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Author Topic: New Video of Mach/Ajax Cnc system cutting complex surface @ 250"ipm  (Read 16933 times)

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« Last Edit: September 01, 2009, 07:10:42 AM by hanglide »

Offline Chaoticone

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Re: New Video of Mach/Ajax Cnc system cutting complex surface @ 250"ipm
« Reply #1 on: August 31, 2009, 02:05:13 PM »
Looks good.  :)

Brett
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Re: New Video of Mach/Ajax Cnc system cutting complex surface @ 250"ipm
« Reply #2 on: September 01, 2009, 06:59:55 AM »
Thanks Brett

Any ideas on how to get the video to embed properly? Never mind- GOT IT!

Thanks

Scott
« Last Edit: September 01, 2009, 11:32:38 AM by hanglide »

vmax549

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Re: New Video of Mach/Ajax Cnc system cutting complex surface @ 250"ipm
« Reply #3 on: September 07, 2009, 09:18:40 AM »
I don't believe that machine is cutting at 300ipm (;-) I have watched a lot of machines run over the years and that is not 300 ipm.

At 300 ipm the machine moves at 5"per SEC


If you look at the first cuts at 100 it takes a five count to cross the block , the 250 it takes a five count, at 300 it takes a five count.

Just because Mach shows 300 does not mean the machine is moving at that rate. I can make th LPT version show the exact same thing.

(;-) TP
« Last Edit: September 07, 2009, 09:23:00 AM by vmax549 »

Offline Dan13

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Re: New Video of Mach/Ajax Cnc system cutting complex surface @ 250"ipm
« Reply #4 on: September 07, 2009, 01:19:11 PM »
Terry,

I'm with you on that. When the guy holds the workpiece at the end you can estimate the workpiece length to be about 7". And it takes about 5 seconds to travel that distance, which means a feed of even less than 100ipm. And the feed looks even through whole the process indeed - no difference between 100ipm and 300ipm can be seen.

One other thing I noted in the video is the feed DRO displaying the speed spot on - no fluctuation. Have never seen this in Mach3 neither with PP or SS. Mine always shows slightly lower value that keeps bouncing over.

Daniel

Offline Sam

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Re: New Video of Mach/Ajax Cnc system cutting complex surface @ 250"ipm
« Reply #5 on: September 07, 2009, 07:18:59 PM »
Sorry they had to disappoint you Scott, but at least now you know. It's still a great looking mustang, anyhow. Post some more stuff when you get a chance. We would love to see them.
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Offline ger21

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Re: New Video of Mach/Ajax Cnc system cutting complex surface @ 250"ipm
« Reply #6 on: September 08, 2009, 08:06:27 AM »
It also looks like the Velocity DRO doesn't work in their plugin, which would have told them it wasn't moving that fast. They just have a feedrate of 100ipm with a 300% override.
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Re: New Video of Mach/Ajax Cnc system cutting complex surface @ 250"ipm
« Reply #7 on: September 10, 2009, 02:33:27 PM »
Mea Culpa...

It turns out you're right Terry.  I didn't run the Mustang myself (that what I get for letting the pubs guys do it) and I didn't question it because we routinely achieve these published rates running that program.

It turns out that Mach doesn't increase the velocities when they cranked up the overrrides (how they -the operators- didn't notice it wasn't changing the speed is beyond me).  We looked into it and it appears that Mach won't increase the velocities of the vectors even when we change the program feedrates?  It will increase rates for longer vectors but that particular program is ENTIRELY made up of .01" moves and Mach just won't put out anything higher than about 100"/min with vectors that short.

Thanks for pointing out the feedrate display as well -we will take control of that shortly- it never occured to me that it wasn't reporting the actual feedrate. I assumed it the feedrate was being calculated based on the vectors that were being removed from the buffer... We already are displaying the actual encoder positions so it should be trivial to derive the combined axes velocites from that to display the feedrate.

FWIW  I will post another video shortly of the same machine ACTUALLY running at 450-500"/min -straight line but pretty good for a 5tpi pitch.  I will also get another Mustang video posted when we can figure out why Mach is limiting the velocities.. I'd understand if it was lookahead related but it seems odd that the commanded velocity curve flattens out well below the max velocity of the axes

FYI All our vectors are brought down as .001 sec (1 milli sec) vectors
« Last Edit: September 10, 2009, 03:33:32 PM by hanglide »

vmax549

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Re: New Video of Mach/Ajax Cnc system cutting complex surface @ 250"ipm
« Reply #8 on: September 10, 2009, 06:05:43 PM »
Basically you will be limited to HOW fast the motors can deliver the movement. Micro segmented code is a real problem on low end machines' they do NOT have the POWER/RIGIDITY  to do the extreme accellerations need to do FAST micro segmented code in a 3D enviroment.

Most of the Commercial machines that can do it well are cabable of " extreme" accelleration as well as velocity rates. Slower machines will never be able to operate at high feedrates with micro segmented code, the motors never have enough time to get to speed.

I think a different CV approach would help but we have what we have(;-)

THat looks to be a GOOD 3d TEST program a decent mix of micro and long segment code care to share the Gcode?

NICE mustang by the way(;-) TP

« Last Edit: September 10, 2009, 06:11:09 PM by vmax549 »
Here ya' go Terry :-) 500ipm, 5 tpi, .008" vectors - tested this time :-)
« Reply #9 on: September 14, 2009, 08:09:55 AM »
 <a href="http://www.youtube.com/v/vgs7efyjV10" target="_blank" class="new_win">http://www.youtube.com/v/vgs7efyjV10</a>

Probably could hit ~750 or so but the machine is on a skid so it rocks a little :-)
« Last Edit: September 14, 2009, 08:11:31 AM by hanglide »