Once I had the eBay cuckoo clock cleaned, adjusted, repaired, and running, I put the hands on. To my surprise, the minute hand kept slipping, no matter how I tightened the hand nut that’s supposed to hold it in place. The solution to this mystery lay in a troubleshooting video from a cuckoo clock seller in the Black Forest.
Frequently you can reassemble the clock based on its original state. Unfortunately, this clock had suffered a bad fall which ruined much of the original hand hardware, and if that wasn’t bad enough the design of the replacement hand hardware was different from the original.
When the clock arrived, it took a bit of work to get the hands off.
Then hand nut was so tight I had to grab the back of the minute post with Vise-Grip pliers to keep the minute post from turning. That crimped the back of the minute post enough that I had to polish it before the back plate would sit properly… but that’s another story.
Someone had staked (jammed) the minute hand bushing onto the minute hand, making it impossible to adjust the position of the minute hand – that is, to make the minute hand point straight up when the clock cuckoo’ed.
Also, when the clock fell off the wall – which probably caused the owner to sell the clock – the fall seemed to have jammed the minute hand bushing sideways on the minute post, requiring pliers to pry it off. Luckily the threads of the minute post were undamaged.
After all this, the original hands and hardware were useless, so I bought new ones. After a lot of trial and error, I found I needed 5 parts instead of the original 4:
- The hour hand – like the original
- The minute hand bushing – a loose fit compared to the original
- The minute hand – with a little larger hole than the original
- The minute hand domed washer – a part not in the original design
- The minute hand nut – like the original
After assembling all these parts I ran into a problem: no matter how much I tightened the minute hand nut the minute hand still slipped when I moved it.
After digging around quite a bit, I found a video that solved the problem for me: Troubleshooting Clock Hands by Black Forest cuckoo clock shop Bavarian Clockworks. In showing how to tighten the minute hand, it showed me what I’d done wrong: I’d installed the domed washer backwards.
The photo below shows the correct order and orientation of the new hand hardware. All the parts are shown with Up being outward (away from the clock) and in order from right to left.
Working from the right:
- Press the hour hand onto the hour shaft.
- Place the minute hand bushing onto the square base of the minute post, with the concave side facing outward toward the minute hand.
- Place the minute hand onto the bushing. It will likely be so loose that you’ll need to hold it in place until you get the next parts on.
- Place the domed washer onto the minute hand, with the concave part of the dome facing the minute hand. This was where I had gone wrong: I had placed the domed washer with the concave part facing out, thinking that the washing should press against the bushing rather than the minute hand.
- Screw the hand nut onto the minute post, with the tapered part of the nut facing outward. Tighten the nut just enough to hold the minute hand, because you’ll be adjusting it in a moment.
Now, of course, the hour hand and minute hand are pointing in arbitrary directions To set the hands’ positions:
- Turn the hand nut clockwise until the clock cuckoo’s the hour. Count the number of cuckoo’s.
- Stop the clock so the time doesn’t advance while you’re adjusting the hands.
- Using two fingers, one on either side of the hour hand, loosen the hour hand by pulling it outward a bit, then move the loose hour hand so it points to the hour the clock just cuckoo’ed, then press the hour hand down onto the hour shaft so that hand won’t slip.
- Unscrew the hand nut enough to loosen the minute hand, position the loose minute hand to point to 12 o’clock, then – while holding the minute hand in place – tighten the hand nut.
Now you should be able to move the minute hand clockwise to set the time, and start the clock running again.
Questions? Comments? Put them on the Twitter Thread about this post.