This is a very unusual piece, and Michael gave it to me for a service, as it didn’t reset properly to 0, and sometimes stopped when running. You can see that the minute recorder (the red hand) hasn’t re-set to 0.
Michael bought this stop watch at Zurich Airport probably 40 or so years ago, as he was involved in car racing.
A closer look… The second recorder hand turns once every 10 seconds, and the movement beats at 36,000 b.p.h., so the stop watch can accurately time 1/10s.
The case back with the reference number C35700.
The top plate of the movement. Only the balance is jewelled.
The bottom plate with the chronograph mechanism. The hammers to reset the second and minute recorder to 0 have pretty impressive spring, and you wouldn’t want to stand in the way of them 😉
The movement looks pristine. No wonder, as Michael has owned the stop watch from new.
The balance with hairspring.
The pallet fork staff isn’t jewelled, either.
The gear train.
That’s a mainspring and a half!
Now I can take the chronograph bits apart.
There is a lot of solidified grease, and that’s what made the watch work properly.
More solidified grease on the column wheel.
Hour and minute recorders.
I give the movement 15 minutes in the cleaning machine to get rid of all the solidified grease.
I start reassembly with the barrel and gear train.
The base movement is beating again, and I can now put together the chronograph.
The movement looks great – clean lines, nice finishes.
I start with the bottom plate.
The hammers are back in place.
The chronograph is complete.
Now I can put the dial ring on.
Time to case the movement.This is a great little stop watch, and probably a very desirable piece for stop watch collectors. It’s great how fast the second hand runs – one turn every 10 seconds. And you can hear the 100 ticks for those 10 seconds very clearly.
As requested, I’ve added a video showing the stop watch in action: