[Ke...] Posted July 11, 2022 Share Posted July 11, 2022 Hello, Recently we got a new computer for our Contura. Since then we have been getting inconsistent measurements. After qualifying the probe we Checked the I.D. to a certified gage ring and get an accurate reading. Then we check the O.D to a gage pin where the measurement will be off be .006 to .008 microns. If we adjust the size of probe ball dia. we can the I.D. to measure correct but then O.D. is not. The Master Probe is qualifying at 3.9994. Also checked Master probe and Master sphere for cracks or blemishes. Any help would be appreciated, thanks in Advanced Link to comment https://qualityforum.zeiss.com/topic/10010-getting-different-measurements-from-od-to-id-with-same-probe/ Share on other sites More sharing options...
[Ri...] Posted July 11, 2022 Share Posted July 11, 2022 I don't know what size these ring/pin gages are, or what class they are. Either way, Ring/Pin gages are certified typically with a laser, and a 2 point check. This is not going to correlate with how you are going to measure it with a CMM. Link to comment https://qualityforum.zeiss.com/topic/10010-getting-different-measurements-from-od-to-id-with-same-probe/#findComment-47560 Share on other sites More sharing options...
[Ow...] Posted July 11, 2022 Share Posted July 11, 2022 2nd what Richard said on the class of gauges and their prescribed accuracy. What size is the pin gauge and how are you holding it? Is it (pin gauge) big or long enough to measure in two different locations, towards the bottom and at the top if measuring in the Z axis. The reason I ask is that if you get two different sizes at different lengths with a significant difference in size (significant pending the accuracy needed) you're probably seeing deflection. The method the pin is being held and how much of the surface is being held is critical because if it's not secure enough, the part will deflect. I've seen that happen many times. Link to comment https://qualityforum.zeiss.com/topic/10010-getting-different-measurements-from-od-to-id-with-same-probe/#findComment-47562 Share on other sites More sharing options...
[Ja...] Posted July 12, 2022 Share Posted July 12, 2022 Are you creating an alignment on the pin before you measure the diameter to ensure the circle path is perpendicular to the pin? Link to comment https://qualityforum.zeiss.com/topic/10010-getting-different-measurements-from-od-to-id-with-same-probe/#findComment-47564 Share on other sites More sharing options...
[Er...] Posted July 12, 2022 Share Posted July 12, 2022 I have no idea if this would make a difference. When the new computer was installed, were the "Save CMM data" and "Install CMM data" programs used? Link to comment https://qualityforum.zeiss.com/topic/10010-getting-different-measurements-from-od-to-id-with-same-probe/#findComment-47566 Share on other sites More sharing options...
[Ke...] Posted July 13, 2022 Author Share Posted July 13, 2022 Both Ring Gage and pin gage are Calibrated/Certified By A2 measuring house to an accuracy of .00001. I am creating base alignments on each gage to ensure Perpendicular contact. Nothing making sense.... for the record this Contura has been a LEMON ,since the day we bought it brand new from Zeiss. Link to comment https://qualityforum.zeiss.com/topic/10010-getting-different-measurements-from-od-to-id-with-same-probe/#findComment-47568 Share on other sites More sharing options...
[Ri...] Posted July 13, 2022 Share Posted July 13, 2022 Please sign in to view this quote. We still need more information. Need sizes and class. Link to comment https://qualityforum.zeiss.com/topic/10010-getting-different-measurements-from-od-to-id-with-same-probe/#findComment-47570 Share on other sites More sharing options...
[Da...] Posted July 13, 2022 Share Posted July 13, 2022 How big is the ring gage? How big is the probe? How big is the pin? All of this information is necessary. Link to comment https://qualityforum.zeiss.com/topic/10010-getting-different-measurements-from-od-to-id-with-same-probe/#findComment-47572 Share on other sites More sharing options...
[Je...] Posted July 13, 2022 Share Posted July 13, 2022 . Elaborate on "LEMON." I'm curious. 🧑💻 Also, what is the weight and length of the probe you are using? If you have an XXT sensor, they tend to not handle long, heavy probes. Here's an example of a cylindrical square I probed on a Contura/XXT Sensor with a 125mm long / Ø8mm Thermofit (carbon fiber) stylus. There was no taper in the square. It's all probing error due to length/weight. .CAD_Evaluation_cylindrical_square.png Link to comment https://qualityforum.zeiss.com/topic/10010-getting-different-measurements-from-od-to-id-with-same-probe/#findComment-47574 Share on other sites More sharing options...
[Ri...] Posted July 13, 2022 Share Posted July 13, 2022 Please sign in to view this quote. The XXT works like a fulcrum. The shorter the fulcrum the more force that is required to move it. The longer the fulcrum the less force that is required to move it. I use this to my advantage when measuring non-rigid parts. Link to comment https://qualityforum.zeiss.com/topic/10010-getting-different-measurements-from-od-to-id-with-same-probe/#findComment-47576 Share on other sites More sharing options...
[Je...] Posted July 13, 2022 Share Posted July 13, 2022 . I wish I had seen this chart a few years ago. Thanks, Richard. . Link to comment https://qualityforum.zeiss.com/topic/10010-getting-different-measurements-from-od-to-id-with-same-probe/#findComment-47578 Share on other sites More sharing options...
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