[Asinity]

This has been an ongoing issue of arguments at my work and there are arguments for both sides of the coin. Which is the best way of turning on a CNC lathe? Right-handed tooling facing down, or left-handed tooling facing up?

We use RH tooling, and with a couple of our lathes taking heavy cuts the concern is that this setup isn't the most rigid due to the forces from the cut pulling up on the turret. The argument to that though is chip control is poor.

The problem that I see with RH tooling is that it's not rigid and that it directs chips into the window (I've replaced my window up to 4 times in a single year) where LH directs them to the back/base of the machine and directs the forces towards the base.

Any thoughts?

[AbsoluteZero]

RH is always your best bet. Then your spindle is running the right way, forward. The pressure on the turret is the same either way, its mounted on a rotary coupler so the force is always taken by the turret nothing else. Also most turrets your hard pocket (surface tool locates from) is for RH. If you use LH then your cutting pressure is on your tightening screws. As for the window upgrade your material used if it is an issue.

[g-codeguy]

I think it was a Hardinge representitive that told me LH tools were more rigid. Think he mentioned the forces being transferred into the bed. I tried it for awhile. Reversing spindle is a pain and time consuming.

We've got Hardinges anywhere from 10 to 20 years old that have been running RH tools with never a problem. Still holding tenths. Amost all are barfeeds, and roughing cuts are less that .1 per side.

[Thawk53]

In my experience it really depends on the job and what type of cut you are making. On our smaller lathes where we do mostly medium to light roughing and finishing, we generally stick to RH tools. On our bigger machines, (Mazak SL80's and Okuma Flat Beds)
we make a point of using LH tooling to transfer the cutting forces into the bed of the machine and not pull up on the turret. Mind you,these are large titanium and steel forgings where depth of cut averages .400/.500 with feed rates up to .025 IPR.

Rick

[juergenwt]

.

Sorry I did not read everything. My post is deleted.

[littlerob]

I think there is a reason that M3 turns the top of the chuck towards you, chip control is certainly a factor. I have made stuff using an M4 many times and never had (serious) problems. The tooling is a little harder to index upside down. J.M.O. Robert

[Asinity]

Thanks guys. I appreciate the responses!