Can a small tool grinder be used as a surface grinder?

[eKretz]

I noticed he was in Brazil. I checked because there is a big auction full of grinders a couple hours away from me soon. Still wouldn't use a T&C grinder as a surface grinder if I could avoid it. They aren't as rigid, aren't as powerful and many don't have enough table speed. Usually a T&C grinder has like ⅓ HP or if you're lucky a ½ HP spindle motor.

 

[EmGo]

Still wouldn't use a T&C grinder as a surface grinder if I could avoid it.

You guys are too spoiled. I used the grinder attachment on the vacuum cleaner (it was a Kirby) to fix the shift linkage so I could get home one night

 

[eKretz]

You guys are too spoiled. I used the grinder attachment on the vacuum cleaner (it was a Kirby) to fix the shift linkage so I could get home one night

That's different. You're not trying to sell the repair to anyone, are you? Heh. I've done my fair share of those too. One memorable one was losing an upper rear suspension control arm bushing on the way to work. Tire was grinding hard on the inside of the wheel well. Jacked that sucker up in the air, got everything in proper position and cut out a rear seat belt to tie it all in place so I could get to work. I really liked that place.

 

[john.k]

The mechanics round from my shop used to drive customer cars ,and have fails like that all the time ....after they had fixed them.

 

[michiganbuck]

A Tc grinder is a handy machine. Good to have a simple vise or an angle swivel vice so it can be a cut-off/chop machine when not busy sharpening tools. Most Tc grinders don't have the bigger hand wheel for wide-spaced lines that allow making half-thousandths increments that are often needed for surface grinder work. One exception is the Brown&Sharpe 13 grinder. It can be an OK Tc grinder and an Ok surface grinder, but one has to regrind the chuck each time the chuck is removed, and the B&S 13 grinder table is not suitable for using various fixtures from other brand machines, and the verticle travel is short..about 8 or 9 inches.

If I was to use a Cinci Tc grinder (type) machine for a surface grinder I would put increment lines on the hand wheels so to have half thousandth lines... but still bending over the reach the verticle hand wheel would be a chore..., the mag chuck would have to be reground each time it was removed.., verticle travel is about 10 or 11", unless in like new condition the long travel will likely not be .001 close/flat... the cross travel ways on a Cinci are massive, better than many surface grinders..Cincinnati Tc grinders used wet(with coolant) have a special cap cover with a seal to keep water out of the spindle bearing (easy enough to make). A 3/4 Hp motor would be the minimum suitable IMHO.
I could fudge up all kinds of tool griding holding fixtures using the tilt swivel vice in post #10..good to have centers with a Tc grinder.

 

[Richard King]

One of the reasons TC grinders are so cheap is not many use them anymore as they have gone to inserts or one time use tooling. People don't regrind anything unless your a small shop. If your down in the boonies and no surface grinders are sold in your area, then as Buck said you could make something out of a TC grinder. Talk with a sheet metal fabricator and make a waterproof pan to set on-top of the table Then make a tank with a pump so you can grind wet. Have them make you some sort of wheel guard incase the wheel explodes.

Check out what Buck said about making a seal so grit doesn't get into the spindle bearings. Or design a new spindle head. Buy a bigger horsepower spindle motor .Buy a magnetic chuck and bolt it to the center of the table and grind the chuck top. Leave it on or as Buck said or you will have to re-grind it every time you use it again.

I remember back in 1971 when my Father had a contract to assemble and get running machines over in Masjid Solymon, Iran and I went with. when I was 21 years old We needed to grind down some hardened bolts and he made a cylindrical grinder out of a lathe by mounting a double end grinder to the lathe compound. It worked, but we didn't need accuracy. Don't expect the spindle bearing to last long and you may be able to make a new spindle out of a double end grinder who knows? You may go down in history :- ) Good Luck

 

[michiganbuck]

Woods Creek Workshop channel in Youtube has a series of videos about a Cincinnati #2 he's rebuilding.
Lots of information about this similar machine (twins or at least siblings) there:

Wow, Great run of Cinci videos...good to mention that the cross-hand wheel lead screw nut can be pushed up from inside the base casting if the lead screw is not wished to be taken out..but the way it was done in the video is the correct method so to avoid bending the lead screw.. Sometimes a piggyback set screw is holding the cross-travel lead screw nut.
Another thing to mention is that the table top can be turned 180* so to give another 2 1/2" of outward location when that space is needed for larger mill cutter sharpening.

*I do have a new cross trave lead screw and new nut surplus to my needs that I intend to post on eBay, I will have to decide what price I will ask for it

 

[luke8888]

Well, in theory if the spindle has repeatable runout, perhaps. In practice, you'll be sparking out for an hour. I say that as a person that has recently rebuilt his surface grinder spindle and instead of 10 minute spark out, I now do 2 passes. That's the difference runout (especially random runout) makes.

Still, this never has stopped me from using tiny inadequate spindles for precision grinding. Mostly for cylindrical grinding thought as I don't have a proper machine for it. I use a proxxon-made dremel like spindle. I never measured it's runout, but it is made for drilling PCBs and it can do it for hours without breaking 0.4mm (16 thou) carbide drill bits so the runout is pretty low(compared with dremels, in surface grinding world it is still huge). If I set it up right I can get really nice finishes and acceptable accuracy.

But recently I was forced to use it with a really long stick out of the little abrasive wheel. This was for ID taper grinding. I lowered the spindle rpm and I upped my workpiece rpm to still get the correct surface speed, but the finish definitely suffered a lot. You can see an example here:

There are concentric scratches. They can't be felt with a finger, and this is a functional part so it is fine, but it could be unacceptable for something visible.

On a surface grinder, depending on table feed speed you'll get waves, repeating scratches, stairstep patterns.... You can chase it all day long with a less than great spindle... There are ways to work around it (randomising your table moves, and lots of time). And there is always lapping.

Personally I'd rather use a surface grinder as a T&C grinder than the other way around.

 

[guythatbrews]

Here is a bit of salesmanship from the B&S #13 manual. In a pinch I guess...

 

[eKretz]

Yup. In a pinch.

 

[michiganbuck]

Here is a bit of salesmanship from the B&S #13 manual. In a pinch I guess...

View attachment 395310

Except for the limited vertical travel the 13 grinder is a very good surface grinder.

 

[EmGo]

Except for the limited vertical travel the 13 grinder is a very good surface grinder.

We had one at Websterville, it was pretty cool. Spent most of its time doing the radius on top of Offlehouser cam buckets.

 

[michiganbuck]

We had one at Websterville, it was pretty cool. Spent most of its time doing the radius on top of Offlehouser cam buckets.

https://www.hemmings.com/stories/article/offenhauser-racing-engine.

My B&S 13 grinder has been converted to an industrial knife grinder to run straight knives to 32" long for a straight or hollow grind edge.
At the bid shop, I ran the 13 grinder for one up and a few up special ODs, making gauges, grinding machine centers to near zero Ro, and grinding live centers to near zero.
Grinding dead centers I would suspend them a set of precision bearings, with a stop at the tail center, and get "no detectable error" checking with a higher quality gage checking machine(CMM) that could find a few microns..Machine centers are very important .0002 error can make a part .0004 off.

 

[michael.kitko]

I will say yes, BUT, only small adjustments. I have done small washers and shims with mine in a pinch with an incredibly small mag chuck. Other than that, it is easier to use a surface grinder to grind tooling than to go the other way and grind surfaces with a tool and cutter grinder.

 

[AlfaGTA]

Interesting about Brazil
Funny about lac of machines.
Romi is built there, pretty sure they are the largest lathe builder in the world
They have all under their roof do their own castings etc.
surprised there isn’t support industries.
Cheers Ross

 

[Miannini]

I noticed he was in Brazil. I checked because there is a big auction full of grinders a couple hours away from me soon. Still wouldn't use a T&C grinder as a surface grinder if I could avoid it. They aren't as rigid, aren't as powerful and many don't have enough table speed. Usually a T&C grinder has like ⅓ HP or if you're lucky a ½ HP spindle motor.

Brazillian manufacturer Mello that was operational until very few years ago (over 60,000 sold worldwide!),
in their catalog http://www.mellfaber.com.br/uploads/Catalogos/635036024070118131.pdf show their latest two TC grinders, very similar to the Cincinatti #2, of a heavy build (1179 kg, almost 3000 lbs), their difference is power and number of axis for the head movement (AMX is 1.5 hp single axis, AMY is 1.0 hp dual axis).

In this catalog they expressively state that the AMX being the more stable is rigid enough and more suited to perform both surface and cylindrical grinding, recommending that you acquire the hydraulic table movement and 4-speed motor table tooling attachment. Here's the pic, showing cylindrical grinding and internal grinding:
AMY can perform SG with cup wheels as wheel:

I have found both types of machine in fairly good condition with good prices. What would you think, considering that my job is home/hobby, parts small enough to fit and usually I can mill the surfaces to 0.03 mm (1.5 thou)?

 

[eKretz]

Brazillian manufacturer Mello that was operational until very few years ago (over 60,000 sold worldwide!),
in their catalog http://www.mellfaber.com.br/uploads/Catalogos/635036024070118131.pdf show their latest two TC grinders, very similar to the Cincinatti #2, of a heavy build (1179 kg, almost 3000 lbs), their difference is power and number of axis for the head movement (AMX is 1.5 hp single axis, AMY is 1.0 hp dual axis).

In this catalog they expressively state that the AMX being the more stable is rigid enough and more suited to perform both surface and cylindrical grinding, recommending that you acquire the hydraulic table movement and 4-speed motor table tooling attachment. Here's the pic, showing cylindrical grinding and internal grinding:View attachment 436042
AMY can perform SG with cup wheels as wheel:
View attachment 436043
I have found both types of machine in fairly good condition with good prices. What would you think, considering that my job is home/hobby, parts small enough to fit and usually I can mill the surfaces to 0.03 mm (1.5 thou)?

Being able to perform surface grinding is not the same thing as being able to perform surface grinding well...

If you're just using it at home for your own projects, it would probably be fine.

 

[michiganbuck]

Can a small tool grinder be used as a surface grinder?​

Not to confuse a Tc grinder with a small tool sharpener.
Yes, but some Tc grinder don’t have as fine graduation as a surface grinder. Perhaps a Tc grinder may have one-thousands graduations and a surface grinder may have half thousandth or smaller. The operator position on a Tc grinder may put one's eye's view in a better place to see the part and part edges, with the surface grinder designed more to see the position of the hand wheel dials. Very often the travel ways on a Tc grinder are every bit as high accuracy as a surface grinder.
Moving the swing table of a Tc grinder might lose the highest accuracy and straightness if the back rail of a ground-in magnetic chuck each time it is moved,

 

[Miannini]

Hmmm, so I just found the KO Lee manual on vintagemachine pages and it states:


Section Six, part I:

So these TC would make a less adequate, inconvient to setup, very small area and not nearly as good surface finish.
Probably my quest continues...

 

[eKretz]

Hmmm, so I just found the KO Lee manual on vintagemachine pages and it states:

View attachment 436100
Section Six, part I:
View attachment 436101
So these TC would make a less adequate, inconvient to setup, very small area and not nearly as good surface finish.
Probably my quest continues...

You believe it when you read it there, but not when we say it here?