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The A21J Movement


tghodin

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Are you sure it's full wound!

Crank it manually, about 50 turns, leave it on your night table, and check tomorow. And if there's a problem, communicate with the member. It's a $15 mvt, you can change it in worst case scenario.

I can add that this kind of mvt can be very very precise.

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Are you sure it's full wound!

Crank it manually, about 50 turns, leave it on your night table, and check tomorow. And if there's a problem, communicate with the member. It's a $15 mvt, you can change it in worst case scenario.

I can add that this kind of mvt can be very very precise.

Well the crown seems pretty lock'd, unless im supposed to screw up the crown, and then crank it up.

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Okay, just recieved my Noobmariner LV A21J from a fellow member. Its unused before me, is it

normal for this piece of movement (im aware its not the best) to drop about 15min/24hours?

Thanks in advance!

The movement probably needs the timing regulated/adjusted. It is possible to adjust an A21j to +0.02 seconds over 24 hours (I've done this myself with nothing more than a small screwdriver, and comparison to a digital clock) but it does require a little watch knowhow. See how the watch behaves over several days. If it constantly loses 15m per day, that is actually a good sign, as it shows that the movement is working consistently, so can simply be adjusted accordingly :) It's when the loss or gain becomes erratic that it could indicate a mechanical problem with the movement :) Best of luck :good::drinks:

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Well the crown seems pretty lock'd, unless im supposed to screw up the crown, and then crank it up.

Let me go out on a limb here and affirm that you DO need to unscrew the crown and then you can wind it up...

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Well the crown seems pretty lock'd, unless im supposed to screw up the crown, and then crank it up.

Turn the crown toward you (CCW) until you feel it "pop out" on it's own. THEN begin to turn it away from you (CW) to manually wind it up.

If the date or time starts adjusting when you start turning, push the crown back in, you've pulled it out.

And 15 minutes +/- per 24hr ?? That's terrible !!! The TS promo 16610's I purchased for gifts were within 6-8 seconds per 24hr. Hope this helps.

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Are you sure it's full wound!

Crank it manually, about 50 turns, leave it on your night table, and check tomorow. And if there's a problem, communicate with the member. It's a $15 mvt, you can change it in worst case scenario.

I can add that this kind of mvt can be very very precise.

Are all 21j mvts 21,600 or are they making 21j 28,000 mvts ???

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Are all 21j mvts 21,600 or are they making 21j 28,000 mvts ???

A21j (j for jewels, so 21 jewel) without mention anything else it's a DG2813 that beat at ~21k bpm. The DG4813 it's the 28,000 mvt (i.e ~28k bpm) version of the DG2813.

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A21j (j for jewels, so 21 jewel) without mention anything else it's a DG2813 that beat at ~21k bpm. The DG4813 it's the 28,000 mvt (i.e ~28k bpm) version of the DG2813.

A21js can be the DG2813, or the ST16. Almost all of the rep watch movements I've seen have been one or the other or a clone of one of those designs.

There are high-beat DG2813's. I don't know why, but I personally have seen and touched movements stamped 2813 that beat at 28.8kbph. They were different from the DG4813.

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I don't know why, but I personally have seen and touched movements stamped 2813 that beat at 28.8kbph. They were different from the DG4813.

Very interesting :g:

Do you know if a DG4813 can be a direct swap for a DG2813 ? I read a lot of different opinion on that. Your input will be welcome.

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Very interesting :g:

Do you know if a DG4813 can be a direct swap for a DG2813 ? I read a lot of different opinion on that. Your input will be welcome.

Yes and no :bangin:

So, the DG2813 and 4813 have the dial feet in the same place. The stem height is the same. The hand sizes are the same. Therefore, it should be a direct swap.

However, like the ETA family of movements, they come with different length pinions. Almost all DG4813s seem to have the low hand stack, so many times when you do the swap, everything fits until you go to install the hands then you find that there's not enough clearance between the hands and the dial.

There used to be high-hand-stack 4813s, but the supply seems to have dried up.

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A21j (j for jewels, so 21 jewel) without mention anything else it's a DG2813 that beat at ~21k bpm. The DG4813 it's the 28,000 mvt (i.e ~28k bpm) version of the DG2813.

Magagne and Sneed...thanks for "sort of" clearing that up for me. I'm basically a Rolex Guy and was under the impression that 99% of the Rollie Reps offered with a 21j mvt aren't going to employ a 28.800 mvt. SO, if it says 21j mvt but does NOT specify or add that its a 28.8 then it's most likely the 21,600??

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Yes and no :bangin:

So, the DG2813 and 4813 have the dial feet in the same place. The stem height is the same. The hand sizes are the same. Therefore, it should be a direct swap.

However, like the ETA family of movements, they come with different length pinions. Almost all DG4813s seem to have the low hand stack, so many times when you do the swap, everything fits until you go to install the hands then you find that there's not enough clearance between the hands and the dial.

There used to be high-hand-stack 4813s, but the supply seems to have dried up.

Great, finaly, a clear explanation. :victory:

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dg2813m.jpg

You just move the regulating arm. Left hand pic, upper right corner of the movement.

All you have to do is take the caseback off, no other disassembly is needed.

However, just fyi, 10-15 minutes is kind of a lot. Usually you regulate a movement just a couple of minutes. Good luck.

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THANKS guys...that's answered my question perfectly. I've passed on many a watch in the sales threads being under the impression that a 21j usually isn't a 28,800bhp mvt. The way they're building the asian clones so reliable these days I have to wonder why they even bother to put a "choppier" 21j 21,600 mvt. in anything but the vintage low-beat replications....gotta be a cost factor, I'd assume. :pardon:

Edited by d-rock
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dg2813m.jpg

You just move the regulating arm. Left hand pic, upper right corner of the movement.

All you have to do is take the caseback off, no other disassembly is needed.

However, just fyi, 10-15 minutes is kind of a lot. Usually you regulate a movement just a couple of minutes. Good luck.

Means i paid for a non-fucntional A21j?

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Those A21j movements are pretty good. I would rather have one of those than a A2836 copy or one of those new silly 3135 copy movements. If its losing 15 min a day, then there is something wrong with it. I dont think you will be able to get anywhere near that much adjustment out of it.

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Those A21j movements are pretty good. I would rather have one of those than a A2836 copy or one of those new silly 3135 copy movements. If its losing 15 min a day, then there is something wrong with it. I dont think you will be able to get anywhere near that much adjustment out of it.

okay, i guess i should contact the seller..

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