Which PP to use ?

[ArchieF]

Hi Les,

I have the rotary axis parallel the x-axis and want to do a regular rotary milling job.

Which pp must I use to convert Y in A in plain gcode converted arcs to line segments?

Thanks

Richard

[Les Newell]

Hi Richard,

I don't have a post for that. Does the A axis need to be scaled or do you just need to change the Y to A?

Go to Options->machine->post processor and slect the 'Minimum g-code noarcs' post. No click on the 'edit post' button and replace every occurrence of " Y" with " A". Save the post and go back to Options->machine->post processor. Make sure you have the edited version of the post selected.

Note that this does not scale the A axis at all. It gets a bit more complicated if you need to scale A.

[ArchieF]

Hi Les,

exactly scaling was what I need. But found a solution : since Sheetcam does the break arc into lines job I can use a little script I wrote years ago .

This script converts X or Y values depending on the given radius of the column into angle values.

A perfect team I think

Thanks

-Richard

[ArchieF]

Okay,

modified the 'Minimum g-code noarcs' post and added some mathematics.

The output is a file with Y-values converted to A-angles and scaled to the diameter you have to define as variable via an operation.

Attached is a job file, a screenshot of my backplotter to show the result and the modified pp.

As always use it on your own risk and use a backplotter to verify the code before working with it on the machine !!

Richard

@ Les

the 'Minimum g-code noarcs' post has an error in the function OnInit() :

if(scale == metric) then
post.Text (" G91\n") --metric mode <==must be G21
else
post.Text (" G90\n") --inch mode <== must be G20
end

[Les Newell]

the 'Minimum g-code noarcs' post has an error in the function OnInit() :

if(scale == metric) then
post.Text (" G91\n") --metric mode <==must be G21
else
post.Text (" G90\n") --inch mode <== must be G20
end

Oops. I'll fix that for the next release. Thanks for letting me know.
Some machines use G20/G21 and some use G70/G71. I have absolutely no idea why I used G90/91!