On Wednesday 05 July 2017 10:41:50 andy pugh wrote: > On 5 July 2017 at 02:58, Gene Heskett <[email protected]> wrote: > > Why? Huge rubber band in series with the z movements, > > associated I think with the z acceleration limits, > > That has nothing to do with the Pi and everything to do with the INI > file settings. Did you guess the accel limits, or derive them by > experiment?
Experimental, for max speed. However, this machine can move z 3x faster than x, so I could go for a lower top speed and a higher accel. This is stuff yet to be fully optimized I'm sure. And this z motor was the one I took back off the G0704 because it was too slow, way too slow when lifting the heavy head by direct coupling to the screw. Its belt drive now, 32 teeth on the motor and 40 on the screw, but it still has the 22mh per coil inductance, so the torque falls off a cliff at 60 rpms, but it has surplus torque for the lathe so can move z at close to 90 ipm. I should cut MAX_VEL's in half, and double the MAX_ACCEL's. (nominally) I am not impressed with the dm860 driver either, and have an automation tech version waiting for me to find a round tuit & swap it out. The microstep mapping of the dm860 misses the mark when running at this motors reduced 3.4 amp current, missing one microstep completely when creeping along. I'd like to get another motor like the 8 wire 950 oz I put on the G0704. Another of those round tuit things. :) But first I need to grind me a better tool than the one I made yesterday, its tapered on the sides way too much. Works in plastic water pipe, sure breakage halfway thru the 10 tpi, 20 thou deep cuts it needs to make in SS. If I make the tool correctly, I won't need near as much stickout. And 2 hours later, after cutting the maxvels in half, and quadrupling the max_accels, I believe I have it. Very good looking threads in the pvc pipe. But I'll next try it on a piece of cold rolled. Gotta go get my sleeping beauty the papers so she has some crosswords to work when she awakes. Take care Andy. 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> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
