Cancel
Showing results for 
Search instead for 
Did you mean: 

Why is option "At Angle to XC" not associative?

Valued Contributor
Valued Contributor

 

Hi,

 

I am trying to make a CSYS based on Absolute CSYS using option "Z-axis, X-axis, Origin". To set X-axis direction, I pick the option "At Angle to XC" and use previously defined expression (called XCangle).

2017-11-16_08h12_25.png

 

 

 

 

 

 

 

 

 

 

 

The new CSYS is located propperly, but when I try to edit the expression afterwards it does not work. When I edit the new CSYS, it shows that X axis vector is fixed:

2017-11-16_08h19_47.png

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

So the connection to the expression has been lost (or never established?).

Could somebody explain this unexpected behaviour? Maybe I am doing something wrong.

I know I can make it associatively with "Offset CSYS" option. I am just wondering why it does not work with "At Angle to XC" option.

 

Thanks in advance!

4 REPLIES

Re: Why is option "At Angle to XC" not associative?

Solution Partner Legend Solution Partner Legend
Solution Partner Legend

XC (also YC ZC) creates an angle between your choosen value and the WCS(WorkCoordinateSystem). The WCS by itself is always fixed in the ABS (Absolute Coordinate System).

 

In every dialog and feature where it is possible to choose XC or YC or ZC  you can see that choosen vectors or points ect... are fixed after leaving the dialog.

 

greetings

Andre

Re: Why is option "At Angle to XC" not associative?

Valued Contributor
Valued Contributor

Thanks for quick response!

Re: Why is option "At Angle to XC" not associative?

Phenom
Phenom

To explain why this behavior is very difficult, I suggest to you a workaround that allows you to achieve what you want.

First you have to define the X axis 'By Expression', this defines a variable 'vector(1,1,0)', then you have to define variables, as I show you in the attached image, and replace the (1,1,0) value whit this.

Note that this definition is based on absolute Xc not on Datum CSYS feature.

 

Ciao

CesareAtAngle.png

Re: Why is option "At Angle to XC" not associative?

Valued Contributor
Valued Contributor

Thank you Cesare. It is a nice solution. I prefer however to use "Offset CSYS" which is also associative, and needs less typing Smiley Wink