On 02/03/2011 02:49 PM, emc-users-requ...@lists.sourceforge.net wrote: > Les, I thought that friction is not at all proportional to speed? > > It is a value that only depends on the direction (sign) of speed, not on the > value of speed. > > Am I mistaken? If I remember properly, Tormach goes over friction, static verses dynamic, in normal machine ways, and when using linear bearings. Greased or oiled steel ways tend to have a difference in static and dynamic friction, and the friction climbs with speed. I believe they said that this increase in friction becomes a problem when speeds are up in the high servo range. The difference between static and dynamic friction is reduced when a Teflon like substance covers the ways. Linear bearings' friction doesn't increase much with the speed of a modern servo system.
See the .PDF linked to below and check out the topic labeled: "Brief History of Linear Motion – Axis design" They go into more detail than I have here. http://www.tormach.com/document_library/TD30204_DesignAnalysis.pdf ------------------------------------------------------------------------------ The ultimate all-in-one performance toolkit: Intel(R) Parallel Studio XE: Pinpoint memory and threading errors before they happen. Find and fix more than 250 security defects in the development cycle. Locate bottlenecks in serial and parallel code that limit performance. http://p.sf.net/sfu/intel-dev2devfeb _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
