[hrowan]

I'm currently working on my dissertation at university am producing a number of g-codes using different post-processors on three different models.

I was wondering if there is any relationship between the length of a g-code and the time it'll take to be machined. I know obviously there are a lot of factors behind this, such as the complexity of the model, tool changes required, feedrates, etc. But if, for the same model, one post-processor produces a g-code of 300 lines, and another one produces a g-code of 10,000 lines, could it be said that the one with 300 lines is more efficient and quicker to machine the model? I'm aware there may be other aspects such as quality of part produced, but I'm wondering if efficiency/machining time can somehow be linked to the length of a g-code.

I'm using CATIA and QuickCAM Pro and the post-processors they use to get a range of g-codes for comparison of the software packages.

Any help or guidance is much appreciated, thanks!

[underthetire]

Depends on the control. A newer Fanuc can blow through lines faster than the machine can move. Old 80s control, probably not so much.

[hrowan]

Thanks underthetire,

That was another area I was unsure about. The CATIA software package contains post-processors such as Cenit, IMS and ICAM. Then each of these offers a choice of files such as Fanuc, Okuma, Bendix, Siemens, Fidia and so on.

I was wondering what to refer to these as. If they're not post-processors themselves, should they be referred to as post-processor controllers or post-processor files or something else?

[angelw]

Thanks underthetire,

That was another area I was unsure about. The CATIA software package contains post-processors such as Cenit, IMS and ICAM. Then each of these offers a choice of files such as Fanuc, Okuma, Bendix, Siemens, Fidia and so on.

I was wondering what to refer to these as. If they're not post-processors themselves, should they be referred to as post-processor controllers or post-processor files or something else?

Hello hrowan,

They're Motion Control Systems.

Even the newer controls with Acceleration/Deceleration Optimization and other smarts, will take longer to complete a program that produces the same shape component but where there are more moves. If for example, an arc can be machined using a Circular Interpolation Code (G02/G03) but the Post Processor creates that arc with small Linear (G01) moves, the Linear Move example will take longer because there will be Deceleration Period at the end of one block and an Acceleration Period at the start of the next block. The difference in time when considering Acceleration/Deceleration is highly dependent on the degree of direction change between successive blocks. For example:

1. A move of 1000mm in a straight path (X0 to X1000.) made up of 50,000 0.02mm moves, at a Feed Rate of F1000. will take 1 minute when Acceleration/Deceleration Optimization is used.

2. A program using Acceleration/Deceleration Optimization that dithers 0.02mm either side of a fixed point (X0) 50,000 times (1000mm moved) will take the same time as the example in point 1 when Acceleration/Deceleration Optimization is NOT used (considerably longer).

Regards,

Bill

[gfacer]

The short answer is there is no relationship between length of file and cut time as a general rule. For same post and similar jobs and settings, perhaps, but even then I'd guess the predictive power of the gcode length would be poor.

[hrowan]

Thanks for the help guys!

I couldn't find anything on the internet about what these Motion Control Systems were called, so thanks for the info!