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, 2023 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.

[bobtheterrible]

An update.

Not a good day.

I finally got the watch back together and running. I set it down next to one of my automatics and could immediately see that it was running fast. Also, I wasn't sure, but it seemed like there was a pulsing motion to the seconds hand. However, this could have been an optical illusion of my eye trying to follow the hand.

It was late and I would look at the pawl adjustment in the morning (at this point, I don't have the right kit for phasing). Come morning, the kids had gone to school and I had just brewed a coffee - it was my day off and I was looking forward to it.

I needed to remove the retaining spring of the back of the movement. First screw and I slipped straight into the hole where the fingers are visible. Sighed, stepped away, finished my coffee, went for a walk, contemplated my life choices.

It was a disaster. Both fingers had been mangled. I had also gone in with enough force to bend the finger posts! I went for another walk.

At this point my options were to look at dismantling a perfectly functional spare movement or try to somehow fix the damage. With nothing else to lose, I figured I would see if it were possible to straighten out the fingers and reposition the posts.

I separated the fingers form their posts and very gently, with a pair of brass tweezers and a microscope, I managed to reset the posts on the fork and pawl arm back to more-or-less vertical.

The fingers required a lot more fiddling. Where ever there was a kink I needed to place the tweezers in such away that when bending, the kink would straighten out rather than add a new kink. I also needed to readjust the vertical positioning of the fingers and stays as they had all been forced down. Lots of bending and preening at 20x magnification.... 

I reassembled everything without much hope that the hours of work I had just put in were going to pay off and installed the battery. It started running!! I have no idea if it is running "well" but it is running. Im also guessing I may have weakened the fingers so will be keeping an eye out for future spares...

I did not take any pictures of the damage (I really should have done for this thread) as I was simply too angry/embarrassed. I will get a better final shot when I have better lighting. 

This was.... a learning experience.

 

 

[JohnR725]

15 minutes ago, bobtheterrible said:

Also, I wasn't sure, but it seemed like there was a pulsing motion to the seconds hand. However, this could have been an optical illusion of my eye trying to follow the hand.

Yes the dreaded is my second hand really doing what I think it's doing? It's one of the annoyances I have a work with LED lighting I sometimes wonder if it has a strobe effect and then the second hand never looks right at all. Although I do have a 214 network that's definitely surging.

 

17 minutes ago, bobtheterrible said:

I reassembled everything without much hope that the hours of work I had just put in were going to pay off and installed the battery. It started running!! I have no idea if it is running "well" but it is running. Im also guessing I may have weakened the fingers so will be keeping an eye out for future spares...

As long as it's running I wouldn't worry about it too much. Other then try not to look at the second hand because they always look like there's surging it's quite annoying. Then unfortunate reality is if you're going to work on tuning fork watches spare parts is definitely an issue. Although brand-new spare parts do show up on eBay from time to time.

Oh and if you go to the link below search for 214 or 218 they don't have much at least they have the gaskets and an index wheel for the 218 which is quite rare. Otherwise the best places eBay for parts and of course watches To be cannibalized for parts

https://www.jewelerssupplies.com

 

 

[bobtheterrible]

Final post.

I had a go at phasing the movement using the link provided by @ManSkirtBrew tho I did struggle with step 4:

Quote

4) At this point, raise the power supply voltage to about 1.75v. See if the index wheel is running normally or fast. If fast, then very slowly adjust the cam a small amount either way to find a spot where the watch again runs at normal speed. Be very careful not to depart too far from the original position found in step 3, or you might end up in another "cycle" of phasing (ie. + or - 1 whole tooth) whereby the pawl finger tension would be wrong.

I mean... how do you tell if it is turning normally or fast without putting the hands back on and running it???

But it appears to be running at a more normal speed compared to before I tried to phase it.

 

OK, so here is a pic of the fingers after I had straightened them out. If you look closely at the root of the pawl finger you can see there is still a kink that I could not quite get to. The index finger has a scar from where I made contact with the screwdriver... Lessons learned...

Random step-down power supply purchased off Amazon (verified the voltage using my multimeter just to be sure)

And finally, after it is all beck together.

 

Many thanks @JohnR725, @ManSkirtBrew for your help and advice!

Edited October 13, 2023 by bobtheterrible

[ManSkirtBrew]

Kink or no kink, I'd call that a job well done.

19 minutes ago, bobtheterrible said:

how do you tell if it is turning normally or fast without putting the hands back on and running it?

I thought this exact same thing when I read the procedure, but when I was phasing my 219, the change in speed was very obvious. I tried to capture it on video here, but I think I need a better frame rate to really get it.

 

[bobtheterrible]

Thanks!!

6 hours ago, ManSkirtBrew said:

I thought this exact same thing when I read the procedure, but when I was phasing my 219, the change in speed was very obvious. I tried to capture it on video here, but I think I need a better frame rate to really get it.

Hmmm.... one possibility is that the variable power supply I was using was very slow to change voltage. I probably would not have noticed any gradual change in speed. I left it for an hour next to a watch I trusted and it seemed to be keeping time. Its close enough for the moment.

[JohnR725]

5 hours ago, bobtheterrible said:

I mean... how do you tell if it is turning normally or fast without putting the hands back on and running it???

  I snipped out something from one ear images I assume you're using a microscope to do the phasing?

Now let's look at something else a design improvement I wonder what that improvement was?

One of my complaints about people who obsess about using their microscope to see better is you don't. Well you argue with me you do but here's a problem if you look at the two images on the 219 they improved something is even though were looking at it with probably a microscope we can see the index wheel. In your image were looking straight down and you can't see the index wheel which now presents a problem a big problem You can see the wheel next to it that will help but ideally you need to see the index wheel so if you really have to use your microscope which is preventing you from seeing the big picture then tipped the movement holder a little so you can look in because ideally you need to see the index wheel because you have to see what it is doing not the results of what it's doing if it's having a problem

now for party your question you didn't ask here's a different image of what phasing is. At work for instance my bosses decided phasing is speed control and he's even asked if I can move the regulator to make up for the speed difference in the answer is no. Phasing can be such a pain in the ass by the way you have to have everything where it's supposed to be an ideally a nice shiny clean index wheel.

So what is the purpose of phasing? Phasing achieves something almost magical and you'll have to study the image the magical aspect is as the tuning fork amplitude varies between One and two Teeth as it shows below the result of that amplitude difference is only one tooth is picked up and the wheel spins at its normal rate.

This is why in one of the documents I had where it talked about factory specifications they would even run the voltage up to 1.7 V to check to make sure the watch would work with the differing voltages a bad race.Because like in the case of a silver cell battery when it's brand-new and this watch represents such a tiny load initially it's almost 1.6 V.

Now what happens if things are not right then if you can see your index wheel it will go up in speed very fast it's not just a variable throttle control of slowly ramping up its speed it will go normal speed double speed and yes it's noticeable but you have to see the index wheel.

 

 

 

 

[bobtheterrible]

Ahh... So If I understand correctly, the speed up is because of double indexing - it happens when it happens?

So one of the goals of phasing is to ensure single indexing throughout the expected voltage range of the cell (please correct me if I am misunderstanding)?

I agree, it is somewhat difficult to see the index wheel through the microscope. I was mainly using it to set the jewel distances/tensions and assumed it would be useful during my attempt at "phasing". 

That diagram is super useful in understanding what is going on. 

[HectorLooi]

I think all of us who have attempted servicing an Accutron are familiar with this phasing diagram.

But all that assumes that the amplitude of the tuning fork is such that the index jewel travels a distance of between 1s and 2.5s over the entire useful voltage range of the battery.

But what all the literature out there doesn't explain is how to make the index jewel travel between 1s and 2.5s.

All they say is that there are some tuning forks out there that cannot be phased properly.

There doesn't seem to be any test equipment out there that is capable of measuring the actual travel of the index jewel. I think it is important to be able measure this travel distance before even attempting to do phasing.

It's like the amplitude of a conventional watch. If the amplitude is too low or too high, proper regulation cannot be achieved. 

I was at my mentor's workshop and we were playing around with his digital microscope and noticed that if the frame capture rate is adjusted, it can actually make the index jewel appear to move in slow motion. And the travel distance can be actually seen.

If anyone out there is into high speed photography or stroboscopic photography, I hope this information is useful to you to develop a "timegrapher" for tuning fork watches.

PS. I am tagging @LittleWatchShop here. If you are planning on developing an Accutron service centre, please read this.

[JohnR725]

8 hours ago, bobtheterrible said:

hh... So If I understand correctly, the speed up is because of double indexing - it happens when it happens?

It happens when the watches not say used correctly. We also get some minor discrepancies between the users mail instructions and the instructions there were taught if you took one of their classes.

When the electric watches came out Elgin, Hamilton and the Bulova had training classes because electric watch was a newfangled thing that the watchmaker didn't understand. Bulova studied Hamilton's failure at education and enhanced their advertising and training they learned from the mistakes of others. The problem though with Bulova is the tuning fork is so much different than anything else it definitely would be a confusion problem so they would have a training class that you could take for the basic course was two days and then later on they threw in a quartz class so would be a half day so for 2 1/2 days you to take an extremely intense and yes everyone there said it was the most intense class that ever taken. The two day class to learn how to phase 214 watches.

So I do remember that we crossed out some items in the book that they don't do and one of them is with one of the index fingers where I think it says half a tool thickness you basically just adjusted so it's off the index wheel's that's all it needs is basically a reference point where lifts off

Now maybe another way to look at all of this is a PDF of some light reading. So there is one of the instructors who was teaching the class of oh and the Bulova class unlike others had a written test and a practical test for which a few past you got a certificate. Where a lot of training classes from watch companies you got a certificate that you attended the class but here if you past you had a certificate with a number. Taxi a very impressive certificate consists laminated to piece of wood it looks really impressive

So it understand what's going on I have a PDF.

 

 

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

[LittleWatchShop]

9 hours ago, HectorLooi said:

I think all of us who have attempted servicing an Accutron are familiar with this phasing diagram.

But all that assumes that the amplitude of the tuning fork is such that the index jewel travels a distance of between 1s and 2.5s over the entire useful voltage range of the battery.

But what all the literature out there doesn't explain is how to make the index jewel travel between 1s and 2.5s.

All they say is that there are some tuning forks out there that cannot be phased properly.

There doesn't seem to be any test equipment out there that is capable of measuring the actual travel of the index jewel. I think it is important to be able measure this travel distance before even attempting to do phasing.

It's like the amplitude of a conventional watch. If the amplitude is too low or too high, proper regulation cannot be achieved. 

I was at my mentor's workshop and we were playing around with his digital microscope and noticed that if the frame capture rate is adjusted, it can actually make the index jewel appear to move in slow motion. And the travel distance can be actually seen.

If anyone out there is into high speed photography or stroboscopic photography, I hope this information is useful to you to develop a "timegrapher" for tuning fork watches.

PS. I am tagging @LittleWatchShop here. If you are planning on developing an Accutron service centre, please read this.

By adjusting the frame rate, you get what is technically called "aliasing" which in sampled data systems is sometimes harmful but in this case, helpful. Great application of it here. I wonder what kind of camera gives you a knob to adjust frame rate?

 

[LittleWatchShop]

3 hours ago, LittleWatchShop said:

By adjusting the frame rate, you get what is technically called "aliasing" which in sampled data systems is sometimes harmful but in this case, helpful. Great application of it here. I wonder what kind of camera gives you a knob to adjust frame rate?

 

BTW, I am not really setting up a service center.  I bought another house about 100 miles away to be close to my son's family (being a grandpa!).  We plan to spend about half and half between the two homes.  I agonized about my time away from my watch shop and did not want to replicate it.  Sooooo, I decided to focus on accutrons at the remote location because I only need a small subset of tools to work on them.  Aaaaand...I have about 50 accutrons in a box waiting for service.  I have yet to work on the first one, so I am starting at ground zero!!  But...I have many smart friends on this forum who will nudge me along.

[markr]

Sounds like a Accutron service center to me.

[bobtheterrible]

On 10/14/2023 at 12:40 AM, HectorLooi said:

I was at my mentor's workshop and we were playing around with his digital microscope and noticed that if the frame capture rate is adjusted, it can actually make the index jewel appear to move in slow motion. And the travel distance can be actually seen.

If anyone out there is into high speed photography or stroboscopic photography, I hope this information is useful to you to develop a "timegrapher" for tuning fork watches.

That is a very interesting idea - do you remember what sort of frame rates the camera was using to achieve aliasing?

My question from this is; what do you do if the index finger travel is out of specification? Is there anything to do or are you looking at replacing the fork?

In the end, my watch was about 7 seconds out before weight adjustments. Im pretty sure I did not "phase" this thing anywhere near correctly (thanks everyone for the discussion!) so perhaps I lucked out.

I did buy a few more accutron projects before realising what I had taken on - I am both more and less confident I know what I am doing going forward now... My next project is to find a case for this movement I found in a lot of other movements.

Again thanks everyone for the discussion.
 

Edited October 15, 2023 by bobtheterrible