Howard Chan wrote: > Dear all, > At first, I used latency-test to check my computer and I set the > BASE_PERIOD to 25000. I used Integrator manual to calculate the > INPUT_SCALE but it is not correct. > My machine requirements: > Unit using mm. > I hope the max rpm of motor is 1200. > I use SANYO DENKI servo motor which has an 2000 ppr internal encoder and > max rpm is 3000. The motor mounts a 16T pulley and connects a 36T pulley. > http://myweb.polyu.edu.hk/~icwfchan/p2.png > 36T pulley mounts a lead screw which is 4 turns per inch > http://myweb.polyu.edu.hk/~icwfchan/p3.jpg > > According to Integrator manual, my calculation is: > INPUT_SCALE=2000 * (36/16) * (4 /25.4)=709 > but the computer displays x-axis value is not the real-distance value. > I try and error to find the value round 1250 > > Would you mind telling me which part is wrong? > Thank you > > Howard
Your calculations appear to be correct. But obviously something is not working. The screw pitch and pulley ratios are easy to verify, but the encoder counts might not be what they should be. Here is an experiment: TURN OFF MOTOR POWER - safety first! Start EMC, then use HALMeter to examine the raw unscaled counts from the encoders. Make a mark on the motor pulley, and write down the number from halmeter. Then rotate the motor shaft exactly one turn by hand. See how much the halmeter number changes. Rotate the motor back to the original position and make sure that the count goes back to the original number. You might want to turn the motor shaft ten turns and divide by ten for more accuracy. Any non-repeatability might indicate problems in the encoder system, which could be electrical connections, noise, or even mechanical - something like a slipping coupling between motor and encoder. Hope this helps, John Kasunich ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
