Measuring a pair of straight cut bevel gears

[Workshopfriend]

While restoring the vertical head on my old Adcock & Shipley mill I discovered that the bevel gears were not correctly meshed. Since assembly and disassembly was less than straightforward I opted for attempting to calculate the correct gear centres. This turned out to be an interesting exercise which resulted in the trial of a pair of custom made tapered gauge pins. This seemed to provide a reasonably accurate way of determining the position of the pitch circle cone in relation to the gear location faces. I hope this might be of interest to someone else. Clive.