I have recently converted a jet 9x20 to CNC using gearhead servos on the x and z and a treadmill motor on the spindle. I made my spindle encoder out of a CD with 20 notches with one deeper than the rest. I read the counts with active electronic optical interrupters so the output is clean and full voltage. I have A, B and Z encoders so I get 80 counts per rev which I think is plenty good enough and doesn't cause crazy high count rates at high spindle speeds. I control the spindle speed with PWM through another optical interrupter for isolation. I actually do my threading with g33 because it was so easy to rewrite my threading programs from servo spindle to indexed spindle. I am very comfortable with my threading program because it works referenced to the outer diameter of the stock or the inner diameter of an internal thread which is the way I think. Also since it's my code I can modify it any time for any reason.
For the little lathe... it works just fine so I'll leave it alone and start working on adding x and Z motors on my newly acquired Monarch 10ee. Before I start getting rotten tomatoes thrown at me for doing such a travesty I must note that this machine is what is called a "base" model. it left the factory with no lead screw, no change gears and no way to add them back even in the unlikely event that I could find them. There is also no taper attachment. So why would I ever buy such a machine??? I didn't. It was a gift. I've sunk about $200 into a rotary converter with idler(no need for variable speed) and I think I can add a ball screw and servo to the Z and a servo to the x for less than $400. Must look into Mesa servo drives. Cecil >You can probably add an index to the spindle and set up for G76 etc. >The motor encoder and belt ratio will give an unusual number of counts >per rev, but it's just a number and computers don't care. >However, you do need one index per _spindle_ rev to do G76 threading. ------------------------------------------------------------------------------ Minimize network downtime and maximize team effectiveness. Reduce network management and security costs.Learn how to hire the most talented Cisco Certified professionals. Visit the Employer Resources Portal http://www.cisco.com/web/learning/employer_resources/index.html _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
