Changing trajectory planner mode within same file?

I have a model that requires a high degree of positional accuracy on some parts. So I'm using G61 and am happy with the results.

However, for those areas where the toolpath is simply removing stock from the model, I am happy to sacrifice XY accuracy for speed. So, something like G64 P0.2 would probably be ok.

I just don't know how to specify this changeover in my g-code.

I have tried manually entering G64 P0.2 while the machine is midway through a job (started with G61) but I just get an error message - something about the mode being set to "auto" and the interpreter not being "idle".

Is what I am asking not possible? Or is there a way to change modes while keeping the spindle running?

Cheers,
Matthew

Hi

There are ways to execute MDI commands whilst a program is paused, but generally you can't and will get that error.

You presumably know at what stage you want to change path modes, what happens if you insert the change into your gcode at that point?

regards

Hi again,

The gcode below cuts a circular recess into a flat surface.
It is not anything like what you are doing, but I chose it because the effect of path blending is very stark when talking about circles.
Half way through the code I changed the path mode to G64 P0.002 (it is imperial code)

The resultant plot is as normal, hard to see if the path mode changed




Change the mode to G64 P0.2 and you can see it definately did change, it is so far off the path, it cuts triangles and squares
(I assume you are using metric, as I normally do, so P0.2 is quite a reasonable value , rather than 2/10s of an inch which this represents )




So changing mode within your gcode works fine and that is the best way to do it.

A MDI command will fail if Linuxcnc is in AUTO or MANUAL mode.
As I said there are ways to pause and drop out of auto mode do something, go back to auto mode and resume, but that is quite an advanced programming subject.

What you want to do can be easily achieved by inserting path mode changes at relevant roughing out sections and reverting to G61 when doing the finishing stuff.

regards

Changing from G61 to G64 px.xx worked as you suggested.

Thanks a lot. I didn't realize it was that simple!

Cheers