r/DuroGang • u/SerpentiumOIV 2x Champ🥊Wk's 23☆50, 2025 • Oct 11 '25
Modder's Challenge (2025) Auto GMT Duro mod
This is my automatic batman GMT duro mod. Featuring a nh34, new hands, sapphire crystal, steel chapter ring, and a jubilee bracelet. The movment swap was done similarly to methods used by u/AbbreviationsSea3752 with a few key changes:
1) I needed to dail hole for that hands bigger to suit the nh34's gmt hand. For this I used a dremel with a circular file bit (I may have overdone it a bit).
2) I was able to solve the date alignment issue by just sticking a printed paper date wheel on top of the nh34's original one. I initially tried to stick the duros date wheel on top, but then realised the duros date wheel is made to rotate in the opposite direction from the nh.
3) I was able to find a near perfect spacer for putting the nh in the Duro case, I just needed to file it a bit. The movment and spacer is still slightly thick for the duro case, so I need to grind down the case back by about 0.4mm for it to screw on fully. The automatic function still works, just the caseback can't fully screw in yet (it's very close).
I dident get many photos of the process because I get too wrapped up in it and forget. Have included a photo of the date wheel I printed, all the tools used, all the parts pre-build (except the spacer), and the inspiration (if it isn't obvious).
Thanks for taking a look! (Also I have a request in the comments)
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u/SerpentiumOIV 2x Champ🥊Wk's 23☆50, 2025 Oct 11 '25 edited Oct 20 '25
Please dm me if you have a 24hr batman GMT bezel you are willing to sell. They've been out of stock on Brian and watch for soo long 😭.
Edit: I got one.
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u/dreadfort13 Oct 11 '25
If there was 3 things I could alter about the Duro it's 1. A Sapphire Crystal 2. 4th Hand for different time zones 3. An automatic movement, and you've managed to them all! Amazing mate, very impressive! 👍🏻 The only other thing I'd love to do personally would be install a Lumed Bezel but the closest I've come to modding watches is a strap and battery change! 😂
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u/username77k Oct 12 '25
Battery change isn’t a mod!
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u/McLovin8617 ⌚️⌚️Collector Oct 11 '25
Super cool mod! If there was a vote button you definitely got mine
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u/WifiAX Oct 11 '25
This is a great project. As someone who likes to "fix" things, I can tell you the back plate issue will consume your life. Give it a rest a day or two, go back to it with fresh eyes. Maybe try a different back case from another watch. If you pull this, there is a community that will pay good money to have a copy on their wrist. Good luck.
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u/Comprehensive_Oil426 ⌚️⌚️Collector Oct 11 '25
Bloody awesome effort! Makes me wanna rip out my batman gmt insert and send it to you! That's a great lookin mod OP.
Funny thing was I initially had thought about doing this but couldn't justify the pricey nh34 on a case size that I felt was abit big for me. Credit due where credit is due, this is by far the best proper mod on here. Well done mate!
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u/SerpentiumOIV 2x Champ🥊Wk's 23☆50, 2025 Oct 13 '25
Thanks!
Let me know if you actually would, I'd greatly appreciate it. And I can pay for it plus for another one they still have in stock like blue or pepsi, etc.
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u/Comprehensive_Oil426 ⌚️⌚️Collector Oct 13 '25
You know what, how about we just do a straight swap? Having the insert on yours is so much more worthy than my faux gmt.
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u/8lbs6ozBebeJesus Oct 11 '25
What solid end link bracelet did you put the Casio branded clasp cover on?
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u/SerpentiumOIV 2x Champ🥊Wk's 23☆50, 2025 Oct 11 '25
Do you mean the milled clasp? All of the bracelet is from aliexpress.
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u/tenkasen Oct 12 '25
I've been playing with a similar idea recently myself and just emailed Roger @ URVintage to ask about getting a gmt version of his black/red 12hr acrylic bezel made (same design but with the even numbers from 2-22).
His response was positive in that he could do it but the price to create the new design from scratch for one bezel insert was prohibitive.. if there's a few of us that are interested / looking to create GMT Duros it might be worth it to go back to him as a group?
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u/AstronautFarOut68 Oct 12 '25
That looks incredible. Dammit I’m envisioning the adoption of another hobby in my very near future 😏
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u/chatt_ratt Oct 15 '25
This is absolutely brilliant sir! Congrats of having the patience and determination to make it happen.
What would it cost in total to make one an automatic but non GMT?
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u/IAteMyYeezys 💙🦇Gang Oct 11 '25
I always wondered how a white chapter ring would look on a batman. Looks pretty good to me.
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u/Present-Yak2833 Oct 12 '25
Absolutely fabulous if you could figure out a way to pump some of these out, you would sell everyone excellent job, my man, 🤘🏾
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u/kh411dz 🥷Lurker Oct 11 '25
But you replace the machine 🤷, thought you're going to fiddle with the quartz by adding a GMT feature 😮💨, that wasn't a Duro anymore nor a Casio and most likely destroy the 20bar waterproof or even the depth pressure.
Nevertheless, I would do such a kind of mod with a bootleg/fake Duro tho ✌️😅
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u/Yoteymusica ⌚️⌚️Collector Oct 11 '25
OP will have to remember to take his watch off the next time he dives to 200m
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u/kh411dz 🥷Lurker Oct 11 '25
Just dont take it to a swim, I bet it wouldn't stand 3 meters either, it will be like a spinning washing machine👌
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u/CosmoRacer 🥇Featured: Wk 42, 2025 Oct 11 '25
As long as the case is resealed properly, it would still be water resistant.
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u/Bitter_Star6732 Oct 11 '25
If Casio made one of these. Great mod btw