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7750 stem release?


kiwi

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Hello,

I have a 3717 and a 3719 from Pure Time, and am attempting to remove the crystals for AR coating. My problem is with the stem release. Both of these have a new asian 7750 28,800 beat movement. I followed the directions in this thread.

I set the hands to 12PM and placed the crown in winding position. However, when I press in the stem release on either watch (using a small round-tipped plastic tool) and gently pull on the crown, the stem does not slide out. If I pull with greater pressure, then the crown engages the date-set and time set positions, suggesting the stem is still fully engaged. Am I missing something? I have tried with gentle pressure on the release lever with different amounts of displacement from barely depressed to fully depressed (until the stopper is reached).

I'm grateful for any helpful suggestions.

Thanks,

D

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The device releasing the stem is a screw on the "unitas" movements. On the 7750 it is a push-in pin.

Strange behavior there, betas. Try and do the same with the hands in a different position. You need to set the hands at 12:00 only if you plan to remove them -- that is not your case as you only want to remove the crystal.

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You're doing it the right way. If you push the release button as on pic #12 in Ajoe's tutorial and pull the stem it is supposed to get out. Maybe you need to put the pressure a little bit up and use tweezers instead of a plastic tool. It's not as fragile as a 2824/36. The pusher can handle some force. But don't overdo it off course.

As long as you don't dissassemble the whole movement you don't need to release the spring.

The more difficult part is getting it back without damaging the keyless works. You need to press the release button and at the same time slowly put the stem back while 'winding' the stem anti-clockwise. When you feel the stem engage you can press it further in and keep pressing the button until the stem is full in. If you don't feel it engage start over again, because you can mess everything up when pushing it in further.

Also be careful with taking the 3717 dial off, since most of the time the black paint can easily fall off just by touching it on the edges...

If you don't feel comfortable with this you'd better send the whole watchhead to your AR guy and have him release the movement and get the crystal out. I know K2222 does that. I'm not sure with Chief, though.

Edited by scoobs1971
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Hi,

once i also had this problem, when trying to get it out in winding position.

I put it in time setting position. And then pressed the release. Easily got it out.

and later also managed to get it in again.

good luck.

J.

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2 schools of thought. Rob (The Zigmeister) says to remove the stem in the winding position...others have had better luck in the time-setting position. Rob's way is the correct way, but can be harder to get the stem back in.

As you push the stem release button on the A7750, turn the stem in the winding direction, and it should disengage. To re-insert, you push the button again, and slowly wind the stem in. It may take a few tries. If it's not in all the way...time-setting may work, but winding not...or you might not be able to wind without the rotor spinning or some other kind of weird operation.

If this is the case, pull it back out, and try again. Other movements (non A7750) should NOT have the stem release button pushed for re-insertion.

Edited by Toadtorrent
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Thanks for the replies. Just tried again, with the same results. I'm not sure what to change, but keep getting the same result.

I actually did try with the hands in a random position, but since I'm sending both these watches to The Zigmeister for service afterward, I figured I'd leave the hands at 12:00 to make his life easier. That is also the reason I prefer to remove the stem in the winding position.

As for pressing harder, there is a little stopper that limits the amount of excursion of the lever, and I'm pushing the lever gently inward until it hits that stopper and I get a large resistance. Unless that stopper is also supposed to move, I'm afraid to push harder.

If I turn in the winding direction with the lever depressed, then the watch just winds.

I am certain I am doing something wrong :-(

D

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To make sure I'm not really misunderstanding the process, here's a picture:

releaselu5.jpg

releaselu5.c9f3838e1f.jpg

The tweezer tips are on the lever (with blue dot at the tip). I am pushing the lever in the direction of the yellow arrow. It stops as it approaches what I believe is a stopper (yellow dot). There is also a metal tab extending down from the lever, which appears potentially to function as a stopper. (between the blue dot and the pivot).

Am I way off base here?

D

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Got it. Thanks so much! I had interpreted the position of the tweezers on the tutorial as touching the button, rather than pointing to it.

So I've got the crown off the 3719 easily. However, the movement does not easily slide out of the case--it seems anchored still in the region of the crown tube and pushers. Is there a special trick for this watch (which has the rotating inner bezel controlled by the chrono reset)? I don't want to force anything.

Thanks,

D

Edited by betas4c
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Got it. Thanks so much! I had interpreted the position of the tweezers on the tutorial as touching the button, rather than pointing to it.

So I've got the crown off the 3719 easily. However, the movement does not easily slide out of the case--it seems anchored still in the region of the crown tube and pushers. Is there a special trick for this watch (which has the rotating inner bezel controlled by the chrono reset)? I don't want to force anything.

Thanks,

D

Hi D,

please don't get me wrong, but don't you think it is wise to let a watch smith take the glass out? I mean if you never opened up a watch, and you did not know what the chrono reset lever was and could not take the crown off, i think getting the glass out, is a little bit too much.

Probably the movement is also anchored to the watch case by 2 or 3 screws.

I think it needs some skill and the right tools to get the glass off. A watch smith can do this very easily and maybe charge you 20usd max. Saves you the risk of breaking your glass or the movement.

Just my 2 cents....

J.

Edited by hooky
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@hooky: Of course, I'd rather have all this done by a watch smith. However, in my town as in the towns of many others here, there's a shortage of watchsmiths willing to work on reps. Therefore, I'm trying to strike a balance of prudence, economy, and expeditiousness, to minimize the burden on the precious few watchsmiths that grace this community. I do have appropriate tools, good work bench (An electronics lab bench), magnifying loupe, and fairly steady hands. I figure it's worth the effort to gain the experience. Of course, I plan to have the watches serviced and re-assembled and crystals installed by an expert.

The 3717 movement came out easily, as did the crystal. It's just the 3719 that is hanging. I don't see any screws or obvious retainer. if anyone does have a suggestion, I'd be grateful!

D

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@hooky: Of course, I'd rather have all this done by a watch smith. However, in my town as in the towns of many others here, there's a shortage of watchsmiths willing to work on reps. Therefore, I'm trying to strike a balance of prudence, economy, and expeditiousness, to minimize the burden on the precious few watchsmiths that grace this community. I do have appropriate tools, good work bench (An electronics lab bench), magnifying loupe, and fairly steady hands. I figure it's worth the effort to gain the experience. Of course, I plan to have the watches serviced and re-assembled and crystals installed by an expert.

The 3717 movement came out easily, as did the crystal. It's just the 3719 that is hanging. I don't see any screws or obvious retainer. if anyone does have a suggestion, I'd be grateful!

D

Sometimes i take the watch case in my one hand and very gently 'slam' it with my other hand in my palm. then it will get out. What you can also do is use a tiny screwdriver to create some leverage. Just make sure afterwards that no small particles are left, by using the small hand Bergeon blower to get the dust etc off.

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Sometimes i take the watch case in my one hand and very gently 'slam' it with my other hand in my palm. then it will get out.

That did it. I just didn't want to jiggle too much if there was something else needing release. Crystals are going in the mail!

Thanks all of you for your help.

D

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