You need to acquire a coordinate measuring machine with high accuracy standards, great speed, DCC controller, and you need it all on a strict budget. The task may not be as daunting as it initially seems – coordinate measuring machines do not see the same kind of wear and tear that most machine tools do, and they can operate for decades, sometimes even 35 years with the right care and maintenance. While portable arms and shop-floor-ready equipment have involved some mechanical innovations, for the most part, these tools do not become mechanically obsolete. Upgrades, retrofits, and software updates maintain the competitiveness of older models in terms of accuracy and speed.
Mitutoyo is one of the oldest manufacturers of coordinate measuring machines as we understand them today, having moved from manufacturing gages and calipers toward electronic measuring technology in the 1970s. Based in Kawasaki, Japan (with American headquarters in Aurora, Illinois), their BHN and Brite models are reaching a vintage where they can be commonly found previously owned at vendors like CMM – Canadian Measurement Metrology. Though the BHN series is from the earlier-to-mid-1990s, many experts argue that they are the most mechanically superior product Mitutoyo has ever produced, and they perform very well with little maintenance. The Brite series from the 90s to the 2000s is a good-value purchase, and the recent Crysta-Apex performs with accuracy in the 1.7 μm range and a temperature compensation system.
The advantage of working with a metrology vendor as opposed to the OEM is definitely access to used equipment, which can save you as much as half of the price of the same machine new, but vendors can also handle all of your repairs, calibration services, and retrofits, according to your needs. If your machine has fallen behind contemporary standards, a vendor like CMM can upgrade your Renishaw probing system, incorporate laser scanners or vision systems, increase the size of its measuring volume, or incorporate the latest software.
The software is one of the most significant aspects you should check before buying any used metrology equipment, as it develops much more rapidly than the mechanically-consistent coordinate measuring machines themselves. Many Mitutoyo systems use an obsolete OEM software like Geopak and Geomeasure, and it’s strongly advised that you update these software programs. Third-party software programs, especially PC-DMIS, are popular because they are more widely adopted than most options unique to the manufacturer, and using the same software across the board makes it easier to share CADs and communicate between systems.
You can get top quality performance and decades of usability out of a used Mitutoyo CMM, especially from the Brite series. Remember that any time you buy pre-owned, you can work with a retrofitter to get the system to meet your specific requirements. In fact, retrofits today have become the norm in order to meet a variety of industry standards and measure complex components. While warranties on preowned products can be hard to come by, do not buy anything without a guarantee that it will be operational on the shop floor. Trust full-service metrologists to get great value on a used Mitutoyo instrument.
Michael Sanduso lives in Toronto, Canada. He is a freelance writer and editor, tech geek, and stay at home father.