## Watchmaking Math

#### by Jordan Ficklin

I have had many questions form individuals wishing to study watchmaking about the kinds of math on which they may be tested for admission and will have to perform during their career. Here is some watchmaking math which I don’t intend to be a reference for useful equations, as I’m not going to give very much information, but I present them simply as examples one should be able to solve.

The formula for determining the theoretical length of a mainspring given the barrel diameter(R), barrel arbor daimeter(r) and the thickeness of the mainspring (e) $L = \frac{\pi ( R^2 - r^2 )}{2 \cdot e}$

A formula used for determining the gear configuration in a multiplying gear train. Given all but 1 value solve the equation: $\frac{n_6}{n_1}=\frac{z_1 \cdot z_3 \cdot z_5}{z_2 \cdot z_4 \cdot z_6}$

Really, folks this is about as difficult as it gets. It is basic algebra and ratios. You will of course be expected to be able to determine which formula is appropriate and which values represent which variables, as well as eliminate unnecessary information, given the information in a word problem, but this you will be taught.