HAAS UMC 500 SS problems after delivery

Hello ,

We received a brand new UMC 500 SS 10 days ago.
First look very good , very powerful machine B and C axis had probably 0,001 deg backlash. I didn't expected such accurate rotaries, probably because of the scales.
After working on the machine a few days I noticed unrepeatable tool offsets. And I mean by 0.05mm up and down during the day. For me this is huge number.
I spoke a few days with the technicians to try to figure out the problem but all the variable we could imagine were not the cause of this problem.
I did a special warm up cycle routine, my factory is climate controlled so the temperature variance is not the problem.
Between a cold and warmed up spindle the difference is about 0,01mm which for this kind of machine I think is acceptable.
MRZP calibration was done several times - major differences in Z , very small in x-y.

We made a 50cm concrete foundation especially for the machine about 2 months before arrival. ( plenty time to cure ).
The machine is not anchored.

After a week of headbanging I understood that another local customer who received the same machine in the same shipment has the same issues ....
Now we wait a response between HAAS and our HFO.

The only thing we could think about is a mechanical or software issue... Backlash in Z is bellow 5 microns. X-Y have a little bit bigger backlash but bushing bores I interpolated were spot ON.
So mechanics seems to be fine.

Any other UMC owners with same issue ?

We are having the same issue here with our UMC500. This is by far the worst machine I've ever worked on. The old Fadal I used to run was more reliable than this thing. Everything runs fine on this thing, it's plenty rigid for what we need, but can not hold tolerance at all. We recently brought this issue up with Selway and they've responded telling me that this is a known software issue with Haas. I don't know how they can sell a piece of equipment like this without fully testing. I notice that the advertised accuracy is nowhere on the website or in the specs that you can see online. They probably know that every single machine they sell has high potential to be a lemon. At this point there is absolutely nothing we can do. Can't make parts, can't make money with it, it's garbage and we want to get rid of it.

They say that you can get around this issue by constantly probing your tools. The issue I see is thermals. If you have a long run the machine tends to heat up quite a bit more. I made a warmup routine that moves the machine to all axis limits, even the rotaries, and brings the spindle up to max slowly then stays there. Program is on a loop. If I come here in the morning, the machine is at around 70° on the spindle temp. If I run my warmup program for two hours I get the spindle up to about 104°. When running my 12hr cycle, the spindle gets up to 130°. Yesterday I ran my warmup program for the entire day and only saw temps go up to 107°. Because of this difference there isn't really a reliable way to tell when and where I need to re-probe my tool offsets. Selway says the difference I'm seeing in my temps is not normal and there could be another underlying issue with the thermal sensor.