Bulova Accutron 2181 Repair

[bobtheterrible]

Hi All,

I thought I would share where I am up to with my latest project. While doom-scrolling Ebay I came across a soon-to-end auction for tidy looking Bulova Accutron 2181 and chanced a bid. The seller was upfront that the seconds hand turned but the minute and hour hands did not move. I had already read elsewhere that this was a common problem and figured I should be able repair or at least replace the seized parts. This is my first Accutron...

The project is a simple stainless steel dress watch with a silver face and simple baton hour markers. Should look nice on a black leather strap.

On first inspection after opening the case it is obvious there has been a battery leak. It looks mostly contained to one area and Im hoping it will clean up.

I checked the "fingers" and while dirty, they look ok. So far so good!

I started by disengaging the fingers from the index wheel - apparently any rough handling during hand removal can cause these to break.

Once I had stripped the dial side down I came across the reason why the hands were not moving. Indeed the canon pinion had seized - and properly so! The minute wheel teeth had been striped!

After wrestling the centre wheel away from the movement it was clear it had rusted solid and the previous owner had attempted to free it up using force applied to the crown.

I used a bit of Rodico to clean up the rust and teeth before proceeding as the forks are magnetised and will attract any ferrous material. Also of note virtually all the components were magnetised to some degree or other so will need to deal with that.

A couple of shots showing just how thin the coil wires actually are!

I finally made it down to the tuning fork and got stuck trying to remove one of the two screws holing it to the plate. I was putting significantly more force in to turning that screw head than I was comfortable with so decided to place a drop of penetrating oil around the screw in the hopes it will have loosened up by the morning.

Now I need to start looking for some replacement parts......

I will update this thread as I progress!

Edited September 14 by bobtheterrible

[ManSkirtBrew]

Oh man, those poor teeth!

I just finished repairing two, 219s and am going to embark on a 218 next.

The screws for the fork were surprisingly tight on both of mine as well. Expect the fork to be extremely tight on the studs once you get those screws off, as well.

If you don't know, the docs say not to pry on the fork to lift it up, but to push it up from the bottom using the hole in the main plate. I put a bracelet pin tool in the hole and gently tap it to release the fork.

Have you read about phasing the watch to run on silver oxide cells, or are you planning to use the Accucell?

[rehajm]

What kind of internal violence leads to losing teeth like that? Yikes!

[bobtheterrible]

9 hours ago, ManSkirtBrew said:

...

If you don't know, the docs say not to pry on the fork to lift it up, but to push it up from the bottom using the hole in the main plate. I put a bracelet pin tool in the hole and gently tap it to release the fork.

Have you read about phasing the watch to run on silver oxide cells, or are you planning to use the Accucell?

That is really good to know - thanks! I have a copy of the service manual but clearly I need to go back and read it again!!

I was planning on using a silver oxide cell and was aware that I would need to "do" something. There was a iinet forum post that did a walkthrough of how to correctly phase this movement but it looks dead now. However in my haste/inexperience during disassembly I have thrown the pawl finger adjustment waaaay out so looks like Im going to have to attempt to correct this whether I wanted to or not.

[ManSkirtBrew]

8 hours ago, bobtheterrible said:

There was a iinet forum post that did a walkthrough of how to correctly phase this movement but it looks dead now.

Try this link instead. I've only done the 219 phasing so far, which is a little simpler, but it's fairly straightforward if you have a variable power supply.

 

8 hours ago, bobtheterrible said:

However in my haste/inexperience during disassembly I have thrown the pawl finger adjustment waaaay out so looks like Im going to have to attempt to correct this whether I wanted to or not.

There's no way to disassemble the movement without rotating the pawl finger out of the way. In fact, I usually rotate the fingers so they're more protected by the parts they're attached to, so I'm slightly less likely to bend the crap out of them. I put the index finger in line with the fork arm, and the pawl finger turned in over the bridge.

[JohnR725]

20 hours ago, bobtheterrible said:

Once I had stripped the dial side down I came across the reason why the hands were not moving. Indeed the canon pinion had seized - and properly so! The minute wheel teeth had been striped!

The classic problem of the center wheel assembly has rusted itself to the post. Then a minute and hour hand no longer turn the secondhand churns the friction part of the center wheel assembly is totally destroyed. Occasionally can flip the wheel over and buy yourself a little time but typically you'll have to replace the wheel. Then if you have really enthusiastic user you'll end up with a minute wheel stripped also. I would recommend not following the lubrication  specification of whatever they say for the center wheel to avoid this ever happening again.

20 hours ago, bobtheterrible said:

Also of note virtually all the components were magnetised to some degree or other so will need to deal with that.

I really wouldn't worry about the magnetized components unless you get rid of the magnets on the tuning fork. Basically magnets on the fork everything else is going to have a problem with magnetism typically is not going to bother anything at all unless of course you have steel tweezers.

20 hours ago, ManSkirtBrew said:

The screws for the fork were surprisingly tight on both of mine as well. Expect the fork to be extremely tight on the studs once you get those screws off, as well.

Oh and when you finally get the screws off and remove the fork be very careful because typically underneath our spacing washers. The color-coded to refer to their thickness. But I find it's usually best to just put the screws back in once you've lifted the fork out of the way that way you don't have to worry about which washer is where and basically is random whatever you going to find. The purpose is to tilt the fork so it agrees with the circuit.

20 hours ago, ManSkirtBrew said:

Have you read about phasing the watch to run on silver oxide cells, or are you planning to use the Accucell?

 

9 hours ago, bobtheterrible said:

However in my haste/inexperience during disassembly I have thrown the pawl finger adjustment waaaay out so looks like Im going to have to attempt to correct this whether I wanted to or not.

1 hour ago, ManSkirtBrew said:

There's no way to disassemble the movement without rotating the pawl finger out of the way. In fact, I usually rotate the fingers so they're more protected by the parts they're attached to, so I'm slightly less likely to bend the crap out of them. I put the index finger in line with the fork arm, and the pawl finger turned in over the bridge.

In watch repair yes you're supposed to pay attention but this is example of where you really have to pay attention otherwise well at least the fingers can be replaced. So they have to be at least one of them rotated out of the way to get the fork out. Then typically I rotated back and after the wheels are out I put the bridge back on to protect the finger when it's in the cleaning machine. Then when you're putting it all back together of course you remember to rotated out of the way and put it back etc. oh and remember to rotate it back before you put the screws in for the tuning fork because typically it sticks up too high and he can't get it past the screw head. So basically there's a lot of rotating that finger around to do things and it has to be in the right place or else, did I mention they can be replaced?

20 hours ago, ManSkirtBrew said:

Have you read about phasing the watch to run on silver oxide cells, or are you planning to use the Accucell?

Phasing on silver cells is interesting. Then yes you really should have a variable voltage power supply but there is something amusing about all of this.

For instance is a technical specification for their watches and notice I marked something? As we know running on a silver cell has too much voltage out of the package brand-new without a load you can get almost 1.6 V and they are originally designed for Mercury batteries so obviously that is way out of specifications but if that is true why on the technical sheet is there the high-voltage run  check? Which by the way is not mentioned in the service manual because normal service manual relies on using the normal meter and your source of power would've been the Mercury battery which cannot get to the voltages listed here

One of the amusements and watch repair is service manual versus the factory? Or sometimes service manual versus other technical documentation that you typically don't have. In one of the other discussion groups is somebody who worked at the factory and she had pointed out that they use a variable voltage power supply and they did test the watch at a higher voltage.

Then I'm attaching a PDF an interesting article about the problems of silver cells.

 

 

 

1996-08-web horological times Accutron silver cells phasing.pdf

[bobtheterrible]

Thanks Both!

The information you have both supplied will be invaluable for the rest of the project. It is good to know that I have not dug myself a hole with the pawl finger - I had already rotated it in line with the bridge in an attempt to shield it.

It sounds like the centre wheel might be a lost cause and due a replacement too.

23 hours ago, JohnR725 said:

I would recommend not following the lubrication  specification of whatever they say for the center wheel to avoid this ever happening again.

Just to be clear, do you mean more or less lubrication than the service manual?? My instincts say more! 

[JohnR725]

1 minute ago, bobtheterrible said:

Just to be clear, do you mean more or less lubrication than the service manual?? My instincts say more! 

We end up with a certain unknown here that style of wheel with friction is common a lot of watches but it's a classic in this watch if it freezes up it's because it's now stuck to the post with what looks like rust. So the best guess is that the lubrication they recommended went bad. My current favorite lubrication is 9504 but basically a grease should work fine just not the one that they recommended.

2 minutes ago, bobtheterrible said:

I had already rotated it in line with the bridge in an attempt to shield it.

Basically you just have to be really mindful of what you're doing which sometimes I have not been. So it needs to be rotated out of the way to get the fork out. But you probably want to rotated back when you put the bridge on because I have this vague memory of putting the bridge on and breaking it off or bending the heck out of it. So unfortunately a nasty more or less in a specific place when the bridge goes back on then at least you can clean it without damaging it

3 minutes ago, bobtheterrible said:

It sounds like the centre wheel might be a lost cause and due a replacement too.

Then yes this is a definite problem sometimes we take them out they will practically literally spin with a puff of air because they are so incredibly worn out . But because you have nothing to lose you can try to tighten it. I think I've seen people use concave punches in the staking set in an attempt to squeeze and bring the metal in word not quite sure how you want to do this but you try something is worth a try

 

 

[bobtheterrible]

Oh thats a shame. The battery leak reacted with the bridge plating. Its not serious but spoils an otherwise blemish free part.  The main-plate seems to be relatively unscathed tho so small mercies.

The tuning fork screw finally budged but will admit it looks less than new now. Its a learning experience...

I am also looking at the main wheel - I have cleaned it, soaked it in Evapo-rust (at this point I figured why not) and cleaned again. The pinion still appears to be frozen.

Before I proceed, I will just ask the question to those with more knowledge - if I run the bridge through my watch cleaning machine with the usual L&R cleaner/rinse solutions am I at risk of damaging the various rubber grommets?

[JohnR725]

2 hours ago, bobtheterrible said:

rubber

they're not rubber this some form of plastic and they go through the cleaning machine just fine.

2 hours ago, bobtheterrible said:

The pinion still appears to be frozen.

it is still stuck on the tube?

[bobtheterrible]

4 hours ago, JohnR725 said:

they're not rubber this some form of plastic and they go through the cleaning machine just fine.

Thats good to know, thanks!

4 hours ago, JohnR725 said:

it is still stuck on the tube?

No, sorry I was not clear, I meant to type centre wheel assembly (109). The centre wheel and pinion eventually came away from the centre tube, but the centre wheel was frozen to the pinion i.e. the friction-fit between the two was such that, in the end I had to put the pinion in a pin vice and manually rotate the wheel to free it up. I was expecting to be loose.

[JohnR725]

1 hour ago, bobtheterrible said:

I was expecting to be loose

it should spin loosely if it's worn out but coming apart you will always have to pop them apart. Resting it on a whole on the bench block you can push on the setter and that it should pop out.