Hi I want to describe my understanding for low feed system. I will use direct drive mounting and that mean 5 revolutions for 1 inch of travel per minute. 5 revolution times 360 degree is 1800 degree per 1 inch per minute. 0.0001 travel per minute means system will have 1.8 degree per minute. My system generate 8192 pulses per quadrate so 4 times 8192 =32768pulses per 360 degree of revolution. So, if I divide 32768 by 360 I will have pulses per 1 degree of revolution, = 91 pulse per degree. For 1.8 degree per minute I will have 1.8x91= 163.84 pulses per minute. Finally, in the case of feed 0.0001 inch per minute I will have 163.84 pulses per minute. Per second it will be 163.84/60 = 2.731 pulses per second. So, is this enough pulses? If I put 1250 K encoder, will it solve the problem on the way in obtaining stable 0.0001 per minute feed?
Is 1250 K pulse is it per rev or it is per 90degree or revolution? Thanks Aram > Hi Aram, > I did find a high res encoder at 1250K counts/rev. I'm not really > certain that is ppr or in quadrature. > > Price is in the $1000 range. > > http://www.opticalencoder.com/pdf/CP-850-950-HHC.pdf > > Dave > > On Apr 22, 2008, at 11:09 AM, [EMAIL PROTECTED] wrote: > >> Hi >> I have 3 questions. >> First if to make motor work on very low feed 0.001 per minute >> need only >> high resolution encoder than may be needed belt reduction to the >> encoder >> shaft only, to get more pulses and not to whole motor shaft. Is this >> correct? >> Second, what is reasonable low feed with direct drive to motors >> that have >> 8192x4 puls per revolution? >> Third, how much those encoder, with 2 250 000 lines, may cost ? >> Thanks >> Aram >> >> >>> [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 >>> >> >> >> >> ---------------------------------------------------------------------- >> --- >> 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 > > > ------------------------------------------------------------------------- > 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 > ------------------------------------------------------------------------- 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
