On Thu, Jan 07, 2010 at 02:54:15PM -0600, sam sokolik wrote: > there are always deals if you are patient. Like... > *KL23BLS-115* <KL23BLS_115.pdf>*: $52/pcs brushless servos > digikey amt102-v encoder 29.95. <-up to 2048 line - adjustable.
I'm thinking of building a chunky machine for wood & aluminium, so the datasheet accuracy of quarter of a degree is OK, even though that 1/1440 of a rev limit means that 2048 ppr is humbug, AFAICT. What causes wrinkles on my brain is the "time constant" of 0.4 ms. If it takes 40% of an EMC2 sampling loop for current motion pulses to work their way through the encoder electronics, then that'll look like backlash when we change direction? And when we're just accelerating, it's fibbing to the PID loop, but no more than if we had a slower sampling loop in EMC2? It would be nice to be able to fit encoders to 3 axes on a woodworking machine for the price of one axis with US Digital encoders, but what's the stability like? Has anyone had problems with the index pulse on servomotors? (Datasheet note 1 warns about steppers) Erik (Hoping to learn from the brave souls who've taken the plunge.) -- You got to learn three things. What's real, what's not real, and what's the difference. - Terry Pratchett, _Witches Abroad_ ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
