On Fri, Sep 09, 2011 at 11:58:56AM +0100, andy pugh wrote: > On 9 September 2011 07:34, Ben Jackson <[email protected]> wrote: > > > When I tried it (before I discovered M67 wasn't working in 2.4) what I > > found was that the motion planner slows down at each segment making it > > useless for engraving. > > As far as I can tell from my tests M67 does not change the motion > speed. (Which is rather the point of M67 in contrast to M68).
M67 is just synchronized with motion while M68 is immediate. The problem for engraving is that a sequence G1 X1; M67 ...; G1 X2 ; ... to make a sweep across X does not just accelerate to peak X speed and stay there. It stutters along. Without the M67 the G64 Q- will see those are co-linear and produce a single, fast move. (actually since M67 isn't implemented in 2.4 I'm sure I tried it with M62/63 when I did it) To engrave I'm now snooping axis.0.motor-pos-fb to synchronize with bitmap data flowing in via "streamer". A gcode subroutine just sweeps X back and forth over a region with no knowledge that the laser is firing. The same technique could drive laser power (via pwmgen) except that the PWM isn't fast enough. I'd need external PWM assistance. -- Ben Jackson AD7GD <[email protected]> http://www.ben.com/ ------------------------------------------------------------------------------ Malware Security Report: Protecting Your Business, Customers, and the Bottom Line. Protect your business and customers by understanding the threat from malware and how it can impact your online business. http://www.accelacomm.com/jaw/sfnl/114/51427462/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
