cuts in wrong places

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Maarten Visser
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cuts in wrong places

Post by Maarten Visser »

Hi folks, I am struggling with C3D cutting places I do not want it to. I have a fairly complex but smooth surface that needs machining the inside only.
C3D setup.jpg
The roughing path however, also cuts outside the material.
C3D rough.jpg
And the finishing toolpath goes through the wall, and also dips in the corners.
C3D finish.jpg
No idea what I am doing wrong here. If someone could point me in the right direction that would be great.
Thanks, Maarten

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Adrian
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Re: cuts in wrong places

Post by Adrian »

Are you trying to machine it all from one side? That won't work as it's a 3 axis program. You need to run from multiple sides to get all the undercuts.

Maarten Visser
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Re: cuts in wrong places

Post by Maarten Visser »

Hi Adrian,
I only machining from the top. The bottom flare is then cut by hand. But I am trying to find out how to make C3D behave.
regards, Maarten

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Adrian
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Re: cuts in wrong places

Post by Adrian »

Sorry, I don't really understand what it is you are trying to do. There aren't that many users of Cut3D on the forum these days since VCarve got 3D capabilities but hopefully someone will help you.

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adze_cnc
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Re: cuts in wrong places

Post by adze_cnc »

There are two things I see here that might confuse Cut3D:
  1. this appears to be an open surface
  2. the “Material Margins Around Mode” having that -0.5 offset
Try entering 0 for that offset (or a positive number such as 0.5) then click apply below. Recalculate your rough and finish toolpaths.

I think when the program is calculating toolpaths it is getting confused about what is inside and what is outside because of the 2 things I noted above.

Maarten Visser
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Re: cuts in wrong places

Post by Maarten Visser »

Thanks, that helps. I made a solid and reset the machining margin to 0. Now I still have the problem that C3D wants to machine the top surface in the finishing pass.
C3D finish pass.jpg
Is there a way to tell C3D not to do that? That would be awesome!
best regards, Maarten Visser

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adze_cnc
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Re: cuts in wrong places

Post by adze_cnc »

You could just cap the bottom of the shape and leave the top as it was.

Maarten Visser
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Re: cuts in wrong places

Post by Maarten Visser »

Hi Adrian.
I tried everything and I am exhausted. Just pulling a surface into C3D and the program does not know the inside from the outside; Making a solid and it wants to cut out the entire thing. I need a software where I can choose a machining strategy for a specific surface. Unfortunately, with other software it does not work either end Fusion does not agree with the Nurbs surfaces from Rhino.
Any suggestions are welcome.
thanks in advance, Maarten

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Re: cuts in wrong places

Post by Rcnewcomb »

If you haven't done so already, you may wish to send your file to support@vectric.com along with an explanation of the problem.
- Randall Newcomb
10 fingers in, 10 fingers out, another good day in the shop

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adze_cnc
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Re: cuts in wrong places

Post by adze_cnc »

Maarten Visser wrote:
Tue Apr 21, 2020 2:20 pm
I tried everything and I am exhausted. Just pulling a surface into C3D and the program does not know the inside from the outside;
See the two attached files. Both have the same wave-like side. One is open the other capped at the bottom. In both cases the toolpaths generate just fine. Note that I used a positive margin.

As I mentioned previously by setting that negative vale for the machining offset such that it was both inside and outside of the surface the program, quite understandably, had to make some presumptions about what was inside and what is outside. It does the best it can but it, in the end, is just merely a computer program. The acronym GIGO might possibly apply.
Attachments
wave-no bottom cap.v3d
Open surface only
(1.9 MiB) Downloaded 167 times
wave-bottom cap.v3d
Water-tight surface
(1.75 MiB) Downloaded 172 times

Maarten Visser
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Re: cuts in wrong places

Post by Maarten Visser »

Thanks for your help. I had a look at the toolpaths in the wave bottom cap model, and the tool again goes outside the machining margin, have a look at the picture. I changed nothing.
C3D bottom cap.jpg
Indeed the problem is that the software doen not know inside or outside of a surface, but I don't thing its asking too much to stick to the model silhouette machining margin?
I capped the bottom of my model, set C3D to follow the silhouette, and this is what I get:
c3d met bodem.jpg
At 1 it cuts out the corner of the material, and at 2 the toolpath goes through the sides of the model surface.
So perhaps its time to move over to other software or even madcam.
best regards, and stay safe,
Maarten

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Adrian
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Re: cuts in wrong places

Post by Adrian »

Have you tried sending your file to Vectric and asking for help?

Maarten Visser
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Re: cuts in wrong places

Post by Maarten Visser »

Not yet, but I am now at I point where I am getting into more complex operations with tool changes etc, so perhaps time to move on.
best regard, Maarten

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