What's new
What's new

Mori MS-850. Not as silky smooth as a 10EE?


Cast Iron
Jan 15, 2011
SF Bay
HI guys,

So I've got the brakes on the new (to me) Mori more-or-less sorted, got the DRO mostly installed, etc. Now it's time to get serious about actually using the damned thing.

And I notice something: the apron Z traverse is sticky.
The bed is in *excellent* shape. I've never seen better.
It's level, no twist, etc.
But as I move it, there's a certain minimum speed that I need to keep above, or it sticks.
Which makes hitting an exact number difficult. It's not stuck, and it's not a location issue, it's just if you stop and try to creep up on a number, it'll stick, and then jump. Seems like it's some sort of sticktion issue. It doesn't jump much, just a thou or two, but that's too much for what I want it for. I'm using Vactra #2 in the apron.
I tried smearing some DTE-Lite on the bed and cranking over that a few times, to see if it was the 'sticky' stuff in the Vactra that was causing the issue. Doesn't seem to be.
I've owned a Cadillac, which is a Taiwanese copy of this style of Mori, and I don't remember that one sticking like this. (Vactra #2.)

My other manual is a 10EE, and that thing is silky smooth. You can roll up on any given tenth and stop right there, with no need to even think about it much. Also using Vactra #2 in the apron.
Comparing most lathes to a 10EE isn't exactly fair, but the Mori is one of the ones I'd expect to be in that class. I know it can do that kind of work, I'm just trying to figure out what the issue is.

Anybody got any thoughts?


Apr 6, 2013
Damascus, MD
What about the underside of the saddle? If it is perfectly flat with no flaking/scraping, you're indeed having stick-slip.



May 26, 2012
Windsor CA
Been using my MS 850 for 8 years now. I have not experienced that problem. Cleaned and re-adjusted the saddle gibs 2-3 years ago and experienced no change, although I went way tighter. The saddle is still effortless to move. I can creep up on a tenth with a gentle rap of my knuckle on the handle.

The manufacturer recommended oil in the US is Shell Tonna 32.

I hate to say, but you may want to remove the apron and look underneath and check the pinion drive train.

Good luck.