So, I am using a romer arm to measure concentricity of two holes. With a traditional CMM (and different software) we have found the concentricity of the holes to be 0.26mm. However, with the romer arm it shows the concentricity to be 2.9mm. If you take the acuals from the two holes and calculate the concentricity it should read like the traditional CMM???? Why is PC DMIS not giving me the correct reading? Any suggestions on how to measure this dimension with the Romer ARM?
So, I am using a romer arm to measure concentricity of two holes. With a traditional CMM (and different software) we have found the concentricity of the holes to be 0.26mm. However, with the romer arm it shows the concentricity to be 2.9mm. If you take the acuals from the two holes and calculate the concentricity it should read like the traditional CMM???? Why is PC DMIS not giving me the correct reading? Any suggestions on how to measure this dimension with the Romer ARM?
A nice fat Friday the 13th softball? Sure. . . I'll take a swing. . .
Pc-Dmis does not calculate concentricity properly per ASMEY 14.5M 1994/2009. The only way to properly check concentricity per the standard requires the part to be rotated about the datum axis and two dial indicators applied to the surface of the feature being evaluated.
But fear not! Most of the time when the concentricity symbol is placed on a drawing it is used incorrectly and what the designer is really trying to control is position.
Pc-Dmis treats concentricity as if it were position.
There are exactly 42,555,069 posts to date about concentricity on various CMM forums should you care to spend the rest of the day reading about exactly why CMMs can't "do" concentricity right, and elaborate possible ways to get sorta close with a CMM.
So, I am using a romer arm to measure concentricity of two holes. With a traditional CMM (and different software) we have found the concentricity of the holes to be 0.26mm. However, with the romer arm it shows the concentricity to be 2.9mm. If you take the acuals from the two holes and calculate the concentricity it should read like the traditional CMM???? Why is PC DMIS not giving me the correct reading? Any suggestions on how to measure this dimension with the Romer ARM?
A nice fat Friday the 13th softball? Sure. . . I'll take a swing. . .
Pc-Dmis does not calculate concentricity properly per ASMEY 14.5M 1994/2009. The only way to properly check concentricity per the standard requires the part to be rotated about the datum axis and two dial indicators applied to the surface of the feature being evaluated.
But fear not! Most of the time when the concentricity symbol is placed on a drawing it is used incorrectly and what the designer is really trying to control is position.
Pc-Dmis treats concentricity as if it were position.
There are exactly 42,555,069 posts to date about concentricity on various CMM forums should you care to spend the rest of the day reading about exactly why CMMs can't "do" concentricity right, and elaborate possible ways to get sorta close with a CMM.
