Safe max lathe spindle speed?

[jderou]

How fast is unsafe when it comes to spindle speeds? Right now we are turning .75 dia stainless rods down to .25". They are held in a collet chuck. I have the max spindle speed set at 2500 rpm. We are taking .040 deep cuts at roughing. I'm not sure what the max spindle speed is, but I know its higher than 5000 (and thats just scary).
With constant sfm, the machine maxes out at the 2500 rpm on the second pass, so when it gets down to .25" it should be going much faster. By my calculations it should be going ~5600 rpm.

this is on a Haas HL-2, and we are using the tailstock.

[gizmo_454]

I suppose it would depend on the situation. We have run our 1940's Brown and Sharpe's at 5000 rpm before, max factory spec is 6000 on that particular machine. I run the spindle in our Mini Mill up to 6000 rpm sometimes without any problems.

I know it sounds scary, but I guess you have to make the call. The recommended feed and speed for the one insert drill I bought for the new lathe we have showing up next week is about 2500 rpm, and .004 feed in 12L14. That is going to be extremely scary for me. Especially since it's a 3/4" drill!!!!

What is the material you are running, and what machine do you have?

[jderou]

material is 15-5-PH stainless (annealed). Machine is a Haas HL-2.

I guess its the horror stories I have heard that scare me.

[HuFlungDung]

If the bar stock is fully contained within the spindle, and a spindle liner, there is nothing to fear from whipping.

If the chuck is in balance, and has jaws, it will have an rpm rating to warn the operator from overspeeding, which could throw a jaw, or open the grip of the jaws enough to loosen the stock.

I don't know what kind of collet chuck you have, but typically, a collet chuck is fairly streamlined, not too massive. It should not be too scary to spin it at whatever it will take. You will have a break in period while you get used to it. The machine doesn't care

[jackson]

yeah i run 3 to 5 grand max pretty much all the time even with the chucks as long as you have the part well chucked its no prob. make sure you have plenty of chuck preasure "but not to much" and run the hell out of them LOL!!!

[Geof]

Originally Posted by jderou material is 15-5-PH stainless (annealed). Machine is a Haas HL-2. I guess its the horror stories I have heard that scare me.

If you have the hydraulic pressure set correctly with the chuck correctly greased and the bar supported and not extending too far you should be fine runnning to max speed on the machine.

But a big chuck whipping round really fast makes a lot of noise and does make you feel uncomfortable I find.

Why such a tiny part on such a big machine?

[jderou]

Big machine? I wouldn't call this a big machine. It has a 2" bore. The collet chuck is probably about 6" diameter.
Thanks for the tips guys, I think I'm going to step it up a notch!
The company has had this machine since '98 and I gaurantee it has never seen above 3k rpm. Time to see what it will do.

[jackson]

push the button and duck HA HA HA

[Geof]

Sorry didn't read the word collet in your first post.
We have a HL1 Big Bore with a 2-5/8" spindle bore and ten inch chuck and I thought that was the same spindle as the HL2 so that is what I was thinking of..

[jderou]

Geof, how long have you had your machine?

A Haas guy was in here recently and he briefly mentioned they stopped making the HL's because they had problems with them. Our machine probably hasn't been run enough for problems to really show up (it sat for two years unused before I started here). I am wondering what kind of problems he was talking about.

[Geof]

Originally Posted by jderou Geof, how long have you had your machine? A Haas guy was in here recently and he briefly mentioned they stopped making the HL's because they had problems with them...

I find it difficult to understand some of the claims people make.

Rant following; not aimed at you but at Haas business relationships.

First was the "Haas guy" really a Haas guy or was he from a 'Haas Factory Outlet'? To my knowledge the only relationship between Haas Factory Outlets and Haas Automation is that the Outlet has a dealer agreement. Have a look at the business card you get from a 'Haas guy' who is with a Haas Factory Outlet and you will probably see on it in little print a division of or[/I] subsidiary of[/I] followed by some other company name. This is what I have seen and I have seen it on advertisements by different Haas Factory Outlets.

So a 'Haas Guy' from a Haas Factory Outlet is not really a Haas guy and I suspect many of them do not know s**t from c**y. Some people characterize them as jumped-up used car salesmen but I would never apply that description.

So be a bit sceptical of anything said by your Haas Guy.

Rant ended.

Haas may have had problems with the HL machines but I have no way of knowing.

Our HL1 BB is a 1997 machine which I bought in 2001, brand new unused from the Haas showroom floor. Other than one turret crash into the chuck, thanfully fairly slow, which required a turret realignment I cannot recall any service calls on this machine. It has over 10,000 hrs Power On Time, over 1300 hours Spindle Run Time and over half a million tool changes.

We also have a 1995 HL1 bought used in 1999. A few weeks after getting it the X axis servo amp went out and repairing it was around $400. A good as I can remember we have never had another service call on this machine. I don't have the operating hours on this because somebody zeroed them all and I don't know how to get into DEBUG to see the permanent records. It has certainly done as much or more time the the Big Bore.

So I am quite satisified with the performance of our machines.

[jderou]

Yeah I don't know what this guy was. He was just called in to set up the machines after we moved, mainly just leveled them. Good to hear you haven't had problems.