We have two Fadal machines that are 4020 VMC one was purchased in 1991 and the other in 2000. The first machine purchased in 1991 we have noticed the temperature on the spindle gets warm after running for a hour at 9000 rpm's, after 1/2 hour temperature is 92 degrees, after 1 hour temperature is 103 degrees at spindle. Often we will run these machines for 4-8 hours continuous. The temperature at the chiller t-fitting is 84 degrees and 87 degrees after 1 hour. We have checked the lines and they are clear. What is normal temperature for the spindle after 1 hour? Does this mean we could be looking at some major repairs on spindle bearings or other parts on the machining center in the near future? We had a problem a couple of weeks ago in which a mold ended up being machined .010" deeper in Z-axis using same toolpaths that machined it at .000" with all conditions being the same prior day. Any suggestions or comments will be greatly appreciated.

We have delt with the same problems. We warm our spindles for at least an hour prior to running long programs.

103 degrees F seems normal. Our Fadal service rep. always told us "warm to the touch". Of course this was when we were dealing with a spindle that was so hot one could not touch it. They (Fadal) never could fix that machine.

Maybe the new Fadals use a thermal compensation similar to the Red machines made in the USA! I recently ran a mold for 36 hours straight run time on one of our Red machines. Z height was not off more than 0.0002".

Check the 2 chiller cooling lines that enter the headstock. The coolant must enter the line that feeds the bottom of the spindle and exits when spindle chamber is full and drains out the TOP. If these lines are swaped then the coolant enters the top and falls to the bottom emediately exits the bottom of the spindle before any heat transfer can be done. I have seen this happen ( In-fact came from factory backwards !) and it may explain the temperature variation between spindle and chiller.

Stephen