View Full Version : Tool Post Grinder

Richard J
02-14-2011, 03:39 PM
To keep a long story short, I have accessed and fitted a Dumore tool post grinder to my 14/40 lathe. I have printed a manual from the internet but question whether the spindle should turn forward or reverse against the direction of the grinder wheel. A friend has one at work and says to reverse the spindle direction but the manual does not indicate to do that. What is correct?

02-14-2011, 03:54 PM

Like most cylindrical grinders, the work turns against the direction of wheel rotation. So reverse spindle.:)


Richard J
02-14-2011, 04:01 PM
Thanks. I suspected as much but was surprised the manual did not mention that.

Davo J
02-14-2011, 09:27 PM
I have always been told to have the two grind faces running with each other rather than against. So if the chuck was going in it's normal rotation (anti clockwise), for outside grinding, you would have the grinding wheel running clockwise. Same with internal grinding.


J Tiers
02-14-2011, 10:54 PM
I was always told to run them opposite.

BUT, I find better finish in many cases running them together (but at very different speed, of course).

02-15-2011, 11:39 AM

I've only ever run one center grinder that would allow for the spindle to rotate with the wheel. That was a Cincinnati Milicron 77. Of course you could choose rotation direction and you could also lock and index the spindle too. Pretty fancy machine and my favorite grinder ever.

I never saw the reason for it. I did try it once though. I did learn that when the rotating part and wheel first touch, there was a tiny bit of "bounce" in the spindle. And it always left a flat spot right there until the work and spindle loaded against the wheel. So I quit trying it.


02-15-2011, 12:53 PM
You are restricted to the nut holding the wheel on. If the wheel rotation loosens the nut you are not going to grind for very long. Peter