> On Sat, 2008-01-19 at 21:11 -0500, John Kasunich wrote: > ... snip > >>Like taking a cut that is heavy enough that the VFD trips on overload, >>and the machine keeps driving the no-longer-spinning cutter through the >>workpiece. SNAP! >> >>My Van Norman mill had the feedmotor interlocked to the spindle motor to >>avoid exactly that issue (designed in about 1939). When I replaced the >>motor starters with VFDs I did the same, and I'm glad I did. That >>little machine is very rigid - enough so that it can take a 1-1/2HP cut >>that will trip the spindle drive with no audible sign of struggling. Practically all VFDs have a fault relay. You just wire this in series with your E-stop chain and it will stop the CNC motion probably before the spindle stops. Whether that will save your cutter is not guaranteed.
Jon ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
