I just purchased a Haas "MiniMill" and after running it for a few days I noticed the spindle getting pretty warm to the touch. Not too hot to touch but enough to wonder if there may be a problem. I'm cutting aluminum with a .500 data flute endmill and the spindle load isn't very high. It's only about 50% on the load meter. Should I be concerned? Is the warm spindle normal? It's been rather cold in the shop I've been running it. About 40 or 50 degrees but I always run a warmup program for a while before running it at any high RPM's. Any help would be greatly appreciated. Thanks.

If you can touch it, it is not overheating.

What is the max RPM of your machine? If your machine has an air/oil mist lubricated spindle it could have excessive oil in the spindle that needs to be purged.

Looked behind the main air regulator, if there is a small regulator with a pressure gage, when the spindle is running this gage should read about 17 psi. This is the air that is used to carry the oil to the spindle.


Loose Nut

The machine has two programs O02020 Warm Up and O02021 Run In.

When the tech installed the machine he should have used the Run In program with the regulator Loose Nut mentions turned up to 30 or more psi to purge oil out of the spindle. Then return it to the 17 for n ormal operation.

If the machine is not used for a day or two or if it is in a cold location ther Warm Up should be run before using the machine; it puts up a warning when you hit cycle start for the first time telling you this.

If the machine has been idle for a couple of weeks the Run In should be done again.

the company i work for just got a mini mill after Christmas and before the tech left after he setup the machine he started the run in program, and every morning i run the warm up program. and so far i havent noticed a warm spindle. but then again i havent really used the machine to its capacity either. we are just using it for small parts for the time being. i think the biggest spindle load i have seen is about 30%.

the company i work for just got a mini mill after Christmas and before the tech left after he setup the machine he started the run in program, and every morning i run the warm up program. and so far i havent noticed a warm spindle. but then again i havent really used the machine to its capacity either. we are just using it for small parts for the time being. i think the biggest spindle load i have seen is about 30%.

Thisn is the way to do it I think. All my machines get the Warm Up every morning before starting work. Provided this is done we may get warm spindles but never hot; in addition I have never found any correlation between load and spindle temperature, speed yes but not load.

Warm up spindle program at Haas manual

O02020 (Spindle Warm-Up)
S500M3;
G04 P200.;
S1000M3;
G04 P200.;
S2500M3;
G04 P200.;
S5000M3;
G04 P200.;
S7500M3;
G04 P200.;
S10000M3;
G04 P200.;
M30;

anybody can confirm it?
Thanks

yes that is right. My machine its for 4 days at a time with no use, run only on weekends. I wrote my own warm up that each P code is 300 and at the end it cuts a rosette in the air each arc faster and faster to warm up the ball screws as well.

The machine has two programs O02020 Warm Up and O02021 Run In.

When the tech installed the machine he should have used the Run In program with the regulator Loose Nut mentions turned up to 30 or more psi to purge oil out of the spindle. Then return it to the 17 for n ormal operation.

If the machine is not used for a day or two or if it is in a cold location ther Warm Up should be run before using the machine; it puts up a warning when you hit cycle start for the first time telling you this.

If the machine has been idle for a couple of weeks the Run In should be done again.

What does the 002021 Run In program do?

What does the 002021 Run In program do?

The explanation I was given by the Haas person is that when the spindle is not used for several days all the oil drains down into the lower bearing. If the spindle is run at high speed in this condition it can cause overheating. (I can confirm it does cause overheating.) The Run In program combined with the increased air purge pressure redistributes the oil and removes the excess.

The explanation I was given by the Haas person is that when the spindle is not used for several days all the oil drains down into the lower bearing. If the spindle is run at high speed in this condition it can cause overheating. (I can confirm it does cause overheating.) The Run In program combined with the increased air purge pressure redistributes the oil and removes the excess.

Where can I find that program?

Where can I find that program?

With your machine you will have got a floppy or a usb drive, the program is on there; O02021 for Run In, O02020 for Warm Up.

I think you can also find them on the Haas website but I do not know the link.