On Feb 17, 2008, at 8:05 AM, Gene Heskett wrote: > <big snip> > > Which means we either use the disable points in the amps, or a > power relay to > kill the AC power to the ps feeding the amps as its not safe to > disconnect > the motors or the driver power with a hard connection. Even the AC > power > thingy could be fun as there is about 1/4 farad in its filters, so > that stop > isn't going to be instant. A second perhaps & way too slow IMO. > The amp > disable is the fastest of the bunch I suspect. And it is what I'll > use when > I re-build the setup for the 4th axis. > > The point about safety is well taken though Ray, thanks. I wish it > was safe > to hard switch the amps supply line, but I don't believe it is in > terms of > amplifier life expectancy. > > I like and use the amp inhibit. I've also tried killing the AC power ( slow if your axis is moving at max velocity). I suppose one could disconnect the AC then crowbar the DC supply with a small (ohms) resistor in series with the SCR to limit dv/dt. If you look at Les Watts' big router he also installed small mechanical shock absorbers to soak up the kinetic energy of the axis.
Dave ------------------------------------------------------------------------- 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
