-I need to measure a gap feature of an assembly. The gap specification is 0.010" +/- 0.002". The gap feature cannot be directly measured without cross-sectioning (destructive).
-One potential way to calculate the gap is to measure length of two components of the assembly. The difference...
Hi There:
We did a bias study on a CMM machine using the reference value representing the expected range for the parts that are measured. The average bias is -0.0002" or 16% of the process variation (total variation row of the Study Var (6*SD) column from Gage R&R study). The P-value for the...
Hello All:
I am working on the set-up of a machining process in order to meet 0.30000" inner diameter with +/- 0.000080" tolerance. The plan is to measure the inner diameter with CMM. The following tasks were performed.
(1) Performed a repeatability study using a ring gage on the CMM...
Hi there. Have anyone done a Gage R&R study for surface profile for instance 0.005"|A|B|C? Would you use the min deviation, maximum deviation, or 2X worst case deviation as the response for the Gage R&R study? Any thoughts is greatly appreciated.
Traditionally a non GRR is performed using n=10 parts, three operators, and three trials. For a GRR for surface profile, would you use the same set-up as mentioned previously and the response measured would be the maximum or minimum deviation? To calculate % tolerance, the 6-sigma of measurement...
Kenat:
I agree that fundamentally the surface needs to fall in the specified zone. But my question pertains to measurement of process capability/performance given use of surface profile to simultaneously control location, form, and orientation. I may be able to use all + dev and - dev and...
Surface profile can be used to simultaneously control different geometric tolerances. For instance 0.002"|A|B can be used to control form, location, and position. How would you address process performance/capability of such GDT callout? How would you know that you need to improve location but...
Any thoughts on the method to determine a sampling method in measuring a 5 lobe circle? In other words, I would like to determine min # of point to measure a 5 lobe circle using laser micrometer/CMM such that the sampling method is capable of detecting lobe amplitude with high %. Thanks.
Hell All: I am going to conduct a Gage R&R study on CMM touch probe machine (software is PC-DIMS). The feature that will be measured is maximum inscribed diameter, which is tricky depending on the spots on the circle where the points are obtained. How do you determine a sufficient/adequate...
Hello unclesyd:
Thanks for getting back to me. My I know what measurement method you use to measure 0.000002 on a broach?
I am dealing with an assembly with tight OD and ID tolerance such as +/- 0.00006. With this tight of tolerance, best fit OD and ID do not ensure assemblility of the OD...
To determine a cutoff length for surface roughness measurement, the idea is to exclude waviness in the surface roughness measurement. But, how can in determine what cutoff length to use?
Thanks
I am working on a heat treatment project which require a comparison of a profile measurement of a surface before and after the heat treatment process. How can I perform a statistical analysis to compare the profile of a surface before and after?
Yes RFS is defined in Datum B FCF. The drawing define a feature with its FCF relates to Datum B, but the modifier for Datum B calls out MMC. Just curious if that is a correct call out.
If an ID is defined as Datum B with RFS on a drawing, can the Datum B be used as a secondary datum for a different feature on the same drawing with MMC call out for Datum B?
I am comparing two designs by evaluating the load vs extension curves. I want to show that the new design is equivalent or better than the old design. How can I accomplish the comparision by comparing two load vs extension curves?
