Watch Jewels

[david pierce]

Paul,
Was Otto Frei able to supply the jewels you needed?
david

[arutha]

Hi David,
looks like they have a good selection, the slight problem I have is measuring the old one, it came out in tiny pieces so I need to get one out of another watch I have with the same movement and measure it. I will let you know what happens
Paul.

[Bob Tascione]

Hi Paul,
Might try turning a quick pin or go-no-go guage that fits the recess and measure that O.D. Would also be good to try and locate an assortment or gross of cap jewels…you’ll use them a lot!

Enjoy,
Bob

[david pierce]

Paul.
If you have a milling machine with a cross slide and a decent dial indicator you might be able to measure it in the watch or measure the hole in the pilar plate. If you put an extremely fine point in the spindle, line it up with one side of the hole, zero in the dial indicator to measure the cross slide movement and crank the point to the other side of the hole, it might be close enough for watch work.
david

[david pierce]

Paul,
I know this idea is out there but here goes. If you have a piece of clear plastic acrylic rod about 1/4 inch in diameter, you can make a homemade spotting scope with it. Cut the rod to a short length, about 3 to 6 inches, polish one end flat and the other end convex. Then take a scribe and scratch two crossed lines on the convex end. Next rub a black colored magic marker on the convex end and polish it. This should leave the black only in the scribed lines. When you look into the flat end you will now have a very accurate spotting scope. Since the rod is plastic it can be heated and bent to a convient viewing angle. Fixture it in your mill and line use the procedure I described with the fine point. This should give you a very accurate measurement.
david

[arutha]

Thanks David,
I will try and locate some, what a great idea!

[david pierce]

Paul,
Anything that can magnify the measurment locations and can provide a reference marker on the lens will work. A dial indicator on the movement bed will provide the most affordable way to measure extremely accurately. If you have a cheap high power loupe laying around that should also work. Pull out a hair and put it across the lens. Rifle scopes use Black Widow Spider Web for the crosshairs. Since you are using this for a linear measurement and not trying to locate a center, the eyepiece can be located in an offset position from the spindle. As long as you don’t bump it it should work.
david

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