3D milling entire part

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dryphi
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Re: 3D milling entire part

Post by dryphi »

Actually this is the same problem I was having before with the 3D Roughing / Finishing toolpaths.
They will not progress more than 1/2 tool width beyond the edge of the material no matter what you do.

See image below; I have increased the Width (X) of my Job Size to 25.4mm (1/8" longer than my actual part) and now it completely clears the front of the part like I desire.
VCarve_3DFinishing_RodSphere2.PNG
Compare that to the toolpath in the previous post. With the material size set to the same size as my actual part, the 3D surfacing toolpaths will not clear the front and sides of the part even with a Boundary Offset sufficiently large to allow them to.
VCarve_3DFinishing_RodSphere.PNG
You can try to "force" it another way by using a vector as the Machining Limit Boundary. That's what I've done below; I created a vector offset from the model by slightly more than the tool radius (1.6mm). But yet the "nub" on the front and sides remains.
VCarve_3DFinishing_RodSphere3.PNG
In short, without increasing the job size, there's no way to make the 3D surfacing toolpaths fully surface the part. Even if you make the Boundary Offset quite large (e.g. larger than the tool diameter), and/or use offset vectors as the Machining Limit Boundary, the tool midline will still stop at the edge of the material.
As far as I'm aware this issue applies only to 3D Roughing and Finishing toolpaths.

I desire to actually machine the front and sides of the part. In order to do that I have to "trick" VCarve by telling it the material size is larger than my actual work piece. That poses a problem however when I go to position the piece because now the zero point on my CNC machine (i.e. the top edge of my vise) does not correspond to the actual desired Y0 on my part.

Maybe I'm missing something? How do I get around this - by using an Offset of the XY Datum in Material Setup (which direction) or something?
Has this "bug" been addressed in a newer release? I'm still running 9.015. Thanks

LittleGreyMan
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Re: 3D milling entire part

Post by LittleGreyMan »

Hello,

Could you please post the last version of you project so we can have a look?

Vcarve and Aspire are excellent products for 2D, 2,5D and bas-relief 3D, but they simply lack the right toolpath types for what we could call "high Z 3D": no roughing toolpath allowing to remove quickly, smoothly and securely large amounts of raw material, no finishing toolpath adequate for steep walls and no collision detection.

You can obviously find workarounds for your model, but if you often have to cut this kind of shapes, maybe Vcarve is not the best suited product.

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adze_cnc
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Re: 3D milling entire part

Post by adze_cnc »

You might try the following with a new file:
  • make a new file with the job size set at 2 inches (or 50mm) larger in width and height. e.g. if your size is 6 inches by 6 inches specify 8 inches by 8 inches
  • for the "XY Datum Position" click "Use Offset" and set the X and Y to -1 (or -25 if using mm)
  • import your model and toolpaths and see if this works
The 1" (or 25mm) border is merely to fool VCarve into believing it has more material to work with than it actually does. This allows the toolpaths to fully engage the model. The offset is to match your real material's position within the false block.

Steven

dryphi
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Re: 3D milling entire part

Post by dryphi »

adze_cnc wrote:The 1" (or 25mm) border is merely to fool VCarve into believing it has more material to work with than it actually does. This allows the toolpaths to fully engage the model. The offset is to match your real material's position within the false block.
Thanks for that Steven. I was thinking something similar. Thanks for the step-by-step though so I get it right.
I could also move the 0,0 point on the actual machine by a set distance after I index the work piece, but doing it in the software is probably better.

Would be nice if VCarve could just allow these 3D toolpaths to go outside the material boundary though. I'm sure I'm not the only one that's been stymied by this. Seems like an easy fix. It could just be a checkbox in the 3D toolpath settings.
It doesn't seem to be an issue with other toolpaths as far as I'm aware, and I'm sure these tools are behaving as they're intended to. But maybe the flexibility of these toolpaths could be increased, because I can't find another tool to do what I have described without "tricking" the software.
Also if this limitation was introduced for a reason, IMO using a Boundary Offset or defining a Machining Limit Boundary should override that limitation, or at least provide the option to if the user wishes.
Just my humble suggestion, take it or leave it, but I hope that customer feedback is appreciated.

dryphi
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Re: 3D milling entire part

Post by dryphi »

LittleGreyMan wrote:Could you please post the last version of you project so we can have a look?
I would if I could but unfortunately the files are over the 3MiB allowed size limit :(

dryphi
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Re: 3D milling entire part

Post by dryphi »

LittleGreyMan wrote:Vcarve and Aspire are excellent products for 2D, 2,5D and bas-relief 3D, but they simply lack the right toolpath types for what we could call "high Z 3D": no roughing toolpath allowing to remove quickly, smoothly and securely large amounts of raw material, no finishing toolpath adequate for steep walls and no collision detection.
The capabilities of VCarve is fine for our purposes. We don't do much machining. When we do, it's typically from a SolidWorks model, and for that the 3D surfacing tools are typically easier to apply, especially for a graduate student who doesn't have much time to spend learning more software. For us, the VCarve / ShopBot combo lies somewhere in between 3D printing and sending a part to the machine shop.
This particular model is just one example. It's not at all representative of the kind of work we deal with, which varies on a daily basis.

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Adrian
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Re: 3D milling entire part

Post by Adrian »

dryphi wrote:
LittleGreyMan wrote:Could you please post the last version of you project so we can have a look?
I would if I could but unfortunately the files are over the 3MiB allowed size limit :(
You can put into a DropBox/OneDrive/Google Drive account and then share the link here.

dryphi
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Re: 3D milling entire part

Post by dryphi »

Here you go. Not real comfortable with sharing a link like this (shows my name etc) so will likely delete after a short while.

dryphi
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Re: 3D milling entire part

Post by dryphi »


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