Your 3D metrology supplier has a job to do, too. It's their job to fill those needs, or if they can't fill them, it's their job to not sell their equipment to you. They should understand your requirements, the environment in which the components will be measured, cycle times, accuracies, operators, and every other aspect of the installation. 3D metrology system suppliers know EXACTLY how their systems operate. It's their business to know, and if they don't provide you with EXACTLY the system you need, then they're not doing their job.
We've heard every excuse in the book as to why 3D metrology system suppliers won't guarantee their systems. "We only supply the product - it's your job to make it work;" "Other customers claim that the system is accurate enough - we can only go by what they tell us;" "The VDI/VDE certification shows our system to be such-and-such. This should be good enough for you." Sound a bit suspicous? If the 3D metrology system supplier is not GUARANTEEING their system, in writing, on your parts, in your environment, at your throughput, to your accuracy requirements, for your operators, walk away. 3D metrology is not a guessing game. No performance = no payment.
What does a system guarantee look like? Something like this:
- "Metrology system will measure 0.25" diameter holes to within 0.002" globally at 2 sigma on a 2' x 2' x 2' part
- Metrology system will measure machined edges to within 0.003" globally at 2 sigma on a 2' x 2' x 2' part
- Metrology system will measure photogrammetry targets to within 0.0015" globally at 2 sigma on a 2' x 2' x 2' part.
- Metrology system will measure 4" x 8" hole pattern of 8 x 0.375" diameter holes to within 0.003" at 2 sigma
- System will hold all tolerances at customer's ambient working conditions, up to 75 foot-candles of ambient light
- System will contain a single "push-button" to collect, process, and inspect all features
- Invoicing of 3D metrology system will not take place until it is installed and proven to meet all requirements
- All features on XYZ Company Blueprint ID#111000, Dated 2/2/2002 will be measured to within 10% of manufactured tolerances, with the exception of feature #22 on page 2.
- The entire cycle time from start of measurement to generation of final report will take place within 30 minutes."
This type of information should be contained directly in the system quotation, and should be referenced on the Purchase Order. Some companies place language in their quotations that "this quotation supercedes all other pre-printed Terms and Conditions, including the Purchase Order." This is standard legal-ese inserted into the quotation, which is fine, but make sure it is very clear between both parties that no performance = no payment.
You, the customer, are empowered. You deserve a system that works exactly as you expect, the first time. This is the year 2010. Expect more. It is our belief that, in the future, ALL 3D metrology companies will have to guarantee their installations. Today, almost none of them do. If they're not guaranteeing the metrology, who is?