DIY-CNC, EMC & Gecko Groups: I have nearly decided to upgrade my controller to Gecko drives. But I'd like to run this by the group before I spend the $. I'd appreciate any feedback anyone has.
I have a Bridgeport size knee-mill retrofit for CNC. It has a Rockford rolled ball screw kit on X and Y and a rolled ball screw on the quill. This all works fine with smooth motion and little backlash. So far so good. It uses stepper motors with 2:1 timing belt reduction between the motors and the lead screws. I have size 34 654 oz-in Motion Control Group steppers on each axis. These are speced at 4.9A/phase (parallel) and 3.7V. The drivers are 5A Chopper kits from Camtronics and use a 36V supply and are set for 4.1A. I bought the motors and controllers from Camtronics in 2000. I've never gotten better than 15-20 in/min without loosing steps. I also tend to loose steps under heavy load, this noted only while drilling with the Z axis. I measured the torque on the X and Y axes with a fish scale and get about 540 oz-in at the motor. These speeds are OK for cutting but a little slow for rapids. I really don't like loosing steps though. I could increase the Z axis reduction from 2:1 to 3:1 which would probably fix the Z axis lost steps. I understand steppers should run hot but these run quite cool. Never uncomfortable to hold ones hand on. Would this indicate the current could be increased? Would the difference between 4.1A and 4.9A rated account for this? Has anyone else run a similar combination? If so was your experience similar? I'm thinking of using Gecko drives at 70V. Will nearly double the max speeds? Would the Geckos increase low speed torque? Thank you. P.S. There's a link showing the machine from the bottom of my web page www.cvc.net/cvcmem/currin. It's becoming dated but I'm just now getting around to working with it again. -- Hugh Currin Klamath Falls, OR USA ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
