Haas positioning error/errors

This one has me really stumped. The machine is an 08 VF3-SS 12K spindle machine. The part im making will take about a week. Day 1 I probe the part setting G54 upper left corner top of material. part runs good all day. Day 2 when cut starts the Z is cutting too deep. I reprobe Z and it is off -.216 from what the offset was. Ok, Im thinking I lost an encoder. I put an indicator and wrote a series of G91 Z rapid commands to see how the error progressed but it didnt change. Now im thinking it was just a glitch. The parts not scrapped yet so i continue. Day 3 I probe the Z after start up and its off .216 again. Im pissed but I have to finish the part so I hit the fire button and the cutter slams into the X+ wall. Now my part is scrapped. Well, I call the probe and pop the X axis. Ill be dammed if it wasnt out .217, WTF? This tells me the encoder should be OK but could it be a software problem? To make matters worse I decide to stick a new block in or 04 VF3 -SS. The machine had been off for about a week. I fire it up and hit "POWER UP RESTART" and I'll be damned if I havnt lost the X axis drive. I kept hitting reset then zero return and the table moves about 1/2 " then alarms out. ARGGGG. Haas service is 5 days out and I have two dead machines. We have a new Mori NMV8000dcg MORI SEIKI GLOBAL WEB SITE | PRODUCTS | NMV Series that we bought about three months ago but nobody has a clue how to run it! This thing has more safety's than a nuclear missle. I cant even figure out how to jog the table so that rules out using that machine. Anyway, If somebody has an idea on the Haas situation I would like to hear it.

is .216 the diameter of the probe tip?

Don't have an answer


Two machines down at the same time makes me think voltage issues...either a spike that took encoders and board or input voltage changed dramatically. Have you checked it?

I don't use probes, but a consistent .216 z error could possibly be a problem with the probe, if you're sure you don't have a program problem, like a G91 z-.216 at the end somewhere and no G90 at the top.
Been there, done that, lol.

As far as the other machine, a week ago, I would have suggested swapping x & y boards to see if you had a bad motor, but............

I was told by the local Haas guy not to do that before checking for shorts in the motor and cable first.
Still waiting on their arrival as well.

Sucks, I know.

Had a similar problem last night with our TM-2.


I probed the Z axis and got a value of 11.500 . Then I manually went in and moved the G54 offset in the offset screen for X & Y (moved them 2.0" each way).

Then I moved the probe to the new z zero point. The G54 was still indicating the original offset but the offset in the offset window had the correct numbers in it.

So I decided to test the code I had. Set the Z up 3" and let it run. The offset for the x&y was incorrect and the Z was off also.

After this I re-probed the Z and got a value of 18.xxx. I then probed a corner of a 123 block and got the x&y offsets to update.