Gene, I also have a home brew encoder disk and interrupter set up on a 9x20 jet with a treadmill motor and an M60 controller. I also have a similar setup on a Monarch 10EE with a 3.5 hp 350 VDC drive motor. I was having a random problem cutting threads on both machines. The thread was losing its pickup occasionally and wiping the previous thread. This was an intermittent problem and it took a while to find the culprit. After watching a scope much more than I enjoyed I found that I was getting an occasional noise spike on the index interrupter which was of course the cause of the problem. My fix was to decouple the Vcc on every interrupter with a 1mf cap and I also snaked a length of "chinese fingercuff" braid over the outside of all the cables (grounded at the power supply end). I also ran a #6 bare copper from the motor frame to the control box chasis ground. I don't know if these attempts completely removed the noise spikes but I do know that I haven't wiped a thread since I did it.
If I ever do another backfit I WILL use differential interrupters or packaged differential encoders. There is a lot of really nasty QRM associated with DC motors, DC motor controllers and relays. ------------------------------------------------------------------------------ Learn Graph Databases - Download FREE O'Reilly Book "Graph Databases" is the definitive new guide to graph databases and their applications. Written by three acclaimed leaders in the field, this first edition is now available. Download your free book today! http://p.sf.net/sfu/13534_NeoTech _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
