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Tool Orientation is not following path
#1
Hi Guys,

I have set up a station Kuka Robot as per attached.


There are 3 shapes to be cut with a circular saw tool, which means that we have selected "Tool Orientation follows path" as the default algorithm under Tools>Options>CAM.

We have created the following NGC files individually from DXF2Gcode and pasted it into the Robot Station.

1. Shape1Dragknife.NGC
2. Shape2Dragknife.NGC
3. Shape3Dragknife.NGC

During the simulation of each of the above-mentioned programs separately, the Blade tool orientation followed each path perfectly. 

Then, to try and save time, we selected all 3 of the above shapes in DXF2Gcode and then exported it as one shape and named it "Shapes123_Dragknife" and then ran a simulation of this program. The Tool Orientation followed all the paths perfectly except for the 3rd shape where the TOOL ORIENTATION DOES NOT FOLLOW THE PATH for the last LINEAR MOVE of shape 3 where it starts with the correct directional orientation at the beginning of the last LINEAR MOVE but incorrectly changes the tool orientation further away from the Move direction as it moves further towards the end of the last LINEAR MOVE of shape 3. WHY DOES THIS HAPPEN?

To do a further test we selected only Shape 1&2 in DXF2Gcode and then exported it as one shape and named it "Shapes1&2_Dragknife" and then ran a simulation of this program.
The Blade tool orientation followed each path perfectly for both Shape 1 & 2. 

This would mean that there is a problem with shape 3. But when simulating Shape3Dragknife.NGC on separately there is no problem. This makes no sense.

Please find the attached RDK file.

.rdk   Test Multiple cuts in single program.rdk (Size: 9.94 MB / Downloads: 45)
#2
This is because when doing all 3 cuts together, the robot start the last cut in a configuration too close to its joint 6 limit.  

Doing all shapes together prevent the "unwinding"  of the joint 6 between each cuts since the "tool orientation follow path" option also apply to the paths between the shapes.

The "Allow a tool Z rotation of +/-" is also set to 180 in your "Shapes123_Dragknife Setting", this mean the robot can rotate the tool if no other solution is found.

To prevent this, I suggest keeping them separate and calling them in a "main" program. 
This way you can have more control with what the robot does between each cut.

   
#3
Also, with your type of application, you should make sure "Allow a tool Z rotation of +/-" is ALWAYS zero. 
Otherwise RDK will try to automatically avoid singularities and joint limited by rotating around Z (or by braking your blade/material in this case...)

   

Jeremy
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