ROO advice (mods-crown/movement/date-window)

[Dan_lie]

Hey Guys,

I was thinking, would it be possible to remove the rotor and basically turn the movement into a 7760 manual wind.

Place the movement lower in the case, weld and drill new crown hole, place a spacer between the dial and movement which would also give it more of a gen sunken date and mod the pushers to work at their original height????

Possible or have i lost it???

 

[Wiz]

How would you fill the old crown hole?

 

[Dan_lie]

The same way sander and everyone else does, weld it closed and drill a new one!

You think it would all work?

 

[Wiz]

Welding without plating? I'm really curious of the result, would you have a link?

That said, the 7750 is unfortunately known for the weakness of its stem, so on the long run I don't think it would be a good idea to manual wind a 7750.

 

[vpx]

Wouldn't it be better to turn down a snugly fitting plug out of stainless that fits into the existing stem hole? You could use the properties of thermal expansion and contraction to get a plug in.

Welding the hole closed would screw up the surrounding stainless and make it look really bad.

 

[guru]

Wouldn't it be better to turn down a snugly fitting plug out of stainless that fits into the existing stem hole? You could use the properties of thermal expansion and contraction to get a plug in.

Welding the hole closed would screw up the surrounding stainless and make it look really bad.

That is a good idea, respect. Welding will not do it, you loose the case. Just talked to an welding expert today. I have all the parts together, I just need to close that hole. Just look at my other posts.

 

[Dan_lie]

So if the hole is filled correctly, is my idea possible?

 

[Wiz]

That filling operation will be really tricky, and even if you can fill the hole, you'll always have a demarcation between the 2 materials.

I'm honnestly wondering if it wouldn't be simpler to get a new case machined.

 

[Dan_lie]

Yes but im trying to make this a cheaper option that getting an lwo movement.

Plus on rwg a few people have filled there cases for lwo projects without problem.

 

[Wiz]

Would you have a link? I'm really curious to see the result.

 

[Dan_lie]

http://www.rwgforum.com/topic/128772-new-franken-ap-lots-of-pics/

http://www.rwgforum.com/topic/123932-do-i-build-franken-aproos/

 

[Wiz]

Thanks

The crown is hiding the filled crown hole but I bet there is visible demarcation between the case material and the filling material.

I wouldn't put that much money in a watch with such a flaw, but if that's ok with you you need to buy some ss stems and a set of threading dies and taps.

 

[Dan_lie]

Im going to look into it, but i mean do you think the whole idea would work? making the 7750 a 7760 and lowering it? it would only be lowering it 00.xxmm down so i doubt it would be noticeable...

I think the hardest part will be somehow extending the hand pins as the dial will need to be pulled from the movement the same distance?

 

[Wiz]

Hum. You would need high cannon pinion, hour wheel, center wheel and chrono wheels.

Tbh I don't even know if these can be sourced. If not you'll need a watchmaker with a lathe to build them for you, and it can end up being quite pricey.

 

[vpx]

I bet there is visible demarcation between the case material and the filling material.

If plugged and subsequently finished properly the border should not be as visible to the naked eye.