> I know I need servos. The only low cost servos I have found so far are > from keling. I'm probably going to go with the KL23-130-60 NEMA 23 > sized servos. The link is here > http://www.kelinginc.net/ServoMotors.html . If anyone knows who else > sells low cost servos, I would very much be interested in any info you > might have.
Brushless is not much more expensive so you could look at those too. > The next part is where I am confused. I was looking at the Gecko Drive > G320X. Is it correct in thinking this would be used just like a stepper > driver with the step, dir inputs and emc would know nothing about the > encoder positions on the servos? If you have fast encoder inputs to emc (mesa or similar card), you could wire the encoder signals to emc also. The gecko-drive would still close the loop, but emc would be aware of the position (or position error) of the machine. This is the way most professional big machines do it (I think). The drive is closely matched/tuned to the motor and closes the loop. The motioncontroller just outputs step/dir signals and just to make sure also reads the encoder signals. > Instead of the G320X, if i got a mesa FPGA card, could I use any generic > h-bridge with the mesa card to control the servo and have the servo > encoders read by the mesa fpga card? This is the cool thing about emc, it can close loops in real-time. On my mill I used a mesa card with pico-systems pwm-input amplifiers for brushed motors. Now I'm converting a lathe and the plan is to use a mesa card+ pwm-input brushless amps. This is roughly how my mill setup looks like: http://www.anderswallin.net/wp-content/uploads/2008/09/dc_servo_schematic_2008jan19.pdf Anders ------------------------------------------------------------------------------ This SF.Net email is sponsored by the Verizon Developer Community Take advantage of Verizon's best-in-class app development support A streamlined, 14 day to market process makes app distribution fast and easy Join now and get one step closer to millions of Verizon customers http://p.sf.net/sfu/verizon-dev2dev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
