I'm doing a LinuxCNC conversion of a huge CNC saw and dual gantry router. I call it The Beast. It's a gantry machine with a 7.5 HP radial arm saw, two 15 HP routers, and two air drills. It's made the enclosures for some of the finest loudspeakers ever built, and needs to do so again.
http://209.197.93.201/beast/Beast04.jpg For a sense of scale, the aluminum bed is 4 feet by 8 feet. Note LinuxCNC running in the lower right of the image. Also note the 44 ounce Mountain Dew next to the monitor... one a night, for too many nights to count. I'm finally close to finishing this LinuxCNC project, but progress has now come to a halt as I try to get the Allen Bradley Ultra3000 servo drive to work with the old Siemens brushless DC servo motor. Depending on the PID parameters, attempts to auto tune result in either a locked rotor or slow jerky motion in one or both directions, but auto tuning always fails. These are ancient motors, some of the first brushless DC motors to be used in CNC machines. Online info is almost nonexistent. Here's all of the data I have on the Z axis motor. Z Axis Motor: Siemens 1FT-5064-0AC01 4.5 Nm = 39.8 inch pounds = 3.32 foot pounds 2000 RPM Max 16.0 Amps Max 7.2 Amps Continuous 4.5 Kp(I) (current controller integral gain) 1.7 ohms (measured with a meter) 11.54 mH (measured with a meter) 100K PTC thermistor 6 pole 3 phase tachometer: 40V @ rated RPM short designation A18, A28, A38, H18, H28 or H38 The motor database in Ultraware, the Allen Bradley Ultra3000 servo drive configuration software, is asking for the motor's rotational inertia which I don't have, and the torque constant, which I don't have unless it's related to the 4.5 Kp(I) shown above. I made some (probably bad) guesses. I think part of the problem I'm having might be caused by not using the Hall Effect sensors. The old Siemens motor uses 15V Hall Effect sensors and the Ultra3000 wants them to be modern 5V Hall Effect sensors, so rather than making a custom circuit for voltage translation, I've been trying to get the Ultra3000 to self-sense the commutation at startup. The old Heidenhain encoders work as they should, for both the Ultra3000 servo drive and LinuxCNC. Does anybody have any suggestions that might get the Siemens motors to work with the Ultra3000 drives? Please contact me off list if you'd prefer. ------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_sfd2d_oct _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
