Problem- File property under Axis- machining time estimate

[Zig]

I have been a happy user of EMC2 for some months now and in general am very happy with the utility EMC2 and Axis offer.

There is one feature of Axis I am not quite sure how to interpret; namely in file properties Axis provides the ngc file summary providing statistics such as idle traverse and cut length as well as time taken ( presumablu to cut the path).

This Axis estimated time to cut the path seems to be a gross under estimate ( at least on my machine) of the actual machining time.

Is there some parameter i need to set/reset/ignor/unignore in order to attain a better estimate of actual machining time?

[atex57]

An earlier version had a problem with time estimates. What version are you running? I am at 2.2.8 and it seems to be fine on my simple programs. Ed.

[Zig]

Hello Ed,

Thanks for Your comments.

Typically my jobs run for about an hour or so and the estimates are always much lower than the actual machine time.

I guess the smaller the job the less aparent the discrepancy becomes.

[atex57]

Well, some of my programs may run for 3 hours as it may have 60-80 loops to run through. What version are you running? Ed.

[Zig]

I too am runing with 2.2.8

Please take a note of what the EMC file property tells you and compare that to the actual duration of machining.

I would be interested to hear of Your experience.

I shall post the same stats on my next job for completeness.

[Zig]

The most recent exaqmple of the time estimation...

FILE >PROPERTIES> time to run 37 seconds

Actual machining time 30 minutes


There must be some assumptions made by the gurus which escape me that a piece of software which in general behaves so well should undrshoot the mark so badly in this one instance

[atex57]

Are your programs written with a CAM system? Just guessing here but if they are written with a zillion short moves to make a radius it could be a problem with acceleration rates to start and stop each line. Do a search the Wiki on linuxcnc.org for, I believe, G64.* to smooth out short moves. Ed.

[Zig]

My work is in PCB milling and the files are full of g02 g03 code.
And yes plenty of short strokes but even so the estimates ought to be unaffected by the file content.

As for blending, there is not much room for blending whenfeatures being milled are of the same order of magnitude as the blending settings.

For an example of work
http://www.cnczone.com/forums/showth...0&goto=newpost

According to Big John the estimation is only an approximation and might get confused by too many Z moves.