I'm about to make some chips with the new GT-10 and want to be sure I'm in the speed and feed ball park. The following is a composite of the Machinery Handbook and ME Consultant. I would be using flood coolant with the 6061, how about the 12L14?

6061

2000 SFM
.02 IPT
.004 IPT cut off

12L14

1000 SFM
.013 IPT
.002 IPT cut off

Since 95% of what I will be cutting is 6061 and less than 2" diameter it looks like I will be running the spindle at it max (3,000 rpm) most of the time.

Vern

Hi Vern,

I just got this from HAAS's website as it pertains to the GT10:

Would this mean that you could actually get 4,000 RPM?

Just something to look at.

5C Pneumatic Chucking System, 1.06" (27 mm) drawtube thru hole, 4000 rpm; includes 5C collet chuck, rotating cylinder and drawtube AC5C-KIT

5.3" (135 mm) Pneumatic Chucking System, 1.18" (30 mm) drawtube thru hole, 4000 rpm; includes chuck, rotating cylinder and drawtube ACH5-KIT

John

For 6061 with carbide tooling go like a bandit; as fast as the machine can go.

With the qualification that if you have an unsupported length of bar in the spindle you might have to back off because it will whip inside the spindle and shake every thing; for short stubs don't worry just go crazy.:D

12L14 at 1000sfm sounds high; I think we generally run at around 500 or slower for turning and around 350 for parting.

I have to admit I have never done a good analysis of the best sfm for 12L14. It is possible that when you look at tool life in terms of number of parts per tool rather than tool life in hours, that 1000sfm is more productive. In other words the tools do not last as many minutes/hours but they do turn out more parts. Our machines run 12L14 barstock un-attended so we tend to be conservative on sfm to avoid catastrophic failures that wipe out multipe holders.

I just re-read your post:

.02" per rev feed???? Yikes that is pushing it for a little baby; I rarely go above 0.01" on my TL2 and on the GT20s we rarely go above 0.005. You are almost cutting a thread at 0.02".

Similarly the 0.013" for 12L14 is very optimistic; maybe if you had a whole flock of horses working for you but I think you are going to redline the spindle load meter.

John,

It looks like you know more about my machine than I do :D I didn't notice that the Pneumatic Chucking System bumped the RPM to 4000. Tomorrow I'll fire it up and see what the max RPM is. From what Geof says that will be handy with 6061.

I missed a zero with the cut off feeds, thanks for noticing it. Do you recommend coolant with 12L14, or steel in general?

Vern

Hi Vern,

I will read some more, maybe I can get it up to 6000 :D

It would probably be fine with the collets but the chuck would probably not be rated for it. See what others have to say.

John

....
I missed a zero with the cut off feeds, thanks for noticing it. Do you recommend coolant with 12L14, or steel in general?

Vern

On the lathe yes, coolant all the time and lots of it on steel.