I am trying to figure out how the winding mechanism works on a Waltham 8 Day Aircraft clock & if perhaps I am missing a part or something.

The winding knob which is attached to the case has a spring on the shaft near the bezel end of the case, then there is a gear that when you pull out on the knob this gear engages the hands & the time can be set.

Next on the shaft is a clutch, then the winding pinion. Then the cap that screws onto the case.

The problem I am having is the winding pinion just slips on the clutch & will not wind the movement.

Any suggestions, am I missing something that goes after the winding pinion to keep it engaged on the clutch?

I tried to take some photos of what I am talking about.

First the movement itself.

Looking into the rear of the case at the winding shaft

The clutch, winding pinion & cap.

Thanks for any help you might give.

Tom

GREETINGS TOM, YOU HAVE A SPRING MISSING, IF I REMEMBER CORRECTLY YOU WIND THE CLOCK IN THE UP POSITION AND SET IT IN THE DOWN POSITION CONSEQUENTLY THE SPRING WOULD SLIP ON SO IT FITS BEHIND THE CLUTCH SHOULDER. I MAY HAVE A SPRING IF I DO YOU CAN HAVE IT. EDDIE

Thanks Eddie, if you have one that would be great!

Tom

Here is a photo of the clock back together minus the missing spring.

About when were these made, the serial number on the movement doesn't return any info in the Waltham database. The serial number is 33865048 & the movement is marked 22 S-8 Day 11 Jewels

Tom

The style of clock is called the A-11. They were produced in the 1940s and early 1950s. Most of them were WW II era make military aircraft panel clocks, but there are post war ones as well. These are all well marked with a military plate on the back. Often they are also well marked with printing in black paint on the black dial. I can see the Waltham name there in the black paint, but the hands are in the way for me to read what is printed above that in black paint.

Sorry about that Jim, it is marked AN5743-L2. There is no plate on the back.

Tom

AN5743 is one of the standard set of specs for A-11 instrument panel clocks of the 1940s and 1950s by the major watch/clock makers, including Waltham, Longines, Elgin, etc. While most of these were used on instrument panels, some were also used in other areas of the aircraft.

The L in the appendix number to the AN5743 means it is the variety that was delivered with the extra long winding knob as opposed to the regular shorter winding knob. It is a shame that the military data plate is missing from the back of your case as that would have provided additional information that could have nailed down more information. Howeer, I did a quick look up of the serial number and from what I can see it appears that the movement was made between 1953 and 1954 and so it is likely the clock would have been delivered to the Air Force around 1954 or maybe 1955.

You can buy manuals for these on Ebay. Just be sure you find one for the -L2 variety as there are differences among the varieties of these.

Thanks Jim

I cleaned it & it has been keeping time up to the minute since Tuesday.

I do need the spring that goes on the back end of the winding stem, I can't wind it with the knob right now without the spring.

Or if someone could post a photo of the missing spring with it's measurements perhaps I could make one.

Thanks again

Tom

Member Mack Davis kindly sent me the missing spring & now the clock is running great, I like the 8-day part to it. I won't have to remember it everyday.

Tom

Tom,

Now that you have it working. You need to re-mount it in the aircraft and use it to navagate your way across the US. I had that happen, but fortunatly the pilot was only joking but wanted it to restore the originality of the aircraft. It still works, but I guess I am just not that confident my old "stuff."

Great job!

Ken

Wish I could Ken.

When I was a kid before I joined the Army, I had a brother-in-law that owned a flight school & I use to go flying everyday with him. He offered to give me free flight lessons so I could get my license. But being a young kid with my only interest being getting out of town & on my own I passed up the chance & joined the Army instead of being drafted