Newbie looking at 6040 (China CNC) for polypropylene 15mm sheet

[Snapper]

Its not much more than standard Alu. The fact that its reasonably flat has many benefits.

Maybe for little odd jobs but for production? At a guess it's about 50% dearer than just buying a bar isn't it?

[JOGARA]

Maybe for little odd jobs but for production? At a guess it's about 50% dearer than just buying a bar isn't it?

Going off AW, 5083 bar worked out more expensive than Plate.
Both cut to size.

This is AW though...

[JAZZCNC]

Maybe for little odd jobs but for production? At a guess it's about 50% dearer than just buying a bar isn't it?

Nowhere near 50% more like 10% if that and the savings in machine time can easily justify that. I rarely buy bar stock anymore

[JOGARA]

Keep getting this strange behaviour from the machine.

Just keeps stuttering, even when just going along a straight path on 1 axis it will judder a lot.
Does it every so often and most of the time I have to turn it off and on again.

Any ideas?

[JOGARA]

Keep getting this strange behaviour from the machine.

Just keeps stuttering, even when just going along a straight path on 1 axis it will judder a lot.
Does it every so often and most of the time I have to turn it off and on again.

Any ideas?

https://photos.app.goo.gl/uAcR70B7vQtYLvs22

[m_c]

Sounds like chatter to me..

[spluppit]

Correct it is resonance. Either lower your rpm or up your feedrate.....a lot. This is where having a machine with no rigidity and physical weight plays a big part and restricts what you can do, there is only so far you can push a machine like that.

[JOGARA]

Just noticed my RPM was 12k not 6k xD

[JOGARA]

Not sure what I am doing wrong here.
It worked before but for some reason is not now...

I am cutting out some holes for some components in the rear of my case.
I am using a 4mm roughing bit to do this (the rough edges help in this case).

I have my part upright in the vice and around 10-15mm clearance luckily.

Here is what it is showing in F360.


Here is the Gcode;

(T5  D=4. CR=0. - ZMIN=-3.5 - FLAT END MILL)
G90 G94 G91.1 G40 G49 G17
G21
G28 G91 Z0.
G90

(POCKET1)
M5
M9
T5 M6
S6000 M3
G54
M7
G0 X22.399 Y9.291
G43 Z15. H2
Z5.
G1 Z4.6 F100.
G3 X22.398 Y9.272 Z4.479 I1.9 J-0.031 F150.
X22.399 Y9.218 Z4.369 I1.9 J-0.013
X22.402 Y9.133 Z4.281 I1.9 J0.042
X22.413 Y9.026 Z4.223 I1.896 J0.127
X22.431 Y8.907 Z4.2 I1.886 J0.234
X26.165 Y9.613 Z3.992 I1.867 J0.353
X22.431 Y8.907 Z3.783 I-1.867 J-0.353
X26.165 Y9.613 Z3.575 I1.867 J0.353
X22.431 Y8.907 Z3.366 I-1.867 J-0.353
X26.165 Y9.613 Z3.158 I1.867 J0.353
X22.431 Y8.907 Z2.949 I-1.867 J-0.353
X26.165 Y9.613 Z2.741 I1.867 J0.353
X22.431 Y8.907 Z2.532 I-1.867 J-0.353
X26.165 Y9.613 Z2.324 I1.867 J0.353
X22.431 Y8.907 Z2.116 I-1.867 J-0.353
X26.165 Y9.613 Z1.907 I1.867 J0.353
X22.431 Y8.907 Z1.699 I-1.867 J-0.353
X26.165 Y9.613 Z1.49 I1.867 J0.353
X22.431 Y8.907 Z1.282 I-1.867 J-0.353
X26.165 Y9.613 Z1.073 I1.867 J0.353
X22.431 Y8.907 Z0.865 I-1.867 J-0.353
X26.165 Y9.613 Z0.656 I1.867 J0.353
X22.431 Y8.907 Z0.448 I-1.867 J-0.353
X26.165 Y9.613 Z0.24 I1.867 J0.353
X22.431 Y8.907 Z0.031 I-1.867 J-0.353
X26.165 Y9.613 Z-0.177 I1.867 J0.353
X22.431 Y8.907 Z-0.386 I-1.867 J-0.353
X26.165 Y9.613 Z-0.594 I1.867 J0.353
X22.431 Y8.907 Z-0.803 I-1.867 J-0.353
X26.165 Y9.613 Z-1.011 I1.867 J0.353
X22.431 Y8.907 Z-1.22 I-1.867 J-0.353
X26.165 Y9.613 Z-1.428 I1.867 J0.353
X22.431 Y8.907 Z-1.636 I-1.867 J-0.353
X26.165 Y9.613 Z-1.845 I1.867 J0.353
X22.431 Y8.907 Z-2.053 I-1.867 J-0.353
X26.165 Y9.613 Z-2.262 I1.867 J0.353
X22.431 Y8.907 Z-2.47 I-1.867 J-0.353
X26.165 Y9.613 Z-2.679 I1.867 J0.353
X22.431 Y8.907 Z-2.887 I-1.867 J-0.353
X26.165 Y9.613 Z-3.096 I1.867 J0.353
X22.431 Y8.907 Z-3.304 I-1.867 J-0.353
X26.198 Y9.26 Z-3.5 I1.867 J0.353
X23.293 I-1.453 J0.
G1 Y8.707 F360.
G3 X23.822 Y8.055 I0.666 J0.
G1 X23.864 Y8.046
G3 X24.136 I0.136 J0.652
G1 X24.178 Y8.055
G3 X24.707 Y8.707 I-0.136 J0.652
G1 Y9.301
G3 X24.217 Y9.943 I-0.666 J0.
X23.783 I-0.217 J-0.792
X23.293 Y9.301 I0.176 J-0.642
G1 Y9.26
G2 X22.603 Y8.329 I-0.972 J0.
G3 X22.326 Y7.204 I0.195 J-0.645
G1 X22.531 Y7.003
X23.165 Y6.667
X23.918 Y6.51
X24.082
X24.835 Y6.667
X25.461 Y6.998
X25.54 Y7.073
X25.965 Y7.49
X26.2 Y7.907
Y10.1
X25.999 Y10.47
X25.546 Y10.939
X24.968 Y11.285
X24.331 Y11.46
X23.669
X23.032 Y11.285
X22.454 Y10.939
X22.001 Y10.47
X21.8 Y10.1
Y7.907
X22.035 Y7.49
X22.326 Y7.204
G3 X22.426 Y7.132 Z-3.48 I0.28 J0.285
X22.531 Y7.097 Z-3.424 I0.18 J0.357
X22.619 Y7.09 Z-3.335 I0.075 J0.393
X22.676 Y7.096 Z-3.224 I-0.013 J0.4
X22.695 Y7.099 Z-3.1 I-0.07 J0.394
G0 Z15.

(POCKET1 2)
M7
G0 X24.892 Y21.659
Z15.
Z5.
G1 Z4.6 F100.
G3 X24.876 Y21.67 Z4.479 I-0.429 J-0.615 F150.
X24.83 Y21.698 Z4.369 I-0.414 J-0.625
X24.753 Y21.736 Z4.281 I-0.368 J-0.654
X24.651 Y21.77 Z4.223 I-0.291 J-0.691
X24.533 Y21.791 Z4.2 I-0.189 J-0.726
X24.391 Y20.298 Z4.118 I-0.071 J-0.747
X24.533 Y21.791 Z4.035 I0.071 J0.747
X24.391 Y20.298 Z3.953 I-0.071 J-0.747
X24.533 Y21.791 Z3.871 I0.071 J0.747
X24.391 Y20.298 Z3.789 I-0.071 J-0.747
X24.533 Y21.791 Z3.706 I0.071 J0.747
X24.391 Y20.298 Z3.624 I-0.071 J-0.747
X24.533 Y21.791 Z3.542 I0.071 J0.747
X24.391 Y20.298 Z3.459 I-0.071 J-0.747
X24.533 Y21.791 Z3.377 I0.071 J0.747
X24.391 Y20.298 Z3.295 I-0.071 J-0.747
X24.533 Y21.791 Z3.213 I0.071 J0.747
X24.391 Y20.298 Z3.13 I-0.071 J-0.747
X24.533 Y21.791 Z3.048 I0.071 J0.747
X24.391 Y20.298 Z2.966 I-0.071 J-0.747
X24.533 Y21.791 Z2.884 I0.071 J0.747
X24.391 Y20.298 Z2.801 I-0.071 J-0.747
X24.533 Y21.791 Z2.719 I0.071 J0.747
X24.391 Y20.298 Z2.637 I-0.071 J-0.747
X24.533 Y21.791 Z2.554 I0.071 J0.747
X24.391 Y20.298 Z2.472 I-0.071 J-0.747
X24.533 Y21.791 Z2.39 I0.071 J0.747
X24.391 Y20.298 Z2.308 I-0.071 J-0.747
X24.533 Y21.791 Z2.225 I0.071 J0.747
X24.391 Y20.298 Z2.143 I-0.071 J-0.747
X24.533 Y21.791 Z2.061 I0.071 J0.747
X24.391 Y20.298 Z1.978 I-0.071 J-0.747
X24.533 Y21.791 Z1.896 I0.071 J0.747
X24.391 Y20.298 Z1.814 I-0.071 J-0.747
X24.533 Y21.791 Z1.732 I0.071 J0.747
X24.391 Y20.298 Z1.649 I-0.071 J-0.747
X24.533 Y21.791 Z1.567 I0.071 J0.747
X24.391 Y20.298 Z1.485 I-0.071 J-0.747
X24.533 Y21.791 Z1.402 I0.071 J0.747
X24.391 Y20.298 Z1.32 I-0.071 J-0.747
X24.533 Y21.791 Z1.238 I0.071 J0.747
X24.391 Y20.298 Z1.156 I-0.071 J-0.747
X24.533 Y21.791 Z1.073 I0.071 J0.747
X24.391 Y20.298 Z0.991 I-0.071 J-0.747
X24.533 Y21.791 Z0.909 I0.071 J0.747
X24.391 Y20.298 Z0.827 I-0.071 J-0.747
X24.533 Y21.791 Z0.744 I0.071 J0.747
X24.391 Y20.298 Z0.662 I-0.071 J-0.747
X24.533 Y21.791 Z0.58 I0.071 J0.747
X24.391 Y20.298 Z0.497 I-0.071 J-0.747
X24.533 Y21.791 Z0.415 I0.071 J0.747
X24.391 Y20.298 Z0.333 I-0.071 J-0.747
X24.533 Y21.791 Z0.251 I0.071 J0.747
X24.391 Y20.298 Z0.168 I-0.071 J-0.747
X24.533 Y21.791 Z0.086 I0.071 J0.747
X24.391 Y20.298 Z0.004 I-0.071 J-0.747
X24.533 Y21.791 Z-0.079 I0.071 J0.747
X24.391 Y20.298 Z-0.161 I-0.071 J-0.747
X24.533 Y21.791 Z-0.243 I0.071 J0.747
X24.391 Y20.298 Z-0.325 I-0.071 J-0.747
X24.533 Y21.791 Z-0.408 I0.071 J0.747
X24.391 Y20.298 Z-0.49 I-0.071 J-0.747
X24.533 Y21.791 Z-0.572 I0.071 J0.747
X24.391 Y20.298 Z-0.655 I-0.071 J-0.747
X24.533 Y21.791 Z-0.737 I0.071 J0.747
X24.391 Y20.298 Z-0.819 I-0.071 J-0.747
X24.533 Y21.791 Z-0.901 I0.071 J0.747
X24.391 Y20.298 Z-0.984 I-0.071 J-0.747
X24.533 Y21.791 Z-1.066 I0.071 J0.747
X24.391 Y20.298 Z-1.148 I-0.071 J-0.747
X24.533 Y21.791 Z-1.23 I0.071 J0.747
X24.391 Y20.298 Z-1.313 I-0.071 J-0.747
X24.533 Y21.791 Z-1.395 I0.071 J0.747
X24.391 Y20.298 Z-1.477 I-0.071 J-0.747
X24.533 Y21.791 Z-1.56 I0.071 J0.747
X24.391 Y20.298 Z-1.642 I-0.071 J-0.747
X24.533 Y21.791 Z-1.724 I0.071 J0.747
X24.391 Y20.298 Z-1.806 I-0.071 J-0.747
X24.533 Y21.791 Z-1.889 I0.071 J0.747
X24.391 Y20.298 Z-1.971 I-0.071 J-0.747
X24.533 Y21.791 Z-2.053 I0.071 J0.747
X24.391 Y20.298 Z-2.136 I-0.071 J-0.747
X24.533 Y21.791 Z-2.218 I0.071 J0.747
X24.391 Y20.298 Z-2.3 I-0.071 J-0.747
X24.533 Y21.791 Z-2.382 I0.071 J0.747
X24.391 Y20.298 Z-2.465 I-0.071 J-0.747
X24.533 Y21.791 Z-2.547 I0.071 J0.747
X24.391 Y20.298 Z-2.629 I-0.071 J-0.747
X24.533 Y21.791 Z-2.712 I0.071 J0.747
X24.391 Y20.298 Z-2.794 I-0.071 J-0.747
X24.533 Y21.791 Z-2.876 I0.071 J0.747
X24.391 Y20.298 Z-2.958 I-0.071 J-0.747
X24.533 Y21.791 Z-3.041 I0.071 J0.747
X24.391 Y20.298 Z-3.123 I-0.071 J-0.747
X24.533 Y21.791 Z-3.205 I0.071 J0.747
X24.391 Y20.298 Z-3.287 I-0.071 J-0.747
X24.533 Y21.791 Z-3.37 I0.071 J0.747
X24.391 Y20.298 Z-3.452 I-0.071 J-0.747
X25.202 Y21.168 Z-3.5 I0.071 J0.747
G1 X25.164 Y21.395 F360.
X24.976 Y21.743
X24.677 Y22.021
X24.314 Y22.181
X23.919 Y22.216
X23.723 Y22.17
X23.53 Y22.122
X23.182 Y21.9
X23.158 Y21.868
Y20.129
X23.182 Y20.097
X23.53 Y19.875
X23.91 Y19.78
X24.314 Y19.816
X24.677 Y19.976
X24.976 Y20.255
X25.164 Y20.602
X25.23 Y20.999
X25.202 Y21.168
G3 X25.163 Y21.284 Z-3.48 I-0.395 J-0.066
X25.099 Y21.375 Z-3.424 I-0.356 J-0.183
X25.032 Y21.433 Z-3.335 I-0.292 J-0.273
X24.983 Y21.461 Z-3.224 I-0.225 J-0.331
X24.965 Y21.469 Z-3.1 I-0.176 J-0.359
G0 Z15.

M9
G28 G91 Z0.
G28 X0. Y0.
M30

For some reason. It plunges into the part and then starts the helix.
The tool Z height is set to the top of the part, and Mach3 confirms this. But Mach3 plunges the bit into the part.

Any ideas?

[Clive S]

(T5 D=4. CR=0. - ZMIN=-3.5 - FLAT END MILL)
G90 G94 G91.1 G40 G49 G17
G21
G28 G91 Z0.
G90

(POCKET1)
M5
M9
T5 M6
S6000 M3
G54
M7
G0 X22.399 Y9.291
G43 Z15. H2
Z5.
G1 Z4.6 F100.
G3 X22.398 Y9.272 Z4.479 I1.9 J-0.031 F150.

Sticking my neck out a bit here.
Seems strange that you have a Z5 then a Z4.6 (I would expect this to be -ve value) I see you have tool length comp on with the G43 Z15. H2 is this correct in your tool table