"..WARNING-possible instability...

[Dizzyhawk]

...due to vertical tool, indicate initial C value"

 

Huh?

 

The simulation of my program looks good, but at the CNC machine, the C axis is 180 out.

 

Any ideas?

[Lee.]

Did you check your WCS?

 

Tool Plane?

[Mike Whitten CAD/CAM Contractors]

Dizzyhawk,

 

This may help:

http://www.emastercam.com/cgi-bin/ultimate...t=011351#000000

 

Mike

[Post dept]

Not sure if you've resolved your issue or not but the gist of the error is that you have most likely started your cut with a vertical tool, which means there is no way for your post to calculate a C-axis value (if c is rotating about Z), as every solution is correct. Without any way of looking forward, the post asks for your input so you don't end up with a large C-axis move when the other rotary axis finally begins to move, which could result in a gouge.

 

HTH

[Jim at Gentex]

What Chris said.

 

This is a common occurrance in 5-axis programming.

 

The post doesn't know which side of C zero (+ or -) to calculate from or to. For example, if I know the desired rotation direction I want is positive, I would enter .001 as the initial C value to let the post know that it is to calculate in the positive direction. If it's a negative move, the value you enter could be -.001 or 359.999 depending upon how the post and the control are set up to rotate the C axis.

 

Does that help, or did I confuse you even more?