Shell inlay on CNC for guitar headstock

[GatorCSM]

I have seen similar questions in searches but they have all been (of what I found) only vaguely to this point or they were specific to a particular piece of software.

I'm using:
Google Sketchup V8
MeshCAM 4
EMC2
Probotix Fireball v90 with Colt router
Bit for project: 1/32" carbide square endmill

First part:
I have an inlay design that has points that can be cut on the shell since it's cutting outside, but can't be cut with the bit on the wood, since it's the negative. I could manually increase the inlay pocket cad file but seems there's got to be an easier way.

Second part:
This kind of goes with number 1, but this part I think I've seen referred to as "wear"? I don't see that setting in MeshCAM and wasn't sure if that was something that should be on the CAD or CAM side of things. I want to make the overall cut just slightly bigger so the pieces slide in well.. I had to increase the size of the holes the first time I did the piece.

The biggest issue is trying to figure out how to force the system to cut the grooves for the tips of the inlay so that I don't have to manually come back and clean up the ends of each slot.. I'm filling in with wood shavings so it's going to cover it up mostly.

Many thanks!
Chris

[ger21]

MeshCAM is not the right software imo (and I'm a MeshCAM user.) Personally, I wouldn't use Sketchup either, due to it's lack of arcs.

Normally, inlays are done with a 2D drawing and a 2D CAM package.
In a 2D CAM package, you'd want to cut a pocket, and most 2D CAM programs have an allowance to let you adjust the pocket size. Alternatively, a 2D CAM program will let you easily offset the outline of the pocket by the desired clearance amount.

If you must use MeshCAM, have you tried to use a Pencil Toolpath to follow your grooves more precisely?
Or, you can Tell MeshCAM you're using a slightly smaller tool, and it will cut a little larger when you use the actual tool.

[GatorCSM]

What would be a better piece of software to replace meshcam. I don't have any visible limitations on sketchup.. I've also used AutoCAD, but it didn't do anything for me that sketchup didn't do for the simple stuff I've needed it for.

Most of the work is provided to me from my designers in Illustrator and then I put it in sketchup so I can tell it how deep I want the cuts and basic outline of the headstock.

I put it in Meshcam and just have it generate the tool paths. Most of the stuff I found that had more options, BobCAM, Rhino, etc, wanted to do both CAD/CAM, all I would want is increased CAM functionality.

The latest cut I did, I did as you described, and told it I was using a smaller tool so it would make it bigger, however that doesn't make the longer cuts at the tips of inlay material so that it will accomodate those longer points (i would have to tell it it was so small that it would make a huge pocket everywhere else).

Looking forward to any software recommendations and what sort of tools I'm looking for in it so I can try it out. Preferably looking for a CAM only solution.

Many thanks,
Chris

[ger21]

Vectric's Cut2D and V-Carve Pro can both import .ai files and work right from those, saving the Sketchup step.
I'd download the demo's of both and play with them.

Cut 2D may be too limiting for you.
V-Carve Pro also has an Inlay function that creates toolpath for both the pocket and the inlay. But it's 3x the price, because it has a lot of other features as well.

[palenn]

You can't have sharp points and expect to cut them with a round cutter. The alternative is to put a slight radius on the "points" of the inlay that will match the radius of the smallest cutter diameter you can use for the inlay pocket.

[GatorCSM]

Originally Posted by palenn You can't have sharp points and expect to cut them with a round cutter. The alternative is to put a slight radius on the "points" of the inlay that will match the radius of the smallest cutter diameter you can use for the inlay pocket.

Well, my problem isn't with sharp corners be cut, I'm getting sharp corners where I want them. Obviously you can't get a sharp inside corner (well, not sharper than 1/32" diameter of the bit.. But again, I get sharp corners on the pieces, so that part is good.

My issue is that I would like to have the machine cut out into the wood where the sharp tips go. As I mentioned earlier, clearly that cutout will be 1/32" wide, but I was looking at my Martin and Taylor and both had been filled in. It's not overly noticeable, but it is there.

I appreciate your feedback.
Chris

[palenn]

I always use polylines to create toolpaths for inlays and inlay cavities. That gives a lot of flexibility. The 2d CAM software creates Gcode by following the polylines. The lines have to be offset by the cutter radius, of course.

[judleroy]

Will it hurt to just match the radius on the inlay? I know on some designs it detracts but on others it's fine.
Judleroy

[Sheridan Basses]

There are some good threads over on the Vectric forum in which someone has come up with a technique using V-bits to do tight inlays with V-Carve pro. By using V-bits, and positive and negative cuts of the design you can get very good results. Shell inlay maybe too thin, but it opens up opportunities for other materials.

Vectric Forum • View topic - A simple way to make inlays

[Montabelli]

Sheridan Basses, That you Martin?

two options use an exacto knife to clean the corner, less fill than extending the slot, also adds that hand made flair. same technique used for putting the bee stingers on violin corners.

the vee cutter will define the edge but you would still need to go in with a knife to pare back the side of the pocket. if you use a 60 degree v and clean the corner with a slid cut going up it will give the least ammount of clean up required

[Kammo1]

I do all my fretboard inlays from cutting plastic and shell to cutting out pockets for them to fit into and use Cut 2D. I have found that this is all you will need and would recommend this for ease of use and excellent performance. I like yourself tried all the free stuff and found alot of it hard to use and a headache at the best of times. Cut 2D is the only software you'll need for inlay work. I'll try and post some pictures of my work that I've done with cutting out black plastic material and inlaying into a maple board. The results are "AMAZING" no filler or glue just an absolutely perfect fit time after time. I for one will fly the Vectric flag for sure it's quite simply the best