ALIO products are incredibly precise, as they focus on all error sources when looking at bi-directional repeatability. As each axis has six sources of error, ALIO minimises the error in all to achieve 6-D nanometer point precision. The errors from one axis of motion are linear, straightness, flatness, pitch, yaw and roll. Other manufacturers only examine errors in 2-D, in terms of accuracy and repeatability. ALIO are helping NIST develop new standards for point precision.
Hexapods have 12 joints or flexures at both ends of the 6 moving linear links each with on-axis and off-axis motion errors. These 6 links once integrated into the hexapod yield stiffness issues which also add to the total system error even when installing forward and inverse motion equations. The summation of all errors will not allow any hexapod to be a True Nano® positioning motion platform. In today's nano precision world the path or straightness of motion is critical. On the other hand, parallel kinematic machines (PKMs) still have real nano value when investigating tripods. ALIO has been designing and improving 6 and 3-axis parallel kinematic machines for industry for the past 12 years with emphasis on the 3-axis tripod mounted on linear axes to improve the hexapod precision.
The ALIO linear motor Tripod has infinite resolution with less than 10 nm repeatability and accuracy less than 100 nanometers. Mounted on a Nano-precision linear XY motion system for 5-axis or with adding an optional rotary to provide full 6 axis "Hybrid Hexapod" motion. ALIO's Hybrid PKM Motion System offers significant advantages over the traditional hexapods from an order of magnitude more precision to increased work envelope with significant improvement in stiffness.