Converting 2846 to GMT movement for a vintage build

[Bonesey]

I think this was already discussed elsewhere but thought I'd put together a little pictorial to show what you need to swap over from your donor movement to your low beat movement. You can also do a more complicated swap by taking the balance wheel, pallet fork and escape wheel and replacing them on the 2836 movement to gain a low beat movement.

Here you can see the original 2836 movement on the left. I have removed and replaced the following components with the original swiss parts on the 2846. These are parts that are modified by the chinese factories to allow the GMT function.

Part 2595 - Date Jumper Maintaining plate - This part has been modified slightly to allow for the modified Intermediate Date Wheel

Part 2543 - Intermediate date wheel - This has a small secondary gearing placed atop the original gear. This turns the GMT wheel during the normal cycle of time. It meshes with a gear on the underside of the GMT wheel.

Part 242 - Canon Pinion with Driver - Taller canon pinion to account for the additional GMT wheel.

Part 255 - Hour Wheel - as above, taller to allow for new GMT wheel.

Part 2567 - Day Corrector - originally the part to allow quick setting of the day disc. Replaced with a new bi-directional gear that allows quick setting of the GMT hand.

Seen below is the GMT wheel itself. The upper gearing meshes with the gear running where the day corrector normally would and the gearing on the underside runs off the intermediate date wheel. And finally as installed on the finished movement with the brass washer in place.

 

[flyinmysoup]

Wow. Just Wow. Thanks so so much for this!

 

[glippy01]

Cool pictorial thanks for the illustrated info.

 

[Debellum]

Great Bons !

Junio


?Gathering XXV with Tapatalk 2?

 

[tt88]

Maybe i wouldn't be using this soon but still a big thanks to you.

Really appreciate you spending time sharing tips and info with us.

Sent from my Bezel using 116610

 

[txrob779]

Fellas FYI, my 1675 uses this 2846 with that clone complication....I love it

 

[Bonesey]

That's where this movement is aiming for, a 1675.

 

[rsh]

I think sneed had written something like this up. It is nice work again !! I think you are missing the actual GMT wheel that sits on the new taller center stack right ?

 

[Bonesey]

Yes, but if I added that then you couldn't see the other important details I'll throw a picture up of that so that I've not misled anyone.

 

[rsh]

swapping Asian parts to a low beat swiss movement is brilliant !! You really cant get a better movement for your vintage GMT builds.

 

[txrob779]

The 2846 or even the 2783 are my favorite for gen builds that replicate a 1570, which is actually 19,800.

 

[Bonesey]

swapping Asian parts to a low beat swiss movement is brilliant !! You really cant get a better movement for your vintage GMT builds.

I much prefer doing something like this than having to use a DG4803 movement if I'm honest.

 

[wan]

Anyone building a 6542 from the ground up to have a vintage looking aged build?

 

[aflop]

Great pictorial! We need more contributions like these!

Sent from my MAR-LX2 using Tapatalk

 

[Nivka]

Necromancy is alive and well

 

[maikols]

I changed the minute wheel too becouse it is taller in the 6460 then the stock 2846 . If no change it it is not possible to add minute hands!
It is a simple task to change hour ad minute pinion but it is necessary for the correct size .
After that you need long post second hand too .

My 2 cents