We have a SL10 which was bought 02/02 that went over 1,000,000 tool changes during the past week. Occasionally people post asking about Haas machines so I decided I would give our experience with this machine. It is used more than 99.9% of the time on bar work ranging from 1/4" to 1-3/8" dia. in brass, aluminum, leaded steel, stainless steel and Delrin. We have a shop designed and built hydraulic barfeed which advances the bar with the spindle running and the design of the barfeed limits it to 4000 rpm maximum for ten to fifteen seconds and 3000 rpm for extended operation. This means we have never used the full 6000 rpm capacity. However we did do some time trials and found on many of our parts the difference in cycle times between running at 2000 to 3000 max and 6000 max was only a few percent. Furthermore, many times the cycles were longer at higher rpm which is probably due to the decceleration/acceleration time down to a suitable speed for parting and barfeed and then back up to the high speed; our per part cycle times are often very short.
Problems requiring service have been practically zero.
During the six month warranty period some problems occurred with the spindle drive shutting down with an overheat alarm. This was when running a short cycle (35seconds) chucking job that we ran at 4500 rpm before the barfeed was installed. I insisted that the spindle drive be replaced before the end of the warranty period and the problem disappeared and has never surfaced again.
Shortly after the warranty expired it started leaking coolant, badly. This turned out to be because the drain holes in the bottom of the chip auger trough blocked up with Delrin chips and the bolts holding the auger motor had not been fully tightened so the coolant leaked there when the level came up. We fixed this and sent Haas a terse letter.
At around 750,000 tool changes the coolant pump motor quit because the starting switch was worn. We switched the pump form on off one of our other machines and I did a crude repair to the faulty switch which is still working.
About a year ago the controller came up with the corrupted program alarm while a program was being edited. We couldn't solve it by the standard procedure of SAVE ALL, DELETE ALL and then reloading the saved file; the service tech had to reload the system.
Many of our parts have a tolerance around +/-0.001; we do a 15 minute warm up in the morning and can run the remainder of a ten hour shift without tweaking anything except for tool wear on the leaded steel parts. Some parts are a bit tighter and to keep at +/-0.0002 it is necessary to tweak things as the machine warms up; once it is warm again it is just tool wear that has to be corrected.
Would I buy another one? Yes; I think Haas is good value for money. If we were bashing away at iron castings or doing everything in stainless maybe it would be a different matter but this machine has made us a lot more money than it cost.