On 8 August 2018 at 03:17, Brent Loschen <brent.losc...@gmail.com> wrote:
> And now for my question. The old Bridgeport had a button on the front panel > titled "No Z" that turned off all z motion and let me "air mill" a part as a > sanity check of my X & Y boundaries/fixtures. I can't find the equivalent > functionality in LCNC and was wondering if anyone here has done this, or > knows the best way to implement it. I suspect this would start off looking easy and turn out to be surprisingly difficult. Turning off the Z is pretty easy, you would disable the Z stepgen and (at the same time) connect joint.2.motor-pos-fb to joint,2,motor-pos-cmd rather than to hm2_5i25.0.stepgen.2.position-fb. Now the machine thinks that Z is moving, so it is happy, and the stepgen is disabled, so no steps are sent. That just needs a mux2 component in the HAL. But what happens when you release the button? Suddenly the machine will realise that the Z axis is not where you told it it was, and you will get an immediate following error. Also, the Z will attempt to move to the "real" position at a speed only limited by the stepgen accel and velocity limits. So you probably need some Hal-trickery to gently move the Z back in to commanded position, while at the same time lying about the position to prevent following error being triggered. -- atp "A motorcycle is a bicycle with a pandemonium attachment and is designed for the especial use of mechanical geniuses, daredevils and lunatics." — George Fitch, Atlanta Constitution Newspaper, 1916 ------------------------------------------------------------------------------ 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 Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
