With a bridge firmly grasped in my hand and a small rectangle of 220 grit scratch cloth carefully laid on the supine violin, I move a delicate piece of carved maple upon the paper, sanding the feet into the curved shape of the violin top. Sometimes one foot wants a little more off than the other. I compensate. Tradition says the rear is to be 90˚ to the top. The front appears pitched, as it is cut to 87˚. Christmas Day we worked upon a beautiful mid-1960s German violin set up by a Reading shop. Their luthier’s trademark? He set up the right angled side forward. A second bridge in the case from the same shop was identically cut. Further reading indicates bridge orientation has no bearing on sound though tradition (and superstition) reign.
We work in fractions of a millimeter. Fairly precise work. Five seconds, about one distracted thought away from disaster. No speakerphone calls, please. Cello bridges, there is more room for error. But getting the bridge shaped to sit plumb on the cello top? A bit more work.
After doing a few by eye, I lust for an edge. A third hand. A bridge jig. When the right job came in, we turned, naturally, to Juzek, the American manufacturer of fine luthier tools. Off to the Performing Arts high school for summer session with a dozen cellos. Juzek again turns out a valedictorian performance. Our cello bridge feet come out square and plumb. Quite the time saver!
That other tool? A leg spreader. Not used with violin bridges but for the cello bridge, quite necessary. The leg spreader simulates what happens to the cello bridge when the pressure of the strings are upon it.