On Wednesday 20 April 2016 04:20:14 Nicklas Karlsson wrote: > > Greetings; > > > > One of the things I am noticing, when running this crippled Z drive > > at various speeds, is that up to about 3/4 rps at its shaft, it > > moves dead silently, but by 2 rps, its rattling tools off the table, > > exactly as if is was being full stepped, and it doesn't become at > > all smooth again until its moving the head at 25 ipm or more, then > > stalls at just under 48 ipm. > > ... > > What say you folks? Will this truly solve it? > > I would guess resonance or step signal have to toggle between two > different frequencies but have no experience. An oscilloscope would > tell if there are problems with the step signal. I can also tell if > stepper driver behave as expected. > > > Nicklas Karlsson
Halscope shows a very small amplitude ripple, perhaps 5% of the instant output at pid.z.output to the 5i25 when this is going on. This while the peck loop using g33.1 is cutting air. Certainly not a rail to rail jog that it sounds like. My thinking is that this driver is keeping the math correct, but is switching off the microstepping long before rotor inertia would result in a smoothed move. The 2m542 drivers doing the x/y, show no evidence of doing that. I have had the microstepping ratios set for everything above 4, currently at 64, and the only noticeable change is from 4 to 8 to 16. At 8, even slow movement is audible, at 64, 1 rps is dead silent. At 3 rps its sounding rough, at 5 rps its rattling tools off the table. Changing the current up and down half an amp has little effect on this noise. I haven't looked at a motor phase from the driver as I've read that the scope probes capacitance can blow the driver. Since the probes are 10x, maybe 16 pf's, that sounds like an old wives tail as its happy driveing 9 feet of a shielded cable to the x motor & 6 feet to the z motor. So that explains why I'd like to change the driver for another type, but thats an expensive way to test... Thats why I am asking for other users experience with this far more expensive driver before I have paypal issue the payment. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ 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
