Need help from the pro’s on a double roller

[Nookster]

I recently took up staffing.

My question is, on some of the staffs for a 987 Hamilton, the roller jewel goes on and is tight. When I put the guard on, it will not tighten and remIns loose. If I try to tighten too hard, the guard cracks. I have done approx 20 or so, but the last few won’t tighten at all and will just slip off after I have attempted to tighten it with the staking set.

I used a platax tool to remove the rollers and old staff. Any help is appreciated on how to tighten these.

 

[Jim Haney]

I have also run into this with the safety roller.

They are so hardened that any attempt to reduce the hole size with a stake is useless because they will shatter.

Watch makers are told not to use super glue or anything like that, so I use some bristles from a brass brush to use as a spacer so when you stake it it will stay in place. I believe the problem is caused by improper sized replacement staffs.

 

[Nookster]

Thanks Jim. Good idea, but I assume bristles are difficult to trim? I will give it a shot. Glue might work, but will it truly hold for years?

Wish they did a single roller on the 6/0’s and other grades. While I was taking off the rollers and de-staffing my balances, I did find one Hamilton 987 with a single roller. I saved it and will test it one day. If it works, it will just make me wonder where the watchmaker got it from.

Thanks again

 

[John Runciman]

My question is, on some of the staffs for a 987 Hamilton,

If you measure the original and the replacement do they measure the exact same size?

Watch makers are told not to use super glue or anything like that, so I use some bristles from a brass brush to use as a spacer so when you stake it it will stay in place. I believe the problem is caused by improper sized replacement staffs.

I was told by my watch instructor in school the use a hair but I always find hair size tends to vary. I think I'd be a little concerned about using brass wire unless it was really fine may be a really fine copper wire superfine perhaps then of course there's some sort of glue that could be used but I'm not going to say which one.

It does present an interesting problem as the rollers typically are superhard and they do not like to be modified.

 

[DeweyC]

If you measure the original and the replacement do they measure the exact same size?


I was told by my watch instructor in school the use a hair but I always find hair size tends to vary. I think I'd be a little concerned about using brass wire unless it was really fine may be a really fine copper wire superfine perhaps then of course there's some sort of glue that could be used but I'm not going to say which one.

It does present an interesting problem as the rollers typically are superhard and they do not like to be modified.

I once had a conversation with Marvin Whitney about repivoting and Loctite. His comment was that had Kullberg access to modern adhesives there was no doubt in his mind that Kullberg would have used them. Technological advances are what interested these guys, not keeping within tradition.

Sticking something into the rollers is fundamentally wrong; the roller will be off center and will act like a cracked roller with varying degrees of safety clearance which can lead to timing problems (dart touching roller) which will then lead some to open the banking pins. While small and near the center of gyration, it also adds a point mass which impacts precision timing.

There are various formulations of Loctite to deal with degrees of fit on shafts. I have used the red to deal with safety rollers (especially the irreplaceable Waltham) when the fit was close but not good.

Other times, you just have to make a new staff or alter one.

Superglue is inappropriate because the next guy will not know to use acetone and on jewels (such as pallets) it makes adjustment problematic.

 

[Karl Burghart]

I have had much better luck with Locktite "sleeve retainer compound" I mostly use when repivioting and crowns. It sets quickly. I've found the other Locktite formulas just don't hold as well.

 

[gmorse]

Hi Karl,

There are just so many different Loctite products which are designed for varying degrees of clearance and permanence. I've used 638 as 'belt and braces' for some things such as centre arbor replacements and re-pivoting in the past, and never had any trouble. I agree with Dewey, if it's a sensible complement to good workmanship and not an attempt at compensation for its absence, I see no problem in using it.

Regards,

Graham

 

[Nookster]

I did not measure the staffs. I only had this issue on about 2/10.

I appreciate the help. So as a group, which glue did we decide on? Lol

 

[Al J]

Hi Karl,

There are just so many different Loctite products which are designed for varying degrees of clearance and permanence. I've used 638 as 'belt and braces' for some things such as centre arbor replacements and re-pivoting in the past, and never had any trouble. I agree with Dewey, if it's a sensible complement to good workmanship and not an attempt at compensation for its absence, I see no problem in using it.

Regards,

Graham

638 is also commonly used for case parts, such as press fitted case tubes, pushers, and correctors:

Cheers, Al

 

[viclip]

I'm surprised that you guys don't use liquid shellac to adhere parts together.

Shellac was the adhesive of choice back in the day of fountain pens, used on metal, rubber & plastic parts. Believe me, it forms quite the strong bond!

A real advantage of shellac is that it softens around 140 degrees Fahrenheit & the pieces then come apart easily. That level of heat won't even harm vintage plastics thus making it a safe & convenient produce to use.

If anyone knows of any downside to using liquid shellac in watchmaking I'd like to know ... thanks!

 

[Nookster]

Thanks. Will give it a shot.

I appreciate all your help