Trying to avoid buying other software

[Mobius]

So I'm in the middle of setting of a post processor to run a plasma cnc. So far it works great, although I'd like to make one change.

This might be a little hard to explain, so stay with me

So I see currently when my G code is generated that before each plunge move there is a rapid move to the plunge location. I've also seen that I can add a 'New Segment' command, which runs before each new toolpath (if multiple toolpaths are combined into one file).

What I'd like to know is if I can specify that rapid move to happen before the new segment command. The reason for this is that I'd like to be able to set up the G28.1 zeroing process to happen at the first plunge for each new toolpath. That way I can generate a toolpath for vectors that are near each other, and only touch off once for each toolpath.

Currently, I am either limited to touching off with each plunge (which sucks if there are many small cuts close together), or only once at the beginning of the file.

[Mobius]

And I guess worst case I can just try and remember to edit the file manually, copy and pasting the G28.1 for each new toolpath.

[Greolt]

Can't think of a way to rapid to the first cut position of the new segment before entering the new segment.

You won't know that first cut position until you enter that new segment.

You really need a "begin FIRST_PLUNGE_MOVE" command, which I am fairly certain, does not exist.

For example.

begin FIRST_PLUNGE_MOVE
//Touch off routine
//Move to pierce height
//Start torch
//Pierce delay
//Go to cut height

begin PLUNGE_MOVE
//Move to pierce height
//Start torch
//Pierce delay
//Go to cut height



Is your touch off slow? Is this what annoys you?

Mine is fairly quick. Doesn't bother me at all.

Maybe you can streamline it a bit.

[ger21]

There is indeed a "First Plunge Move".
See the Post Processor manual.

[Mobius]

Can't think of a way to rapid to the first cut position of the new segment before entering the new segment.

You won't know that first cut position until you enter that new segment.

You really need a "begin FIRST_PLUNGE_MOVE" command, which I am fairly certain, does not exist.


Is your touch off slow? Is this what annoys you?

Mine is fairly quick. Doesn't bother me at all.

Maybe you can streamline it a bit.

Already thought of that. Unfortunately, it works exactly the same as PLUNGE_MOVE, I'm guessing because they aren't consecutive plunge moves. There are other commands in between.

The touch off isn't exactly slow, but a few seconds at the start of each vector can add up. For instance, yesterday we cut something that had 30 smallish closed vectors within a 5x4 area. Probing each of those would turn a 1 minute cut into a 5 minute cut, and then if I had 100 of those to do....

So I was hoping I could edit the PP to only probe at the start of each toolpath. That way I could theoretically group a couple of the 5x4 sections together under the same toolpath, and only touch off 25 times instead of 3000.

[Mark]

Hello Mobius,

You should be able to achieve what you are trying to do by adding an "INITIAL_RAPID_MOVE" section
and adding the commands for your G28.1 zeroing process as the first line of this section and the standard
line from the existing "RAPID_MOVE" section below this.

I hope that this helps.


Cheers,

Mark.

[Greolt]

There is indeed a "First Plunge Move".
See the Post Processor manual.

Gerry
You are absolutely right. I did not look well enough.

[Greolt]

That way I could theoretically group a couple of the 5x4 sections together under the same toolpath, and only touch off 25 times instead of 3000.

Wow that is a lot of starts. When I cut a full sheet of decorative parts, it would never get above 100.

Touch off probably takes about one second (though I have never actually timed it)

That "INITIAL_RAPID_MOVE" should allow you to do what you are after.

[Mobius]

Hello Mobius,

You should be able to achieve what you are trying to do by adding an "INITIAL_RAPID_MOVE" section
and adding the commands for your G28.1 zeroing process as the first line of this section and the standard
line from the existing "RAPID_MOVE" section below this.

I hope that this helps.


Cheers,

Mark.

Hi Mark,

You had me excited, but sadly no dice. The INITIAL_RAPID_MOVE still only occurs at the beginning of the file. I had hoped it would treat the NEW_SEGMENT as requiring a new INITIAL_RAPID_MOVE, but this doesn't seem to be the case.

I do like that I was able to flip what you said and put the standard RAPID_MOVE line first (under the INITIAL_RAPID_MOVE command), followed by the G28.1 process. This allows the zeroing to happen at the first cut location, rather than at the X0 Y0 location. This is perfect to use as a PP for smaller jobs, where I estimate only needing to zero the Z once.

Wow that is a lot of starts. When I cut a full sheet of decorative parts, it would never get above 100.

It was a theoretical exercise, based on that particular part, should someone have ordered 100 of them. And yes, there is definitely room for optimization, but it was more to illustrate how the time could add up on a bigger job with the unnecessary movements.

[Mark]

Hello Mobius,

Apologies, I think I understood how you are trying to apply this.
What are you including currently within your toolpaths to trigger your new segment moves?

[Mobius]

Hi Mark,

Usually it would be an inside profile toolpath, generated on several closed vectors in relatively close proximity. Then a second separate profile toolpath on the next set of vectors that are near each other, and so on.

All these toolpaths are then output to g-code as one file. I was hoping to find a way to insert the G28.1 for each segment, to manually mimic a feature in other software where it will touch off if the vectors are further apart than a set distance.

[Mark]

Hello Mobius,

Many thanks for the reply.

Drop me a copy of your post processor along with a test CRV file to support@vectric.com and let me know the
some information about the set distance that you have mentioned.

Many thanks in advance.

[Greolt]

I will be very interested to see if you can come up with something Mark.

[Mobius]

Email sent!

[Mobius]

Mark has gone above and beyond! He wrote a script for my post processor which automatically inserts the required G28 process if the start points on the vectors to be cut are further away than a specified distance. All I have to do is select the vectors and generate a toolpath as per normal. I'm ecstatic!