[EMAIL PROTECTED] wrote: > Hi > I want to build system to tool grinder and that means that my system > should behave stable on very low RPM. > Minimum PRM 0.0001 per minute. I want to use direct drive with ball screw > 5 rev per inch or 1 rev for 5 mm in case of metric system. > My motors have 8192 pulse per ….. it takes 4x8192 per revolution. It is AG > industrial from servo dynamics. > Any fundamentals ideas? > Should I use higher resolution encoder? If you really need .0001 Rev/Minute, that is 32768 counts * .0001 = 3.3 encoder counts/MINUTE, or 18 seconds between each encoder count. You can't get smooth motion like that. Of course, .0001 RPM x 5 TPI on the screw is a movement rate of .00002 IPM. Do you truly need it this slow?
To get smooth motion, you really want an encoder count rate of maybe 15 counts/second, or even better, 60. So, for 15 cts/sec at .0001 RPM, you need 15 * 60 * 10000 = 9 000 000 counts/rev, or 2 250 000 pulses/rev. This will be a pretty expensive encoder. (Multiply by 4 for 60 counts/sec.) Jon ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
