C-Axis Brake question

So I have another strange one. Programming in EIA on Integrex Matrix and trying to mill on the main spindle and the whole chuck, jaws, and part are shaking. The 1/2" endmill I'm using is in the B0. position and milling around the out side of the part (10.700 dia. 1018 steel) with the C axis. The tool is taking .500 depth of cut in the Z and roughly .050 depth radially. I've fired a M211 before it starts to mill and have verified in the CNC signal that it is in fact braking. I tried slowing my feed down to .001 chip load/ revolution and it still shakes. Is there a parameter that adjusts the clamping force of the brake? I don't think this would be considered a heavy cut especially in 1018 but maybe I'm wrong. Any Ideas?


N6990 ( MAIN SPINDLE, Z-AXIS ROTARY TOOL )
N6991 ( ROUGH1 SIDE OUTSIDE )
N6992 G00 G17 G40 G80 G98
N6993 G30 P3 U0. V0.
N6994 G30 P3 W0.
N6995 M901 ( MAIN SPINDLE )
N6996 M200 ( MAIN MILL MODE )
N6997 T096.04 T097 M06 D96 ( 1/2 4FL VARIPITCH STUB-ROTARY )
N6998 G30 P3 U0. W0.
N6999 M250
N7000 B0.
N7001 M251
N7002 G53.5
N7003 G97 S2406 M203
N7004 G00 Z1.0
N7005 X11.5719 Y0. C0. M08
N7006 G17 U0. H0.
N7007 M211
N7008 G12.1
N7009 G00 X4.8605 C-5.2508
N7010 Z0.1
N7011 G01 Z-0.5 F12.0
N7012 G03 X4.5689 C-5.1648 I-0.1458 J-0.0804
N7013 X4.4081 C-5.1855 I0. J-0.1665
N7014 G01 X3.9849 C-5.3022
N7015 G02 X3.8389 C-5.3352 I-0.244 J0.4422
N7016 X0. C-5.67 I-1.9194 J5.3352
N7017 X-3.8389 C-5.3352 I0. J5.67
N7018 X-3.9849 C-5.3022 I0.171 J0.4752
N7019 G01 X-5.3974 C-4.9126
N7020 G02 X-7.9267 C-3.9633 I2.6987 J4.9125
N7021 X-11.21 C0. I3.9634 J3.9633
N7022 X0.0001 C5.605 I5.605 J0.
N7023 X11.2101 C0. I0. J-5.605
N7024 X5.4152 C-4.9076 I-5.605 J0.
N7025 X5.4144 C-4.9079 I-0.1236 J0.223
N7026 G01 X4.4081 C-5.1855
N7027 G00 Z1.0
N7028 G13.1
N7029 M212
N7030 M09
N7031 M205
N7032 G30 P3 U0. V0.
N7033 G30 P3 W0.
M1

OLD machines (my 1986 10N) used a hydraulic brake for the M211 and the clamping force was adjusted via hydraulic pressure and gauge.

Your machine surely has an intergral spindle motor, so no clue how the spindle brake / clamping is handled on newer machines.

That said, how much RPM you got on the milling spindle? Our old Integrex 35 Y (integral main spindle) had 6,000 RPM for the milling tools and yours is probably 10K or 12K. 2406 RPMs on a 1/2" endmill on 1018 at .050" radial is way too slow.

Look at the condition of the brake pads.

Had similar issues with a Daewoo machine. The problem was that both brake pads broke off the caliper piston.

The machine was only 3 years old when that happened.

Heck - that much action at 11 inches D I can see the brake not holding.


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