Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: rrc1962 on February 03, 2012, 06:08:10 PM

Title: Strange CV behaviour
Post by: rrc1962 on February 03, 2012, 06:08:10 PM
Just noticed this issue.  When cutting a circle made up of individual line segments, Mach is running in exact stop mode even though it is in CV mode.  None of the CV boxes are checked on general config.  The same circle written to use arcs cut fine.  The offending code is below.  The circle below is code that I've run before successfully, but I don't know how long ago it was, so this is a problem that has come on fairly recently.  Other programs seem to run fine.  Has anyone seen anything like this?  Is there a CV setting somewhere that I changed that could cause this? 


G20 G40 G91.1 M7
G00 X1 Y0.5
G01 X0.9997 Y0.5174F80
G01 X0.9988 Y0.5349F80
G01 X0.9973 Y0.5523F80
G01 X0.9951 Y0.5696F80
G01 X0.9924 Y0.5868F80
G01 X0.9891 Y0.604F80
G01 X0.9851 Y0.621F80
G01 X0.9806 Y0.6378F80
G01 X0.9755 Y0.6545F80
G01 X0.9698 Y0.671F80
G01 X0.9636 Y0.6873F80
G01 X0.9568 Y0.7034F80
G01 X0.9494 Y0.7192F80
G01 X0.9415 Y0.7347F80
G01 X0.933 Y0.75F80
G01 X0.924 Y0.765F80
G01 X0.9145 Y0.7796F80
G01 X0.9045 Y0.7939F80
G01 X0.894 Y0.8078F80
G01 X0.883 Y0.8214F80
G01 X0.8716 Y0.8346F80
G01 X0.8597 Y0.8473F80
G01 X0.8473 Y0.8597F80
G01 X0.8346 Y0.8716F80
G01 X0.8214 Y0.883F80
G01 X0.8078 Y0.894F80
G01 X0.7939 Y0.9045F80
G01 X0.7796 Y0.9145F80
G01 X0.765 Y0.924F80
G01 X0.75 Y0.933F80
G01 X0.7347 Y0.9415F80
G01 X0.7192 Y0.9494F80
G01 X0.7034 Y0.9568F80
G01 X0.6873 Y0.9636F80
G01 X0.671 Y0.9698F80
G01 X0.6545 Y0.9755F80
G01 X0.6378 Y0.9806F80
G01 X0.621 Y0.9851F80
G01 X0.604 Y0.9891F80
G01 X0.5868 Y0.9924F80
G01 X0.5696 Y0.9951F80
G01 X0.5523 Y0.9973F80
G01 X0.5349 Y0.9988F80
G01 X0.5174 Y0.9997F80
G01 X0.5 Y1F80
G01 X0.4826 Y0.9997F80
G01 X0.4651 Y0.9988F80
G01 X0.4477 Y0.9973F80
G01 X0.4304 Y0.9951F80
G01 X0.4132 Y0.9924F80
G01 X0.396 Y0.9891F80
G01 X0.379 Y0.9851F80
G01 X0.3622 Y0.9806F80
G01 X0.3455 Y0.9755F80
G01 X0.329 Y0.9698F80
G01 X0.3127 Y0.9636F80
G01 X0.2966 Y0.9568F80
G01 X0.2808 Y0.9494F80
G01 X0.2653 Y0.9415F80
G01 X0.25 Y0.933F80
G01 X0.235 Y0.924F80
G01 X0.2204 Y0.9145F80
G01 X0.2061 Y0.9045F80
G01 X0.1922 Y0.894F80
G01 X0.1786 Y0.883F80
G01 X0.1654 Y0.8716F80
G01 X0.1527 Y0.8597F80
G01 X0.1403 Y0.8473F80
G01 X0.1284 Y0.8346F80
G01 X0.117 Y0.8214F80
G01 X0.106 Y0.8078F80
G01 X0.0955 Y0.7939F80
G01 X0.0855 Y0.7796F80
G01 X0.076 Y0.765F80
G01 X0.067 Y0.75F80
G01 X0.0585 Y0.7347F80
G01 X0.0506 Y0.7192F80
G01 X0.0432 Y0.7034F80
G01 X0.0364 Y0.6873F80
G01 X0.0302 Y0.671F80
G01 X0.0245 Y0.6545F80
G01 X0.0194 Y0.6378F80
G01 X0.0149 Y0.621F80
G01 X0.0109 Y0.604F80
G01 X0.0076 Y0.5868F80
G01 X0.0049 Y0.5696F80
G01 X0.0027 Y0.5523F80
G01 X0.0012 Y0.5349F80
G01 X0.0003 Y0.5174F80
G01 X0 Y0.5F80
G01 X0.0003 Y0.4826F80
G01 X0.0012 Y0.4651F80
G01 X0.0027 Y0.4477F80
G01 X0.0049 Y0.4304F80
G01 X0.0076 Y0.4132F80
G01 X0.0109 Y0.396F80
G01 X0.0149 Y0.379F80
G01 X0.0194 Y0.3622F80
G01 X0.0245 Y0.3455F80
G01 X0.0302 Y0.329F80
G01 X0.0364 Y0.3127F80
G01 X0.0432 Y0.2966F80
G01 X0.0506 Y0.2808F80
G01 X0.0585 Y0.2653F80
G01 X0.067 Y0.25F80
G01 X0.076 Y0.235F80
G01 X0.0855 Y0.2204F80
G01 X0.0955 Y0.2061F80
G01 X0.106 Y0.1922F80
G01 X0.117 Y0.1786F80
G01 X0.1284 Y0.1654F80
G01 X0.1403 Y0.1527F80
G01 X0.1527 Y0.1403F80
G01 X0.1654 Y0.1284F80
G01 X0.1786 Y0.117F80
G01 X0.1922 Y0.106F80
G01 X0.2061 Y0.0955F80
G01 X0.2204 Y0.0855F80
G01 X0.235 Y0.076F80
G01 X0.25 Y0.067F80
G01 X0.2653 Y0.0585F80
G01 X0.2808 Y0.0506F80
G01 X0.2966 Y0.0432F80
G01 X0.3127 Y0.0364F80
G01 X0.329 Y0.0302F80
G01 X0.3455 Y0.0245F80
G01 X0.3622 Y0.0194F80
G01 X0.379 Y0.0149F80
G01 X0.396 Y0.0109F80
G01 X0.4132 Y0.0076F80
G01 X0.4304 Y0.0049F80
G01 X0.4477 Y0.0027F80
G01 X0.4651 Y0.0012F80
G01 X0.4826 Y0.0003F80
G01 X0.5 Y0F80
G01 X0.5174 Y0.0003F80
G01 X0.5349 Y0.0012F80
G01 X0.5523 Y0.0027F80
G01 X0.5696 Y0.0049F80
G01 X0.5868 Y0.0076F80
G01 X0.604 Y0.0109F80
G01 X0.621 Y0.0149F80
G01 X0.6378 Y0.0194F80
G01 X0.6545 Y0.0245F80
G01 X0.671 Y0.0302F80
G01 X0.6873 Y0.0364F80
G01 X0.7034 Y0.0432F80
G01 X0.7192 Y0.0506F80
G01 X0.7347 Y0.0585F80
G01 X0.75 Y0.067F80
G01 X0.765 Y0.076F80
G01 X0.7796 Y0.0855F80
G01 X0.7939 Y0.0955F80
G01 X0.8078 Y0.106F80
G01 X0.8214 Y0.117F80
G01 X0.8346 Y0.1284F80
G01 X0.8473 Y0.1403F80
G01 X0.8597 Y0.1527F80
G01 X0.8716 Y0.1654F80
G01 X0.883 Y0.1786F80
G01 X0.894 Y0.1922F80
G01 X0.9045 Y0.2061F80
G01 X0.9145 Y0.2204F80
G01 X0.924 Y0.235F80
G01 X0.933 Y0.25F80
G01 X0.9415 Y0.2653F80
G01 X0.9494 Y0.2808F80
G01 X0.9568 Y0.2966F80
G01 X0.9636 Y0.3127F80
G01 X0.9698 Y0.329F80
G01 X0.9755 Y0.3455F80
G01 X0.9806 Y0.3622F80
G01 X0.9851 Y0.379F80
G01 X0.9891 Y0.396F80
G01 X0.9924 Y0.4132F80
G01 X0.9951 Y0.4304F80
G01 X0.9973 Y0.4477F80
G01 X0.9988 Y0.4651F80
G01 X0.9997 Y0.4826F80
G01 X1 Y0.5F80
G00 Z0.375
G00 X0 Y0
Title: Re: Strange CV behaviour
Post by: rrc1962 on February 03, 2012, 06:53:24 PM
Might have something to do with the distance between the points.  The above circle is 1" in diameter with 180 points.  This circle is 20" in diameter with 180 points.  It runs through the first 3 points in exact stop mode then finishes the rest of the circle in CV.  Seems like a circle less than 10" in diameter cause Mach to run in exact stop.  The larger the circle the smoother it runs.  I can set the acceleration down to 5 or less and that smooths it out, but that's way too slow for everyday use.

Regardless of how large the circle is...12" or 48"...the first 3 points always run in exact stop, then the last 177 points run in CV.

G20 G40 G91.1 M7
G00 X10 Y0
G01 X9.9939 Y0.349F200
G01 X9.9756 Y0.6976F200
G01 X9.9452 Y1.0453F200
G01 X9.9027 Y1.3917F200
G01 X9.8481 Y1.7365F200
G01 X9.7815 Y2.0791F200
G01 X9.703 Y2.4192F200
G01 X9.6126 Y2.7564F200
G01 X9.5106 Y3.0902F200
G01 X9.3969 Y3.4202F200
G01 X9.2718 Y3.7461F200
G01 X9.1355 Y4.0674F200
G01 X8.9879 Y4.3837F200
G01 X8.8295 Y4.6947F200
G01 X8.6603 Y5F200
G01 X8.4805 Y5.2992F200
G01 X8.2904 Y5.5919F200
G01 X8.0902 Y5.8779F200
G01 X7.8801 Y6.1566F200
G01 X7.6604 Y6.4279F200
G01 X7.4314 Y6.6913F200
G01 X7.1934 Y6.9466F200
G01 X6.9466 Y7.1934F200
G01 X6.6913 Y7.4314F200
G01 X6.4279 Y7.6604F200
G01 X6.1566 Y7.8801F200
G01 X5.8779 Y8.0902F200
G01 X5.5919 Y8.2904F200
G01 X5.2992 Y8.4805F200
G01 X5 Y8.6603F200
G01 X4.6947 Y8.8295F200
G01 X4.3837 Y8.9879F200
G01 X4.0674 Y9.1355F200
G01 X3.7461 Y9.2718F200
G01 X3.4202 Y9.3969F200
G01 X3.0902 Y9.5106F200
G01 X2.7564 Y9.6126F200
G01 X2.4192 Y9.703F200
G01 X2.0791 Y9.7815F200
G01 X1.7365 Y9.8481F200
G01 X1.3917 Y9.9027F200
G01 X1.0453 Y9.9452F200
G01 X0.6976 Y9.9756F200
G01 X0.349 Y9.9939F200
G01 X0 Y10F200
G01 X-0.349 Y9.9939F200
G01 X-0.6976 Y9.9756F200
G01 X-1.0453 Y9.9452F200
G01 X-1.3917 Y9.9027F200
G01 X-1.7365 Y9.8481F200
G01 X-2.0791 Y9.7815F200
G01 X-2.4192 Y9.703F200
G01 X-2.7564 Y9.6126F200
G01 X-3.0902 Y9.5106F200
G01 X-3.4202 Y9.3969F200
G01 X-3.7461 Y9.2718F200
G01 X-4.0674 Y9.1355F200
G01 X-4.3837 Y8.9879F200
G01 X-4.6947 Y8.8295F200
G01 X-5 Y8.6603F200
G01 X-5.2992 Y8.4805F200
G01 X-5.5919 Y8.2904F200
G01 X-5.8779 Y8.0902F200
G01 X-6.1566 Y7.8801F200
G01 X-6.4279 Y7.6604F200
G01 X-6.6913 Y7.4314F200
G01 X-6.9466 Y7.1934F200
G01 X-7.1934 Y6.9466F200
G01 X-7.4314 Y6.6913F200
G01 X-7.6604 Y6.4279F200
G01 X-7.8801 Y6.1566F200
G01 X-8.0902 Y5.8779F200
G01 X-8.2904 Y5.5919F200
G01 X-8.4805 Y5.2992F200
G01 X-8.6603 Y5F200
G01 X-8.8295 Y4.6947F200
G01 X-8.9879 Y4.3837F200
G01 X-9.1355 Y4.0674F200
G01 X-9.2718 Y3.7461F200
G01 X-9.3969 Y3.4202F200
G01 X-9.5106 Y3.0902F200
G01 X-9.6126 Y2.7564F200
G01 X-9.703 Y2.4192F200
G01 X-9.7815 Y2.0791F200
G01 X-9.8481 Y1.7365F200
G01 X-9.9027 Y1.3917F200
G01 X-9.9452 Y1.0453F200
G01 X-9.9756 Y0.6976F200
G01 X-9.9939 Y0.349F200
G01 X-10 Y0F200
G01 X-9.9939 Y-0.349F200
G01 X-9.9756 Y-0.6976F200
G01 X-9.9452 Y-1.0453F200
G01 X-9.9027 Y-1.3917F200
G01 X-9.8481 Y-1.7365F200
G01 X-9.7815 Y-2.0791F200
G01 X-9.703 Y-2.4192F200
G01 X-9.6126 Y-2.7564F200
G01 X-9.5106 Y-3.0902F200
G01 X-9.3969 Y-3.4202F200
G01 X-9.2718 Y-3.7461F200
G01 X-9.1355 Y-4.0674F200
G01 X-8.9879 Y-4.3837F200
G01 X-8.8295 Y-4.6947F200
G01 X-8.6603 Y-5F200
G01 X-8.4805 Y-5.2992F200
G01 X-8.2904 Y-5.5919F200
G01 X-8.0902 Y-5.8779F200
G01 X-7.8801 Y-6.1566F200
G01 X-7.6604 Y-6.4279F200
G01 X-7.4314 Y-6.6913F200
G01 X-7.1934 Y-6.9466F200
G01 X-6.9466 Y-7.1934F200
G01 X-6.6913 Y-7.4314F200
G01 X-6.4279 Y-7.6604F200
G01 X-6.1566 Y-7.8801F200
G01 X-5.8779 Y-8.0902F200
G01 X-5.5919 Y-8.2904F200
G01 X-5.2992 Y-8.4805F200
G01 X-5 Y-8.6603F200
G01 X-4.6947 Y-8.8295F200
G01 X-4.3837 Y-8.9879F200
G01 X-4.0674 Y-9.1355F200
G01 X-3.7461 Y-9.2718F200
G01 X-3.4202 Y-9.3969F200
G01 X-3.0902 Y-9.5106F200
G01 X-2.7564 Y-9.6126F200
G01 X-2.4192 Y-9.703F200
G01 X-2.0791 Y-9.7815F200
G01 X-1.7365 Y-9.8481F200
G01 X-1.3917 Y-9.9027F200
G01 X-1.0453 Y-9.9452F200
G01 X-0.6976 Y-9.9756F200
G01 X-0.349 Y-9.9939F200
G01 X0 Y-10F200
G01 X0.349 Y-9.9939F200
G01 X0.6976 Y-9.9756F200
G01 X1.0453 Y-9.9452F200
G01 X1.3917 Y-9.9027F200
G01 X1.7365 Y-9.8481F200
G01 X2.0791 Y-9.7815F200
G01 X2.4192 Y-9.703F200
G01 X2.7564 Y-9.6126F200
G01 X3.0902 Y-9.5106F200
G01 X3.4202 Y-9.3969F200
G01 X3.7461 Y-9.2718F200
G01 X4.0674 Y-9.1355F200
G01 X4.3837 Y-8.9879F200
G01 X4.6947 Y-8.8295F200
G01 X5 Y-8.6603F200
G01 X5.2992 Y-8.4805F200
G01 X5.5919 Y-8.2904F200
G01 X5.8779 Y-8.0902F200
G01 X6.1566 Y-7.8801F200
G01 X6.4279 Y-7.6604F200
G01 X6.6913 Y-7.4314F200
G01 X6.9466 Y-7.1934F200
G01 X7.1934 Y-6.9466F200
G01 X7.4314 Y-6.6913F200
G01 X7.6604 Y-6.4279F200
G01 X7.8801 Y-6.1566F200
G01 X8.0902 Y-5.8779F200
G01 X8.2904 Y-5.5919F200
G01 X8.4805 Y-5.2992F200
G01 X8.6603 Y-5F200
G01 X8.8295 Y-4.6947F200
G01 X8.9879 Y-4.3837F200
G01 X9.1355 Y-4.0674F200
G01 X9.2718 Y-3.7461F200
G01 X9.3969 Y-3.4202F200
G01 X9.5106 Y-3.0902F200
G01 X9.6126 Y-2.7564F200
G01 X9.703 Y-2.4192F200
G01 X9.7815 Y-2.0791F200
G01 X9.8481 Y-1.7365F200
G01 X9.9027 Y-1.3917F200
G01 X9.9452 Y-1.0453F200
G01 X9.9756 Y-0.6976F200
G01 X9.9939 Y-0.349F200
G01 X10 Y0F200
G00 Z0.375
G00 X0 Y0
Title: Re: Strange CV behaviour
Post by: stirling on February 04, 2012, 06:16:21 AM
Just ran your samples and I see similar results here except that the number of exact stop moves I see at the front is different. That might be down to our different lookahead settings/steps per/motor tuning etc. However when I take the F off from every line (just stick it in once at the beginning) on my system they BOTH run in CV just as they should. I'm guessing it's more of a case that the F on every line is killing the interpreter on small moves.

Looks to me like your CAM/POST could do with a slap  ;D

Title: Re: Strange CV behaviour
Post by: rrc1962 on February 04, 2012, 09:02:30 AM
Thanks Ian.  That makes sense.  Could be at some point I was monkeying with that post.  I'll give that a try today.
Title: Re: Strange CV behaviour
Post by: docltf on February 04, 2012, 10:47:04 AM
move your start point

Title: Re: Strange CV behaviour
Post by: rrc1962 on February 04, 2012, 04:13:44 PM
Problem solved by removing the feedrate from every line.  Thank for that tip Ian.  It must have slowed the interpreter enough to cause a pause at each line.
Title: Re: Strange CV behaviour
Post by: Hood on February 04, 2012, 04:34:08 PM
Can your cam not output arcs instead of hundreds of short lines?
Title: Re: Strange CV behaviour
Post by: rrc1962 on February 04, 2012, 06:36:47 PM
This code comes from a simple app that I wrote a few years ago.  I rarely use it which is why I haven't noticed the issue before now.  I use SheetCAM for my day to day work, which does output arcs.