Skeleton watch build 6497
My latest build is based on a Unitas 6497 movement design. This movement was developed in the 1950’s for pocket watches and seems well suited as a skeleton watch because it’s a large simple mechanical movement. This particular movement is a Seagull ST3600K (‘K’ for skeleton), and can be purchased for about $60.
This movement presented a few new issues for me.
Without a dial, dropping any of the hands or screws means it could fall into the inner workings. My biggest fear was dropping something onto the hair spring. Fortunately it didn’t happen. I utilized the cleaning putty as a part holder since I figured it’s less likely to yeet parts into the inner workings like a tweezer might.
The offset second hand at 9 o’clock is smaller than on an NH35 build. I don’t think I could have placed this without a hand press.
I appreciate the NH35 stem removal engineering over this 6497. The 6497 requires a screw loosening 1.5 turns to pull out. It also can be tricky to place back in and verify that one has completely seated the set screw, which is primarily an issue when one is sizing up the stem for cutting and placing crown. The issue is compounded if one is doing this for a crown lock case where tolerances are less forgiving (DAMHIK)
The movement is held in place by two mounting brackets and screws. This old way of doing it makes one appreciate the snap in surrounding movement holders.
There is no doubt a skeleton watch makes it harder to read the time. I’m a huge appreciator of highly visible lume and dial functional watches for daily wear. I decided this watch would be more about seeing the internal workings, and I’ll likely wear it when the kids are home for the weekend.
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,...
Nice job on the build! Ever consider etching hour markers into the crystal? I would think that would help tell the time and obscure the movement not to mention I think it would look cool!
Nice job on the build! Ever consider etching hour markers into the crystal? I would think that would help tell the time and obscure the movement not to mention I think it would look cool!
Woah… etching the crystal sounds like an intersting new direction. I’ll have to put that one on the research back burner. Thanks for the idea.
Woah… etching the crystal sounds like an intersting new direction. I’ll have to put that one on the research back burner. Thanks for the idea.
Anytime! Let us know if you do it, would love to see how it works out!
Cool! 🍻fancy hand setter tool…
Looks awesome!
Cool! 🍻fancy hand setter tool…
Yeah, I got that because I messed up a pricey 7750 movement, and I’m committed to finishing a 7750 and 7751 build.
Yeah, I got that because I messed up a pricey 7750 movement, and I’m committed to finishing a 7750 and 7751 build.
You’re brave my friend!! I will step up to the plate eventually and perhaps do a chrono build 🍻
Fantastic