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Chris,

I think the answer to that question depends on what you're using your 3D models for and who is processing your work. I use MoI3D for CAD and Vectric Cut2D and Cut3D for CAM. The CAM programs are good but stripped down. Cut3D for example will spit out accurate Gcode for complex 3D shapes, but doesn't have the ability to cut a single 3D spline (arched fret slots). So, when I cut a fretboard I'll have to split up the modeling operations. I'll loft some curves for the radius and run that model through Cut3D to make an arched fretboard blank. Then I'll switch to 2D modeling for slots, inlays, purfling and the final cutout. When I first got involved in this I assumed that CAD would be the hardest thing to figure out. Now I realized that to get a high quality part there is almost as much skill required in both CAM, tool selection and machine setup.

I'm thinking about upgrading my CAM package, so I'd love to hear how the full featured packages work.

Bob

If the cutter is going to be following a specific curve at different heights, or if it's a flat bottomed pocket, then use curves to define it.
ex: Outline of an electric body, pickup pockets, fret slots, engraving paths, holes, etc

If the toolpath needs to be 'clever', ie: the software needs to figure it out and it's not a pocket, then you'll need 3D surfaces.
ex: Back of a neck carve, electric top carve,

In general, the first thing to look for in CAM software besides basic 3D finishing paths (XY stepover and Z stepdown parallel paths, flowline or scallop if you're really lucky) is the ability to follow a 3D curve for a cut. The niftiest cuts I do aren't calculated by CAM at all: I draw the cutter path in Rhino and then just tell CAM to follow it with the cutter. Not for everyone, but it allows you to make the tool just a bit smarter than the software could.

_________________
Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

Yep. You can grab windows in Rhino as images by right clicking on the name (Perspective, in this case) and going down to Capture->To File

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

Guidelines?

1) Well as a Solidworks user I would say don't bother to radius the bottom of the fret slots in your software and leave out the edge break radii. It makes the model file somewhat larger and makes generating toolpaths more work.

2)Also try to have your work origin in a normal place on the part. Like top center, bottom center, or in any logical place that is normal to the working plane of the machine that is going to cut the part. Try to orient the X axis along the longest edge of the part, Y axis along the shortest, and Z to coincide with the depth of the part.

3) If you can output a solid model this would be preferred to a surface model or wireframe.

4) File extensions? for best cross-platform compatability use .iges or .stp. -.dxf and .dwg are ok for wireframe and basic blueprint drawing and .pdf is best for printing. Sorting through a gang of file converters to open up a file wastes time.

This is pretty basic stuff but you'd be suprised how many mangled models I've seen in over 25 years of cad/cam work. It's always best to give your cad/cam person the easiest possible job. Healing model files takes a bit of time and is irritating too.

I find it much faster cutting slots on the table saw unless it is a multi scale FB. if that is the case then I slot my MS FBs on the CNC at a flat depth on a radiused FB. Not because it is easier but I simply don't know how to draw it up with a radius on the bottom of the slots ;(

BobK,
FWIW, I am using Vectric software too, privately labeled and tweaked under ShopBot's name. It is super easy for this novice to use and I have found it can do most of what I need it to do.

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tim...
http://www.mcknightguitars.com

Tim are you using Rhino for your cad? If so, there are several of us here that can help you with the curves for the frets. Does vetric cut along curves?

Mike

C'mon Tim, live a little: make blind slots and hide those fret edges!

_________________
Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services