2012/8/16 andy pugh <bodge...@gmail.com> > On 16 August 2012 17:35, Andrew <parallel.kinemat...@gmail.com> wrote: > > > What's the difference between DEFAULT_ACCELERATION and MAX_ACCELERATION? > > I think one predated the other, and currently both are accepted by > some interfaces and not others. > I think that DEFAULT... is the more generally applicable. > > > If I don't have MAX_ACCELERATION in my ini's, is it taken from axis > > settings? > > Only in Joint mode or trivial kinematics. > > Thanks, Andy. According to my observations, for non-trivial too. And, I assume that for non-trivial kinematics velocity and acceleration limits are in world-mode, which is a pity.
2012/8/16 Stephen Dubovsky <smdubov...@gmail.com> > negative acceleration is deceleration (well, depending on direction and > reference frame.) ANY change in speed is acceleration. Thanks, I see now. 2012/8/16 John Kasunich <jmkasun...@fastmail.fm> > > Also, can you explain me "The acceleration and deceleration phase each > > use > > half the ini file MAX_ACCELERATION. In a blend that is an exact reversal, > > this causes the total axis acceleration to equal the ini file > > MAX_ACCELERATION" (User concepts). How is it possible that an axis > > decelerates and accelerates simultaneously? > > Each move consists of an acceleration period, a cruise period, and a > deceleration period. In exact stop mode, one move completes all three > periods, then the next move starts. > > When blending, the accel portion of a new move is overlapped with the > decel portion of the previous move. If both moves are in the same > direction, then the accel and decel cancel, and the actual speed > remains constant - perfect blending. > Thanks, that is helpful. To tell the truth this is the first time I completely aknowledged this information about acceleration. That's pretty bad feature of Linuxcnc... And it's a pity that I did not think about it before. Say, I got actuators with 5m/s2 acceleration, with usual G64 mode I can not use their full power! I set MAX_ACCELERATION to 5000, but only 50% is engaged all the time, except reversal blending which uses 100%. But if I set MAX_ACCELERATION to 10000, the actuators will be overloaded when reversal blending occurs. That is... very disappointing to me. Now the only way to use full acceleration is G61 and MAX_ACCELERATION = 2*actuator_acceleration, isn't it? Andrew ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
