Hi all. I want to construct big 2D plotter (working area 1,5 x 2,5meters). It should be capable to do: linear, circular and spline contouring. I wanted to use ballscrew linear systems, but price was too high for demanded accuracy (aluminum profiles + linear modules + ball screws all pre-assembled). The next choice was rack & pinion, but there is question of clearance. So the questions are: Is it possible to compensate progressive clearance in rack & pinion by means of incremental linear encoder or LVDT? (position loop). What motion controller would You recommend: Bus based (PCI or ISA card) or standalone device for plasma cutting systems? Accuracy should be 0.1mm per axis. Regards, Ivan.