Nothing beats bridge style CMMs for a combination of precision, reliability, repeatability and cost. This simple structure and design is still the mainstay of coordinate metrology today and has been with us since the late 1970s. With simple mechanical modifications the bridge design has remained the most popular structure available.
Air bearings systems are the first choice for the lab or clean room, the bearings are situated along the x-axis (bridge) and are generally captive in that for every bearing creating pressure in one direction, another bearing is applying force in the opposite direction. Brown and Sharpe and DEA machines have triangular bridges that easily facilitate this approach, in that three precision surfaces are utilized. On the y-axis (long axis) most new CMMs will have a drive side usually equipped with captive bearings, and a slave side. This slave side is the non-driven leg that supports the structure and generally has air bearing support. The z-axis also contains captive bearings and is generally balanced by either a pneumatic or counterbalance (weight) system.
Hard bearing or roller bearing systems are also available in bridge designs. These are particularly suitable for the shop floor CMMs, as generally speaking the bearing surfaces are located under protected guide ways where air contamination is non-existent.
We have the widest selection of bridge machines available today. Contact us and we will help you select the best CMM equipment for the job.