Microscopes for Horology

Being able to see what you're doing is one of the central problems in watchmaking. Good equipment in this area makes all the difference between perpetual aggravation and comparative ease.

Watchmaker's microscope

This watchmaker's microscope features a watch plate holder and a pair of centers for holding arbors. Centering microscope

I mark the location of a new hole on the lower plate with the aid of a depthing tool. The plate is then transferred to a face plate on the lathe. The mark is aligned using a centering microscope held in the tailstock. The hole can then be spot centered and drilled undersize. The drill cannot make a round or centered hole however, so the drilling is followed up with a boring bar which enlarges the hole for reaming and makes it truly circular. Before removing the plate, the bridge is attached (that holds the other end of the arbor) and the whole process is repeated for the bridge hole. This insures that the arbor will be truly upright. The bridge and plate are then jeweled as described above. Leitz toolmaker's microscope

This is a microscope looking down on an X-Y rotary table. The table coordinates are read from illuminated glass scales using a vernier eyepiece. I use it to lay out holes and other features on the watch plate. Over the 6 inch range of travel, it is accurate to 0.0001". This machine was made by the industrial side of the company that builds Leica cameras. I don't deserve it. Wilder shadow graph projector

This WW2 vintage box projects the outline of parts on a frosted glass screen. The calibrated optics keep a flat field of view at 100x. Placing a watch gear on the stage, I can measure all the features with an ordinary 6" rule. Each 0.1" on the rule is 0.001 on the part. When making wheel cutters, I form the addendum radius on the end of a sharp lathe bit entirely by eye using a diamond file and the projected image of the tool tip. After the addendum curve is formed, I use the lathe bit to turn the sides of the circular cutter as show in the pinion cutter section above. Microscope for surgeons

Not a horological tool as such, but one of the most frequently used in my shop. This beast features coaxial fiber optic illumination through twin Nikon stereo binocular zoom heads. The X and Y axis, focus, head angle and zoom motions are controlled by individual servo motors, each operated by a foot switch. One head looks along the lathe axis while the other looks along the bed toward the headstock.

It is amazing what you can find in consignment shops. While haggling over the price, the salesman asked me what this machine was for. I told him it was made for someone seriously into stringing beads.