Hi All,
Hoping for a little help on the best route forward for a reliable roundness measurement.
We are producing two PC rings sample #1 & #2 (Dia both around: 14" (+/-0.01" Roundness: <0.016)
Measurement device: Micro VU + touch Probe (also done same study with CMM)
Roundness: 16 points. Least Square Circle method.
Sample #1 - Ring has Internal support
Ring placed on fixture, location is positioned in x,y
Diameter pass GRR
Roundness requires part to be measured 3x and average taken - Passes GRR
Sample #2 - No center support
Ring placed on fixture, location is positioned in x,y
Diameter passed GRR
Roundness measured 3x and average taken - Can not pass.
I believe that the variation, is caused due to product loading into fixture, and in-part-variation. Due to if I repeat the measurement without replacing the part the results are incredibly consistent.
I know the clear thing may be looking to fixate the part better but I am wary to restrain the part too much to effect the result and i feel the part is incredibly sensitive to touch and any forces applied on it.
How do other people measure roundness on flexible parts that have in-part-variation?
Is 16 points too little based on my diameters?
Any advise would truly be appreciated.
Thanks,
Hoping for a little help on the best route forward for a reliable roundness measurement.
We are producing two PC rings sample #1 & #2 (Dia both around: 14" (+/-0.01" Roundness: <0.016)
Measurement device: Micro VU + touch Probe (also done same study with CMM)
Roundness: 16 points. Least Square Circle method.
Sample #1 - Ring has Internal support
Ring placed on fixture, location is positioned in x,y
Diameter pass GRR
Roundness requires part to be measured 3x and average taken - Passes GRR
Sample #2 - No center support
Ring placed on fixture, location is positioned in x,y
Diameter passed GRR
Roundness measured 3x and average taken - Can not pass.
I believe that the variation, is caused due to product loading into fixture, and in-part-variation. Due to if I repeat the measurement without replacing the part the results are incredibly consistent.
I know the clear thing may be looking to fixate the part better but I am wary to restrain the part too much to effect the result and i feel the part is incredibly sensitive to touch and any forces applied on it.
How do other people measure roundness on flexible parts that have in-part-variation?
Is 16 points too little based on my diameters?
Any advise would truly be appreciated.
Thanks,