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Why the CHS GMT movements are failing

Dr Fun Socks

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Well we see where they got the idea from. Could always break that spindle off the 2824 movement and drill a little hole in the plate, haha.

Haha i like the idea but id rather buy a whole new bloody watch and sell the bits i dont need for that kind of money! On a side note im 99% sure the issue with my movement is that the intermediate date wheel is rising up. As before gmt and minute hands have kept time, the hour stopped at 7 last night and still hasnt moved, and neither has the date. Going to try and work out the distance from the underside of the dial and shim the hell out of it.
 

KJ2020

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Haha i like the idea but id rather buy a whole new bloody watch and sell the bits i dont need for that kind of money! On a side note im 99% sure the issue with my movement is that the intermediate date wheel is rising up. As before gmt and minute hands have kept time, the hour stopped at 7 last night and still hasnt moved, and neither has the date. Going to try and work out the distance from the underside of the dial and shim the hell out of it.

Something like this with a dial dot on the underside of the dial. It's a decorative cover for rotor screw.

There would be concern for too much pressure causing slow down from dragging, and for parts erosion casing debris. Maybe a really slick piece of plastic like a piece of credit card.

ZWUlS.jpg
 
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Dr Fun Socks

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Something like this with a dial dot on the underside of the dial. It's a decorative cover for rotor screw.

There would be concern for too much pressure causing slow down from dragging, and for parts erosion casing debris. Maybe a really slick piece of plastic like a piece of credit card.

ZWUlS.jpg

If i had that piece id be cooking on gas! Its bloody hard to measure the exact distance between the dial and the wheel, but i put a microscope bit of rodico on the wheel and pressed the dial down firm. Its very similar in hight to a 0.2mm shim, which coincidentally is the thickness of the gmt wheel...



So ive got a sheet of 0.15mm shim i was going to make the spring replacement from. Just knocked up a small plate (drew a circle around the wheel when it was rodico’d to the dial). Should leave 0.05mm which is obviously nothing but if it all goes tits up ill just use acetone to get the shim off the back of the dial. Holding it in a vice without messing up the dial of feet will be hard but ive got an idea!
 

Dr Fun Socks

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So this is my attempt. I hope it works because its going to be a real pain in the ass to get off if it doesnt haha. When the epoxy is set tomorrow ill give an update.


 

KJ2020

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If i had that piece id be cooking on gas! Its bloody hard to measure the exact distance between the dial and the wheel, but i put a microscope bit of rodico on the wheel and pressed the dial down firm. Its very similar in hight to a 0.2mm shim, which coincidentally is the thickness of the gmt wheel...
That's the hour wheel I tell ya! :cool:

Great job measuring that distance. I might try drilling a center hole and epoxying a small piece like the rotor screw cover or a tiny washer on top of the IDW. With a hole in the middle of it, I can make sure it's free of glue and if it's too thick, sanding it down some is a snap.

There's potential advantage to the way you did it though, in that if there is incidental contact, there is virtually no risk of separation due to rotational shear.

DG2813s use this washer trick to keep the setting wheel gear from popping up. You can see in the pic I put the washer on upside down and there is wear on it from being forced up and the setting wheel grinding on it.

ZWx7R.jpg

ZW0LQ.jpg


When you do your next dozen or so repairs after we prove this works, clamping the sheet to the back of the dial can also be done this way. Dial protector on your bench, dial face down, crystal die, then weight. I use this concept to glue new dial feet on. The dial face never touches anything, it is held off by the markers.

ZWbrL.jpg

.
 
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Dr Fun Socks

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That's the hour wheel I tell ya! :cool:

Great job measuring that distance. I might try drilling a center hole and epoxying a small piece like the rotor screw cover or a tiny washer on top of the IDW. With a hole in the middle of it, I can make sure it's free of glue and if it's too thick, sanding it down some is a snap.

There's potential advantage to the way you did it though, in that if there is incidental contact, there is virtually no risk of separation due to rotational shear.

DG2813s use this washer trick to keep the setting wheel gear from popping up. You can see in the pic I put the washer on upside down and there is wear on it from being forced up and the setting wheel grinding on it.

ZWx7R.jpg

ZW0LQ.jpg


When you do your next dozen or so repairs after we prove this works, clamping the sheet to the back of the dial can also be done this way. Dial protector on your bench, dial face down, crystal die, then weight. I use this concept to glue new dial feet on. The dial face never touches anything, it is held off by the markers.

ZWbrL.jpg

.

Honestly if i had a punch and die that small, or a screw cap that would fit I probably would of tried it. I guess the only worry doing it that way is the hour wheel could float up but its nothing a dial copper spring washer wouldnt fix. Fingers crossed it will be the last time i have to take the bloody thing apart! Ill probably never repair one again, im no pro watch maker like you im just a tool maker who likes to solve problems. Recently very tiny fiddly problems! I am tempted by your quick date fix idea but it will live on a winder with my other gmt and hopefully i wont need to change the date more often than every other month. Im happy to try and make the hour wheel interlocking mech should the glue ever fail though. Between that and the hour wheel problem thats pretty much the chs thing cracked? I know the hour wheel wont be independently adjustable but it seems a small sacrifice for a working movement! Good call on the clamping mechanism though, my way is pretty ghetto, but it works!
 
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KJ2020

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Ha, no pro watchmaker here bro. Just a dedicated hobbyist with a lot of time (pieces) on my hands. Or is it a lot of hands on my time, hehe. I've picked up a few things from you, problem solving is at the very heart of watchmaking. To your point about the hour wheel floating, I think the GMT hand hole surround should keep that from happening. So once the IDW is made to stay down, this has got to work.
 
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KJ2020

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If this works, I think you should do the quickset date fix. That's another significant improvement that will really make this worthwhile. Double bonus! I'm waiting on some files, will practice on a spare plate first but I think this is able to be completed easily enough.
 
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Dr Fun Socks

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Ha, no pro watchmaker here bro. Just a dedicated hobbyist with a lot of time (pieces) on my hands. Or is it a lot of hands on my time, hehe. I've picked up a few things from you, problem solving is at the very heart of watchmaking. To your point about the hour wheel floating, I think the GMT hand hole surround should keep that from happening. So once the IDW is made to stay down, this has got to work.

Well fair play sir you make it look easy! Its amazing how quick you pick it up though. I think i just got bored of crawling around on the dining room floor looking for the bloody screw i dropped so i upped my game :p its really bloody fun when you get it working though, id take a watch ive dinged and scraped up but made work myself over a fresh new one from a td any day. Yeah your right good thinking! Cant wait until this glue is set haha!

Not sure if you’ve ever opened up a dual retrograde split second dual time zone watch but i had a go, im sure as a fellow movement guy you’ll enjoy the way they get it to work :)
https://forum.replica-watch.info/fo...it-retrograde-second-repair-movement-nerd-out
 
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KJ2020

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Well fair play sir you make it look easy! Its amazing how quick you pick it up though. I think i just got bored of crawling around on the dining room floor looking for the bloody screw i dropped so i upped my game :p its really bloody fun when you get it working though, id take a watch ive dinged and scraped up but made work myself over a fresh new one from a td any day. Yeah your right good thinking! Cant wait until this glue is set haha!

Not sure if you’ve ever opened up a dual retrograde split second dual time zone watch but i had a go, im sure as a fellow movement guy you’ll enjoy the way they get it to work :)
https://forum.replica-watch.info/fo...it-retrograde-second-repair-movement-nerd-out

Very interesting thread bro. That's a beautiful and unique piece! Nice work!
 

Dr Fun Socks

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Nope. You're not going to find a stock part to fit these movements. They're custom designs.

Ah balls! Well i hope mine holds up in the long run. It could turn out to be the only reliable part of the movement... oh wait, it’s already needed modification!
 
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Dr Fun Socks

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So a little update, no joy! in fact the hour hand now skips whilst winding! As annoying as that is i didnt have to wait hours to see if the bloody hour hand stopped. Weird thing is it was always roughly around 3 oclock and around 7 oclock it stopped. Last chance saloon before i throw the bloody thing away is go through every tooth of ever wheel related to the problem, and check side to side play in the intermediate date wheel. Im rapidly losing hope of ever getting it to work! I checked the plate to check its parallel, its within 0.02 mm, total height is 0.19mm +/-0.01. Seems like it cant be vertical play but never say never i guess!

ZrycI.jpg


i did however however get some macro lenses so just to put a bright note to a depressing post, you’ve got to love a blue hair spring!

 
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