Rotary Toolpaths pre positioning- 5 Axis Machine - Syntec/Fanuc Controller

[ray.taylorDN6MT]

Machine/controller: Syntec 220MA-5, Syil X11 5 axis.

When generating rotary toolpaths the tool is "pre-positioned" directly above the trunnion (N70 G00 X17.123 Y0.)

In the following line the G43.4 is called which now "updates" the controllers calculated position for the WCS. This causes a 3 axis linear move which in some situations will attempt to drive the tool through the centre of the trunnion or fixtures etc, while moving to the correct starting position.

(ROTARY2)

N45 T1 M06

N50 S7100 M03

N55 G54

N60 M11 M13

N65 G00 B90. C0.

N70 G00 X17.123 Y0.

N75 G43.4 X28.91 Y-17.123 Z0. H01

If I manually break line N75 into two separate lines as follow:

G43.4 Y-17.123 Z0. H01

X28.91

The first line will position the X,Y correctly with the second line then bringing the tool down in the Z to approach the part.

I have two questions:

How can I fix the pre-positioning so the X,Y position (physically) is correct relative to the location of the part in the machine? I believe line N70 is attempting to do this, however given the G43.4 has not yet been applied the actual position of the part/wcs is not correct.

The use of G43.4 in this situation requires the X and Z axis to essentially be swapped. This makes reading/interpreting the program incredibly confusing. Would it be possible/beneficial to apply a G68.2 to update the controller with a new work plane so the axis are no longer inverted? In the same manor a 3+2 toolpath would be generated.

[frederik.mide · Accepted solution]

What post are you using?

I have recently had the generic fanuc post modified in order to position correctly above a part with TCP turned on. This is on a Head/head machine, not a lathe. The initial positioning won't be correct for the global position if you use g68.2, as the xyz values are those of the tilted plane. Running as pure 5-aksix with all position being relative to the global coordinate system was the solution proposed and made by the Autodesk developers. Technically one can transform the coordinates from the feature/tilted coordinate system back to the global coordinate system through some elaborate matrix transformation, but it's not simple. So unless you really need the g68.2 to allow editing on the controller, I wouldn't recommend it.

Changing the order for positioning and separating into two blocks in the post is quit easy once you know where to look.