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onzenuub

Adding a Regulator to the A7750 28800

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onzenuub

Francisco'DIY Tutorial:

 

INTRODUCTION.

 

The Asian 7750 movement, a clone of the ETA 7750, has no precision accuracy regulator. This regulator helps to obtain a better adjustment easily. However, this is not so important. With the A7750, without this precision regulator, it is possible to obtain good adjustment.

 

The problem arises with watches where the case back is transparent. In these cases, it is very easy to detect that the watch is a replica. For example, the Hublot Bing Bang. In the webpage of Hublot there is a small tuto for distinguishing a replica, and the regulator is one of the main points to look for. A picture from this website:

 

4093704836_9e9b49da7a_o.jpg

 

One of the solutions is to employ an Asian 7750 working at 21600 bph. However, this movement seems to be more problematic that the version working at 28800, with has no regulator. On the other hand, there is a new version of Asian 7750 at 28800 with has a regulator. However, this new movement is still not present in the Hublot replicas and probably is going to be more expensive.

 

In this small tuto we show how to add a regulator to an Asian 77500 at 28800, using genuine parts of the ETA 7750.

 

 

MATERIALS.

 

• Regulator of the ETA 7750. The following two pieces from www.cousinsuk.com are needed.

VAL77503035 Valjoux 7750 303.5 Two Piece Regulator £2.25

VAL7750358 Valjoux 7750 358 Regulator Corrector £1.50

 

• Superglue, Loctite.

 

• Dremel with a stone for sanding.

 

• A piece of wood.

 

• Tape.

 

 

PROCEDURE.

 

In first place it is necessary to see how the regulator is placed on the gen ETA 7750. Here a couple of pictures taken form an ETA 7750 that I own:

 

4092939655_53b0f8d1e6_o.jpg

4092939701_208728cfb5_o.jpg

 

Next pictures show the pieces that come with the reference VAL77503035. There is a 1 euro coin to show the small size of these pieces.

 

4092939759_b5b1b1be87_o.jpg

4093705092_8f27c343c1_o.jpg

 

We only need the two pieces marked #1 and #2. Piece #2 has to be modified. This piece has two small pins, one in each face as shown in next picture. One of the pins is for a hole that the plate of the balance wheel has, but this hole exists only in the ETA 7750. The other pin connects with piece #1.

 

4092939857_5f3ec92ccd_o.jpg

 

As the Asian 7750 has no regulator there is no hole for the pin in the plate. However, some versions of the A7750 has a small hole more or less in the same place. We discuss this later. However, this hole is too small. That is the reason we have to remove this pin. Otherwise the piece #2 does not rest well on the surface of the plate. It is a precision work, but following the next steps is not so difficult.

 

We need a piece of wood and we have to make a very small hole to put the piece #2 as shown in the picture. You can use a needle to make the hole.

 

4093705190_912af56278_o.jpg

 

Be careful. Only one pin has to be removed and you have to choose the correct one. For that reason, check carefully the pictures of the ETA 7750 at the beginning of this tuto.

 

4092939953_a48e87bdc6_o.jpg

 

Then, the piece #2 is fastened using tape.

 

4092940003_66e4546504_o.jpg

 

Next step is to sand the pin. Be careful. You have to use the loupe to do it (the pin is extremely small) and there is no room for safety glasses. Close well the other eye.

 

4093705364_ae4dbf6116_o.jpg

 

Next pictures show the piece #2 when the job is finished.

 

4092940113_168ebde440_o.jpg

4093705448_80aeb76717_o.jpg

 

Here we show the Asian 7750 used for this tuto. As it is possible to see the balance whell plate has a very small hole, perhaps in the correct place. I have checked many A7750 and the majority of them have not this hole. However, this hole is too small for the pin of piece #2. In addition, I consider very difficult to make a correct hole in that place. And the dust produced by drilling can damage the movement. A solution could be to remove the balance wheel, for drilling purposes. My suggestion is that is very much easy to remove the pin. Do not try drilling a hole here.

 

4092940211_961e715267_o.jpg

 

Next picture shows pieces #1 and #2 before placing them correctly.

 

4092940257_c92a4b57ea_o.jpg

 

It is not easy to joint these pieces. Tolerances are quite tight. Do it slowly, pushing piece #2 to piece #1.

 

4093705624_095abbde16_o.jpg

 

Next step is to glue the regulator. I have placed the ETA movement close to the A7750 for trying to obtain the same location of the regulator. See next picture. You can use the first pictures of this tuto if you do not have an ETA 7750.

 

4092940361_982f73a500_o.jpg

 

Once the regulator is in the correct position, do not move it. We are going to glue it. Just drop a small glue of superglue of Loctite on a plastic surface, in this case, a piece of tape.

 

4093705758_386bb9b375_o.jpg

 

And with a needle take a very small amount of glue. Where to place the glue? A good question. The weight of the regulator is very small; we do not need to put a large amount of glue. And, very important, we cannot put glue close to the balance wheel, just to avoid serious problems.

 

I have put glue with the needle in the places shown in the next picture. Capillarity will take glue to the correct place to join the regulator on the surface of the plate.

 

4092940515_22575545f0_o.jpg

 

The excess of glue can be removed using absorbing paper. However, do not worry too much. This glue is transparent.

 

Here the final result.

 

4092940591_a3effbdf1f_o.jpg

 

And if you are wondering, yes, you can still adjust the precision, but no with the added regulator, of course, it is not functional.

 

Francisco.

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jameo210369

Great addition Onze, if I had to do that work I would ask the borrowers to do it for me.

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kurcina

So, how then to adjust precision ???

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onzenuub
So, how then to adjust precision ???

 

 

The regulator is not functional.

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kurcina
So, how then to adjust precision ???

 

 

The regulator is not functional.

 

 

I know it is not functional, but you said we can still adjust precision without regulator, so how ???

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sconehead
So, how then to adjust precision ???

 

 

The regulator is not functional.

 

 

I know it is not functional, but you said we can still adjust precision without regulator, so how ???

Like this,

The arrowed part is what you need to move...

A7750-1.jpg

Move it to the right, as per the direction of the arrow, to slow it down...

A7750-2.jpg

Obviously, in the other direction to speed it up. Be aware though, small adjustments at a time!!!

 

Hope this helps...:)

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kurcina
So, how then to adjust precision ???

 

 

The regulator is not functional.

 

 

I know it is not functional, but you said we can still adjust precision without regulator, so how ???

Like this,

The arrowed part is what you need to move...

A7750-1.jpg

Move it to the right, as per the direction of the arrow, to slow it down...

A7750-2.jpg

Obviously, in the other direction to speed it up. Be aware though, small adjustments at a time!!!

 

Hope this helps...;)

 

 

Thank you very much on your answer. :group:

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trailboss99

You got the right lever there sconey? Ain't the rate the big one and the small the duration? Move the wrong one and it will need to go on a timeing machine to be put right.

 

'cause I can never remember so I'm proberly back to front.

 

 

 

Col.

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dingle

one of many quality post from sconehead. thanks. :facepalm:

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sconehead
You got the right lever there sconey? Ain't the rate the big one and the small the duration? Move the wrong one and it will need to go on a timeing machine to be put right.

 

'cause I can never remember so I'm proberly back to front.

 

 

 

Col.

Yeah, the one with the two pins is the regulator arm...as Col say's though, never touch the one with the stud on or you'll open up a can of misery...

 

@ DB...read 'em and weep...:lol:

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