Brian,
My machine is a home/school built machine using THK linear slides and ballscrews all round. It is rather unusual in that it is hung off a wall and the gantry is cantilevered. Cutting area is 1800mm x 500mm x 125mm. 430oz/in servos and gecko 320s, running Mach3. I have max jerk set to 7500 and am getting significantly better vibration damping with Quantum.
Below is post put on my build thread on CNCZone that describes some of my findings.
http://www.cnczone.com/forums/showthread.php?t=6840Loaded Quantum today and had a play. Before Quantum, the maximum acceleration I could safely muster on X (
this is the axis that has to work the hardest and the one that faults first) was 150mm/sec^2. It was this setting that was giving me the radiussed corners when operating at high feedrates with CV (
constant velocity) on.
I am not sure whether to believe the figures or not but with Quantum, I have crept my acceleration up to 10000, yes ten thousand, mm/sec^2 and the machine still runs fine and at fairly high feedrates the jerking is negligible - I'm gobsmacked. Obviously I cannot jog at this acceleration as Quantum is not yet set up to use all the functionality of Mach3 and if I did jog the X axis it faulted at anything over 200mm/sec^2. Interestingly, the Y and Z axes both coped admirably at the very high rates, even when jogging.
A question to those who know better than I - Although I could increase my acceleration substantially, I did not notice a significant difference between say, 5000 and 10000 mm/sec^2. Is this a case of diminishing returns and/or is there an optimum setting?
However, all this increase in acceleration did not manifest itself in a staggeringly faster running of the 'Roadrunner' file than my previous settings, but the accuracy was an order of magnitude better along with the jerk free operation.
Art and Brian, you are definitely on a winner here and may it not be too long before you can give it some of your precious time.
Mike
