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Qualification Sphere Standard settings

Is there a standard setup for calibrating tips on a qual sphere? Number of hits? Prehit/retract? Move speed? Touch speed? Levels? Number of shank hits? start/end angles? etc...

Or is it all about preference? Min of 5 on 2 levels?

Also is there a way to add avoidance in a certain axis during calibration? I have a 10mm star probe and when measuring T5 at a90b180 the Tp20 is hitting the 1 inch shpere while trying to come around the back side of the sphere. So if I could drop it in the Z before it makes that move, I could get to the last hit without it crashing.

Any help is appreciated!
  • Settings depend on your machine and tolerance for the product you will be measuring. For avoidance in the calibration cycle: Probe Utilities>Setup: Clearance Distance. <-These settings apply to all probes once set.
    There is a lot of useful information in this forum for ways to determine optimal calibration settings, most of which will need to be tested out with your own equipment.
    The Clearance Distance settings should be the 'fix' for the crash you are seeing.
  • Meaning these settings. Is there a "best practice" when calibrating single tips or angles?

    Attached Files
  • I believe that 2 levels are not enough...
    The speed of calibration must be the same than measuring speed.
    If you have to calibrate a star probe at A90B...,the sphere stem must be at an angle (not 0,0,1) or you have to use 2 spheres.
  • For a touch probe (Either one of the Tesa/Hexagon ones or the TP20) then you need min of 5 hits on two levels. More hits should be more accurate up to a point, personally I probably wouldn't go above 13 hits over 3 levels.

    Touch speed can be anything from 1 or 2 mm/sec, up to 8 to 10mm/sec. I always used to think 2mm/sec was most accurate, however I'm now more inclined to think that anything from 2 to 5 mm/sec you won't see much variation (it can be machine dependent).

    As Jeffman said - touch speed in the program should be the same as touch speed for calibration.



    For the Hexagon scanning probes you want either 15 or 25 hits over 3 levels. If you do a lot of scanning you can also calibrate Scan RDV for more accurate scanning results.

    Touch speed should be 2mm/sec.



    For SP25 it's a canned routine which scans over and around the sphere.
  • I think he's talking about a TP20... Wink
    But your answer can help other peoples, thx !
  • Thank you. I'm using a 2 sphere set up. I've always used 13 hits but when hexagon came to calibrate the machine, I noticed they only used a 5 hit. It made me curious if there was a standard. Thank you for the responses!
  • Measuring the location of a sphere accurately needs 12 hits (old rule here : 3 times the number of point that define a feature (3 for a plane and a circle, 4 for a sphere...)
    Calibrating a probe is the same than measuring a sphere, except that the sphere that you are measuring is the tip... So I would say that 5 by far not enough !