Diamond polishing

 
Raju,
If it’s not measurable, how do you know if it’s working? What’s good and what’s bad? And if you can’t measure it, how will you know when you’ve improved it? Can you give more specifics?

BTDT,
Someone walked right into your area of expertise!
Regards

Raju:The simplest project I can think of would be based on weight retention from rough. The financial benefits are easy to calculate and the potential influencing factors could come from technical issues to work scope definition and training.
Too much variation during polishing will result in low quality polished. The relationship between the largest size with the best cut can be modelled using existing standards for the GIA or AGS, and combining those with market prices for loose stones. Our analysis showed Table, Polish and Symmetry as contributing equally to the price of the final polished stones. The error in the model was 1.31% for SRB. We did not include the smaller, single cut stones you may be working with.
Get yourself a Sarin machine for facet measurement and incorporate periodic measurements as part of your Control plan.
BTDT

Raju:My point was NOT that you have a monitoring program while the diamonds are on the dop chuck. You apply Six Sigma to the entire process of polishing. This includes the accuracy of the dial stop gauges, grinding/checking time intervals, pressure, lap speed, different index wheels, etc.
Checking angles and meet points on the final stones is done after they are removed from the chuck. This data is used to identify to sources of variation in the final product.
The amount of repair will decrease. This is related to the first-time-yield, also covered in a Six Sigma project.
Whether you can get accurate measurements on 3-6mm stones will be part of a Gauge R&R study for any project directed at measuring the quality of the polish.
BTDT

Raju,
While BTDT’s idea of tracking weight retention is a good basis he is incorrect about table, polish & symmetry. Beyond color  & clarity today’s quality criteria is based on light return (brilliance). The range of acceptable critical angles in the pavilion, in conjunction with the corresponding crown angles then table size and finally polish & symmetry result in the true cut grade.
He is also correct about using a Sarin, it’s th only way you can plan or measure your results.
mzs