Some Haas machines use a burner out of an electric stove as a resistive element. Don't know what the resistance is but, might be worth checking.
Steve Rob ----- Original Message ----- From: "Gene Heskett" <[email protected]> To: "Enhanced Machine Controller (EMC)" <[email protected]> Sent: Saturday, May 11, 2013 8:45 PM Subject: [Emc-users] Question on stopping a 1HP treadmill motor > When I did the PMDX-106 for the mill, I used 2 relays, one to switch > between the output of the controller with its DPDT poles, the back side of > which dropped a 10 ohm 20 watt resistor across the motor to make use of > its > generating ability as a means of stopping it fairly rapidly. As in 2500 > revs to zero in just a hair over 1 second. The 2nd relay was used in the > usual DPDT reversing circuit. > > There isn't that much inertia in that setup, but this will have a cast > iron > fan cum flywheel that weighs a good 2 pounds to stop. So a 10 ohm 20 > watter, taking the dump from 7000 rpm, is likely to be considerably hotter > than bright red internally by the time its down to 100 rpms as that will > translate to about a kilowatt of stored energy. > > 20 ohms won't have to take quite as much of a rapid thermal shock, but the > wattage will be similar, so I don't see any way to make it work that > doesn't involve a panel of at least 8 similar resistors. > > Unless someone else has a better idea? How about I find some sockets for > the 500 watt halogen lamp sticks & use 2 of them in series? > > Basically anything I can make off the local walmart shelves (for under 50 > bucks that is). ------------------------------------------------------------------------------ Learn Graph Databases - Download FREE O'Reilly Book "Graph Databases" is the definitive new guide to graph databases and their applications. This 200-page book is written by three acclaimed leaders in the field. The early access version is available now. Download your free book today! http://p.sf.net/sfu/neotech_d2d_may _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
