Thanks for all the help everyone, I think I have the problem resolved. For anyone that cares, here are the sordid details. We had been having a problem with the knife rotational axis losing a very small number of encoder counts (generally less than a couple of degrees over a full pattern). The problem had been isolated to one length of robotic cable but the error was small enough to live with for all but the densest material we were cutting. So the problem was initially attributed to the knife. Last weekend we re-ran the one length of robotic cable, and the encoder problem went away, but not the fit problem with the one material.
It also seemed that the inset pieces were always coming out large by just a few thous, and mostly on curves. Note: I had previously run some tests just scoring cardboard, so as to have no load on the knife, and those all came out dead nuts. Closer examination when cutting the dense material revealed that the error was almost entirely in the Y axis. So I went back to the tuning for Y, and pushed up mainly P. I am now getting a small amount of hum in that motor, but the accuracy, and hence the fit is much improved. The motor still runs cold, so I do not think it is harming the motor. There is about a two week backlog that needs to be cleared out, but once that is done, I can play with it a little more and see if I can get turn out the hum. Thus in the end I did not need the tool offset, but perhaps uncovered an oversight in use of auxiliary outputs with tool compensation. Thanks again, Eric is the part moving or the kerf filling with swarf thus affecting the size? tho i cant picture how the part gets larger maybe in some direction and not overall? or some sort of stress relief is ocurring if the above, try glue-stops or tabs else, i dunno (fiddler on the roof said. you want to know why? I'll tell you.. I dont know ) ------------------------------------------------------------------------------ Attend Shape: An AT&T Tech Expo July 15-16. Meet us at AT&T Park in San Francisco, CA to explore cutting-edge tech and listen to tech luminaries present their vision of the future. This family event has something for everyone, including kids. Get more information and register today. http://sdm.link/attshape _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
