A Mac, a CT Scanner, a Custom CNC Machine, and a Stradivarius

“If Stradivari was working today, I wonder what he would do with an Apple Mac computer, a CT scanner, and a CNC machine.”

One amazing violin.

Violin maker John Waddle asks this question from a special perspective.  He and fellow violin maker Steve Rossow and radiologist Steven Sirr have reproduced a celebrated Stradivarius violin, the 1704 “Betts,” using computer tomography (CT) imaging and a custom-made computer numerical controlled (CNC) machine.  He describes the process, explains what his analysis revealed about the instrument, and speculates on the new possibilities of this high-tech approach in his article, “The Progress of Progress,” for the May 2010 issue of The Strad magazine.

Steve Rossow's custom CNC machine at work recreating a Stradivarius. Photo from waddleviolins.com

Although copies of Stradivarius violins have been made for centuries based on measurements taken from originals as well as images, Waddle asserts his approach is unique.

However, the violin parts that we carved on the CNC machine from the CT data have exactly the same detail as the original violin: the same beautiful archings, the same graceful outlines – even the texture of the flame has been recreated in the copy of the back.  Our process is less one of making a new creation using our own ideas, and more one of helping a new violin emerge from wood and the digital data from an existing violin.  We have copied exactly what the original maker did, not what we think the violin should be like.

The CT scans of the “Betts” were turned into a 3D stereolithographic file (STL) which was programmed into a computer guiding a CNC machine designed and custom-built by Steve Rossow specifically for carving violins, violas, and cellos.  Wood that matched the wood of the original Stradivarius was selected for the replica, notes Waddle, which was assembled and finished by hand after it was machined.

The result?

The replica "Betts" violin. Still from the video at auntminnie.com.

And, for the pudding in which the proof is, what does the replica sound like?

You can listen to the instrument being played during the last 20 seconds of this NPR story on the replica “Betts” and interview with Steven Sirr (at 4:26).

You can hear another brief performance in this video from auntminnie.com beginning at 1:02.  (Unfortunately, there is a voiceover).  You can also hear from the principals behind this project: Steven Sirr, Steve Rossow, and John Waddle.

CNC machining and 3D imagery are tools in the toolkits of many custom artisans today, and custom reproduction is just one area of expertise for these craftspeople.  Although Waddle writes that this particular project is not about creating something new, what could be the impact of CT scanning, 3D imaging, and custom CNC machining on the creative process and the custom manufacturing of new, unique pieces?  One possibility Waddle foresees is an explosion of experimentation made possible by the ability to make multiple, accurate copies.

Being able to make the same parts again and again will allow research that has not been possible before.  For instance, if the top and back can be carved accurately, experiments can be made with the wood.  What if a lower density top is used? What if a higher density back is used? What effect will wood treatments have if the archings are kept the same? Having the three-dimensional form of the instrument digitised, it is also possible to reduce it or enlarge it.  This will allow us to experiment with making the same instrument a bit larger or smaller, which will be a great help in making violas, for example.  The possibilities are endless.

Makers and connoisseurs, what are your thoughts?