ETA / TC 2824 Based Watches Operation Manual

[tc670207]

A member whom just received his TC Sub V6 emailed me asking why ETA / TC 2824 based TC Sub changes date at noon instead of mid night.

 

I thought it was a joke and felt funny in the beginning. Then I realized it was not a joke at all, I decided to write a proper operation manual for all ETA / TC 2824 based watches. Same operation guidline apply to Sellita SW200 as it shared the same design with ETA / TC 2824 movement and thus inherit the same design flaws.

 

 

Let's take this TC Sub V6 (with red second from Yacht Master 16622) as demonstration. There are a total of 3 gears on ETA / TC 2824 movement. But when fully assembled, the watch crown has 4 positions for operations.

 

The first position (as pictured below) is with the crown fully screwed in or screwed tight. Only when the crown is fully screwed tight, the owner should then wear the watch. If the crown is screwed open, dust and water could sneak into the watch and damage the movement.

 

 

The second position is when the crown is unscrewed and popped out. This is actually the fist gear of an ETA or a TC 2824 movement. At this position or gear, the owner could give the movement power by winding the crown in clock wise direction.

 

If you ever want to manual wind the movement to give your ETA / TC 2824 based watch power, be sure to give the crown an additional half turn in counter clock wise direction first after the crown initially popped out to first gear.

 

By doing so would ensure the clutch spring inside the crown to engage to its proper working position. Then you could wind the crown in clock wise direction to give the movement power.

 

If you ever felt the crown slipped when manual winding, be sure to stop, turn the crown in counter clock wise direction for another half turn. Then restart manual winding.

 

Note, if you continued winding the crown when you felt the crown slipping in the beginning, you will most likely destroy the clutch spring inside the crown in no time. This is why whenever a gen Rolex is sent to service, a new crown is replaced.

 

A full wind takes about 24-30 rotations depending on the travel of each turn. Do not go crazy fast just to get the job done. Be sure to wind the movement gently. Although each ETA/TC 2824 movement is equipped with an over-winding protection mechanism, you still do not want to over wind it.

 

If you are a desk top guy and don't generate a lot kinetic energy in your daily routine, laying the watch still in night would most likely let the power reserve run dry. So, wind the crown a few turns in the morning before you wear the watch is totally fine.

 

Although over-winding or winding too many times may cause faster wear on the movement, I'm not asking you to not to wind it. I'm saying wind it whenever after the watch movement runs out of its power reserve and stops. Just be sure the clutch spring inside the crown engages. And be sure to turn the crown in a steady and gentle force.

 

 

The third position is where you could quick set the date by turning the crown in clock-wise direction.

 

Do not, I repeat, DO NOT, quick set date when the watch is in between 19:30 and 02:00. Why? This affects ETA part #2555. Its purpose is to fast jump and advance the date wheel to the next tooth. It advances the date to the next one during mid night.

 

How does it work? By the time flows, ETA part #2555's blade shape spring gradually engages the date wheel's tooth. When time is reaching mid night, it releases all the power the blade shape spring reserved and drives the date wheel a tooth ahead.

 

 

In reality, this changing date process happens at some point between 23:45 to 0:30. Depending on how close the builder mount the hands set on when this date change action takes places. If a builder mount on the hands set spot on the action, the movement jumps date at mid night sharp.

 

Back to the topic why I say DO NOT quick set date when the watch is in between 19:30 and 02:00? This happens. The date wheels tooth touches and pushes #2555's blade shape spring.

 

 

 

Knowing the date wheel is made of a thin stainless steel sheet and ETA part #2555's blade shape spring is made of bronze, the dates wheel's teeth wear out #2555's blade shape spring every time they run over.

 

So if you quick set the date when in between 19:30 and 02:00, you will eventually damage ETA part #2555. Then this part will lose its capability to advance date. When this happens, there is no other fix but to replace ETA part #2555 by dissecting the watch movement, then build the watch all over again. No one wants that to happen. This is an ETA part #2555 with the blade shape spring being damaged.

 

 

The fourth position is where you could adjust time. When the crown is in this position, the movement hecks, and the second hand stops.

 

You could set the time by turning the crown in clock wise direction or counter clock wise direction. It won't break the movement.

 

However, NEVER set time backwards across mid night. Why? Same reason #2555's blade shape spring will travel backwards and touches the date wheel's teeth and then be run over by the date wheel's teeth, causing damage to the bronze blade shape spring.

 

Sometimes you could not pull the crown all the way and let the movement to clutch in. Thus the second hand still moves. This happens. DON'T panic. Just push back the crown to position 2 and pull it to position 4 again.

 

 

So, how exactly is a good way to set time and date?

 

I would:

 

1. pick up the watch and turn the crown open, give the crown an additional half turn to let the spring inside the crown to clutch in. Then wind the movement in a few gentle and steady turns to kick start it.

 

2. pull the crown all the way to the 4th position, and advance the hands set to jump over mid night until the hands set indicates 2:00.

 

3. push back the crown a clutch back to position 3. Quick set the date to the date a day before current date.

 

4. pull the crown all the way to the 4th position again. Then advance the hands set to jump over mid night and set time to the current time. This way I get my watch in the correct date and in correct time.

 

If the current time is in the afternoon, I will make sure the hands set passes 12:00. So my watch does not change date at noon :-)

 

 

That's all. The logic is really simple and straight forward. If you always operate your ETA or TC 2824 based watch in correct method, expect your watch to have a way much longer period between each service than your car does. That is, you would only need to send your ETA or TC 2824 based watch to service every 3 to 5 years.

 

Thanks for reading.

 

TC

 

9/10/14