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...regarding cutting a neck on a CNC. I have a neck modeled up in Aspire. I cut a test neck using a polystyrene block to make sure the toolpath works. That came out fine.

Now the question - the test in polystyrene was a full block measuring 3x3x24 (it’s for a uke) and the model and toolpath in Aspire is made based on this.

For an actual wood test I wanted to use Walnut and so I used the bandsaw to prep the blank just as if I was going to carve it by hand. This gives me two blanks from one block.



If I run the toolpath it’s going to be cutting air for a lot of it. That’s OK because I’m not worried about time to cut, but this can’t be how production shops do it.

So is it a side effect of using Aspire where the toolpaths are made with an assumption of starting from a block of wood? Do other software packages let you create toolpaths which take into account a pre-cut blank?

Thanks,
Brad


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I’m not super familiar with aspire as I just have Vectric, but yes other packages (Ie MasterCAM) let you start with a stock model closer to reality so you cut less air.

Edit - Vectric/Aspire has a pretty darn good forum - could be a good place to research this.

Ok, that makes sense. I use Aspire for other woodworking things and it’s fine for me to take forever to carve a neck.


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You might be able to tweak the "project tool paths" to simulate a stock model. If you make a 3D model of the bandsawed neck blank, and then project the other tool paths onto that, it might work. I don't know for sure, but might be worth a try.

Dave

Not a dumb question at all I think. As Chuck said, other CAM packages do allow you to specify the exact dimensions of the stock and the software will try not to cut air.

Generally speaking, most higher end CAM packages give a lot of control over the very fine minutiae of how the toolpaths behave at the cost of generally more complex user interface that sometimes can be kind of intimidating, especially for those just getting started.

[edited to add some more anecdotes:]
When I first started CNC-ing, I went with VisualMill for Solidworks (AKA RhinoCAM for Rhino) which is maybe two or three steps up from Aspire in my mind and it took quite a while to get the hang of it. At the same time, HSM-works (which is also now part of Fusion 360) was free for 2.5D work to try to get you hooked and while its 2.5D is a few steps above VisaulMill, the interface was so intimidating that at the time, I couldn't get anything done with it. Now with several years under my belt, that same HSM-works is pretty straight forward.....now .

Vectric traded more control of the toolpath for ease of use for a lot of different CNC woodworking applications and I think they did an absolutely outstanding job on that, It's just not the ideal tool for making production code for carving necks. I actually own Vcarve Pro because there's a decent number of things I can do on there a lot faster than I can with Fusion360 or SolidWorks+HSM or SolidWorks+VisualMill and it's worth it.

While I think that while Dave's idea might actually be possible, I suspect it would feel a lot like as I pondered how fun it might be to use the project toolpaths to basically hand draw a roughing toolpath for each Z-level.... (No offense Dave )

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None taken--I would think that would be a bear to try. Like you, I use VCarve Pro for things where I don't need 3D, but I use Rhino/MadCAM for 3D stuff, and MadCAM allows creating stock models.

Dave

Fusion 360 certainly allows you to select bodies you model as the stock. It even allows you to simulate a cut, save the result as an STL, and use that in a new file as your stock model. I've not used that feature, but it is how it calculates rest machining. I took a training once where they did some super cool things machining blanks that were then used in a variety of ways in subsequent machining operations.