3D Carving - Roughing boundary?

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ExperiaUSA
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Joined: Tue Apr 26, 2016 2:02 pm
Model of CNC Machine: ShopBot PRT (older)

3D Carving - Roughing boundary?

Post by ExperiaUSA »

I everyone. I'm new to 3D work, so please bear with me.

I do not understand why the roughing toolpath is doing what it is doing. I am wanting to carve an Orthodox cross, and the roughing toolpath leaves approximately .125 of a border on the outer edge of the model (see image). That leaves a lot of material for the 1/8" ball nose bit to remove. Plus, it creates a ton of Z-up and Z-down moves that take a ton of machine time.

I've messed with changing the machining allowance and roughing strategy with all possible variants, and it still leaves the finishing toolpath to clean it up. Anyone know why, and how to have it NOT do that?

Thanks in advance,

Andy
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Adrian
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Re: 3D Carving - Roughing boundary?

Post by Adrian »

Have you set the Boundary Offset in the roughing toolpath. Ideally that should be the tool radius or slightly bigger to allow the tool to machine down the edge.

ExperiaUSA
Posts: 8
Joined: Tue Apr 26, 2016 2:02 pm
Model of CNC Machine: ShopBot PRT (older)

Re: 3D Carving - Roughing boundary?

Post by ExperiaUSA »

I am using a 1/4" bit for roughing, and originally I had a 0.2" boundary offset. I thought that might be it, so then I re-calculated the roughing toolpath with a 0.135 offset. No difference.

I then tried it with 0.00 boundary offset, with no difference.

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sharkcutup
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Re: 3D Carving - Roughing boundary?

Post by sharkcutup »

Andy,

What version of V-Carve are you using?

Please post/upload .crv file so that we forum members can analyze it to help solve your problem. Photos/images do help but they do not always define/show the nature of the problem.

Sharkcutup
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ExperiaUSA
Posts: 8
Joined: Tue Apr 26, 2016 2:02 pm
Model of CNC Machine: ShopBot PRT (older)

Re: 3D Carving - Roughing boundary?

Post by ExperiaUSA »

Now that the finishing toolpath is 2/3 done, I think I know what it is. Around the edge is a small upward-sloping ridge, right near the edge. I could not discern it in the model, but can see/feel in in the finished part.

Now, my concern is whether or not it will break off when I do it in wood. In the MDF, the thin edge broke off in several places of the MDF. The finished piece will be in mahogany. It should hopefully have enough strength to hand on. I might try to open the model in Solidworks and eliminate that raised lip.

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