I changed the search to "covel 6 tool cutter" I found this discussion. It makes SO MUCH more sense now!

I registered here because I want to pick your brain about this machine. Any update on yours? Is it working well? Any shortcuts you can share with me regarding what will fit on it?

Presumably because my father and brother didn't realize that it does more than just surface grinding, the rest of the tooling is gone. All I have is the permanent magnetic chuck, a nice "toolroom sample pack" of grinding wheels from the Carborundum Company, a dressing tool, and a few setup blocks and angle plates. While that is plenty to get me going with surface grinding, once I get it cleaned up, I am suddenly very interested in learning to use the rest of its potential.

Seriously, ANY information you can share would be beneficial. I've been reading book after book and watching one YouTube video after another for the past couple years learning about machining, but I'm really just getting started. I have less than 10 hours on the lathe and it has very little tooling and only the lantern-style tool holder. And a tailstock drill chuck that slips. And only homemade dead centers that aren't hardened and therefore deform in no time. And it was disassembled to clean it up and paint it but then never fully reassembled so there is no leadscrew or leadscrew gears. It's a sorry state for a good lathe.

I hope that makes it clear how much I have to learn here. Practically everything. One of the reasons I like it is that I realized that I now have no need to ever buy anything like a Drill Doctor (my handheld bit sharpening attempts have been largely successful roughly 60% of the time), and I have a box of dull drill bits I've held onto over the years. I figure that's as good a task as any to learn how to use this. So what do I need to look for?

I hope you don't mind me bringing this thread back from the dead and asking so much here (in my first post on this forum), but there is precious little information about T&C grinders out there, and even less about this universal type. Thank you for any help and direction you can provide!


- Jon

Likely the wheel mount taper will be the brown and Sharpe 3” TPF or the Cinci 4.5 “ TPF we just called them the stub or long taper. I think best to restore the spindle with lining up bearing rotation marks and a little over ¼ fill best quality grease (if you choose grease or oils spindle). Pre-load if you can find specifications (often I just did a little past hand tight if the threads were smooth a distance past in a try with no bearings. The nose is best restored in place as the centers may not be best after long use. I would run under a tenths indicator to see error and mark high then hone off high. Grinding is a tough job because you only want to just clean up high side with taking nothing from the low side. I have honed in to remove .002 (or so) from the high side and the held a hone to the running nose to make a perfect nose in less time than it might to set up a grinder to do the job. The taper is found and proved by blue-up the nose and feel hone to correct high side to touch in two places with light (or a slight under section at middle. Yes a good quality mount is best for blue-in. High speed spindles 8k+ or so should go by the book for preload and heat tested(all spindles should be heat tested to get a little warm running an hour but never hot. IMHO... Much the mount is made running true to get best balance by having the nose run true, The wheel is dressed to get best running surface and also balance.

ulf,

I'm curious, what is the serial number on your machine. I'm sitting here looking at my Covel and it's #6-113.

Stuart

6-593 here.

intjonmiller said:

View attachment 138600

6-593 here.

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Wow..assuming the serial numbers are in some chronological order my machine is a dinosaur. It looks and feels new, has a million attachments..and it was almost free-to-me. A very versatile grinder in my book.

I called the company that purchased Covel, spoke to a old hand and asked him if he had any literature on the grinder. He said he had a real comprehensive "how to/setup" book and he would have his secretary copy it and send it to me. Must have been too much trouble to copy....he sent me the original book instead, what a nice guy.


Stuart

That's incredible! Any chance you're able to share that book with me? Either by scanning it or by sending it to me to scan? I have a lot of experience there, as most of my working life has been in the printing and digital imaging industry.

I would love to see what you have for yours as well. Photos, videos, anything really. It makes me sick to think that the tooling for this one was scrapped or dumped some time ago because no one knew what it was or how to use it. But then, knowing my grandfather and how he acquired a lot of his tools, they may have been gone before he picked it up.

OK Guys, don't stop now. What ever you provide gives me ideas to use on my Cincinnati #2. I have had mine for a year now and after rebuilding it because it was dumped off a forklift while loading it. From the other shop to mine. It is finely up and running. As incentive to still take the grinder off his hands he threw in all kinds of tooling and accessories. Except for a gear grinding set-up, a large saw blade jig, and a tool height gauge I pretty much have all the parts shown in the parts book. Been flustered a couple times wondering why I even bought the thing. But now that I am doing simple grind jobs, lathe tool bits(threading etc.), grinding tapered collets to finish size I am really starting to appreciate the thing.

It is truly amazing how nicely a lathe tool works when all the angles are as advertised. By hand is good, by machine is perfect. Had to turn a short lead screw with a 6 TPI square thread. Material jumped and hopped while between centers. With the tool correctly ground it cut like butter with the big thick chips just curling away. I was sold. Correctly done the tool nose had a slight rake which allowed it to clear and not rub and bind on the previously cut portion of the thread. Way cool when things work as advertised!!!!!!!!!!!!!!!!!

Keep blazing away and pay attention to that Michigan Buck guy. Seems to know his stuff, or he fools the hell out of me.

Thanks for the complement rdhem ..but there are other guys with help as good (some times better than) as mine so don't not give them credit also.
Good you mention the #2 because one can down-load the manual for free and it is good for many other TC grinders.

gulloj said:

Congrats on that nice find. I just brought home a T&C grinder; a KO Lee B600. The ways on this one are worn, but nothing that seems to contribute to inaccuracy in table movement. Spindle has less than 0.001" runout. I've gotten about as far as taking it all apart, cleaning the dried dirty grease off the screws and ways, and getting everything moving smoothly with a film of fresh oil. It's heavily used and the paint is ugly. But I don't think I will invest the time to repaint it. I liked this KO Lee because it's small and seems pretty versatile. Once I get some projects going I will know for sure.

Sorry I didn't answer any of your questions.

-Justin

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"Ways are worn"
Much of work of a TC grinder is a short swipe of an inch (more or less) and because of having all swings and movement a little wear doesn't matter very much for most jobs. The trick of line up with the old edge, an eyeball look with a 6 inch scale, a view test with a square or protractor can get very good work from a machine that is a little out.
Not at all like a surface grinder where the condition of the chuck, the square of the bump rail and the straight of the back rail determine the quality.

Just thought I resurrect this old thread to see how the rehab is going on the Covel #6 that followed you home.

Seems I had the same thing happen to me last May and it’s slowly coming together to the point now that I’d better figure how to use it. The machine (6-981) has been thoroughly cleaned, repainted near original color with missing parts made or scrounged. All ready to start sharpening some milling cutters… I think. Any helpful guidance here would be greatly appreciated as this seems a bit more complicated than my previous grinding experience of sharpening drill bits on a Lisle. Thanks all.



PS... how do you rotate these pics?

Most spindle extensions run out..what is that for ..surface grinding?
.0007 is fairly close for for an old or home made extension but not much good for surface grinding..

The grinder has been sitting for quite a while after I put it together with NTN 6206-C2 bearings. The clearance was to small in them and they were running hot so I lost interest for some time. (3 years....) I finally took it apart today and am going to give it another shot. I also got a nice motor and a VFD for it so that will make a nice addition.

Ulf

tribologist said:

The grinder has been sitting for quite a while after I put it together with NTN 6206-C2 bearings. The clearance was to small in them and they were running hot so I lost interest for some time. (3 years....) I finally took it apart today and am going to give it another shot. I also got a nice motor and a VFD for it so that will make a nice addition.

Ulf

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Can you expand on that conclusion? Was the preload on the bearings too great or do you mean the bearing themselves lacked clearance? Given your training as a tribologist, your thoughts on this will be very interesting/valuable.

Denis

dgfoster said:

Can you expand on that conclusion? Was the preload on the bearings too great or do you mean the bearing themselves lacked clearance? Given your training as a tribologist, your thoughts on this will be very interesting/valuable.

Denis

Click to expand...

Sorry for the late response. The C2 bearings i used has nearly no clearance. It can be as low as 2um if im remembering right. When you load them axially the contact angle will be very small and since the force on the balls is roughly Faxial/Sin(contactanlge) you end up with a large number if the angle is small. Ideally i should use bearings with about 15 deg like spindle bearings. You can see it on equations for combined load that they debit axial load harder on C2 bearings compared to CN or C3. Electric motors typically use C3 since they get exposed to all kinds of load. To make them run quiet they add preload springs. C3 bearings under pure radial load are noisy and the life is reduced due to smaller load zone carrying the load.


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I found a great writeup in a NSK publication that has a table showing a C3 in that size has approximately 15 deg angle.

http://www.jp.nsk.com/app01/en/ctrg/index.cgi?rm=pdfDown&pno=NSK_CAT_E1103_partC






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Your bearings running hot may NOT have anything to do with whether they are tight or loose, but simply a lot of shielded bearings just have way too much grease packed in them for higher speed use. I typically fill my bearings with about 25% fill with grease. I use Kluber spindle grease which is expensive but works great. If I overfill my bearings, my spindles run too hot to touch, but with the proper fill, run cool. I think I've assembled about five hundred spindles at this point, so am speaking with a bit of experience.

I bought a Covel #6 about 20 years ago and totally loved it. Had just about every attachment Covel made for it. I used it a lot, and then decided to buy a bigger heavier Cincinatti #2 tool and cutter grinder too. Still have the Covel, but haven't turned it on for probably five years.I do have the original manual, and I think a sales brochure for it.