5-axis curve C-axis output won't go above C 179.9

[Justin Beebe at Folsom Tool]

Hello,

I'm trying to finish a profile on a part using 5-axis curve.  The toolpath backplots and verifies great.  When I post the code the C-axis starts at C173.445 and rotates in the positive direction.  When it gets to C179.981 it jumps to C-179.822 instead of continuing to rotate positive past 180.00 degrees.  I'm using Mastercam 2018 and the post is and updated In House Solution Post. I have tried signed continuous, signed direction, and shortest direction under axis supports continuous positioning in the machine definition but get the same result.  It seems like something is limiting the post from going past C180. but I can't find it.  Also if I post a toolpath from the left plane I get C180. 

Please see sample code below.

 

(T32 - 0.375 BULL-NOSED ENDMILL  - H32 - D32 - D0.3750"  - R0.0200")
N100 G00 G17 G20 G40 G49 G80 G90
N110 M11 (B-AXIS UNLOCK)
N120 M69 (C-AXIS UNLOCK)
N130 (ROUGH CLEARANCE FOR BALLMILL)
N140 (TOOLPLANE NAME - LEFT SIDE)
N150 T32 M06 (0.375 BULL-NOSED ENDMILL)
N160 G00 G17 G90 G55 C173.445 B100.505
N170 X-9.1868 Y3.7997 S3500 M03
N180 G43 H32 Z4.2694
N190 G94 Z-.6306
N200 G01 Z-.7306 F12.
N210 X-8.9847 Y3.6634 F30.
N220 X-8.9056 Y3.6048 Z-.7079 C173.643 B100.428
(This section of code has been removed to make it easier to read)
N490 X-6.7301 Y2.047 Z-.1838 C178.994 B98.296
N500 X-6.6481 Y1.9902 Z-.1679 C179.192 B98.215
N510 X-6.5661 Y1.9334 Z-.1524 C179.389 B98.134
N520 X-6.484 Y1.8767 Z-.1372 C179.587 B98.053
N530 X-6.4017 Y1.8201 Z-.1222 C179.784 B97.972
N540 X-6.3194 Y1.7636 Z-.1075 C179.981 B97.891   <------- Last line of positive code for C-axis Should keep going past 180.00
N550 X-6.237 Y1.7071 Z-.0931 C-179.822 B97.81      <--------Jumps to C-179.822
N560 X-6.1546 Y1.6507 Z-.079 C-179.625 B97.729
N570 X-6.0721 Y1.5943 Z-.0652 C-179.428 B97.647
N580 X-5.9894 Y1.538 Z-.0516 C-179.231 B97.566
N590 X-5.9067 Y1.4817 Z-.0384 C-179.034 B97.485
N600 X-5.8239 Y1.4255 Z-.0255 C-178.838 B97.403

 

Any help is greatly appreciated.

 

Justin Beebe

What I meant to say is when I post a three axis toolpath from the left plane I get C180 output

[crazy^millman]

Singularity event. Need to find a way to keep the tool from getting to perfect Zero for all 5 axis. I had the same thing happen on an Okuma. I had 20 spins of the table going from one side of the part to the other. Problem was the A and C axis were coming to perfect Zero. I broke what I wanted as one 5 Axis cut into two 5 Axis cuts and one 3 Axis cut. See if you can mount the hole thing at 5 degrees and try that. To test copy our main WCS and tilt it 5 degrees. Then pick that as your new WCS for the operation and repost. If that works then you have your answer. Since you are using Curve 5 Axis the other thing to try it changing the tilt lines .05 degree near the singularity. That should be enough to trick singularity and shouldn't effect the quality of the part. 

[Justin Beebe at Folsom Tool]

Thank you.  I will look into those options and let you know how it works out.  

 

[Justin Beebe at Folsom Tool]

Thanks for the help.  I ended up ball milling the area that caused the C-axis direction change and split the 5-axis curve into two tool paths.  One path had all C+ numbers and the second path had all C- numbers. In the meantime my reseller and IHS are looking into the the post to see if there is anything they can do about it.

[crazy^millman]

15 minutes ago, Justin Beebe at Folsom Tool said:

Thanks for the help.  I ended up ball milling the area that caused the C-axis direction change and split the 5-axis curve into two tool paths.  One path had all C+ numbers and the second path had all C- numbers. In the meantime my reseller and IHS are looking into the the post to see if there is anything they can do about it.

Justin no problem and short of just letting you know you have hit the singularity event not much Mastercam can do since it is not looking at the Kinematics when programming. In the advanced 5 Axis toolpath you have that option to check for that in the Tool Axis control and does a job of preventing issues like singularity.