Post by Fergus on Jun 13, 2024 0:34:35 GMT -8
A very common and well documented issue with 2.5mm diver's bars.
The cause,
a) the spring bar tips are 1.1mm diameter while the lug holes are 1.3mm diameter.
b) the inside surface of the lugs may not be the best surface finish.
c) the hole has not been deburred to the best of their ability.
I assume a) is to eliminate tolerance errors when fitting bracelets with machined end links. It's not an issue with rubber/leather/nato straps other than the click is heard when these are fitted. Also the holes have to be larger because when fitting straps it's common to introduce one end first so the bar will be at an angle. We know that a pin will only enter a hole normal (close to 90) when holes are fit for fit. Ref my 3rd cure.
The Issue
The slack tip allows the bar to move resulting in the pin shoulders rubbing the inside of the lugs. This movement results in a metal to metal click. Most of the sound is from the rubbing of the shoulder against the lug surface. This sound may be double depending on their surface finish. On the watch I have been diagnosing, an SPB079, it has one well finished surface and one not so.
The Cure
The optimum cure is to have pins with 1.25 tips but that is not feasible unless someone knows of a manufacturer.
Added to this is to rework the inside of the lugs to a better surface finish. Again not easily accomplished and it may introduce odd lug widths. Included in this would be to correctly deburr the inside holes.
Solution...otherwise known as a quick fix.
Add a cushioning device (rubber/plastic) between shoulder and surface.
Using materials to hand.
Rubber gaskets.
PTFE film shims.
Both successfully cure the issue.
The gaskets might be a little thick at 0.5mm but Cousins have micro rings 2.05 x 1.1 x 0.3 (G61411) which I am going to try.
The ptfe shims are not easy to make so for most are out.
3rd Cure...bush the lug holes to bring them closer to 1.1mm diameter.
It's all good clean fun.
Happy Tinkering.
The cause,
a) the spring bar tips are 1.1mm diameter while the lug holes are 1.3mm diameter.
b) the inside surface of the lugs may not be the best surface finish.
c) the hole has not been deburred to the best of their ability.
I assume a) is to eliminate tolerance errors when fitting bracelets with machined end links. It's not an issue with rubber/leather/nato straps other than the click is heard when these are fitted. Also the holes have to be larger because when fitting straps it's common to introduce one end first so the bar will be at an angle. We know that a pin will only enter a hole normal (close to 90) when holes are fit for fit. Ref my 3rd cure.
The Issue
The slack tip allows the bar to move resulting in the pin shoulders rubbing the inside of the lugs. This movement results in a metal to metal click. Most of the sound is from the rubbing of the shoulder against the lug surface. This sound may be double depending on their surface finish. On the watch I have been diagnosing, an SPB079, it has one well finished surface and one not so.
The Cure
The optimum cure is to have pins with 1.25 tips but that is not feasible unless someone knows of a manufacturer.
Added to this is to rework the inside of the lugs to a better surface finish. Again not easily accomplished and it may introduce odd lug widths. Included in this would be to correctly deburr the inside holes.
Solution...otherwise known as a quick fix.
Add a cushioning device (rubber/plastic) between shoulder and surface.
Using materials to hand.
Rubber gaskets.
PTFE film shims.
Both successfully cure the issue.
The gaskets might be a little thick at 0.5mm but Cousins have micro rings 2.05 x 1.1 x 0.3 (G61411) which I am going to try.
The ptfe shims are not easy to make so for most are out.
3rd Cure...bush the lug holes to bring them closer to 1.1mm diameter.
It's all good clean fun.
Happy Tinkering.
