3D Arc Support

[slstechs]

Hi, I am struggling to get my G code output as G2s/G3s and not all linear segments. I have tried adjust smoothing tolerance and editing post properties but am still getting very long G Code. I am pretty certain that my controller (Fagor 8065) supports arcs. Do I need to modify my post processor?  Attached is an example file and my post processor. Any help is much appreciated.

[seth.madore]

At this point in time, Trace does not create arcs when using Smoothing. We are working on improving upon that, so hopefully a future release will give us smoother motion. 

That said; you're working with line segments, not arcs. I don't think Smoothing (with any toolpath) is going to give us actual arc motion..

[slstechs]

Thanks for the reply. I've tried it with Project instead of trace and am still getting linear motion. Is this due to the DXF file that I'm importing being made up of line segments? If so is there a way I can convert the DXF vector into arcs in Fusion?

[seth.madore]

It's almost not going to matter, honestly. Arcs can only be generated in an XY, ZX or ZY direction. What you have going on with that part is XYZ, no arc is possible.

[slstechs]

Okay. So there would be no way to generate a toolpath for that vector using G2/G3?

[zwelsh91]

Correct. Arcs are only output on the 3 planes. Those being G17 (XY) G18 (XZ) and G19 (YZ). Are you trying to trim the outline of the skate deck? If so, you will need to use a multi axis toolpath that can tilt the tool and follow the edge. Does your machine use Tool Center Point Compensation? Also known as G48 S1 on FAGOR 80XX controllers?

[slstechs]

Hi yes, I am cutting out skateboards from a pressed rectangular blank of maple veneer. My machine is a 3 axis DMS Arches. Right now I am using a custom bit with a radius that gives slight curvature around the edge. Since it is a 3 axis machine and the tool cannot tilt It does not get a perfectly rounded edge so this is finished with hand sanding. This method is working alright however when I switched to the new bits with a radius the nose and tail of the skateboard get chip out damage occasionally. I believe this is due to the machine stuttering quite a bit on the nose and tail due to the G code being many small linear movements which is why I was trying to figure out how to change it to arc movements.

[zwelsh91]

Have you tried using the Controlled Corner rounding command? G51 in the Fagor 80XX controller? you can either turn it on with a default value (set in machine parameters) by just adding G51 to the start of each toolpath or you may also use it with an E and A modifier. Where the code would be input just after the Tool change or Safety line. The code should look like this: G51 Axxx Ex.xxxx   The A is an adjustment of the machines acceleration value as an expression of percent from 0 to 200% (if i remember correctly) the E is the adjustment of the Error value expressed as a positional value be it inch or metric EX: .0001" or say .001mm.  When I was running DMS Machines with twin tables and 5 axis heads we would use the E and A values to adjust how the machine would execute small linear code at speed. With the right A and E values you can get nice smooth machine movement. Do you have the programming manual for your 8065 controller? If so look up the G51 command, there is a great explanation of how it works in the manual.

[slstechs]

I am using G501 with an A and E value which I think is the same as what you are talking about? I lowered the acceleration value from 100 to 75 which seemed to help lower our chip out rate a bit with out increasing the cycle time too much. I will keep playing with the acceleration and error and see if I can get those curves to run smoother. Thank you for your help!

[zwelsh91]

You may also look at section 18 on HSC, High Speed Machining in the 8060-8065 programming manual here: https://dmscncrouters.com/wp-content/uploads/2016/05/Fagor-CNC-8060-8065-Programming-Manual-English....

And see if the HSC function of your controller can help with your machine motion.