Totally baffled. Seiko 4006A won't run. Ideas please !

[mikepilk]

After 6 years and about 60 watch rebuilds, I thought I was getting better at fault finding. But this one has me stumped. 

I've stripped, examined, re-tried many times but I've run out of ideas. Something is wrong somewhere.

Is anyone familiar with this movement, who could tell me possible problem areas ?

I cleaned a Seiko 4006A Bell-Matic, and unfortunately it fell off the Timegrapher (it was running 270° amplitude) on to the desk. 
It didn't seem a hard fall, but it broke the centre wheel pinion. So I fitted a new centre wheel+cannon pinion, and new second wheel.

Now it won't even run continually.

I examine everything under a microscope.

Balance - when blown with the puffer, oscillates for nearly 1 minute. Hairspring dead flat. Good end shake. Roller+jewel both secure.

Pallet - Jewels fixed (there wasn't much shellac so I added some). Fork at good height on roller, and no fouling . 

Gear train - all jewels and pivots examined under microscope. Each wheel tested separately and blown with puffer.
Full gear train + barrel can be turned by blowing with the puffer on the escape wheel - see below.

Barrel - when wound with screwdriver there is good resistance, and more than 6 turns to let down. Arbor turns freely in barrel, and no excessive wear in brige or mainplate.

Looking at all angles under the microscope, I can't see anything touching that shouldn't be (eg long screws in the wrong place).

If I 'help' by turning the barrel arbor screw with a screwdriver, the balance spins nicely. So doesn't seem to be the pallet/balance ?

I can't understand why, what seemed like such and innocuous fall, should cause such a problem 

 

 

[Nucejoe]

Hi Mike, let me wish you happy holidays since this one can ruin a holiday.

I suspect a fault in escapement especially pallet-escape teeth damage, pallet move/misalighned, cuz giving barrel/ gear train more power can force an escapement at pallets-escape teeth, as long as the lock is not heavy there.

Good luck.

[mikepilk]

26 minutes ago, Nucejoe said:

Hi Mike, let me wish you happy holidays since this one can ruin a holiday.

I suspect a fault in escapement especially pallet-escape teeth damage, pallet move/misalighned, cuz giving barrel/ gear train more power can force an escapement at pallets-escape teeth, as long as the lock is not heavy there.

Good luck.

Hi @Nucejoe, happy holidays to you.

I did suspect the pallet could take some damage in a knock.

I just took another look, and the entry jewel is angled down a touch. Is that enough to cause such poor performance?

[Nucejoe]

I would say if angled "yes". 

My word is based on the fact that extra torque does force escapements which wouldn't with regular barrel torque.

[mikepilk]

I'll get the pallet warmer out tomorrow and straighten it up.

[Nucejoe]

23 minutes ago, mikepilk said:

I'll get the pallet warmer out tomorrow and straighten it up.

Beat adjustor arm( stud carrier) commonly gets knocked out of beat, so I check tgat too.

[JohnR725]

43 minutes ago, Nucejoe said:

I would say if angled "yes". 

In addition to being angled it also indicates that it broke the shellac to do so. This would mean conceivably it's loose and could wiggle up and down.

3 hours ago, mikepilk said:

but it broke the centre wheel pinion. So I fitted a new centre wheel+cannon pinion, and new second wheel.

Personally I always get concerned about changing components in a watch. This is because typically am working on vintage and components tend to vary in size or just be different. But this is a modern watch it shouldn't be a problem but you did change components. So basically conceivably you now have two issues whatever happens from being dropped if anything and new components.

[mikepilk]

13 minutes ago, JohnR725 said:

In addition to being angled it also indicates that it broke the shellac to do so. This would mean conceivably it's loose and could wiggle up and down.

There was very little shellac on, and the jewel did seem loose when I checked - though it's not easy, as checking can cause it to break the shellac.  That's why I added more shellac.

[Melt]

Maybe too much play in barrel arbor bushes is causing the barrel to bind?

 

[mikepilk]

4 minutes ago, Melt said:

Maybe too much play in barrel arbor bushes is causing the barrel to bind?

 

The arbor bushes are OK, with little play

[mikepilk]

20 hours ago, Nucejoe said:

I would say if angled "yes". 

My word is based on the fact that extra torque does force escapements which wouldn't with regular barrel torque.

I reset the pallet jewels nice and flat. Stripped and examined everything once more. All gears run freely, I'm happy with the barrel/arbor/mainspring. 

It ticks over, just : 20 - 30 deg amplitude !  Which makes examining the pallet/escapement under the microscope easy.

The pallet jewels look to be set OK. And as the balance swings so freely, I'm pretty sure it's something in the gear train.

I've run out of ideas. I'd start swapping parts but I can't see anything wrong.

I guess I'll just have to look for a replacement movement, and strip this one for spares.

Pity, as when it was first on the timegrapher, I was seeing 270°, which for a Seiko, is a first for me !

I've never been beaten before (nearly was with a 19J Smiths movement which I stripped 4 times before discovering the 'new' mainspring was duff. It wasn't hardened at all). But I'm ready to wave the white flag on this one.

Edited December 22, 2020 by mikepilk

[Nucejoe]

Hi Mike,

This is a tough one to fault find.

Could the roller have gotten knocked grossly out of beat?  or impulse jewel gotten loose? 

I take it you have none of the parts to bell complication on mainplate and have

checked end shakes and side shakes on all arbours starting from fork back to the barrel. Barrel lid might have got knocked and sit unlevel now, so pushes on barrel arbour or MS coil, even rub on its own bridge. You may even see an arbour wobbling.

Loosen bridge screws one at time to see if more power flows through the train, A bridge can gather pretension stress, specially if it got knocked as it landed.

Sure it would have been nice to have a scrap to keep swapping parts.

Regs 

Joe

 

 

[Nucejoe]

3 minutes ago, Nucejoe said:

Hi Mike,

This is a tough one to fault find.

Could the roller have gotten knocked grossly out of beat?  or impulse jewel gotten loose? 

I take it you have none of the parts to bell complication on mainplate and have

checked end shakes and side shakes on all arbours starting from fork back to the barrel. Barrel lid might have got knocked and sit unlevel now, so pushes on barrel arbour or MS coil, even rub on its own bridge. You may even see an arbour wobbling.

Loosen bridge screws one at time to see if more power flows through the train, A bridge can gather pretension stress, specially if it got knocked as it landed.

Sure it would have been nice to have a scrap to keep swapping parts.

Regs 

Joe

 

 

Oh is it seventeen jewels, is center hole jeweld or is it metal hole?

[mikepilk]

20 minutes ago, Nucejoe said:

Oh is it seventeen jewels, is center hole jeweld or is it metal hole?

The centre wheel is jewelled both ends. I checked that the jewels haven't been moved in the fall. 
The centre seconds wheel isn't jewelled at the top.

I checked all that you mentioned in the previous post - all end shakes and trueness of wheels. They all spin freely.

I took the barrel apart to check that the arbor spins freely with no mainspring. Checked that the lid is properly fitted, then put it in the movement to check it spins freely. Holding the barrel in my fingers and hand turning the ratchet wheel, the spring seems to wind/let down smoothly without binding.  

I did loosen bridge screws - didn't have any effect. 

I just removed the balance to check that the collet wasn't loose. The roller is secure, as is the jewel.

I have none of the bell parts on the mainplate. Just the keyless work and gear train.

If I wind the mainspring, it picks up and runs well for a few seconds, then slows down until it's barely running.

As these watches become more collectable, good scrap movements are harder to find, and getting more expensive.

 

[Nucejoe]

If strong enough to break the center pinion,  it could have moved or knocked a jewel unlevel, or slightly bend center tube.

Do you wind through ratchet screw?   if so you are pushing on the screw hence on barrel arbour, that can push the arbour or barrel down enough to let free a possible rubbing, rubbing might take place inside the barrel.

Funny, we can't see a fault thats starring at us. 

Regs 

Joe

 

 

 

[JohnR725]

19 minutes ago, Nucejoe said:

Funny, we can't see a fault thats starring at us.

This is actually a problem with the discussion group as a whole. We can't see the problems at all because we can't hold the watch in our hand. We rely on the original posting person to give an adequate description of whatever they are seeing. But the problem is if whatever you're seeing isn't registering then none of us can see the problem. Then unfortunately with watch repair we do get problems like this.

On 12/21/2020 at 7:11 AM, mikepilk said:

I examine everything under a microscope.

I tend to have a different view of microscopes then other people. It's a common feeling in watch repair the microscope allows you to see things better and it does not. It allows you to see things bigger and bigger isn't necessarily better? You still have to understand what you're looking at.

Perhaps another way to think about this looking at the forest with a microscope you can see the needles on the pine tree. The problem is you can't see the tree or the forest for that matter.

On 12/21/2020 at 7:11 AM, mikepilk said:

cleaned a Seiko 4006A Bell-Matic, and unfortunately it fell off the Timegrapher (it was running 270° amplitude) on to the desk. 
It didn't seem a hard fall, but it broke the centre wheel pinion. So I fitted a new centre wheel+cannon pinion, and new second wheel.

Now it won't even run continually.

Sometimes I'm amused with my reading skills lacking. Yes I read that but for some reason I kept thinking it fell a greater distance. Probably because when I was timing my own personal pocket watch on the timing machine at work it didn't like the pocket watch And maliciously tossed it off the microphone and it hit the floor and broke the balance Staff. Here just being thrown onto the desk you're right that shouldn't of been that bad not for a wristwatch?

What was the condition of the watch before you serviced it? In other words how was running and did you have it on the timing machine? There is always the possibility that there was an issue with the watch and you didn't have enough time to run it afterwards to find the problem. So you conceivably may be still dealing with original problem perhaps.

Then a momentary distraction when I was looking for something. One of the things interesting about the 4006 watch is it's one of the few technical bulletins that actually specifies the amplitude that Seiko is expecting. So the minimum amplitude that's acceptable for this watch is 180° which is always amusing for everyone obsessed with more amplitude.

3 hours ago, mikepilk said:

I checked all that you mentioned in the previous post - all end shakes and trueness of wheels. They all spin freely.

Yes and action rereading everything for the most part it looks like it should run? Except for the minor problems with checking each of the wheels and checking everything without having the pallet fork in is that they will a lot of times feel free. More common and clocks were there is way more pressure on things if the bushings her oval in shape without pressure they will feel fine but under load they will not. With just the pallet fork in it and the watch wound up gently push on the pallet fork doesn't snap nicely? If not then your problems in the gear train.

Reading through it looks like it should work. There's another option here take a break Go away don't touch it for a day or two yes I know that's really really hard. Then when you look at it again you're more likely to see things that you just can't see right now. Those really obvious things like the elephant in the room that one day You notice has elephant always been here?

6 hours ago, mikepilk said:

Pity, as when it was first on the timegrapher, I was seeing 270°, which for a Seiko, is a first for me !

This is a really long shot and it does not help at all but visually was the balance wheel going at 270? The reason I bring this up it's a common problem of all timing machines if the amplitude is too low or it's noisy the machine will read the wrong part of the signal and give you something like this. So it's not entirely helpful I'm pointing out that may be perhaps the amplitude wasn't 270 it only looked that way on the timing machine but as I said that's absolutely no help for the problem at all.

I found what I was looking for was the tech sheet and it's been a long long time since I've worked on one of these as I remembered it's complicated. So obviously for diagnostic purposes right now all you want to have in the watch is just whatever you need to get power from the mainspring to the balance wheel and nothing else.

 

 

[mikepilk]

2 hours ago, Nucejoe said:

If strong enough to break the center pinion,  it could have moved or knocked a jewel unlevel, or slightly bend center tube.

Do you wind through ratchet screw?   if so you are pushing on the screw hence on barrel arbour, that can push the arbour or barrel down enough to let free a possible rubbing, rubbing might take place inside the barrel.

Funny, we can't see a fault thats starring at us. 

Regs 

Joe

 

 

 

Good points @Nucejoe. I have to wind through the ratchet screw as this movement doesn't wind through the crown. I'll take the top off the barrel again and have a look. The spring did measure as correct. I don't want to take it out again as it's reverse wound, I don't have reverse winders, so I have to wind it in to a washer, which is fiddly. Also I have to use the next smaller winding centre in the winder. Something obvious is wrong, I just need to spot it! 

[mikepilk]

1 hour ago, JohnR725 said:

This is a really long shot and it does not help at all but visually was the balance wheel going at 270? The reason I bring this up it's a common problem of all timing machines if the amplitude is too low or it's noisy the machine will read the wrong part of the signal and give you something like this. So it's not entirely helpful I'm pointing out that may be perhaps the amplitude wasn't 270 it only looked that way on the timing machine but as I said that's absolutely no help for the problem at all.

I found what I was looking for was the tech sheet and it's been a long long time since I've worked on one of these as I remembered it's complicated. So obviously for diagnostic purposes right now all you want to have in the watch is just whatever you need to get power from the mainspring to the balance wheel and nothing else.

Hi @JohnR725, you make some interesting points, and I agree, I need to step away for a few days and ponder.

I am fairly confident the amplitude was about 270° when it fell off the timegrapher. I was using the service sheet you posted from and was surprised the amplitude listed was only 180 deg. That was what I was testing when it fell off ! (The lift angle is 58.4 for this movement, and I was seeing about 240 deg).

In these situations, stepping away and thinking is the best option - tinkering can cause more problems.

[steve1811uk]

It's it possible that the centre second wheel upper metal bush has been moved slightly and reduced end shake? I personally have encountered that on a 7006 where that bush also doubles up as the arbour for the winding weight. I pushed down too much when tightening the winding weight screw and dislodged the bush slightly causing the watch to stop running. I removed the bridge and could see under a microscope that the bush had moved very slightly. I pushed it back flush to the bridge with the flat handle of my tweezers and has been fine since.

[mikepilk]

7 hours ago, steve1811uk said:

It's it possible that the centre second wheel upper metal bush has been moved slightly and reduced end shake? I personally have encountered that on a 7006 where that bush also doubles up as the arbour for the winding weight. I pushed down too much when tightening the winding weight screw and dislodged the bush slightly causing the watch to stop running. I removed the bridge and could see under a microscope that the bush had moved very slightly. I pushed it back flush to the bridge with the flat handle of my tweezers and has been fine since.

Good idea. Just re-checked all bushes and jewels, and they're all at the correct heights. End floats of all gears and pallot with mainspring wound are good. Took the top off the barrel, no signs of rubbing.

Here are some videos of parts blown with a puffer (no lubrication) :

Just the barrel - no other gears:

Just the centre wheel :

Gear train (centre, centre second, third, escape) NO barrel :

 

 

 

 

 

 

Edited December 23, 2020 by mikepilk

[mikepilk]

Very strange. Re-assembled yet again today, and suddenly I'm seeing 220° amplitude (no lubrication).

Took it apart, lubricated and ...... back to barely running !

I need to check the barrel/train wheel bridge for flatness - maybe it's the order I'm doing up the screws.

When I disassembled the watch, all the screws were very tight - surprised there were no broken screws or stripped threads. Maybe the previous owner distorted something,

 

Edited December 24, 2020 by mikepilk

[mikepilk]

Problem sorted !   I'll explain, as it may help others.

I found the problem by checking the barrel with a straight-edge. The bottom was bowed in slightly, restricting the mainspring. When I wound with a screwdriver it gave me the impression of good spring resistance. 

You were right @Nucejoe when you said "possible rubbing in the barrel".

It happened because I was using my new barrel closing tool. It has a concave surface on the bottom (black bit) so that the pressure is on the outer edge of the barrel. I hadn't spotted that the inside of the top bit is flat, and that this barrel has a raised section on both top and bottom. So pressing too hard (which I probably was) results in the barrel being pushed in. This explains why things got gradually worse every time I took it apart to check. 

It's something I should have checked sooner.  But it's now something I won't forget.

I have since used a drill to make a slight depression on the top surface of the tool.