test bar for Monarch 10EE

Hi All,
I've been monitoring this forum for a while (since I recently bought a 1952 10EE lathe), and I really appreciate the information available here. My machine is in pretty good condition, but it has one problem: on most parts (held in a collet, not between centers) it turns tapered. I've been investigating, and reading Connelly, and think that I need to make or find a test bar (12" long, 1-1/2" dia. like he says) with a Jarno taper to fit the spindle. I might try making one from a piece of precision ground bar, though I'm concerned about getting the taper accurate enough. Is anything like this available commercially, or should I have one made with a ground taper, or can I safely make one myself?

Any comments would be appreciated.

p.s. I'm also going to borrow a precision level to check the ways for twist, but nothing real obvious has emerged that's causing this problem.

Thanks,
John

Test bars with integral taper shanks are available for use in tool presetters...Kennametal used to sell them.... but doubtful a Jarno version exists.

Hi John:
I have the same problem with my machine.
I have diagnosed it as uneven wear on the ways that causes the carriage to drop down and away from the long axis of the machine as the carriage is moved toward the headstock.
It doesn't take much to get a noticeable taper.
The pattern of wear on my machine is concentrated on the front third of the front vee way.
Makes sense when you think of where all the chips usually fall when you are turning.
The solution is to grind the bed.
It's very unlikely that the bed is twisted.
These machines are so heavily built that they are virtually immovable.
I'm pretty sure they also sit on 3 point contacts with the floor which should make them relatively insensitive to non-level conditions
Cheers

Marcus

Hi Marcus,
Thanks for your comments. I agree that it's not very likely that the bed is twisted, and it must be some form of wear. And I know that the 3-point base probably makes leveling irrelevant. However, I held a precision shaft (3/4" ejector pin) in the Jacobs collet and indicated it horizontally and vertically, and it shows very little error that way. But when I cut a diameter, I get a considerable taper. The difference, I guess, is that there is force when cutting as opposed to indicating...

If you get the ways ground, I'm curious what everyone does about the saddle: what is the turcite process like? I know that FADAL and other mills use it for their ways. How does it compare to re-scraping? Also, if you grind the ways, do you have to compensate the alignment of the leadscrew and feed screw?

Thanks,
John

Yes, when you grind the ways, the carriage/apron are lowered in relation to the leadscrew/control rod. In order to maintain alignment, you would have raise the apron. Either scrape the underside of the carriage where the apron bolts to it.(educated guess) OR raise the carriage way bearing surface to original geometry. Turcite comes in sheets of different thicknesses and is glued to the bearing surface that rides on the ways. It is kinda like teflon and can be scraped for final fit. My buddy and I have decided on Moglice for the way bearing material. Basically, you ladle the stuff in your carriage v's, set it down on your freshly ground ways and it molds precisely. You have to pre jig your carriage for alignment, but no scraping.
www.moglice.com stuff is made in Germany and our precision grinder here (dallas) says its good stuff. We'll see. Will post a update
Daryl