On 28 April 2016 at 23:29, Gene Heskett <ghesk...@wdtv.com> wrote: > Worst case, 18 u-s to do a dir reverse and one step then revert the dir. > 12 u-s for dir_setup+dir_hold, and 6 more for the step=18. > > Grabbing a copy of kcalc, enter 18 as .000018, do a 1/x to get the max > freq=55,555.5555555555556 or a but over 55 kilohertz. Drive claims it > can do 200 kilohertz. driver is set for /8 microsrepping. Screw is a > 16x5mm. > > So how fast can it go when the pulses are at 200 KHz?
You don't need to consider direction changes when looking at top speed. 48.7 IPM and a 5mm screw is 247 rpm. x 8 microstepping and 200 steps per rev is 6.5kHz or 150 uS per step. The max step rate that the drive can handle is not relevant here, the f-error is calculated internally to LinuxCNC. What do you get if you just wire motor-pos-cmd directly to motor-pos-fb so that the step generator is not even part of the f-error loop? -- atp "A motorcycle is a bicycle with a pandemonium attachment and is designed for the especial use of mechanical geniuses, daredevils and lunatics." — George Fitch, Atlanta Constitution Newspaper, 1916 ------------------------------------------------------------------------------ Find and fix application performance issues faster with Applications Manager Applications Manager provides deep performance insights into multiple tiers of your business applications. It resolves application problems quickly and reduces your MTTR. Get your free trial! https://ad.doubleclick.net/ddm/clk/302982198;130105516;z _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
