Rossow Stringed Instruments

probing a violinProbing/Digitizing

One of the unique services that I provide to other luthiers is the digitizing (also known as probing) of plates (i.e., tops and backs) for their violins, violas, and cellos. When I probe a plate, a three-dimensional computer model is created which I then use to carve an exact replica of the plate on my computer numerically controlled (CNC) machine. Unlike mass-produced, pre-carved “in the white” violin plates – which give the luthier little or no creative freedom, my probing services allow a luthier who has had success with a unique model or particular archings to re-create his or her instrument with precision - and without the ergonomic wear and tear that comes from repeatedly hand carving plates.

probing a violinHow does the process work?

The probe is a small, extremely precise device that houses several sensors. It has a stylus with a small, rounded tip that makes contact with the instrument plate being probed (see photo). The probe mounts to a CNC machine and is connected to a computer.
The plate to be probed is positioned on and secured to the CNC table. I then determine the number of contact points the probe needs to make with the instrument. The contact points (which constitute the “resolution” of the three-dimensional model that will ultimately be created) are entered into a computer-aided machining (CAM) program and the probing process begins. The probe works its way back and forth in a grid pattern over the instrument plate until each point of contact has been made. (The probe makes such delicate contact that it leaves no markings whatsoever on the plate, even on soft spruce.) Once the probing is completed, the points are automatically connected and blended into a seamless 3-D digital model. The digital model directs the movements of the CNC machine as it carves the instrument plate. The result of the entire process is an exact replica of the probed plate.


Steve Rossow
Luthier/CNC Services