After tackling the long and arduous process of shipping the Grasmere commission, I have returned from England and can finally focus all my attention on my latest project.
This week I started working on the mechanism for the calendar/date/moon, starting with the long lever that goes from the center of the clock to the mechanism itself. This lever will be lifted and released once an hour, clicking the 24 tooth ratchet counter clockwise. 24 teeth means that ratchet will go around once per day. Attached to that ratchet will be two snail cams. One snail will lift and release a lever triggering the hand that shows the day of the week, and the other will lift and release the lever for the perpetual calendar mechanism.
Earlier, before I left for England, I completed the two main gears for the gear train, along with the pinions that they mesh with. Once those were finished I could figure out the exact depth between the gears and pinions, and therefore know the precise distance between the center of the clock and the escapement. This is important because the design of this clock must be proportioned to accommodate that distance, since the area around the escapement has an arc struck from the center of the escape wheel.
Now I’m going to tackle the perpetual mechanism for the same reason. Once I finish all of these parts I’ll know the exact distance from the center of the clock to the center of the perpetual mechanism. That distance needs to be perfect because of course the hands need to come out of the center of the calendar dials.
Once I have those two measurements I’ll be able to jump on a CAD program to get the entire frame and numbers of the clock drafted and cut. This isn’t to say I’ve been flying blind until this point. I’ve measured and calculated this stuff on paper already, so everything is very close. But paper and practice are two different things, and proportions often need to be tweaked a tiny bit once the pieces are finished and mechanically refined.
Next week will be more perpetual calendar stuff.
