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

eKretz

Diamond; Mod Squad
Joined
Mar 27, 2005
Location
Northwest Indiana, USA
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.
 

eKretz

Diamond; Mod Squad
Joined
Mar 27, 2005
Location
Northwest Indiana, USA
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 :D

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. :D
 

michiganbuck

Diamond
Joined
Jun 28, 2012
Location
Mt Clemens, Michigan 48035
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.
 
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Richard King

Diamond
Joined
Jul 12, 2005
Location
Cottage Grove, MN 55016
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

Diamond
Joined
Jun 28, 2012
Location
Mt Clemens, Michigan 48035
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
 
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luke8888

Aluminum
Joined
Aug 11, 2017
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:
Compress_20230503_022015_5813.jpg
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.
 

michiganbuck

Diamond
Joined
Jun 28, 2012
Location
Mt Clemens, Michigan 48035
We had one at Websterville, it was pretty cool. Spent most of its time doing the radius on top of Offlehouser cam buckets.
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.
 
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michael.kitko

Cast Iron
Joined
Oct 30, 2012
Location
Pontefract, UK
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

Diamond
Joined
Dec 13, 2002
Location
Benicia California USA
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
 








 
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