QTPlasmaC with fourth axis - rotary

linuxcnc.org/docs/devel/html/plasma/qtpl....html#_keep_z_motion

mariusl wrote:

According to the Sheetcam tutorial, the THC will take care of cutting over the corners of a square tube.

 

Yeah ... no!
At very slow turning speeds, yes
Made it work at normal cutting speeds, but required building a new Z axis with float switch that can do 6m/m at least, for it to be usable, for up to 60x40 oval, not square.
If you have a look at industrial 4 axis machines, they all have the tube stationary while cutting with plasma. Lasers are a different beast, so there are some that do cutting and moving at the same time.
All this can be done, it just complicates things a bit, and must settle on the main thing, what will the machine be cutting, from this to that, no "i would like to .. later".
Using 4 full axis absolutely works, the CAM is the issue there. SheetCam did have something for it, never used so no idea how good it is.
Also radius's cause issues, so must be accounted for.
-
If we can agree on what we need the machine to do, say from 30x30 to 100x100 with 2,3,5 and 10mm radii, maybe we can convince Phill and Snowwy to make a wizard for it, for most uses the wizard is OK.
As for cutting complicated stuff on square tube, no need for 4 axis, cut one side, turn, repeat. We do this a lot.

Would be helpful to see their gcode file.

@Marius
Not done by Mach, done by CAM, mach is just moving stuff.
CAM has to do the synchronized moves required.
@Snowwy
It just needs a bit of logic and math for most stuff, with some material presets, then add those together.
Simple enough until actually start programing, then it get very complicated, very fast.
Thing to be aware of, shorts:
100x100 with a 3mm radius on corners does not have the same perimeter as 100x100 with 5 or 10mm radii.
That same difference has to be accounted for also for the Z axis movements during turning of the material, as if set for 3mm the 5 or 10 will be to far and vice versa.
-
I did write some of the stuff here somewhere, but if there is interest we can do a separate topic just for this so it is all in one place.
-
Just to be clear, i am thinking same as before, simple shapes/lines/circles/etc from a wizard, just done for 4 axis.

I would leave the complicated stuff to SheetCam, it is quite good for the price.
And there is a free version, and it works in Linux, so i am OK with it.
Also Les helps a lot, thank you Les.