Today I continued making the hand assembly. I made the cannon pinion plus the hour pipe and minute wheel which fits over it. I cut the cannon pinion from the end of the 15-tooth pinion stick. I decided to use size-reduced and toothless end of the stick to make the minute hand shaft. First I reduced the diameter to about .180", then used a cut off tool to remove the pinion from the pinion stick. Then I inserted it into a 36-size collet in the old Mosely watchmakers lathe and made a center divot in the pinion end with a center tool.
I drilled the shaft with a 3/32" through hole by first drilling it undersize, then final-drilling with a 3/32" bit. This shaft is about 3/4" long, which is a rather long hole for a small drill, and there was the danger that the drill would wander in the process, making the hole out-of-center on one end. But it turned out fine -- one reason being that it was first precisely centered with a center drill, then the drill itself was started slowly, thus starting out perfectly aligned. If the drill wobbles even a tiny bit out of center, then the hole will be crooked for sure.
Also, some of the cannon pinion teeth were cut off on the inside side of the pinion to form a small collar. On this collar there will mounted be a disk upon which the hand clutch spring will press.
The hour pipe is made from 1/4" brass drilled through with a .180 bit, since the minute hand shaft will fit through this hole. The pipe was reduced in diameter and a recess was cut where I will mount the 48-tooth hour wheel. The wheel is held onto the pipe by slightly peening the back of the pipe.
The parts fit well together and run true.
Today's links: