finish problem on mori seiki lathe

[positiverake]

I have a sl-25 mori seiki lathe and can't hold a good finish facing parts,roundness and finish on turns are good? backlash is good, any ideas would be great.

 

[mrainey]

What sort of problems are you having? Are you "running out out of RPM" and creating a dull, torn finish at the smaller diameters? Are you using G96 (constant surface feet mode), and if so, do you have your top speed restricted with a G50 command?

What's the diameter of the material, and how far is it sticking out unsupported? Do you see chatter on the face?

Describe the material, depth of cut, insert style, etc.. There are a lot of possibilities here.

Manufacturing Freeware and Shareware

http://mrainey.freeservers.com

 

[positiverake]

It's a kind of a liney looking finish,it don't matter what kind of material I'm running,yes I use a G96,I have tryed every thing I could think of as far as depth of cut,feed per rev,surface speed,G50 clamp,inserts. I have machined for 20 years, belive me I tried every thing,it has to be the machine,dont have any problem on my other lathes, could it be the z servo? or the gib (if it has one) back lash on x and z are good. I'm out of Ideas besides the service guy thing,I would rather fix it myself if I can, let me know if you have any Ideas. thank's

 

[BillPSU]

Movement between the workpiece and the tool creates the problem you are a seeing. Endplay in the spindle. Bad spindle bearings. Bad roller packs on the way. Damaged way. Chuck mounting problem. Chuck master jaws worn out. Z axis movement problem. Z axis ball screw backlash. Loose curvic coupling in tool turret. Tool not on centerline. Insufficient clamping force on tool turret. Those are a few of the various conditions which I would try to look at.

 

[positiverake]

If it was the spindle bearings would'nt I have roundness problems? its a box way machine so it can't be roller packs,z axis backlash checks good,tools on center,chuck seems ok,but you got me wondering about the turret,I'll take a look,thanks for the great ideas!