topic Re: Post processor outputs plunge moves and links as G00 not G01, how do I change this? in PowerMill Forum

Post processor outputs plunge moves and links as G00 not G01, how do I change this?

Anonymous — Wed, 17 Feb 2021 15:38:40 GMT

One of our post processors outputs the NC code for plunge moves without a G01 on the line so the previous line being G00 remains the modal command. (It does output the first plunge of each toolpath with a G01, but non on the following plunges for further depths of cut)

Also links such as straight or circular arc get output as G00 rapids.

How do we modify the post processor to have it output these moves as G01 with the defined feedrates.

Re: Post processor outputs plunge moves and links as G00 not G01, how do I change this?

Anonymous — Wed, 17 Feb 2021 19:28:26 GMT

Make sure in you Linear Move command line there is a motion mode parameter call out - pic1 - check that your motion G code commands are applied to the motion mode under parameters - pic2

Re: Post processor outputs plunge moves and links as G00 not G01, how do I change this?

Anonymous — Thu, 18 Feb 2021 09:24:21 GMT

Thank you for the response. These details do appear to be correct within out Post Processor, but from your advise I believe I have identified where the incorrect commands are coming.

In a previous revision, the Post Processor output the Z axis approach and retract move as a G01 linear with the skim feedrate. We wanted these two moves to be G00 rapids, so had the Post Processor altered to make that correct, but then following that retract and approach move between different cuts within one toolpath it does not define G01 again until the first X/Y axis move after the plunge. Therefore the plunge move follows the G00 defined on the previous line for the X/Y rapid position.

I can alter the post to remove this forced G00 on the Z retract and approach, and that causes the plunge moves to be output correctly. But we still want these Z retract and approach moves to be defined as G00.

What other ways can we alter the post to achieve the Z retract and approach to be G00 rapid, and have the plunge and link moves (such as straight/circular arc) as G01 linear moves?

Attached is a picture showing how the forced G00 Z retract and approach.

Re: Post processor outputs plunge moves and links as G00 not G01, how do I change this?

Anonymous — Thu, 18 Feb 2021 10:13:02 GMT

After altering the Post Processor to remove the forced G00 on the Z retract and approach, which causes the plunge moves to be output correctly. I have discussed when outputting a NC Program with only one toolpath in, all the approaches and plunges work correctly. But when there are multiple toolpaths in the NC Program, the retract moves get output as G01 Skim feeds.

Any advise on how the post decides this would be very helpful?

Re: Post processor outputs plunge moves and links as G00 not G01, how do I change this?

Anonymous — Thu, 18 Feb 2021 11:01:49 GMT

Further clarity... I have now discovered that the code is output correctly if multiple 3 axis toolpaths are included in the NC Program. But if there is an 3+2 axis toolpath then all code is output with G01 Skim moves instead of G00 rapids. I have made the equivalent alterations to the post for both 3 axis and 3+2 axis toolpaths but this still persists.