Getting bad tool paths from cut3d into mach3

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LordThrash
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Getting bad tool paths from cut3d into mach3

Post by LordThrash »

I dont know if this is a problem with cut3d or mach3...

I have been playing with cut3d on a few custom models. Every time one or both rough paths place large circles larger than the actually piece after each rough pass "level". I then saw the paths look wrong as soon as I load them into mach3. I broke 2 bits before figuring it out. The finishing paths dont show the error. These errors dont show up in cut3d's preview.

Here is one of the worst I saw: shallow bowl 3.0"x3.0"x0.6"

Image
you can see most of the paths staying withen the 3" + 0.1" tollerance. Except those pesky giant circles in cyan!

Image
This is the correct finish path for the same piece.

I have a giant file of the little bowl here that anybody can have. (as long as you show me the results if you make it :lol: )
http://chaingunstudios.com/Temp/cnc/Bow ... rock01.v3d

Any help would be welcome!
-Thrash

LordThrash
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here is the cut3d preview of the same bowl

Post by LordThrash »

Here it is
Image

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BrianM
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Post by BrianM »

Hi Thrash,

I've downloaded the file, are the toolpaths in the file above the oines which you show with the large circlkes in Mach3? I can see no sign of this in the toolpaths you sent but I just want to be sure that I'm lookinga t the same file.

What does the toolpath sections being drawn in Cyan in Mach 3 mean?

You can contact us directly at support@vectric.com to try and get to the bottom of this, but if anyone else on the board with mach 3 can check if they are seeing similar problems that would be very useful.

Brian

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dighsx
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Post by dighsx »

The cyan path is the actual path the tool took when running. (At least that what it means in my Mach3, not sure if you can set custome colours or not)

Thrash, I'm assuming other things cut fine via Mach3 for you?
Take it easy.
Jay (www.cncjay.com)

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dighsx
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Post by dighsx »

I just generated the toolpaths and loaded them into Mach3 and everything looked fine. I rain the roughing path in sim mode and it looked good too. For you screen shot of the circle what did you do to get that? Just saved the roughing path from Cut3D and then loaded it up in Mach3 and it came up that way?
Take it easy.
Jay (www.cncjay.com)

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BrianM
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Post by BrianM »

Thinking about this further, my guess would be that small flat arcs in the toolpath are being machined as large circles for some reason.

From what Jay has said, do the Cyan paths only appear after the toolpath has been run? If that is the case it would seem that Mach isnt following the toolpath that it has drawn in blue correctly. We do have posts for Mach which don't output circular arc moves. As the circular arcs would only appear on some roughing passes I doubt using these would make much difference to machining times for Cut3D.

If you drop us a mail at support@vectric.com saying exactly which post-processor you are currently using I'll send you the 'non-arc' version of the post and we can see if that cures the problem.

Brian

LordThrash
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More info

Post by LordThrash »

The large circle arc show up as soon as I load into Mach3. I have saved the path exported out of cut3d with the mach2/3 Arcs inch post processor. The G-code is "as-is" in mach3.

http://www.chaingunstudios.com/chaingun ... /Temp/cnc/ Roughing Toolpath - Bottom.txt (damn those spaces)

I have only ran simple things with my setup of mach3 but with no problems. Only things with multiple roughing levels out of cut3d show this problem.

As far as the cyan versus blue, the section of gcode currently executing is cyan and the rest is blue. I think its the current to last 1000 lines of of executed gcode are cyan. When I run the whole code every part starts blue goes cyan and returns to blue.

I'll contact support as well.

Thanks for the input.
-Thrash

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NSchlee
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Post by NSchlee »

Have you played with changing/verifying the absolute and incremental settings in Mach?
I vaguely remember having a similiar problem with some files when I was testing Mach a year so ago.

Neal

LordThrash
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Post by LordThrash »

NSchlee, I think your on to something. I'll check that tonight. So does cut3d use absolute or incremental arc coordinates?

I'll also try the non-arc processor in cut3d.

-Thrash

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Yes it was absolute versus incremental setting in Mach3

Post by LordThrash »

:D Got it working. In mach3, I set IJ to incremental and the tool path looked great.

thanks everybody.
-Thrash

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NSchlee
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Post by NSchlee »

Thrash YW, my memory banks may be fading, but some useful stuff still gets recalled once in a while! :-)

Neal

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