Erratic movements

[[Ti...]]

This is hard to describe: The CMM will begin to make erratic movements in CNC mode, even on programs that have run before with no problem. It has caused crashes and the most recent event caused a 1mm stylus to be snapped off. Yesterday it zoomed all the way to the top limit and I had to physically pull the column down in order to restart the drives. This has happened sporadically over the years, but has happened 4 times in the last three days. I can't tell if the problem is coming from the Calypso software or from the machine itself, but today, after re-booting everything my program in Calypso had shifted all my measuring surfaces on my current job in the +Z direction by 14.5mm....that happened to be the height of the part. That was the first time I'd ever seen that happen. Before rebooting the slightest joystick movement will cause the Vast XT head to jerk in random directions and by random amounts...in any or all axis' at the same time. Anyone else has similar experiences?

[[SH...]]

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No, Do you have any proper anti virus system in your company network??

[[Am...]]

Here is 3 Hardware related things to check anything software youre just gonna have to look at the program but keeptrack of what you are running when it happens.

Is the feature in your base alignment for the Z zero a different probe? If everything is shifted off my guess would be too look at the probe doing your Z zero feature and see if its damaged. What I have seen before is some probes like the cylinder or probes under .8mm the shaft can actually slide up into the connection if crashed in Z, making your points read at the original length of the probe not where you are actually touching, if the rest of the alignment is done with a different probe it ends up shifting only Z and causing other probes to clip into the part. This would not explain erratic behavior but it would explain the shift.

For the erratic behavior first i would look at if this behavior happens only with 1 stylus system look at the adapter plate, is there anything bent or any burrs from a crash? if so when the spring moves up during contact it might be catching inside the head causing it to hold the adapter which makes the head think its still making contact because the spring is still compressed, I've noticed the head will try to move away from contact and if its being held in place its just going to keep moving, either your adapter plate is catching on the hard stops in the head, or the other option is there is something loose in the head getting wedged in between the pate or spring during movement. Take the head off and see if there is any rattle there shouldn't be anything loose if there is it could be it would explain why it randomly happens but not repeatedly.

[[Ti...]]

@Shabu: the CMM computer is isolated from all other systems in the company and has no internet connection. It has always been set up that way. I will run some scans for viruses though to see if I find anything.

[[Ti...]]

@Amel: I will inspect all the holders for damage and loose parts. The erratic movements have happened with all of the 3 main stylus systems I use. I ran all the stylus verification tests and had to requalify a few, but they were only off by <0.008mm....almost normal / expected deviations.

[[SH...]]

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USB pendrive can export virus to your computer...