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.