Hi there,
I have a PRO4896 Avid CNC with Fusion 360 and the Avid Post Processor. Everything has been set up accurately as per Avid's instructions.
The project I am running is carving a Terrain Map (3D carving) using 3 passes - Pocket, Parallel roughing and Parallel finish.
I am trying to reduce the shake / jerk / stutter when the machine changes direction. I have had some success with changing toolpath settings in Fusion 360 and I am experiencing this with low feedrates. It's obviously much worse with higher feedrates.
In the X/Y plane on the Pocket pass, changing the reduced feed radius and distance has helped, along with leads, transitions, reduced feedrate.
In the Z direction, the same phenomenon happens but I'm unsure how to help.
I want to get the machine moving smoothly between directions and instructions, then build up the speed from there. Any help would be much appreciated.
Example of GCode from finishing pass:
(1003)
(MACHINE)
( VENDOR AVID)
( DESCRIPTION AVID CNC)
(T1 D=3.175 CR=1.587 - ZMIN=-29.537 - BALL END MILL)
G90 G94 G91.1 G40 G49 G17
G21
(PARALLEL2)
M5
T1 M6
S15000 M3
G54
G0 X751.104 Y19.993
G43 Z15. H1
G1 Z-24.515 F2000.
G18 G3 X746.104 Z-29.515 I-5. K0.
G1 X602.84
X602.023 Z-28.706
X600.727 Z-27.2
G2 X599.896 Z-26.734 I-1.162 K-1.096
G1 X598.596 Z-26.42
X598.338 Z-26.384
X595.354 Z-26.114
X594.403 Z-26.022
G2 X586.434 Z-25.589 I-43.21 K-721.79
G1 X584.968 Z-25.653
X583.97 Z-25.664
X582.638 Z-25.483
X580.205 Z-25.081
X578.911 Z-24.823
X577.626 Z-24.527
X576.332 Z-24.271
X576.145 Z-24.245
X574.81 Z-24.143
X574.519 Z-24.145
X573.233 Z-24.192
G2 X566.68 Z-25.286 I3.911 K-43.615
G1 X565.538 Z-25.361
X564.212 Z-25.306
X562.785 Z-25.348
X561.712
G2 X557.467 Z-24.939 I-13.886 K-121.646
G1 X556.296 Z-24.924
X554.949 Z-24.983
X553.542 Z-25.153
X552.235 Z-25.327
X550.901 Z-25.428
G2 X545.926 Z-25.731 I1.456 K-64.795
G1 X545.053 Z-25.747
G2 X539.174 Z-25.796 I-1.901 K-124.454
G1 X537.906 Z-25.798
G3 X529.718 Z-25.89 I-6.773 K239.269
X524.982 Z-25.781 I-0.816 K67.639
G1 X523.617 Z-25.753
X522.13 Z-25.797
X520.878 Z-25.807
G3 X511.909 Z-25.472 I3.27 K207.732
G1 X510.319 Z-25.327
X509.368 Z-25.235
X507.979 Z-25.162
X506.174 Z-25.167
X499.857 Z-25.15
X497.528 Z-25.172
X495.844 Z-25.091
G2 X489.03 Z-24.988 I-4.531 K-74.331
G1 X486.786 Z-25.031
X485.518 Z-25.025
X484.543 Z-25.004
X483.415 Z-24.904
X482.114 Z-24.674
G2 X479.338 Z-24.145 I-9.779 K-43.743
Other small issues that may help zero in on the problem:
- When Rapid Feedrate is at 100% (when it moves to first coordinates) it can sometimes skip and jump along it's way and vibrate.
- The stutter is not totally confined to a change of direction. It sometimes happens in the middle of a linear move.
- Mach 4 will not allow be to home or jog the machine if it is already in the home position (from the previous day / emergency stop). I have to manually push it off the limits to get it working.
If some of this vibration is normal then let me know. Previous experience is on a MPCNC so I'm new to an Avid machine but not a total newbie.
Many thanks