Chronograph centre seconds hand tube height

[Pedro]

Hi everyone, I have just visited the Cousin's parts website to purchase a chronograph centre seconds hand. They state the length and the tube size they stock but not a height size. The tube height I need is 1 mm, am I missing something? They have a height size for ordinary seconds hands.

Regards.

[Poljot]

25 minutes ago, Pedro said:

Hi everyone, I have just visited the Cousin's parts website to purchase a chronograph centre seconds hand. They state the length and the tube size they stock but not a height size. The tube height I need is 1 mm, am I missing something? They have a height size for ordinary seconds hands.

Regards.

I believe there are only two options: with or without the tube. Tube height should not vary.

[Poljot]

My assumption is based on my previous project with 1973-ish automatic Timex :-).

There were two options listed for the Central Second Hand (no-no-no, it's not a Chronograph

- with tube (no length variations)

- tubeless

[Pedro]

The Chronograph is a 'Lea' mechanical which I just received today, I think it's from the 1940's. I will post some pics tomorrow morning. The original centre seconds hand is a bit loose so when the fly back button is pressed it doesn't quite return to top dead centre...a couple of seconds to the right or left depending which side of the dial the hand is located when the return button is pressed. I would rather keep the original as a brand new hand would look out of place. Is the tube height a standard length for all vintage mechanical chronograph's? As I said I will post pics tomorrow.

Regards

[Poljot]

11 minutes ago, Pedro said:

The Chronograph is a 'Lea' mechanical which I just received today, I think it's from the 1940's. I will post some pics tomorrow morning. The original centre seconds hand is a bit loose so when the fly back button is pressed it doesn't quite return to top dead centre...a couple of seconds to the right or left depending which side of the dial the hand is located when the return button is pressed. I would rather keep the original as a brand new hand would look out of place. Is the tube height a standard length for all vintage mechanical chronograph's? As I said I will post pics tomorrow.

Regards

It sounds as you simply need to remove the central hand, align it properly and press down carefully. You may, which i doubt at this point, need to tighten the tube slightly if it's lose. This will require some skills and basic tools as it is so easy to crash the tube if you use too much force. Replacing the tube is very challenging for majority of hobbyists (that would be me )

[Pedro]

19 minutes ago, Poljot said:

It sounds as you simply need to remove the central hand, align it properly and press down carefully. You may, which i doubt at this point, need to tighten the tube slightly if it's lose. This will require some skills and basic tools as it is so easy to crash the tube if you use too much force. Replacing the tube is very challenging for majority of hobbyists (that would be me )

Hi Poljot, thanks for the reply, I did remove the hand  and aligned it and then tested it and it returned to top dead centre if the hand was positioned at about ten seconds either side to the 12 O'clock marker. Any more than that and the power of the flyback would shift the seconds hand slightly out of alignment, so I believe the centre seconds hand tube has become slightly worn and is unable to to withstand the force. 

[Poljot]

1 hour ago, Pedro said:

Hi Poljot, thanks for the reply, I did remove the hand  and aligned it and then tested it and it returned to top dead centre if the hand was positioned at about ten seconds either side to the 12 O'clock marker. Any more than that and the power of the flyback would shift the seconds hand slightly out of alignment, so I believe the centre seconds hand tube has become slightly worn and is unable to to withstand the force. 

You maybe right as there are two possible scenarios in my opinion:

a. tube ID is slightly larger than it used to be. In this case you can simply squeeze it a tiny bit (this would be a suitable tool for this task https://www.watchmaterial.com/bergeon-5679-pin-vice-stem-holder/ )

b. you did not push the Central Hand deep enough. Push it gently down right in the centre using proper tool or a sharp pegwood (do not use tweezers or you will leave scratches) 

Edited December 18, 2020 by Poljot

[Pedro]

I will go for option a. I want to keep the watch as original. All the hands are coppered coloured wether by design or age. Replacing the centre seconds hand with a brand new shiny gold finish from Cousins would ruin it. Many thanks.

[Poljot]

12 minutes ago, Pedro said:

I will go for option a. I want to keep the watch as original. All the hands are coppered coloured wether by design or age. Replacing the centre seconds hand with a brand new shiny gold finish from Cousins would ruin it. Many thanks.

You are very welcome and good luck!

You may want to take and share a good photo showing the bottom of the second hand tube and another one showing if pivot is worn.

[Pedro]

Some pics of the watch. Still don't know if I buy a new centre seconds hand from Cousins if the tube lengths are all the same. This one is 1mm long.

[praezis]

Hi,

look carefully at your tube: if it is cracked, it will never more sit tight. If there is no crack, you can tighten it with care (e.g. in a lathe chuck).

Sweep second hands have rather short tubes, chronograph hands should have a long tube.

You are sure that the hand is moving on its pivot? The same sloppy reset will show if the hammer was not properly adjusted. 

Frank

[Pedro]

Hi Frank, the watch is in very good working condition and the centre seconds hand is working as it should. It is just the power of the flyback that is sending it out of alignment. The tube is not cracked but I did notice that the hand sits well on the pivot but not what you would call snug.

[Poljot]

4 hours ago, Pedro said:

Some pics of the watch. Still don't know if I buy a new centre seconds hand from Cousins if the tube lengths are all the same. This one is 1mm long.

You should be able to see the tip of the pivot through the hole in Central Seconds hand tube.

If you don't - probably you did not press it down enough.

Take a side-view photo so we could see the space between Hour, Minute and Central seconds hands.

[Poljot]

In this example, the Central Seconds hand has not been pushed down enough.

[Pedro]

8 hours ago, Poljot said:

You should be able to see the tip of the pivot through the hole in Central Seconds hand tube.

If you don't - probably you did not press it down enough.

Take a side-view photo so we could see the space between Hour, Minute and Central seconds hands.

Thanks to everyone for their input. I have decided to replace the centre seconds hand from Cousins and re copper it. Then I will reilluminate the minute and hour hands and the hour plots.  Also I will  treat it to a brand new Hirsch strap!.

[Jakub]

Hi I am just going through same thing with pretty much same watch. I have mine with Landeron 51 and measured dial side end of pin 0,29mm. Cousins provide hands up to 0,27mm. So just a friendly reminder that if have the same measurement, note you will have to drill 0,01mm of and fine tune with broach. Excellent process explanation was provided in this thread 

 

cheers 

 

Edited December 19, 2020 by Jakub