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Knife and segments end

Posted: Tue Nov 13, 2018 8:39 am
by shineworld
Hi all,

we are CNC controls makers and we are using sheetcam to produce a knife path for a ultrasonic cnc cutter.

Strangely when we import a NC (Gcode path) or a DXF path a lot of "segment end" are placed in continous curve
and this create a lot of UP/ROTATE/DOWN knife movements which invalidate any working.

There is a way to say "this line is continous don't place a UP/ROTATE/DOWN" every little segment ?

Re: Knife and segments end

Posted: Tue Nov 13, 2018 12:43 pm
by Les Newell
g-code can only cut lines and arcs. If your dxf contains curves that do not fit an arc they have to be broken into lines.

What post processor are you using?

Re: Knife and segments end

Posted: Tue Nov 13, 2018 5:09 pm
by shineworld
I'm using this post: RosettaCNC tangential cut

In sheetcam:
001.png
001.png (8.37 KiB) Viewed 1911 times
In rosettacnc:
002.png
002.png (26.35 KiB) Viewed 1911 times
Job file:

Re: Knife and segments end

Posted: Wed Nov 14, 2018 12:34 pm
by Les Newell
The main problem is that you are using the drag knife plugin with a tangential knife. The drag knife plugin should only be used with kives that are free to rotate on a bearing. Those odd moves are the realignment moves that are needed for drag knife.

Define your knife as a milling tool and use a 'no offset' contour operation.

Re: Knife and segments end

Posted: Fri Nov 16, 2018 3:07 pm
by shineworld
The issue seem to be solved using a new post-processor for Mach3 tangential V2 found in this forum :)