lukewang Posted September 2, 2011 Share Posted September 2, 2011 when we run G02/03 circular path on a clipper, we found clipper command positions are slightly different from mathmatical positions of G02/03. With increased feedrate, this position difference is getting bigger. We dont have any kerf turned on when doing this test. I can provide data collected if needed. Pls advice. Thanks. Link to comment Share on other sites More sharing options...
Sina.Sattari Posted September 2, 2011 Share Posted September 2, 2011 Lukewang, Please see the section "Interpolation Errors" described under Turbo PMAC User Manual. Interpolation Errors The cubic-spline interpolation technique that Turbo PMAC uses to connect the intermediate segment points is very accurate, but it does create small errors. These errors can be calculated as: Error = V^2 * T^2 / (6*R) where V is the vector velocity along the path, T is the segmentation time (watch the units!), and R is the local radius of curvature of the path. For example, if the speed is 100 mm/sec (~4 in/sec), the segmentation time is 0.01 sec (Isx13 = 10 msec), and the minimum radius at this speed is 50 mm (~2 in), then the worst-case interpolation error can be calculated as: Error = 100^2 mm^2/sec^2 * 0.01^2 sec^2 / (6* 50mm) = 0.003mm=3um Regards, Link to comment Share on other sites More sharing options...
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