I finished the deadbeat clock about six months back and though I would share some of my feedback and observations. First I would like to say that it was very easy to build and keeps amazing accuracy. As has be pointed out in some other post, I need to move the magnet about half way up the flipper for it to work correctly, when placed too low the switch always stays closed. I also need to add some foam to the end of the flipper to hold the magnet a bit farther away from the switch when it is closed, otherwise it just sticks to the switch and does not fall back. (I think the magnets that came with the switches are a bit on the "too strong" side).
I noticed that the clock was running through its batteries every three months, far more quickly than expected. But what I found more concerning was that also after three months the weight being put on motor's gear train was enough to cause it's gears to start skipping and the motor was no longer able to rewind the weight (I think the last gear arbor in the motor became slightly skewed to the gear teeth no longer engaged fully). Thinking this was just a one-off bad motor I replaced it (along with the batteries) and the clock ran well for another three months. At that time the exact same thing happened again, the batteries started to run dead and the gears on the motor started skipping. For these first two motors I was using a 20 RPM motor.
So after a bit of thinking and tinkering around I decided to make some modifications to the weight. First I replaced the batteries with a USB port so I can just plug it into an outlet. Second I used the now empty space in the weight to add a ratchet system to (I hope) take some of the back pressure off the motor's gears and make the motor last longer this time. I also switched to a 10 RPM motor in case the extra torque helps with the back pressure. (I briefly tried a 120 RPM motor and it was rewinding way to fast and the flipper would not always reset. Also for a low torque motor the gears spin freely in *both* directions when no power is applied and the ratchet becomes needed for the clock to work).
Even with all of this said, this is my favorite clock I have printed so far (I have also made the 32 days easy-build, and the electromagnetic clocks).
What motor are you using now? For me it's now the second time the gearbox on an N20 motor broke (gears are skipping) and before I buy another one I'd like to look at alternatives.
I have no pennies in the shell, so it's not that heavy, so I am a bit surprised that the gears start skipping after a few months. I did even lubricate everything the second time arround.
I seem to hit a bad lot of magnetic switches as well, after a few weeks/months of working the switches would become permanently magnetized and cause to clock to rewind into itself. After a bit of tinkering I decided to add a simple metal ball tilt switch to the paddle, seems to be working just fine. Although I did have to use very thin wire so it does not interfere with the paddle's movement. This should have far less chance of failing as it fully relies on gravity now rather than magnets being in the correct position and a delicate glass switch that stops working when cracked.
At some point I might modify the paddle to hold the switch at the correct angle, but at the moment the blue tack seems to be doing the job (and I don't feel like soldering those thin wires again if I can help it).
Interesting. Thanks for sharing your feedback and modifications.
I was able to get 3-4 months of life out of batteries that were already partially drained. They were pulled from the TV remote after becoming too weak to control the TV, yet they still lasted a long time in the clock. Motor variations might account for some of the difference, especially if your motor unwinds from the static weight. I have never seen my motors run backwards. It seems like it would
I experimented with variations in magnet placement. Too close and it can stick. Too far away and it doesn't always trigger. Gluing one or two magnets on the back side of the lever is an option.
A pure mechanical switch could also be an option. It should be more reliable since gravity alone would determine if the motor is enabled. Magnetic attraction would not be a factor. I didn't use this method because every switch tested was incredibly loud. The snap action to provide reliable contact makes a lot of noise.
I just released some new desk clocks with a different gear style and a lot more dynamic action.