Bruce Klawiter wrote: > I have just switch my mill over from linear scales to rotary encoders and I > can't get my input scale right. OUTPUT_SCALE is 1, Units-inch > > X axis has a 1250 CPR differential encoder, motor 14 tooth gear, screw 21 > tooth gear, .200 pitch screw. 1250 X 4 X 1.5 X 5 = INPUT_SCALE = 37500 > > Y axis 5000 CPR differential encoders, motor 14 tooth gear, screw 21 tooth > gear, .200 pitch screw. 5000 X 4 X 1.5 X 5 = INPUT_SCALE = 150000 > > Z axis 5000 CPR differential encoders, motor 14 tooth gear, screw 28 > tooth gear, .200 pitch screw. 5000 X 4 X 2 X 5 = INPUT_SCALE = 200000 > > If these calculations are correct they don't work, to even be in the ballpark > of one inch of actual travel (+/- .020) equaling the DRO showing one inch I > need. > X axis INPUT_SCALE =38500 > Y axis INPUT_SCALE =750000 > Z axis INPUT_SCALE =1000000 > > What am I missing here. > > Are you absolutely sure your encoders are counting correctly? Have you turned each motor as exactly one turn as possible and observed the difference in reading? (This should be done in both directions with the pos option of the diagnostic program. Note the program starts with an oddball value of 517 in the position counters.)
Having gears between the encoder and leadscrew is a bad idea, unless you actually mean timing belt sprockets. The fact that the numbers keep going up at vast rates between axes indicates something is quite wrong. Are you absolutely sure these values are being sent to the input scale parameter of the ppmc driver? Possibly there is something wrong in your ini files (it would likely be either in the .ini file or in ppmc_motion.hal, which reads the parameters in the .ini file and sets the, into the driver with a line like : setp ppmc.0.encoder.00.scale [AXIS_0]INPUT_SCALE If this line is somehow being tricked into picking up the wrong value from the .ini file, that might be the problem. You should examine the actual value with the "show hal configuration" utility that is available from the Machine drop-down menu in Axis. Examine the values of ppmc.0.encoder.02.scale, for instance, and see if it is what you are putting into the .ini file. Jon ------------------------------------------------------------------------------ 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_d2d_feb _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
