Edit post processor to increase dwell time

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mday
Posts: 23
Joined: Mon Aug 19, 2019 6:19 pm
Model of CNC Machine: Omni 1212

Edit post processor to increase dwell time

Post by mday »

Hello everyone.
I have searched unsuccessfully for the code to increase the dwell time at the beginning of a program. My spindle needs more time to come up to speed before the tool engages the material. I also use other software and the post processor has a graphic utility where you can input things like dwell time, post job behavior, etc. So I know it is possible to do this, but unfortunately every post I see in my searches comes with the answer "Just edit your post processor" like we all know how to do that.
I have read the Vectric guide to editing post processors but I fail to find the syntax of the code to increase the dwell time nor the location of where it should go. I assume something like that would go in the header, but I don't even know what language post processors are written in.
My controller is the Centroid Acorn.
I have attached that Vectric guide and my post processor.
Attachments
Post_Processor_Guide.pdf
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Centroid_Arcs_mm.pp
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dealguy11
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Re: Edit post processor to increase dwell time

Post by dealguy11 »

If you look in the post-processor, you will find a Toolchange section about halfway down.

Look for the following command:

G4 P2

G4 is a dwell command - it tells the controller to wait some number of seconds before moving. P2 means it will wait for 2 seconds

Change the number 2 to whatever higher number you want it to be. Do a search for "G4 " (include the space) - I noticed there are 2 in this program. Save the post-processor. I would save it as a copy with a slightly different name. Use that one going forward.
Last edited by dealguy11 on Mon Aug 02, 2021 6:27 pm, edited 1 time in total.
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martin54
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Re: Edit post processor to increase dwell time

Post by martin54 »

I'm the same as you & have no idea how to edit a post processor but have you checked your contol software to see if you can do it in there? I use a different controller but I am sure I set the dwell in the control softwarthee rather than alter post processor. Could be wrong as it was some time ago but seem to remember thats how I did it :lol: :lol: :lol:

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Re: Edit post processor to increase dwell time

Post by ElevationCreations »

mday wrote:
Mon Aug 02, 2021 6:05 pm
Hello everyone.
I have searched unsuccessfully for the code to increase the dwell time at the beginning of a program. My spindle needs more time to come up to speed before the tool engages the material. I also use other software and the post processor has a graphic utility where you can input things like dwell time, post job behavior, etc. So I know it is possible to do this, but unfortunately every post I see in my searches comes with the answer "Just edit your post processor" like we all know how to do that.
I have read the Vectric guide to editing post processors but I fail to find the syntax of the code to increase the dwell time nor the location of where it should go. I assume something like that would go in the header, but I don't even know what language post processors are written in.
My controller is the Centroid Acorn.
I have attached that Vectric guide and my post processor.
For Centroid - You can edit the M3 macro in CNC12 v4.64 ( mfunc3.mac ), the default dwell time is set to .1 second. By doing this it will also help with the dwell time for the tool check function on CNC12 v4.64. Then you won't have to edit your PP's to add additional dwell time. If you need to add dwell time to the spindle off to allow the bit to come to a complete stop prior to another motion, you can do this with the m5 macro, or PP at the end of the g-code file, or use a spindle stop alarm from the VFD to an input on the Acorn or Ether1616 and modify the macros accordingly.

If you need help with the Centroid macros the Centroid CNC Users forum is probably the best place to reach out to.

mday
Posts: 23
Joined: Mon Aug 19, 2019 6:19 pm
Model of CNC Machine: Omni 1212

Re: Edit post processor to increase dwell time

Post by mday »

Thank you to all. I found the line G4 P2 right below M3 "Spindle on CW", and changed it to P6 as that is the dwell time I set in Fusion and it seems to be about right. I saved the PP file and will give it a roll this afternoon.
It's good to know that I can also control this with a macro in CNC12. There are other things I need to do with macros but one thing at a time. This issue was a pretty important one though. My tools were engaging material while the spindle was still ramping up and that isn't good.

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