On Thu, Aug 9, 2018, 2:59 AM Gregg Eshelman via Emc-users < [email protected]> wrote:
> Well that's certainly a failure in design / programming by the > manufacturer. I'd have it so that when re-enabling Z the first and only > thing it would be able to do is rehome Z up so it knows where Z is. Even if > the manual says the operator has to power cycle and rehome everything after > using Z disable, that's just passing the buck on bad design. > Machinery should, wherever and whenever possible, be designed to make it > impossible for operator action to damage the machine using controls on it. > An all too common example is soft serve ice cream machines that have > completely independent freeze and stir functions. That makes it possible to > engage freeze without stir, then turn on stir and break things. A simple > change in the switch wiring makes that damage impossible to do, while > leaving the ability to stir without freeze, but *not* freeze without stir. > > The real issue with the Mazak was being allowed to switch to handle / mdi in the midst of modal operation, change the position of the machine and begin move off without restarting from a prep line. The machine advances from the last point while still referencing machine position plus , move off. Restarting at the prep line would have reset the g54 command and the machine would have moved from that reference point. I was fairly green ten years Ago when this happened and I've not ventured to repeat that mistake any time soon. I'm a big advocate of setting 2 inches of offset for dry run as it prevents crashes, the speed of that machine certainly did not help matters . > > ------------------------------------------------------------------------------ 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
