Run time taking much longer then stated
- scottmcphee
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28 Jun 2012 01:43 #21419
by scottmcphee
Run time taking much longer then stated was created by scottmcphee
Hello,
I purchased a probotix comet the runs Linux cnc, not sure of the version I bought the machine about 6 months ago.
It came with 2 sample programs, a AXIS logo ( 2d cutout) and a HD logo that is for v-carving.
The first program says it takes 3.1 mins to run in the properties and the Harley logo says 8.2 mins to run.
When I run both programs at 100% I get about 3.1 mins for the first program (as estimated) but the second ( 3d) took 17 minuets to run.
All I do is v-carve, and 50% of what I do are curves ( script fonts). When I run one of my programs and the tool comes to a curve is when it slows to a craw. I know these curves are as smooth as I can get them (points reduced to a minimum)
My questions is…is it the Linux software that can’t look ahead and process the lines that fast, or could it be a setting?
Could it be the how I’m writing the g-code?
Here are a few lines…
%
N10 G90 G54 G17 G40 G64 P0.0001
N20 (60 Deg Conic )
N30 G0 z.5
N40 S18000 M3
N50 G0 X3.139 Y4.359
N60 Z0.25
N70 G1 Z-0.009 F25
N80 X3.139 Y4.359 Z-0.009 F60
N90 X3.138 Y4.359 Z-0.01
N100 X3.137 Y4.358 Z-0.011
N110 X3.136 Y4.358 Z-0.012
N120 X3.135 Y4.358 Z-0.013
N130 X3.134 Y4.358 Z-0.014
N140 X3.133 Y4.357 Z-0.014
N150 X3.133 Y4.357 Z-0.015
N160 X3.132 Y4.357 Z-0.015
N170 X3.131 Y4.357 Z-0.016
N180 X3.13 Y4.357 Z-0.016
N190 X3.13 Y4.356 Z-0.017
N200 X3.129 Y4.356 Z-0.017
N210 X3.128 Y4.356 Z-0.017
N220 X3.128 Y4.356 Z-0.018
N230 X3.127 Y4.356 Z-0.018
N240 X3.126 Y4.355 Z-0.019
N250 X3.124 Y4.354 Z-0.019
N260 X3.122 Y4.353 Z-0.02
N270 X3.119 Y4.352 Z-0.021
N280 X3.115 Y4.351 Z-0.021
N290 X3.113 Y4.35 Z-0.022
N300 X3.109 Y4.349 Z-0.022
N310 X3.107 Y4.348 Z-0.023
N320 X3.053 Y4.324 Z-0.026
N330 X3. Y4.303 Z-0.0
Thank you for your time
Scott
I purchased a probotix comet the runs Linux cnc, not sure of the version I bought the machine about 6 months ago.
It came with 2 sample programs, a AXIS logo ( 2d cutout) and a HD logo that is for v-carving.
The first program says it takes 3.1 mins to run in the properties and the Harley logo says 8.2 mins to run.
When I run both programs at 100% I get about 3.1 mins for the first program (as estimated) but the second ( 3d) took 17 minuets to run.
All I do is v-carve, and 50% of what I do are curves ( script fonts). When I run one of my programs and the tool comes to a curve is when it slows to a craw. I know these curves are as smooth as I can get them (points reduced to a minimum)
My questions is…is it the Linux software that can’t look ahead and process the lines that fast, or could it be a setting?
Could it be the how I’m writing the g-code?
Here are a few lines…
%
N10 G90 G54 G17 G40 G64 P0.0001
N20 (60 Deg Conic )
N30 G0 z.5
N40 S18000 M3
N50 G0 X3.139 Y4.359
N60 Z0.25
N70 G1 Z-0.009 F25
N80 X3.139 Y4.359 Z-0.009 F60
N90 X3.138 Y4.359 Z-0.01
N100 X3.137 Y4.358 Z-0.011
N110 X3.136 Y4.358 Z-0.012
N120 X3.135 Y4.358 Z-0.013
N130 X3.134 Y4.358 Z-0.014
N140 X3.133 Y4.357 Z-0.014
N150 X3.133 Y4.357 Z-0.015
N160 X3.132 Y4.357 Z-0.015
N170 X3.131 Y4.357 Z-0.016
N180 X3.13 Y4.357 Z-0.016
N190 X3.13 Y4.356 Z-0.017
N200 X3.129 Y4.356 Z-0.017
N210 X3.128 Y4.356 Z-0.017
N220 X3.128 Y4.356 Z-0.018
N230 X3.127 Y4.356 Z-0.018
N240 X3.126 Y4.355 Z-0.019
N250 X3.124 Y4.354 Z-0.019
N260 X3.122 Y4.353 Z-0.02
N270 X3.119 Y4.352 Z-0.021
N280 X3.115 Y4.351 Z-0.021
N290 X3.113 Y4.35 Z-0.022
N300 X3.109 Y4.349 Z-0.022
N310 X3.107 Y4.348 Z-0.023
N320 X3.053 Y4.324 Z-0.026
N330 X3. Y4.303 Z-0.0
Thank you for your time
Scott
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28 Jun 2012 02:18 #21420
by PCW
Replied by PCW on topic Re:Run time taking much longer then stated
I would take a look at the
G64 command in the gcode reference especially the G64 P Q code
linuxcnc.org/docs/html/gcode/gcode.html#sec:G61-G61.1-G64
G64 command in the gcode reference especially the G64 P Q code
linuxcnc.org/docs/html/gcode/gcode.html#sec:G61-G61.1-G64
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28 Jun 2012 10:35 #21424
by BigJohnT
Replied by BigJohnT on topic Re:Run time taking much longer then stated
scottmcphee wrote:
No, the number reported in properties is simply a sum of the rapid moves and the feed moves. This number does not take into account acceleration and deceleration both of which add to the time. The shorter the G code file and the longer the lines the closer the sum of rapid and feed moves will be to actual time. The slower the maximum acceleration the longer your run times with many short moves. As Peter pointed out using G64 Pn will turn on the naive cam detector that will blend together lines within the tolerance you supply with P and optionally Q for G64. If you have not read the Important User Concepts I suggest you read it a couple of times.
If you really want to know your run times I suggest you look at the time comp .
John
My questions is…is it the Linux software that can’t look ahead and process the lines that fast, or could it be a setting?
Could it be the how I’m writing the g-code?
No, the number reported in properties is simply a sum of the rapid moves and the feed moves. This number does not take into account acceleration and deceleration both of which add to the time. The shorter the G code file and the longer the lines the closer the sum of rapid and feed moves will be to actual time. The slower the maximum acceleration the longer your run times with many short moves. As Peter pointed out using G64 Pn will turn on the naive cam detector that will blend together lines within the tolerance you supply with P and optionally Q for G64. If you have not read the Important User Concepts I suggest you read it a couple of times.
If you really want to know your run times I suggest you look at the time comp .
John
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28 Jun 2012 17:32 #21433
by andypugh
Replied by andypugh on topic Re:Run time taking much longer then stated
scottmcphee wrote:
LinuxCNC always goes at a speed such that it can stop before the end of the next segment, so runs very slowly on short segments.
You will probably find that you get better results by increasing the segment length then using G64 to blend to curves.
Converting curves to arc moves is an even better idea, but most CAM doesn't know how.
(This requirement to stop before the end of the next segment is likely to be removed in a future version for just this reason)
This is actually the problem, not the solution.I know these curves are as smooth as I can get them (points reduced to a minimum)
LinuxCNC always goes at a speed such that it can stop before the end of the next segment, so runs very slowly on short segments.
You will probably find that you get better results by increasing the segment length then using G64 to blend to curves.
Converting curves to arc moves is an even better idea, but most CAM doesn't know how.
(This requirement to stop before the end of the next segment is likely to be removed in a future version for just this reason)
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- scottmcphee
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28 Jun 2012 17:58 #21434
by scottmcphee
Replied by scottmcphee on topic Re:Run time taking much longer then stated
Thanks for your quick reply's, I added the Q code and played with the tolerance and see a big improvement on how smooth the tool moves around the curves. I v-carve TT fonts and need to work on how I clean them up.
Thank again
Thank again
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28 Jun 2012 21:09 #21437
by BigJohnT
Replied by BigJohnT on topic Re:Run time taking much longer then stated
andypugh wrote:
The naive cam detector will actually combine lines and arcs so I'm not sure converting to all lines or all arcs will help in any way if you use G64 Pn.
John
Converting curves to arc moves is an even better idea, but most CAM doesn't know how.
The naive cam detector will actually combine lines and arcs so I'm not sure converting to all lines or all arcs will help in any way if you use G64 Pn.
John
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