Full-depth contour cutting always failed

Mostly Printed CNC - MPCNC Troubleshooting
1

hi all ,
I always cut failed on full-depth contour cutting
it become crazy and trill when 2 or 3 passes and the bit will be pull in

pocket is ok , but contour cutting always failed …

S__4300837
S__43008371478×1108 270 KB

S__4300838
S__43008381478×1108 430 KB

here is my test graph

2022-03-16_09-06-36
2022-03-16_09-06-36897×657 94.2 KB

and NC code
0315.gcode (73.2 KB)

Material : 8mm Bakelite (phenolic resin) ,
Bit : 1/8" single flute endmill ((1/8" Single Flute Carbide Endmill – V1 Engineering Inc))
parameter: F(xy):10mm/sec / F(z):5mm/sec / DOC : 1.6mm
(use SKR pro control lcd to change F percentage to 80%)
Spindle: Makita RT0700C (dial speed ~= 2.5 )
CAM:Aspire 10

What should I do …

2

Lower your stepover distance. It’s taking too big of a bite into the plastic. Plastics are a pain in the ass sometimes.

3

It looks like your stiffness is not the same in X and Y. One looks okay and the other is not good.

Grab it with your hand and feel if it is sloppier one way compared to the other when you push on it. If so, then look for issues with belts, grub screws, or if the bearings are not in contact with the rails.