View Full Version : Solid body guitars

12-19-2001, 03:39 AM
I am a luthier who hand builds guitars.
The demand for these hand built instruments is very high , I find myself turning work away! The shopbot would be a very big help to me in my shop. I have bodies aready made. Will the 3-D digitizer work here if I scanned a body?

12-19-2001, 09:05 AM

There are a couple of ways you could use a probe to record the shape of an instrument body. One is to use the probe routine that outputs a ShopBot file and set the resolution very small. It will create a file that's a pretty exact copy of the thing your probing, but if you want to make changes to the shape it won't be easily editable. It can also create an incredibly large file and take a VERY long time to do.

Another is to use the routine that outputs a 3d dxf file and scan at a larger resolution; if you have too many points your editing work will be un-managable. Then open this file in a program like Rhino and add, delete, and move the points around to get the shape you want.

When you're done you'll need to create a surface from the points. In Rhino I usually connect the edited points using a series of curves to make a girdwork of sorts, and use the "surface from curve network" command. I'm sure that there are other ways to do it, but this seems like the easiest to me. You probably won't get clean edges this way, but you could use one of the edge-finding routines to create an outline and then project it onto the surface in Rhino. Once you've created the surface you could use a program like MillWizard to create your ShopBot file.

The learning curve on the 3d software is pretty steep, but once you get the hang of it you can do some pretty amazing things. You can download a demo copy of Rhino to play with from www.rhino3d.com if you're interested.

Hope this helps,


12-19-2001, 09:48 PM

I have scanned chair seats to make copies and rough out the blanks uning a probe and have been very happy with the results. The curves are very gentle, so the distance between points in the travel direction can be about 1/2" while the distance between paths can be abotu 1/8" using a 1" round nose bit. Some sanding is required to blend out the tool paths, but not too much, probably about 5 min per seat. While Bill is right that this method is not editable, it is scalable in all three directions when you run the program. I also use this technique for making short pieces of moulding from a customer's sample, and it works pretty well. If you'd liek I can scan a body for you and make you a duplicate to see what you think.

Jim Turner

12-19-2001, 10:11 PM
Another method is to take a picture of the object and using a CAD program 'trace' about the object. From there one can create DXF files............ what one does form there is a lot of personal preference.