Complete Noob working on a V

[JLight]

I got the bright idea that I wanted to build my own guitar body. It's styled after the Jackson King V with a recessed tuneomatic and string thru body. My friend has a Practical CNC machine that uses WinCNC. I built a 3d model in Autocad and used meshcam to create the program. It came out horrible. I'm hoping to cut the whole thing with a .5"x2" endmill. This is just a simple top cut for the body shape, neck pocket, bridge, and pickups. Attached are the dwg file and a picture of what came out of it. I ran a roughing pass, an X axis finish pass, and a "pencil cleanup" finish pass. The dwg file was built with 1 unit equals 1 foot.

Anybody have any tips or know how I screwed it up so bad? If you're bored, feel free to create a program that I can use with this CNC. I should mention that nobody knows how to run the machine my friend has. He bought it with intentions of making signs but never got around to figuring it out. Any help is appreciated. Thanks.

[ger21]

Anybody have any tips or know how I screwed it up so bad?

MeshCAM is the wrong tool for that job. All you need is a 2D drawing and a .dxf to g-code converter. I can do the code for you later, as I'm at work right now. How fast do you want to cut, and how deep per pass?

[JLight]

I was running 100 ipm with .25" depth per cut. It seemed to work pretty well.

How do you get the depth of the cuts with a 2d drawing? I'm guessing you have to put them in by hand?

I also don't have a vacuum system to hold the part down so I need some sort of supports built in to hold the center.

[ger21]

Usually, you put different depth cuts on different layers, and assign the depth in the conversion program.

I use an AutoCAD macro I wrote to create the code, and it'll let me assign depths to polylines, or it'll cut at the depth the lines are drawn at, so if I move the line down 1", it'll cut 1" deep.

[JLight]

I see. I don't have a 2d drawing of the guitar. I added the humbucker, neck, and bridge routes after it was already a solid. I think it's possible to pull a face to make it 2d but I don't know how to do it.

Attached is a scale 3d model. 1" - 1 unit.

[JLight]

This drawing has just poly lines that correspond to the bottom of the cuts. The stock will be 1.75" thick.

[ger21]

Try this, but test in some scrap!

I attached the drawing I used, and here a link to my macro if you want to play with it.
AutoCAD 2 G-Code macro

[JLight]

Try this, but test in some scrap!

I attached the drawing I used, and here a link to my macro if you want to play with it.
AutoCAD 2 G-Code macro

Thanks. I should get a chance to run it on some pine tomorrow.

[JLight]

I ran the program and it cut it beautifully except it's too small. Everything was just a little bit small. I'll post exact dimensions tomorrow. Is it possible that I need to make some changes in winCNC to make sure what it thinks is an inch, is really an inch?

[JLight]

Looks like I gotta mess with the resolution in the ini file.

[ger21]

Don't use WinCNC, so I don't know.