Valjoux 72 Chronograph Pusher Screw Head Length

[Chrono15]

Hello all!

 

I am struggling with a repair I have currently. It is a Valjoux 72 Wittnauer, with two broken chronograph pushers. Attached you will find photos.

I have since managed to remove the broken off stems from the pushers, but am at a loss as where to get the screws (shanks?) that will be long enough. The head portion of the screw seems to measure 4mm in length. Here in the states, every parts house seems to be out of stock of all shanks in even 3mm, let alone 4mm.

Any thoughts, input or advice? 

Thanks so much!

[rodabod]

Are you going to re-use those pusher caps by dissolving the remaining threads?

In a pinch, you could cut the plunger threads a couple more turns with a die, assuming the pushers can sit a little closer to the case. 
 

Alternatively, you should just be able to buy complete pusher sets (eg. from Cousins) and reduce the plunger length to suit. 

[Chrono15]

34 minutes ago, rodabod said:

Are you going to re-use those pusher caps by dissolving the remaining threads?

In a pinch, you could cut the plunger threads a couple more turns with a die, assuming the pushers can sit a little closer to the case. 
 

Alternatively, you should just be able to buy complete pusher sets (eg. from Cousins) and reduce the plunger length to suit. 

Correct, I have dissolved the threads already.

I thought about cutting them, but they would indeed sit too close to the case.

I cannot find any pusher sets that have a long enough screw. The head on these is 4mm, the largest is 3mm in all the sets I can find. They don't quite reach the chronograph levers of the movement.

 

[nickelsilver]

I've run across pushers where the screw was capped with a tube, a slip/light friction fit on the screw, adding the needed length. Never seen them for sale though, although I just make the screws when needed so haven't really looked.

[StuartBaker104]

If you don’t have the equipment to make these then it’s not the perfect solution but you may be able to make up what you need from stem extenders. I have some that are tap 9 x tap 9 and the plain section is about 2.5mm long, so you would need to stack 2 of them to make what you need here...

[Chrono15]

51 minutes ago, nickelsilver said:

I've run across pushers where the screw was capped with a tube, a slip/light friction fit on the screw, adding the needed length. Never seen them for sale though, although I just make the screws when needed so haven't really looked.

I will look around for those! Thank you for the insight!

[Chrono15]

7 minutes ago, StuartBaker104 said:

If you don’t have the equipment to make these then it’s not the perfect solution but you may be able to make up what you need from stem extenders. I have some that are tap 9 x tap 9 and the plain section is about 2.5mm long, so you would need to stack 2 of them to make what you need here...

I may try that If I can't find anything. I don't currently have the proper way to make threads on these.

Thank you again for all the help.

[rodabod]

I’m not sure if you could get a stem extender to be short enough, if that makes sense. 
 

If you have a lathe, but don’t want to turn a screw, then you could turn a simple brass sleeve like NS describes and use this with a new plunger. I checked the cousins ones and the screw head is 2.1mm. 

[Chrono15]

14 minutes ago, rodabod said:

I’m not sure if you could get a stem extender to be short enough, if that makes sense. 
 

If you have a lathe, but don’t want to turn a screw, then you could turn a simple brass sleeve like NS describes and use this with a new plunger. I checked the cousins ones and the screw head is 2.1mm. 

Thats beginning to look like the best option, at this point. I think finding a proper size one is a lost cause.

 

Thank you!