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Travel Limit Error (inside travel limits)

Today I got a travel limit error when the hit in question was well within the travel limits. I can move there with the jogbox, or even with a move point command.

If that wasn't strange enough, I get this error on "hit 3 of 4" on a 7 point circle. It never even attempts to take hits 1 & 2. And what about hits 5-7??

I should also mention that this program has been around for a couple of years and has run without any problems until this morning.

I've been using PC DMIS since there was PC DMIS and I've never seen anything like this.

Anyone have any experience with issues like this?

Thanks,

Jon
  • When something really funky like this happens I zoom out and start from scratch

    I would recommend you:

    -Restart controller, cmm, cpu...everything
    -Turn everything back on & home the cmm
    -Calibrate your probe tips you need for your program
    -Re-run program & see if you have issues still

    If you still have issues check back and we'll dig deeper
  • The closest I have come to the problem you are describing is I have worked with machines that sometimes shifted the home position when the encoders are dirty. The encoder scales had little marks on them every 50mm and if they got too dirty the machine would miss the first marker when homing out and stop at one of the other markers. This would shift the machine's home position by some increment of 50mm and sometimes make it think that an instructed move is outside of the measuring volume even when it is not. Or worse, it would think it could move to some position that is actually outside the measuring volume and hit a hard stop on the axis. Not terrible, but not the way I want to treat a precision machine.

  • When something really funky like this happens I zoom out and start from scratch

    I would recommend you:

    -Restart controller, cmm, cpu...everything
    -Turn everything back on & home the cmm
    -Calibrate your probe tips you need for your program
    -Re-run program & see if you have issues still

    If you still have issues check back and we'll dig deeper


    Clean those scales
  • Thank you for all the input.

    I cleaned the scales, restarted, and re-homed. I also moved to another spot on the plate as we have had some recent "waiting for in position" errors where this setup was placed. This is an older machine (B&S Microval). Anyway, some combination of the above fixed the problem for now.

    Position errors on a machine this old is to be expected to some degree. What really threw me this time was that it was attempting to measure a 7 point circle beginning with "hit 3 of 4". That one is entirely new for me. Has anyone seen that before?

    Jon
  • Thank you for all the input.

    I cleaned the scales, restarted, and re-homed. I also moved to another spot on the plate as we have had some recent "waiting for in position" errors where this setup was placed. This is an older machine (B&S Microval). Anyway, some combination of the above fixed the problem for now.

    Position errors on a machine this old is to be expected to some degree. What really threw me this time was that it was attempting to measure a 7 point circle beginning with "hit 3 of 4". That one is entirely new for me. Has anyone seen that before?

    Jon


    LOL no that sounds scary...who knows where it will try to start next time?!:scream;

    Our two validators that are 20+ years old run all day every day. They can go 250mm/sec but we run them at 100mm/sec-ish and clean the scales on a regular PM schedule. They are also very careful about calibrating the probe tips more often on those machines and everyone is aware of the fact that "weird" data should be scrutinized a bit more even though the programs are "validated"

    All things considered...glad you're back up & running Sunglasses
  • Home position "pulse" is most often determined using HALL sensor magnets, and have ZERO relevance to the readhead/scales.
    Hall sensors are not necessarily very accurate as they are sensing the presence of a magnet stuck to each axis, next to the scale (Usually marked with an "N"). they can shift your home position each time by upwards of 0.200" in each axis, so if you have a component that you are measuring super close to the machine's volumetric extents, re-homing can often render that method of measure sporadically functional and non-functional. lol.