Problems with XXT Stylus System Change - Solution

[[To...]]

I had a customer that was experiencing problems whenever they were dropping off a stylus system in the probe rack. Sometimes, the dust cover would get stuck or the dust cover would push the stylus system out of the rack holder (notice the corrective action taken to minimize probe damage). It might fall to the table or get attached to the XXT body.

I had him make sure the probe rack was aligned parallel with the X and the table. Still, the problem continued. He decided to check the level front to back and noticed a slight tilt. He placed a shim under the base of the MSR-Mini and the problem went away. Earlier in the troubleshooting conversation, he mentioned that when un-bolted from table, the rack would rock on the base which could indicate the rack base was bowed or bent.

I tested this theory by manually tilting the adapter plate which would simulate the probe rack tilted toward the back of the machine and the dust cover would get stuck.

XXT Probe Holder Issue 1.jpgXXT Probe Holder Issue 2.jpgXXT Probe Holder Issue sm.jpg

[[Ri...]]

You can't park there! 🤣 🤣 🤣

XXT Probe Holder Issue 2.jpg

[[Mi...]]

We have that issue on DuraMax machines on our shop floor too, we find dirt and oil accumulates on the bottom of the racks, making the stylus systems not drop down as fast as they normally would.

What I wish is I could make the head rise higher after it drops the stylus system off before it moves out of the rack. Even better if I could program a delay to give the stylus system a bit more time to settle in the rack before the door closes.

[[Ju...]]

This has information about adjusting rack approach parameters. I believe the Offset controls how far the head moves in Z before and after a stylus system change.
viewtopic.php?t=9922

[[No...]]

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I'd be glad to be proven wrong, but I doubt these settings will allow you to manipulate the head's movement while it's inside the rack. Too dangerous. As far as I know, movement in the rack is controlled by macros in the controller unit. I'm not sure if every head / rack combination uses macros at all, but our VAST XT / ProMax does.

[[Jo...]]

I am happy to report that things seem to be functioning normally as of now; two days of running the machine with no probe change issues and thankfully no more broken probes, thanks in no small part to Tom's continued assistance. It was a continuous problem that got worse over time... my head was going to explode.
It's unfortunate, and confusing, as to why so much shimming was required to fix the issue, but I'm not complaining. My only guess is the MSR was slammed hard, possibly more than once, but I'd like to think an operator would be transparent if a major collision occurred or that there would be visible evidence of such an event. But that can be wishful thinking. It works now, time to move on.
I am curious though, for those of you with an MSR Mini on your machines, if you have the unit unbolted does it sit on a surface plate nice and flat or does it have a tendency to "rock" at all?

[[Jo...]]

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This was my favorite. When I was not watching the machine and this would happen those graphite shanks make a satisfying "splintering" sound when it they hit something they're not supposed to.

[[Je...]]

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Jon,

Whether or not your MSR was hit, this particular version of the MSR has failed in the same way for numerous customers over the years. The frame does not provide enough support for the bays to remain square and level.

We decided to start building our own probe racks from extruded aluminum. Not only does this save 40-60% on cost, but the racks we build could have a gorilla hang from them and still remain square and level, and they're easy to build.

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[[Th...]]

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This has happened to us. We have to occasionally clean whatever shop grime accumulates on the underside of the racks too, along with the stop ring on the adapter plate itself. Another half second delay on the machine movement out of the rack and it probably wouldn't be a problem.

[[Jo...]]

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It's a avenue I've considered pursuing. We definitely have the capabilities in-house to machine something that should be able to resemble what the MSR does, which is simply to hold the sockets in a stable location and be square to the machine.

[[Je...]]

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Here's an example on a Prismo Ultra with VAST sensor, but the build is the same for any Zeiss sensor. It could also be revised in a more compact form if measurement volume was an issue.


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[[To...]]

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Obviously, you're not considering your shop rate to build this, right? Plus, the loss of potential revenue? 😃

[[Je...]]

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It's true. We have a beginner machinist who needed a project, and his machine was available (we're low volume).

[[Jo...]]

Our manager was ready to place a new one on order immediately, I think the cost was around $1,100 on the website if I remember right, which seemed dirt cheap for anything with a Zeiss logo on it. Death be damned, Carl Zeiss is gonna get paid even if it was from beyond the grave. 🤣
What I couldn't understand was that whole MSR unit was so "cheap" but one 3-socket holder which seems to be made only out of cheap plastic and a few screws and springs, is almost $2K.

[[Da...]]

All this talk of how to account for a poorly made product... Ask Zeiss to replace the defective product. Free of charge.

[[Sh...]]

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Exactly! This has been an issue with the XXT since the beginning. Make your very expensive product better Zeiss!

[[Jo...]]

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The unit is almost 8 years old... something tells me they wouldn't just send me a free MSR at this point. If it were brand new, or even if a year old or so I would have barked up that tree already.

[[Je...]]

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Probably true, but I will still gladly vouch that our MSR experienced the same problem, and we used the same duct tape "solution" of shimming under the base. It's a known defect. And even after we shimmed the base, the arms of the rack were still wobbly.

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