Well the Z (torch) is an axis but what the thc component does is to hijack the position commanded and send a corrected position to the stepgen based on the tip voltage while lying about the actual position. The change is not instantaneous by any stretch of the imagination. The correction is dribbled out once per period in the amount you set by the correction velocity which is not named properly now that I think about it. The only reason it could stall the stepper is if you set the correction velocity too high to start with. IMHO the correction velocity should be less than a step and has to be arrived at by watching the tip voltage as you slowly increase it from some insanely small amount. Too much in my experience causes the correction to overshoot and the torch (Z) will bob up and down. Too little and the tip voltage will not stay within an acceptable range.
And I might add that the thc component will only work with steppers due to the hijack/lying about position stuff. JT On 7/8/2014 6:51 AM, Gene Heskett wrote: > On Tuesday 08 July 2014 06:45:14 John Thornton did opine > And Gene did reply: >> Seems to me the biggest problem is swapping topics of the conversation >> back and forth between corner lock tolerance (which works fine) and >> correction velocity. It has my head spinning and gives me a headache. >> > Me too John. I use naproxin. ;-) > > This is two different subjects, which are not even remotely equivalent. > > For the THC mechanics in general, it still has the constraints of accel & > decel, expecting its motors to move the torch an eighth of an inch up or > down instantly simply is NOT going to happen so its motion commands, just > like any other axis, should be constrained exactly like any other axis is > for obvious reasons. > > Perhaps this should be treated as an axis, obtaining these limit values > from another entry stanza in the .ini file? Seems like the best solution > to me, no more than I know about it. > > [...] > > Cheers, Gene Heskett ------------------------------------------------------------------------------ Open source business process management suite built on Java and Eclipse Turn processes into business applications with Bonita BPM Community Edition Quickly connect people, data, and systems into organized workflows Winner of BOSSIE, CODIE, OW2 and Gartner awards http://p.sf.net/sfu/Bonitasoft _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
