"Eric H. Johnson" <[EMAIL PROTECTED]> wrote: > John, Jeff, > > If synchronized I/O can be implemented, that would sure seem to be the way > to go, recognizing where Jeff indicates it likely still doesn't or won't > work, at least in the current form. > > Alternatively, could I not do something like?: > G1 X1 Move to X=1 with the laser off > G1 X1.00001 Z30 Raise to 30% power over very short distance > G1 X2 Move X at 30% power > G1 X2.00001 Z60 Raise to 60% power over very short distance > G1 X3 Move X at 60% power
That exact example won't work, because you are using G1 moves and the Z numbers are large. If you were to load that program in axis and look at the preview, you would see a very very tall part (60 inches tall, 3" wide). G1 moves obey a feedrate that is based on tooltip velocity along the path, not just in the XY plane. The XYZ distance from 1,0,0 to 1.000001,0,30 is 30 inches, and at F60 would take 30 seconds. The subsequent cutting move from 1.000001,0,30 to 2,0,30 is just under one inch and would only take 1 second. It could be made to work by squashing Z. If you use Z0.00100 as 100% laser power, then the path is no longer so "tall". At F60 feedrate, it would only take 1.414mS to travel from 1,0,0 to 1.001,0,0.001. So this would work: G1 X1 G1 X1.001 Z0.0003 G1 X2 G1 X2.001 Z0.0006 G1 X3 I'm not sure exactly what effect those short segments would have on blending. In the example, all of the moves are in a straight line, but in practice, you might be making a 90 degree bend at the same time as you change the laser power. Adding a very short segment right before or right after the bend would probably change the blending results. If you want to try the squashed Z approach, the EMC side is easy. HAL has a scale component that can be used to multiply the Z position command by any number you want before sending it to a DAC or PWM generator. (Actually, the DAC and PWM generators have user adjustable scale parameters already.) The CAM side might be tougher. > Basically if the distance is less than can be traversed in 4-5ms, > then that is less than the response time of the laser anyway. > > I have to check with my CAM guy, but I believe the post-processor for the > laser CAM package could do this. Sounds like a decent short term solution, but I'd like to do it right. IMO, that means synchronous I/O. > I will be sure to check in on IRC on Sunday, or let me know if it > will be at another time. Probably tomorrow evening (Eastern USA time) unless something comes up. Regards, John Kasunich ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
