Toolroom Lathe spindle warm up

[JohnJW]

I didn't see a spindle warm up program in the memory of the TL2 and I am wondering if I need to run a spindle warm up program for the TL2?

Searching through the forum I found donkey's spindle warm up program at,

TL-2 Noisy Spindle

Why cap to 1200rpm? Do I need to modiify donkey's spindle warm up program if the max spindle speed is 3500rpm?

On a side note, the cabinet fan noise on the TL2 is a lot louder than the VF2 and how come there are no vents on the cabinet door like the VF2? So is it just a loud fan pushing air around the cabinet?

[Bryan33]

Yes take that same program and adjust it for your spindle RPM

[JohnJW]

Can I shorten the warm up program to just 10 minutes, instead of 20 minutes?

[Bryan33]

all your doing is warming up the spindle bearings and getting lub to them. If you machine runs every day then ya, but if you have it off for a week or so then I would run the hole thing

[JohnJW]

The original spindle warm up program posted by donkey only goes up to 1200rpm, but the standard toolroom lathe spindle goes up to 2000rpm. Why only run up to 1200 rpm during the spindle warm up?

[Donkey Hotey]

I don't want my scroll chuck to unscroll and throw the jaws out of the chuck. Actually, 1200 RPM is excessive and scares me with loose chuck jaws. I don't use that warmup program anymore. I usually start the spindle at something like 400 RPM and just let it run for a few minutes to stir the grease.

[JohnJW]

Donkey, how long do you run the warm up program for? Thanks.

[Donkey Hotey]

It's in my previous post: I don't use it anymore. I pre-run the spindle until I'm good and ready to use it...3-5 minutes...maybe.

[Geof]

My experience warming up the TL2 spindle until it runs quietly is that it depends on temperature and time. If you are using it every day and the room temperature is 65 degrees or higher a 10 minute warm up stepping up to top speed is fine. If it has been sitting for a week or more and the temperature is down around 50 degrees I let it run at 500 rpm for around 10 minutes before continuing with a normal warm up. If I try running it up to higher speeds any earlier the cold grease makes a lot of noise. And if you are worried about loose scroll chuck jaws just run them in and clamp them against nothing to stop them moving.

[JohnJW]

donkey, geof, thank you guys for entertaining what seems like a trivial issue. . . . the toolroom lathe didn't even come with a spindle warmup program. How high of rpm should the warm up goes to? 100% of max? 80% of max?

For mill, a cold machine will give a warning to run the spindle warm up, but I don't see it with the lathe. Is the spindle warm up not as critical with the lathe? because of the lower rpm? or the cutting force? or the way the spindle is constructed? or something else? just curious, thanks.

[Geof]

Here is the story I got (I won't say where from.)

Mill spindles, the air over oil lubricated type, need a Warm Up (or Run In) program to purge the oil out of the lower bearings. Oil accumulates here when the machine is idle and if it is run up to high speed, i.e., above two or three thousand rpm, after a period of two or three days idle it is possible to overheat the bearings.

Grease lubricated bearings don't need a warm up because the grease does not drain into the lower bearings like oil does.

Lathe spindles don't need a warm up because they oil does not accumulate in the lower bearing; there isn't one.

However:

Haas received some complaints about noisy bearings in the TL spindles and on investigation it seemed to occur immediately on start up after the machine had been run extensively to get the spindle nice and warm and then left for a few days which allowed the warm grease to pool in the lower half of the bearing.

The fix seemed to be to run the spindle at low speeds for a period of time to re-distribute the grease and warm everything up slightly; hence write a Warm Up for the TLs.

As I mentioned it is my experience that if a TL is run hard for a full day and then sits idle for many days it is noisy when first run, especially noisy if the temperature is cool.

The program I wrote starts at 500rpm and steps up to full speed at 500rpm per step with a 200 second pause at each speed. But when the machine has been idle and cold for a couple of weeks I will use Single Block and hold it at 500 rpm for 20 or 30 minutes.


There is another reason for doing a Warm Up and that is the spindle does indeed 'warm up' and it grows slightly longer. Strangely enough on my TL it also seems to move sideways slightly and if I set offsets on a cold spindle they are wrong once it has warmed up. Not much but noticeable.

And I don't mind spending time on 'trivial' issues. I figure it is impossible to know too much and one person's trivial might be another person's interesting.

[JohnJW]

Thank Geof for explaining the reasoning behind the warm up programs. Now, I know why I run the warm up instead of just doing it because the manual said so.