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Re: automatic/mechanical watches on a budget.
gave it a shot - $10 on Amazon for the blue demagnetizer seen everywhere. No luck. I dropped it off at the local watch shop to see if they could demagnetize. No luck. Confirming my suspicions, I was politely told that "the service cost would exceed the value of the watch."Originally Posted by dgaddis
I looked around for a bit for a replacement, but I really just wanted my old watch back. I ordered a watch kit from DIY Watch Club. My hope was that I could learn enough to repair my old watch. If not, worse case I have a new watch. The kit was fun. While it's essentially the horological version of IKEA furniture, it's still a bit of fun to see how it all gets put together. A bit pricey, but I was really just in it to buy the confidence and basic knowledge to DIY my movement replacement.
The Maratac takes the Miyota 8247 movement. Hours and minutes are on the central posts with a separate seconds indicator at 6:00. I ordered a replacement movement only to have the order cancelled by the seller - out of stock. I did some more Googling, found out the 8245 was a modified version of the 8215 movement, which has H/M/S all on the central post. I was able to find CAD drawings of the movements and found that all the important "landmarks" were the same between the 8215 and 8245. I considered getting the 8215 and ordering a seconds hand, but I really like the little seconds indicator. Miyota also makes the 8247 which features the same seconds indicator as 8245 but also includes a 24hr indicator at 10:00. I took a gamble and assumed that all 82XX movements shared the same basic geometry and would fit.
Watch disassembled. The movement is held in the case by the little screw-down clips.
I realized that I'd need to have a movement holder if I wanted to work on the movement without putting pressure on the rotor. I quickly drew up something in Fusion and 3D printed it.
Here I've got everything apart. You can see the first movement holder I printed before I realized I'd want to have a cutout for the crown/stem. At least it's convenient for holding all the screws and little pieces.
Here's the new 8247 movement. You see that little pin sticking up in the middle of the picture circled in yellow? That's the post for the 24hr indicator. You can see the seconds indicator in the background, just in front of my index finger. If you play guitar, I'd say these little pins are probably about as thick as .008s. maybe thinner. I'll have to snip off the 24 hr post if I want the dial to fit.
Here's the movement before snipping the 24hr post. You can see the cover for the 24hr mechanism over on the right side of the pic. The 24hr indicator post is at about 7:00 in the middle of the grey gear.
After a successful post-ectomy, here's everything put back together before I put the case back on. I was able to reuse the existing stem and crown so I did not have to deal with sizing and cutting the stem.
And the wrist shot. I swear it’s not dusty inside!
Despite my best attempts to damage the new movement, it's keeping fine time. I've got my old watch back, and now I've got some new tools and skills that are going to open up a whole new rabbit hole of tinkering and modding. Unsurprisingly, the biggest challenge was size. Everything is tiny and impossible to see. My well-lit desk might as well have been a dungeon. If I decide to tinker with watches more in the future, I’ll definitely get a bright and maneuverable lamp.
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