• Tired of adverts on RWI? - Subscribe by clicking HERE and PMing Trailboss for instructions and they will magically go away!

Why the CHS GMT movements are failing

KJ2020

Time Traveler
Supporter
12/3/18
34,661
66,750
113
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!

Yep, noticed the hairspring, nice touch. REMOVE the date corrector and the 2 intermediate wheels and see if that stops the hour hand moving while winding. If those are still in place, you have a link to the hour wheel from the setting wheel in crown position 2, and you might have a sloppy keyless halfway toward position 2.
 

KJ2020

Time Traveler
Supporter
12/3/18
34,661
66,750
113
BTW, please don't throw it away if you give up! I can use it for further investigation. My GMT wheel is pretty damaged, I am trying to fix it.
 
  • Like
Reactions: kennygconspiracy

Dr Fun Socks

I'm Pretty Popular
Supporter
Certified
28/2/17
2,382
1,951
113
Yep, noticed the hairspring, nice touch. REMOVE the date corrector and the 2 intermediate wheels and see if that stops the hour hand moving while winding. If those are still in place, you have a link to the hour wheel from the setting wheel in crown position 2, and you might have a sloppy keyless halfway toward position 2.

Ok cool man ill give it a go later. Its just bloody annoying, I've never taken a watch apart and put it back together so many times with no success! You think you’ve got the fix sorted then POW still a shit movement. Don't worry i wouldn't really throw it away, if i really do get to the end of my tether its yours!
 
  • Like
Reactions: KJ2020

KJ2020

Time Traveler
Supporter
12/3/18
34,661
66,750
113
I got the quickset date feature to work. I just scratched out an outline with the tip of a file and filed it out. Only took a few minutes, a thin mainplate is no match for a diamond file. It's not as pretty as my next one will be, but it works. My files were medium grit, fine grit would take longer but would look better. Really should be done with a 600 grit file. It's not a visible groove, but I like to do closer tolerance work.

I had to switch to a regular 2824 minute bridge, with the support arm to press the date corrector down. That reminded me that 2836 date jumper maintaining plates sometimes come with a similar anchoring extension to hold the IDW down. I might try that approach next.

Some pics.

Zpk8i.jpg


ZpdAX.jpg


Zpmjk.jpg


​​​​​​​
ZpoOo.jpg


ZpavD.gif
 
  • Like
Reactions: Vvvlllooo

Dr Fun Socks

I'm Pretty Popular
Supporter
Certified
28/2/17
2,382
1,951
113
I got the quickset date feature to work. I just scratched out an outline with the tip of a file and filed it out. Only took a few minutes, a thin mainplate is no match for a diamond file. It's not as pretty as my next one will be, but it works. My files were medium grit, fine grit would take longer but would look better. Really should be done with a 600 grit file. It's not a visible groove, but I like to do closer tolerance work.

I had to switch to a regular 2824 minute bridge, with the support arm to press the date corrector down. That reminded me that 2836 date jumper maintaining plates sometimes come with a similar anchoring extension to hold the IDW down. I might try that approach next.

Some pics.

Zpk8i.jpg


ZpdAX.jpg


Zpmjk.jpg


ZpoOo.jpg


ZpavD.gif

It worked! Well done mate! Skeletonised gmt movement next or leave that to micasol... I think most people would take a quick set date over an adjustable gmt hand, i imagine the majority of people dont have a winder so going through the days is so looong! Do you think the 2836 plate would fit without interference with the hour wheel? 2824 one looks perfect for the job because its half the size but does the same job.
 

KJ2020

Time Traveler
Supporter
12/3/18
34,661
66,750
113
It worked! Well done mate! Skeletonised gmt movement next or leave that to micasol... I think most people would take a quick set date over an adjustable gmt hand, i imagine the majority of people dont have a winder so going through the days is so looong! Do you think the 2836 plate would fit without interference with the hour wheel? 2824 one looks perfect for the job because its half the size but does the same job.

Sorry bro, I didn't mean uae the 2826 minute bridge, I meant the 2836 date jumper maintaining plate.

ZCzLQ.jpg


The 2836 versions have an extension that covers the IDW gears and holds them down. But I just tried it and that extension is not long enough because the bottom gear on the CHS IDW is so small. So nevermind. We're back to an IDW shim or a dial underside shim. Where did you get your .15 mm metal? You did such a nice job on that, Id like to see it work - no rotational shear worries.
 

DiverFan

Active Member
17/11/13
426
13
18
HK
Would anyone happen have a spare of this spring, broken or not? I am interested to take stab at drafting it and seeing what it would cost to tool replacements out of a higher quality material.
 

Dr Fun Socks

I'm Pretty Popular
Supporter
Certified
28/2/17
2,382
1,951
113
Sorry bro, I didn't mean uae the 2826 minute bridge, I meant the 2836 date jumper maintaining plate.

ZCzLQ.jpg


The 2836 versions have an extension that covers the IDW gears and holds them down. But I just tried it and that extension is not long enough because the bottom gear on the CHS IDW is so small. So nevermind. We're back to an IDW shim or a dial underside shim. Where did you get your .15 mm metal? You did such a nice job on that, Id like to see it work - no rotational shear worries.

Man not as much as id like to see it work! Still no joy! Hour hand got stuck around 7 again :( and now the second hand has started with some funny business going forward a few ticks then backwards a few ticks. Ill open it up again when i get back from work but its looking like its a bit out of my capabilities to get this hunk of junk working! I got my shim from the bay, only £2.55 delivered in the uk.
https://www.ebay.co.uk/itm/0-006-qu...S-POST-/253790710252?du=1&txnId=2511564077015


Would anyone happen have a spare of this spring, broken or not? I am interested to take stab at drafting it and seeing what it would cost to tool replacements out of a higher quality material.

Sorry man i have only got the one epoxied in my watch at the moment. If the bond breaks ill clean it up with acetone and send it over.
 
  • Like
Reactions: DiverFan

KJ2020

Time Traveler
Supporter
12/3/18
34,661
66,750
113
Man not as much as id like to see it work! Still no joy! Hour hand got stuck around 7 again :( and now the second hand has started with some funny business going forward a few ticks then backwards a few ticks. Ill open it up again when i get back from work but its looking like its a bit out of my capabilities to get this hunk of junk working!

Wow that's so bizarre. you did take off the two intermediate wheels? i think those could definitely cause some trouble buckling the IDW up. i'm going to service mine tomorrow. The movement isn't running but I have enough spare parts to make a whole new movement if I have to. I got the GMT wheel cleaned up and reconnected using staking tools. I put two hands on it and everything is rotating smoothly with the crown like it should. I didn't even glue the GMT halves together and the hour/GMT wheel rotation is spot on. I wonder if your date wheel driving wheel is a factor? Maybe take it off if you haven't.
 

Dr Fun Socks

I'm Pretty Popular
Supporter
Certified
28/2/17
2,382
1,951
113
Wow that's so bizarre. you did take off the two intermediate wheels? i think those could definitely cause some trouble buckling the IDW up. i'm going to service mine tomorrow. The movement isn't running but I have enough spare parts to make a whole new movement if I have to. I got the GMT wheel cleaned up and reconnected using staking tools. I put two hands on it and everything is rotating smoothly with the crown like it should. I didn't even glue the GMT halves together and the hour/GMT wheel rotation is spot on. I wonder if your date wheel driving wheel is a factor? Maybe take it off if you haven't.

I just took off the one that contacts the hour wheel for quicksetting, figured the other one doesnt make much difference! I was actually thinking the same earlier, its the only part left of the mechanism i havent really paid much attention to. Im thinking its possible theres some glue or just general shit in it from where the previous owner tried to glue the crown in... if theres a bit of crap in the date changing wheel it would push up/out the idw. But it works fine whilst manually setting the time! I guess im putting a lot more force through the system than a spring will. Ill get it under a loupe and have a look!
 
  • Like
Reactions: KJ2020

Dr Fun Socks

I'm Pretty Popular
Supporter
Certified
28/2/17
2,382
1,951
113
KJ2020 Well the movement is overbanked and thats way above the level of microscopic stuff im comfortable with. Tried reinstalling the balance but even with no balance theres a point on the escapement the pallets arent happy going past. Think the whole watch could be coming your way. At this point ill just have to chalk it up as a loss and keep the prof crystal. Stupid watches!
 

KJ2020

Time Traveler
Supporter
12/3/18
34,661
66,750
113
KJ2020 Well the movement is overbanked and thats way above the level of microscopic stuff im comfortable with. Tried reinstalling the balance but even with no balance theres a point on the escapement the pallets arent happy going past. Think the whole watch could be coming your way. At this point ill just have to chalk it up as a loss and keep the prof crystal. Stupid watches!

Ack, sorry to hear that bro. Was nice having a parallel effort going on and you had some great ideas! I'd welcome the chance to have another one to tinker with if you really are at your limit.
 

KJ2020

Time Traveler
Supporter
12/3/18
34,661
66,750
113
I just took off the one that contacts the hour wheel for quicksetting, figured the other one doesnt make much difference! I was actually thinking the same earlier, its the only part left of the mechanism i havent really paid much attention to. Im thinking its possible theres some glue or just general shit in it from where the previous owner tried to glue the crown in... if theres a bit of crap in the date changing wheel it would push up/out the idw. But it works fine whilst manually setting the time! I guess im putting a lot more force through the system than a spring will. Ill get it under a loupe and have a look!

Update. I was able to get my GMT wheel apart, cleaned and reassembled using staking tools. I reinstalled the circlip which I didn't have to start with. It is (not surprisingly) the exact size of the one used for a daywheel at 1.5mm. After I got it together I used the conveniently pre-placed glue holes to ooze some epoxy in. I coaxed it into the holes with a needle making sure no excess ran to the teeth on either the upper or lower gears. I cleaned off the excess before curing with an alcohol wipe.

jdUwY.jpg


jd28E.jpg


After curing, there's a nice round bed of epoxy between the gears. This will keep the hour hand synched to the GMT hand with their proper individual periods of rotation. (For others reading along)

jde33.jpg


After servicing the movement, I noticed the balance assembly was missing its impulse pin. This is probably what made yours do the crazy second hand swings.

jdWcD.jpg


jdA7n.jpg


I put in a spare but the amplitude was still way low so I also installed a new main spring.

Now for the good news. It's been running flawlessly for 24 hours. No datewheel driving wheel yet. I'm going to add that and a datewheel tonight and see if the IDW can handle it.
 

jiro

I'm Pretty Popular
Certified
10/12/06
2,835
1,094
113
This is some seriously interesting awesome amazing fantastic cool thread!!!!!

Learned so much!!! Thank you guys!!

So.....should I NOT buy the noob pepsi? LMAO!!!
....seriously tho...should i?

Sent from my SM-G965U using Tapatalk
 
Last edited:

KJ2020

Time Traveler
Supporter
12/3/18
34,661
66,750
113

Dr Fun Socks

I'm Pretty Popular
Supporter
Certified
28/2/17
2,382
1,951
113
Update. I was able to get my GMT wheel apart, cleaned and reassembled using staking tools. I reinstalled the circlip which I didn't have to start with. It is (not surprisingly) the exact size of the one used for a daywheel at 1.5mm. After I got it together I used the conveniently pre-placed glue holes to ooze some epoxy in. I coaxed it into the holes with a needle making sure no excess ran to the teeth on either the upper or lower gears. I cleaned off the excess before curing with an alcohol wipe.

jdUwY.jpg


jd28E.jpg


After curing, there's a nice round bed of epoxy between the gears. This will keep the hour hand synched to the GMT hand with their proper individual periods of rotation. (For others reading along)

jde33.jpg


After servicing the movement, I noticed the balance assembly was missing its impulse pin. This is probably what made yours do the crazy second hand swings.

jdWcD.jpg


jdA7n.jpg


I put in a spare but the amplitude was still way low so I also installed a new main spring.

Now for the good news. It's been running flawlessly for 24 hours. No datewheel driving wheel yet. I'm going to add that and a datewheel tonight and see if the IDW can handle it.

Nice work mate i hope the plan comes together! Was the spring still inside the hour wheel or just glue? I was lucky enough to have the spring, albeit it broken) to fill up with glue as a template before slapping the top back on and clipping it.


I had a look at the impulse pin, i mean its there but theres no guarantee its straight! Im still pretty convinced its possibly the escape wheel as unlikely as that is. Ill let you dissect it as soon as ive swapped some bits over though :)
 
  • Like
Reactions: KJ2020

KJ2020

Time Traveler
Supporter
12/3/18
34,661
66,750
113
Nice work mate i hope the plan comes together! Was the spring still inside the hour wheel or just glue? I was lucky enough to have the spring, albeit it broken) to fill up with glue as a template before slapping the top back on and clipping it.


I had a look at the impulse pin, i mean its there but theres no guarantee its straight! Im still pretty convinced its possibly the escape wheel as unlikely as that is. Ill let you dissect it as soon as ive swapped some bits over though :)

12 hours strong with datewheel driving wheel installed, 36 hours total running time.

I never had a spring so I had to rotate the wheel around to control any flow of glue til it was cured enough.
 

Dr Fun Socks

I'm Pretty Popular
Supporter
Certified
28/2/17
2,382
1,951
113
12 hours strong with datewheel driving wheel installed, 36 hours total running time.

I never had a spring so I had to rotate the wheel around to control any flow of glue til it was cured enough.

That’s dedication right there man! Controlling the flow like a tampax! Could be where i went wrong, i filled her up and left it high and not so dry... on the plus side ive started my new project, ill let you know when it comes to fruition :)
 

KJ2020

Time Traveler
Supporter
12/3/18
34,661
66,750
113
That’s dedication right there man! Controlling the flow like a tampax! Could be where i went wrong, i filled her up and left it high and not so dry... on the plus side ive started my new project, ill let you know when it comes to fruition :)

Haha, yep taking it slow. There's no dial on it and I have the GMT and hour hands from ICHS on it so as not to risk further damage to the CHS hands. Which means the GMT hand is really the hour hand so I constantly do a double take when I look at it. Aww crap it's messed up no wait it's still good, yay!
 

Dr Fun Socks

I'm Pretty Popular
Supporter
Certified
28/2/17
2,382
1,951
113
Haha, yep taking it slow. There's no dial on it and I have the GMT and hour hands from ICHS on it so as not to risk further damage to the CHS hands. Which means the GMT hand is really the hour hand so I constantly do a double take when I look at it. Aww crap it's messed up no wait it's still good, yay!

I can see where the confusion comes from man! Ill have a set of proper (disregarding the gmt hand pinion!) hands over to you as soon as my next piece arrives. Who would of ever thought swapping the order of 2 hands would cause this much hassle!
 
  • Like
Reactions: KJ2020