ETA Valjoux 7750 build…fail, fail, fail… it tells Time!
After completing my first NH35 build, I was inspired by @martin1111 7751 build, and decided to go for doing a chronograph. I would do things differently next time, like for starters, perhaps try a few more NH35 builds first. This was going to be my second build, but as it turned out, it’s my 4th, and actually the goal is a 7751 which will be next. Anyway, thought I would share my screw ups and maybe save some other builder some pain.
Screw up #1:
I picked up a new Sellita SW500 on eBay from a parts vendor in Switzerland for $360. A Sellita SW500 is a Swiss made Valjoux 7750… just made by Sellita instead of ETA. To place the hands, I used the same hand held pencil-like presser tools that are commonly used for NH35 builds. I’m now of the opinion that those are not the right tool for placing the tiny chronograph dial hands perfectly aligned as they need be. The short of it is, I ended up bending the hour counter pin on the SW500, and when I tried to bend it back, the movement pin broke off. … yes… It broke off.
That was the end of the SW500…. Until I get the gumption to learn how to tear down a brand new 7750 and put it back together.
I found a new ETA Valjoux 7750 on eBay for $300, though having just destroyed a pricey movement, thought I should maybe practice on a $100 Shanghai 3LZF2 which is also a Valjoux 7750 clone sold on AliExpress.
(3 Valjoux 7750 movements: Selita, ETA and Shanghai)
Additionally, I found a really nice hand press/ hand release tool that allows for a very controlled placement, positioning, and pushing. I practiced it first on an NH35 build and then a 6497 build, and it went so well that my confidence was restored enough to try it again on the 7750.
Screw up #2:
So, pressing the hands on went well enough with the new tool. Nothing was bought as a kit, but rather pieced together from various vendors. Not all vendors supply all dimensions necessary to make informed decisions, like inside case dimensions Being new to building, I was more focused on…oh, I need 7750 case and 7750 hands for a 7750…and didn’t pay as much attention as I should about the different dimensions. As you can see, the 7750 minute hand doesn’t quite fit inside the chapter ring of the dial.
Fortunately i had ordered another set of hands that did have a minute and chronograph second hand that fit. The other problem is the white chronograph hands were so fat, one couldn’t tell how many minutes had passed with the chronograph. So I decided to switch those back to the other set…the skinny metal pointers.
Screw up #3:
You may notice that the chronograph hands are skinny metal, while real time seconds is a red pointer. I wish I could say that it was entirely my intent to make the real time second hands the red hand. The truth is i had one of those tweezer part pinging moments. My tweezer snapped the tiny chronograph dial hand, yeeting it into oblivion, though not before first ricochet off my forehead on it’s way out. It was never seen again. So yeah, I meant to use the red hand 😜
Screw up #4:
I like like the functional look of this dial. The tachymeter chapter ring seems useful, but I forgot to check the diameter of the dial vs inner diameter of the case. I’m not even sure if the case inner diameter was published when I bought it. I noticed the gap when I did the final assembly. While the gap between case and chapter ring was not the look I intended, I decided that it’s interestingly different and unique😜. Wife thought it was an attractive black edge ring. For now, I’ve decided that’s how I’ll spin it….. the black gap is intended to look like a vantablack edge ring…. A color reserved for night stealth Lamborghinis Yeah that’s how I’ll spin it…. I meant to do that. It’s good enough for now 😜
I trimmed the stem, avoiding the stem trimming screw up from my 6947 that delayed things a few weeks since I didn’t have spared 6497 stems. I might trim a little more off the stem, after I pick up a spared 7750 stem.
The watch is fully functional. Thanks for reading. Hope I can save another builder some unforeseen issues, else provide some company in journey hardship. Please tell me what you think of the finished watch. I’m looking for outside opinions.
I’m a software engineer and watch enthusiast. I’m not excited about brand or heritage, but rather engineering tech.... spring drive, solar GPS, electrostatic drive, transistor tuning fork regulation,...
Yes! Misery loves company. I learned the hard way about that rodico in place of tweezers. I now stick a little rodico on a tooth pick to hold things. The one time I didn’t, and I lost the second hand. Cheers 🍺
This sounds like me a few months ago when I did my builds 😆 I broke hands, hands went flying, ordered too big dial, cut off the tip of the hands because they were too long to fit inside the case, and probably some more
It's a journey of learning for sure. I've just put back together a ETA 6497/ST36 and felt accomplished that it actually ran again!
Good luck on your projects.
This sounds like me a few months ago when I did my builds 😆 I broke hands, hands went flying, ordered too big dial, cut off the tip of the hands because they were too long to fit inside the case, and probably some more
Ha!, I’m glad I’m not alone! Yes, on another build I cut the ends of the hands so they fit 😂
It's a journey of learning for sure. I've just put back together a ETA 6497/ST36 and felt accomplished that it actually ran again!
Good luck on your projects.
I intend to do that. 6497/ST36 looks like a perfect one to do that with.
Now I know why I do the cheaper builds...your build looks good in the end
Now I know why I do the cheaper builds...your build looks good in the end
Wise move for sure! And thank you
Thanks for sharing your experience. I’ve been thinking about buying a Seiko SRPD diver and to dabble with modding. I’m impressed with your willingness to jump right in.
Thanks for sharing your experience. I’ve been thinking about buying a Seiko SRPD diver and to dabble with modding. I’m impressed with your willingness to jump right in.
Thanks, yeah I probably would have benefited by going a little slower. I love my SRPE93 diver. Another option to consider might be modding a Steeldive SD1970 diver since they have a similar Seiko movement and can be gotten for around $60.
Thanks for sharing. A longer post that I didn't tire of reading through, with helpful photos too. Good job on the watch, good job on the post 👍
Thanks, yeah I probably would have benefited by going a little slower. I love my SRPE93 diver. Another option to consider might be modding a Steeldive SD1970 diver since they have a similar Seiko movement and can be gotten for around $60.
Thanks for the tip. That sounds much better.
Sure, I buy everything either through eBay or AliExpress. The only thing 7750 related on AliExpress are the Shanghai movement (which I didn’t end up using). Everything else Valjoux-ish related came through eBay. “Swiss-Made-Time” also known as “b-line” has a store in Switzerland in addition to a web presence on e-bay, that seems to focus on European style build stuff. His e-bay site is: https://www.ebay.com/str/swissmadetime He has a great selection of parts but not always the best price on movements. I got my ETA 7750 from watchsnparts007 (Indiana, US) -eBay, and an ETA 7751 from “neven-Swiss”. Both of them had relatively good prices. https://www.ebay.com/str/nevenswiss All things 7750 seem so much more expensive relative to NH35 world. Cases are 4-5 the prices I would expect relative to NH35 world. dials and hands are also more expensive. The awesome hand placer/remover came for AliExpress, and I can’t imagine anything better exists on the market…but it cost around $145 for the full set.
Thanks for sharing an interesting build. With chrono hands it's complicated but over time when a person gains experience it becomes easier. The good practice is to buy the movement and hands from the same supplier. It is very important to be precise in these micro dimensions and each supplier may have a different deviation. The golden rule applies in these builds; the fewer suppliers, the fewer problems. I also like that gap in some way, but if you get tired of it over time than I can recommend a solution like the one I used. I also had that gap during the built.
As you can see those little red partials (pointing arrows) I've been trying all different ways of how to fill it up. The best solution was to go to a goldsmith to make a custom-made ring for me. Since it was a very thin band, he made it for me out of white gold, so it didn't cost me a lot of money, but if it should be a lot, you can use a cheaper material. I'm attaching an other picture for further inspiration. I was very pleased that my effort to built that watch has inspired you 🍻
Admire your perseverance my man! I wouldn't even try to attempt a build myself, much less a chronograph! I could just imagine the fulfillment of success after the final product comes to life. Congratulations and enjoy your VERY OWN unique watch! 😎
Thanks for sharing an interesting build. With chrono hands it's complicated but over time when a person gains experience it becomes easier. The good practice is to buy the movement and hands from the same supplier. It is very important to be precise in these micro dimensions and each supplier may have a different deviation. The golden rule applies in these builds; the fewer suppliers, the fewer problems. I also like that gap in some way, but if you get tired of it over time than I can recommend a solution like the one I used. I also had that gap during the built.
As you can see those little red partials (pointing arrows) I've been trying all different ways of how to fill it up. The best solution was to go to a goldsmith to make a custom-made ring for me. Since it was a very thin band, he made it for me out of white gold, so it didn't cost me a lot of money, but if it should be a lot, you can use a cheaper material. I'm attaching an other picture for further inspiration. I was very pleased that my effort to built that watch has inspired you 🍻
Ahh! Yes, I just need a spacer ring around the edge. I’ll see if that’s something the local gold smith can do. I actually already see that I messed up in the same way with my upcoming 7751 build. The dial is quite a bit smaller than the case, and I had not decided yet whether to resell the case and find something smaller or not. Perhaps I’ll consider the gold-smith custom ring as an option too:
Admire your perseverance my man! I wouldn't even try to attempt a build myself, much less a chronograph! I could just imagine the fulfillment of success after the final product comes to life. Congratulations and enjoy your VERY OWN unique watch! 😎
Well, I certainly learned to appreciate much more, being able to buy a nicely finished 7750 that a micro brand has gone through the trouble of working out the kinks. Thank you. It is the learning process that I appreciate the most.
The valjoux 7750 is tricky. But you’ll get the hang of it. The watch turned out well.
Oftentimes the end result itself isn’t the most important thing anyway. It’s the journey and the lessons learned along the way.
The valjoux 7750 is tricky. But you’ll get the hang of it. The watch turned out well.
Oftentimes the end result itself isn’t the most important thing anyway. It’s the journey and the lessons learned along the way.
I definitely agree, that’s it’s about the journey rather than the destination. I think I got the hand placement down now. Next time I’ll be t paying more attention to dimensions. That’s a beautiful Oris!
I recently built my first watch from parts, NH35 based. I love chronographs, but just doing the seconds had on the NH35 gives me stress, I don't even want to think about trying to do 3 tiny little hands and the chronograph second hand, and getting them all lined up perfect! You are brave! I love the red running servings hand, but the way.
Ahh! Yes, I just need a spacer ring around the edge. I’ll see if that’s something the local gold smith can do. I actually already see that I messed up in the same way with my upcoming 7751 build. The dial is quite a bit smaller than the case, and I had not decided yet whether to resell the case and find something smaller or not. Perhaps I’ll consider the gold-smith custom ring as an option too:
Please don't get me wrong but since I have a gold spacer ring there, the watch is much more valuable to me. I don't like to wear gold in the form of chains and pendants, but they add a lot of emphasis to the watch every time I look at it. I think it would look very good with the case you have 🍻
I recently built my first watch from parts, NH35 based. I love chronographs, but just doing the seconds had on the NH35 gives me stress, I don't even want to think about trying to do 3 tiny little hands and the chronograph second hand, and getting them all lined up perfect! You are brave! I love the red running servings hand, but the way.
Yeah, I know what you mean…. the second hand is the hardest. Good light and good magnification was a key for me on the NH35 second hands. On the chronograph tiny hands that have to be aligned too… I’m not sure how it can be done with the pencil type setters without super human patience.
Please don't get me wrong but since I have a gold spacer ring there, the watch is much more valuable to me. I don't like to wear gold in the form of chains and pendants, but they add a lot of emphasis to the watch every time I look at it. I think it would look very good with the case you have 🍻
Perhaps I’ll ask around from parts sellers if they have pre-made dial spacer rings for this use case. It seems to me that they could be inexpensive if made in quantity and not of precious metals.
About the 7751 case, thanks! I hope I can make it work… will see
The valjoux 7750 is tricky. But you’ll get the hang of it. The watch turned out well.
Oftentimes the end result itself isn’t the most important thing anyway. It’s the journey and the lessons learned along the way.
This watch looks stunning 😮👌
This watch looks stunning 😮👌
Thank you, it’s an Oris TT3, it was the first chronograph I repaired. I bought it non-running. The previous owner had dropped it and sheared the upper pivot of the oscillating pinion.
Thank you, it’s an Oris TT3, it was the first chronograph I repaired. I bought it non-running. The previous owner had dropped it and sheared the upper pivot of the oscillating pinion.
It's amazing that you can repair such movement. I'm not confident enough to take apart chrono movements but hopefully over the upcoming years I'll buy some special tools and will be able to do a service myself 🍻