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Jerky Movement
« on: October 15, 2007, 05:48:45 PM »
Well I'm running some 3d surfacing, but mach is constantly accelerating / decelerating , i tried running the code on quantum and it's nice and smooth constant velocity, even with jerking turned off?? how come in mach 3 feeds range from 10 to 50 in quantum it stays at 145 except when changing directions weather the jerk option is on or off, any way to get this running smooth in mach 3 ? it's for production work using mastercam....

N190 G01 Z.1879 F50.
N200 X-1.4597 Y1.4908 Z.1871 F145.
N210 X-1.2639 Y1.2711 Z.1791
N220 X-1.2711 Y1.2555 Z.1797
N230 X-1.316 Y1.2084 Z.1831
N240 X-1.3496 Y1.171 Z.1856
N250 X-1.3968 Y1.1142 Z.1892
N260 X-1.4281 Y1.074 Z.1917
N270 X-1.4671 Y1.02 Z.1948
N280 X-1.4988 Y.973 Z.1973
N290 X-1.5379 Y.9097 Z.2006
N300 X-1.5646 Y.8631 Z.2029
N310 X-1.5976 Y.8003 Z.2058
N320 X-1.6275 Y.7376 Z.2085
N330 X-1.6478 Y.6917 Z.2104
N340 X-1.6732 Y.6277 Z.2128
N350 X-1.6948 Y.5667 Z.215
N360 X-1.715 Y.5022 Z.2172
N370 X-1.7322 Y.4394 Z.2192
N380 X-1.747 Y.3766 Z.221
N390 X-1.7594 Y.3139 Z.2227
N400 X-1.7694 Y.2511 Z.2242
N410 X-1.7753 Y.204 Z.2253
N420 X-1.789 Y.1941 Z.2263
N430 X-2.0872 Y.2112 Z.2434

Offline Whacko

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Re: Jerky Movement
« Reply #1 on: October 17, 2007, 12:25:24 AM »
Is this a motor tuning issue? Have you tried changing the acceleration parameters?

Whacko
Nothing's impossible

Offline PatM

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Re: Jerky Movement
« Reply #2 on: October 17, 2007, 04:18:04 PM »
Is constant velocity turned on? Exact Stop mode will give herky-jerky movements.
Re: Jerky Movement
« Reply #3 on: October 17, 2007, 06:29:27 PM »
My current setting is 900 for speed and 9 for accel, runs nice on everything else, i noticed on one strange pocketing routine if i enable the output filter for arcs on mastercam it runs smooth and not jerky, but there is no option to do this in scalloping..

Offline Chip

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Re: Jerky Movement
« Reply #4 on: October 18, 2007, 01:18:12 AM »
Hi, Chrispol

Try setting your Accel UP some, Between lines it's slowing to 9 every time.

If "F" speed is below your accel speed it takes priority.

I usually set the accel up to a point that steppers will slip or servos would trip, From a stopped condition (well maybe not that fast for some servos thy get pertty scary).

Then take the value and reduce it some for no slip/lost steps, 900 to 9 is pretty large.

Use G00 Moves to test these speeds, May need to back off your 900 max. value after testing.

Hope this Helps, Chip