Drag knife compensation: lifting the tool while changing direction about heekscnc

[GoogleCodeExporter]

Hi Felix,

Currently, the function is receiving a Curve and modifying it.
https://code.google.com/p/libarea/source/browse/trunk/Curve.cpp#783

If it finds a sharp corner, it adds an arc
https://code.google.com/p/libarea/source/browse/trunk/Curve.cpp#826

We would need to change the function to return a list of curves.
I could add a parameter to the OffsetForward function, to specify to break it 
up like this.
Would the compensation move still need to be the same shape?

Original comment by [email protected] on 14 Oct 2014 at 8:26

• Changed state: Accepted

[GoogleCodeExporter]

Hi Dan,

yes, I think so.

This is the text from 'Donek Tools': 'Sharp corners are achieved with what are 
referred to as corner actions within the CNC tool path. These corner actions 
instruct the CNC to raise the blade such that the tip is just barely in contact 
with the material surface.  The machine then moves through a very small circle 
around the tip of the blade causing the blade to rotate, while the tip of the 
blade remains in the same location.  The machine then moves the blade back to 
the cutting depth and resumes cutting.'

It confirms the way you calculate the compensations by using parts of small 
circles.
The only difference is the added vertical movement for making the rotation easy 
and smooth.

Eventually, it is helpful to allow a lower speed (e.g. 300) while performing 
the compensation movement because cutting speeds (e.g. 6000) could be very 
high…this would be perfect!

Thanks a lot and with best regards,
Felix

Original comment by [email protected] on 14 Oct 2014 at 8:48