Greetings everybody; I just redid part of my-lathe.hal, and now the dynamic braking works well while executing a G33.1 loop.
The braking is pretty brutal though, stopping around 25 lbs from 300 rpm in perhaps 1.5 seconds. The two 40 watt 8 ohm NI resistors in parallel used from 450 down to about 150 in the brake sequencing do get fairly warm as the loop runs. My setup is actually dropping a short across the motor as the revs drop below 150 rpms. This is delayed slightly by the limit2 that allows only a 400rpm change in a cycle, used to stabilized the pyvcp tachometer display. But even at 300 rpm, its overshooting the stop point by 2+ turns. However, the thought of capturing the overshoot, dividing it by 2 or 3, and massaging the end point by subtracting 2/3rds of the overshoot and using that as a target to massage the #<_end_point> for the next pass through the loop is stymied by there not being an obvious way to capture the z point at the spindle stopped point so it can be subjected to the math needed to do that in the gcode. One could converge on an #<_end_point> value that would result in a quite small amount of overshoot in just 2 or 3 cycles of such a loop. The same general logic could also be used to pre-stop the rewind backout if those variables are exposed to the hal interpreter, resulting in a rigid tapping cycle that was self-optimizing, potentially speeding the operation up by saving at least 50% of the time it now spends in the overshoot regions beyond the gcode src file start and stop positions. Are the in-memory vars available to the hal interpreter that would allow such a self-optimizing G33.1 to be synthesized on the fly? I seems to me that on the production line, this would be quite a time saver, increasing the number of holes tapped per hour. And this is $ in the pocket in a job shop. Can it be done? If so, what part of the docs do I need to memorize? Thanks Guys. -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: <http://coyoteden.dyndns-free.com:85/gene> is up! My views <http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml> It is illegal to say "Oh, Boy" in Jonesboro, Georgia. A pen in the hand of this president is far more dangerous than 200 million guns in the hands of law-abiding citizens. ------------------------------------------------------------------------------ This SF.net email is sponsored by Windows: Build for Windows Store. http://p.sf.net/sfu/windows-dev2dev _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
