[haastec]

On machines with linear ways there is no need for any warm up program for the X Y Z, it does not hurt anything but just not needed,

I respectfully disagree. You can have thermal expansion affecting accuracy, therefore, a good warm up program can help minimize this.

[mactec54]

I respectfully disagree. You can have thermal expansion affecting accuracy, therefore, a good warm up program can help minimize this.

If your machines are in a shop with a stable temperature, it makes no difference at all, & is a complete waste of wear & tear on the machines ballscrews & linear rails, it takes many hours of running to have any change in the X & Y axes in a temperature controlled shop, you always get a Zaxes adjustment as this is caused by your spindle having thermal expansion, even after a spindle warm up, it takes some time for it to stablilize

If you are in a shop that does not have a stable temperature, then it would always be a good idea to run a complete machine warm up

[Machineit]

I respectfully disagree. You can have thermal expansion affecting accuracy, therefore, a good warm up program can help minimize this.

Ohhhh, I have to disagree with you. No heat what-so-ever will be generated with a "Warmup" program in X, Y, or Z. If you ran it a 100% rapids for several hours, maybe, but why do that then run parts when it will cool down from there. Just excessive wear and tear. Just have a ballscrew failure under warranty and then tell Haas that you ran a warm-up program for two hours each morning at full rapids over the full range to the machine. I would hate to hear what they would say to that.

Spindles are where heat is generated for almost all machines. The heat will affect lathes farm more than mills, just because the spindle are larger etc.

A so called warm up program for the ways on a mill will do nothing but spread lubrication and that should be done by running the program anyway.

Sorry!

Mike

[dertsap]

Ohhhh,

A so called warm up program for the ways on a mill will do nothing but spread lubrication and that should be done by running the program anyway.

Sorry!

Mike

under normal circumstances it's probably not much of a problem , but under extreme tolerance conditions thermal expansion can take place within minutes and generally starts the second the machine stops . Ive worked on parts which we bored a 16 inch 7 hole bcd , once we calculated the drawing tolerance we had .00025 xy machine positional tolerance to a pre-machined center shaft . These bores were machined in three steps , first to clean and measure the machine position , second open up the bore some more and recheck the position , third finish bore . Sounds easy , but the 4140 forgings were at times temperamental and more so was the machine temperature change
Taking too much time to measure the bores and their position was enough to throw out the machine enough to scrap a part , we had to be quick with our calculations otherwise we'd have to re-pick up the work position and take our chances . This was done on mori and enshu 650 mills which were highly calibrated and inspected before we'd run these jobs . If thermal expansion problems exist on those mills , then from my experience it is extremely likely on a haas

[Machineit]

Taking too much time to measure the bores and their position was enough to throw out the machine enough to scrap a part , we had to be quick with our calculations otherwise we'd have to re-pick up the work position and take our chances . This was done on mori and enshu 650 mills which were highly calibrated and inspected before we'd run these jobs . If thermal expansion problems exist on those mills , then from my experience it is extremely likely on a haas

If what you say is correct, then no amount of "Warm-up" would be usable, as it would start changing right away and just be very inconsistent.

Your measuring time probably changed the part more than the machine ways/ballscrews and nuts. But, I'll quit and just take your word on it.

Mike

[dertsap]

If what you say is correct, then no amount of "Warm-up" would be usable, as it would start changing right away and just be very inconsistent.

Your measuring time probably changed the part more than the machine ways/ballscrews and nuts. But, I'll quit and just take your word on it.

Mike

No , the part itself did not change due to the measuring time , it was the machine itself which changed , the cmm would get the exact measurements as I was getting on the machine just before pulling the part off the machine . It was a highly controlled process since there was so much riding on them parts .
from cold start it would change significantly under those circumstances . And the inconsistency is there in an extremely small amount once the machine has sat for any period of time , for a period we began charted the changes so that we can predict when and how much it would change (not so easy)
Under normal circumstances thermal doesn't affect much and isn't a concern , but it is certainly there . I think that it is good to add axis moves in a warmup program and have done it many times in the past , it definitely doesn't hurt anything
Anyhow I suppose this isn't helping the thread

[Geof]

I have followed this little discussion about thermal effects with some amusement. I think this is the third iteration in the almost nine years I have been on CNCzone. Maybe I should put a reminder in my phone to watch for the next one sometime in 2017.

[haastec]

I have followed this little discussion about thermal effects with some amusement. I think this is the third iteration in the almost nine years I have been on CNCzone. Maybe I should put a reminder in my phone to watch for the next one sometime in 2017.

I would have guessed much more than 3 in that time!