Mark,

There are several options out there for scanning. Each has its distinct advantages and disadvantages. My suggestion is not to concentrate on the probe etc. but instead on what it is that you actually need - reliable measured data. Data which is accurate and repeatable and therefore, data which you can make solid decisions with.

The only way to do this is to perform a gage study (using your part) and on the machine/probe system that each CMM builder is suggesting.

Of course, it goes without saying that you must also understand the product offerings of each company. Sometimes however, (and we all do it) you get yourself wrapped the proverbial wheel. As an example, you want to investigate scanning machines but have been led to believe that because Zeiss VAST, Leitz or SIP heads don't articulate, it may cost you big bucks for tooling. If after your gage studies are complete, it turns out that the only machine that passes is the Zeiss VAST machine, then the rotational debate is meaningless. Keep in mind that I am not trying to "sell" you on the VAST..... it may not be the right machine for your job. I am just trying to illustrate my point.

Also, don't place too much weight on the measurement of artifacts (ring gages, gage blocks, etc.). These are easy for most CMM companies to demonstrate good gage repeatability numbers. Accurate/repeatable measurement of real geometry (geometry that has form errors) is not so easy. You must use your own parts for the gage study.

Finally, we at Zeiss do believe that more measurement data is better. "...What you don't measure you don't know". Once you arrange the demonstrations, make sure the respective CMM builders use scanning techniques on all features (planes, cones, cylinders, etc.) in your study.

I hope this is helpful.

Best Regards
Kevin Legacy
Carl Zeiss IMT Corporation