making calculations in a post processor

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rscrawford
Vectric Wizard
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Joined: Mon Jan 17, 2011 6:49 pm
Model of CNC Machine: CAMaster Cobra 408 ATC, ShopSabre IS408
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making calculations in a post processor

Post by rscrawford »

Is is possible to have a post processor make calculations to come up with a number?

I have a Cobra with recoil, and I want the linear speed of the A-axis to match the speed of my Y-axis.

So what I want is my post processor to assign a separate feedrate to the A-axis that would be calculated as
([FC]114.65/[WRAP_DIA]).

For now, I put in a line "[N] F 10000 A", where I can make that calculation myself and manually change the '10000' to whatever angular speed I need. But it would be nice to have the post processor make that calculation automatically, so I don't have to edit the G-code for each tool that uses a different speed.

"[N] F ([FC]114.65/[WRAP_DIA]) A", where everything in the parenthesis would be calculated automatically.
Russell Crawford
http://www.cherryleaf-rustle.com

ThomasD
Vectric Apprentice
Posts: 5
Joined: Tue May 17, 2016 9:32 am
Model of CNC Machine: Biese Rover A3.4

Re: making calculations in a post processor

Post by ThomasD »

Hi,

Did you get a solution on this issue? I need to make some small calculations to output spoilboard thickness in my code.

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IslaWW
Vectric Wizard
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Joined: Wed Nov 21, 2007 11:42 pm
Model of CNC Machine: The Ultimate Woodworking Machine
Location: Marquette, MI, USA

Re: making calculations in a post processor

Post by IslaWW »

Thomas....
This is an old post, but not an uncommon ask. Russell's problem has been solved as the current CAMaster post processors have this calculation, in its corrected form, included. Your solution is more dependent on your controllers features than the ability to modify or place those calculations into a Vectric post processor. You will need to find out if or which operands you can use with your controller and what is the acceptable syntax.
Gary Campbell
CNC Technology & Training
The Ultimate Woodworking Machine
GCnC411 (at) gmail.com

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