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Acrylic Crystal, Bale shape, convex 2 sides, no luck

KOwatch

By KOwatch
in Watch Repairs Help & Advice

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KOwatch Watch Enthusiast

KOwatch

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I've searched in GS and Sternkreuz with no luck for this crystal.  The old one is very crazed.

28.5mmx25.8mm, I haven't taken the specific radius of the sides or the corners

By Sternkreuz reconing it's Bale shape BX, 4 sides domed, closest I can get there is the BR 285 series:

BR 285X215X285X215
BXR 285X235X250X200
B 285X240X265X210
BR 285X245X245X195
BR 285X250X205X175
BX 285X255X285X255
BZ 285X260X215X160
BR 285X260X220X135 Platine
BR 285X265X150X110
B 285X275X195X175
BR 286X230X261X210 Talon
BR 287X250X262X217

But none of these really look like a winner. Also not sure why the 4 numbers vs 2, and what "Platine" and "Talon" are.

GS doesn't seem to have anything either. Any sources I'm missing? Suggested replacement alternatives?

From a Jean Perret with a 73-4N. Nothing special, just a project.

 

IMG_0166.JPG

IMG_0167.JPG

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KOwatch Watch Enthusiast

KOwatch

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I usually look directly at the GS and Sternkreuz catalogs, I hadn't seen the BB "catalog", thank you for that link.

The document says "supplement", is there an actual main BB catalog? This document is insane, it's scanned crooked, and it has pages of crystals identified by code with no measurements or other information. OK, Ofrei has BB catalogs for sale ($5), is this a real company or a historical catalog of a company that no longer exists?  It looks from these images that BB and Stella are the same catalog.

I'm not too hopeful they'll have a match, now I'm just interested. Does anyone have a story on these product lines?

Perfit seems to still exist selling Casio and other replacement parts from NY.

 

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jdm Distinguished Member

jdm

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On 1/10/2021 at 8:31 AM, KOwatch said:

I've searched in GS and Sternkreuz with no luck for this crystal.

You can't expect a perfect match for any crystal. The question becomes, will be an available one an acceptable fit after filing it to match.

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KOwatch Watch Enthusiast

KOwatch

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Yeah, that's what I was thinking, that I'm in for a custom fitting. I'm usually dealing with round hi-dome crystals and similar, so there's almost always the right size available.

In this case there's nothing really close (within 1mm), and since it's a dome (with sides, like a hi-dome acrylic, but bale shape), filing it more than 1mm will reduce it to a flat, arced section (no sides) . I'll have to check if it has clearance for the hands, then I can just pick a flat, double-arc acrylic and cut it to size.

Has anyone every heated acrylics to increase/decrease the arc radius (or slumping I think it's called in glasswork)?

 

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