On Friday 28 August 2015 22:02:51 Jason Burton wrote: > Just an heads up to the list, and for future Google searchers. > > First, let me thank all you developers for building pncconf in the > first place. Great tool for quick setup and learning. > > I have been working on getting my VFD mill spindle to work with proper > scaling for some time now. > > Turns out Pncconf was generating a couple lines incorrectly. Easy fix > only if you know what is wrong. Thanks for the patient help Peter > Wallace! > > Hardware: big vertical machining center + Mesa 5i25/7i77 + 0-10 VDC > controlled VFD spindle. > > Software: all recent linuxcnc/pncconf versions dating from current > live cd Debian with master branch to at least as far back as the > Ubuntu 10 live cd. > > Both the problem and the fix are described here: > > https://sourceforge.net/p/emc/bugs/433/ > Interesting. pncconf generated a spindle scale factor of 1.0 here, and its relatively non-linear but does cover the range of speeds I can get with my hardware, the following.
Grizzly GO704 mill, OEM 1 hp motor, PM DC brushed. Locally built 115 volt dc power supply good for at least 1 KW. One of the Pico Systems pwm servo amplifiers, currently fed at 40 KHz by the pwmgen in a Mesa 5i25 by bypassing the optos for that line on my BoB. Still 1 more opto though, one to translate between the BoB's 5 volt swing and the 12 volt swing the pwm servo expects. Overall its working, just not dead accurate, an s2100 actually gets me about 2700, but an s80 gets me about 40 revs. Huge amounts of Pgain will stiffen it some but I get the impression I could make Pgain 1500, up from the current 150 and it would still be sagging 40% while driving a 4-40 tap in 1/2 thick alu using the G33.1 rigid tapping cycle. This with the heads backgear in high range. So, how might I apply this to my situation to both stiffen the speed regulation and tighten up the commanded speed to actual speed obtained? Also related, do we have a canned halui (or gladevcp) button to change the gear scale according to the heads gearshift? I have 3 machines with this hi-lo gear choice, but only 2 have encoders for speed feedback, this new to me mill being one of them. > Best, > Jason Burton > (LatheBuilder) Currently rebuilding mine again. I need a 2x2x5" block of steel for the next step, but I expect some gasolene will locate that. 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> ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
