On Wed, 20 Apr 2016, Gene Heskett wrote: > Date: Wed, 20 Apr 2016 14:13:38 -0400 > From: Gene Heskett <ghesk...@wdtv.com> > Reply-To: "Enhanced Machine Controller (EMC)" > <emc-users@lists.sourceforge.net> > To: emc-users@lists.sourceforge.net > Subject: Re: [Emc-users] Question on DM860 stepper drivers > > On Wednesday 20 April 2016 11:36:58 Jon Elson wrote: > >> On 04/20/2016 03:20 AM, 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. >> >> You can also hook up an old PC speaker with a 150 Ohm >> resistor in series to the step signal and listen to it. The >> ear has a great system for picking out multiple >> frequencies. Since my (Pico Systems) stepper board is >> essentially a servo, where the computer sends a velocity, >> step pulses are counted as if they were coming from an >> encoder, and then run through the PID hal component, bad PID >> parameters can cause nasty frequency hopping at certain >> speeds. So, I listen to it and twiddle until I get smooth >> tones that sound like turning the dial on an audio >> oscillator. (You can also do this with Halscope.) >> >> Jon > > For software stepping, halscope is neat, but the 5i25 does not expose the > step/dir signals for halscope perusal so a real scope or better yet the > speaker is needed for this. And its an idea I hadn't thought of to try, > thanks Jon. The ear is a fantastic device for hearing odd sounds that > aren't supposed to be there! The eyes are overloaded trying to analyse > a moving target. > > 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>
Not quite true, you can look at the step/dir signals with halscope (by looking ta the assosciated GPIO input pins), but you will not see much on the step signal unless you have a very wide step pulse width (or quadrature mode) If you think there is step generator misbehaviour, the best way to check is via the following error, its not difficult to get the error less than a very small fraction of a step (say 1/100) with proper tuning. > > ------------------------------------------------------------------------------ > 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 > Peter Wallace Mesa Electronics (\__/) (='.'=) This is Bunny. Copy and paste bunny into your (")_(") signature to help him gain world domination. ------------------------------------------------------------------------------ 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
