Seiko 7017 - low amplitude

[Khan]

Hi 

I have cleaned, oiled and assembled the watch. But when Chrono running, the watch stops around indice 2. The Chrono wheel (4th wheel) is straight from all angles. I see a bit wavyness when pallet fork removed and let the wheels run freely with Chrono activated. When not activated, the wheel runs straight round.

But there is some resistance when Chrono is stopped. I tried many scenarios by removing each part to diagnose location of the problem. I realised that the barrel Arbor is sticky when removed from the movement plate. So it doesn't sit smoothly in the hole in the plate. Had to pull the Arbor a little to release it.

The balance runs smoothly without pallet fork installed. When shaking the watch, the amplitude seems good and decreases after some minutes. The pallet fork seem to have good force when banking right and left.

I have posted some images before service and let me know if other images needed for inspection. Thanks alot. 

Edited November 17, 2022 by Khan

[Khan]

Anyone that can help? 

[Ammar]

I remember seeing someone with the same problem on youtube but I can't remember who they were or how they solved it. I think it was Mike from My Retro Watches.

[Nucejoe]

22 hours ago, Khan said:

 But when Chrono running, the watch stops around indice 2. 

 I would ink mark all points of contact ( where it stops)  and examine each part ( under high magnification)  near the marks. 

Is this a new mainspring or the old one been presumed strong enough? 

Would adding a bit of power to the barrel help? 

Rgds

 

 

 

 

 

 

[Khan]

Hi Nucejoe 

Okay, will have a closer look of the train wheels in particular. 

I used the same mainspring assuming it has enough strength.

When I turn the barrel wheel screw and put power into the mainspring, while pallet fork removed, the train wheels stops for a while and runs again if I put more power into the spring. I guess it´s either resistance in the lower arbour pivot or damage on one of the train wheels. I´m confident with the chrono parts are intact. 

[Nucejoe]

2 hours ago, Khan said:

When I turn the barrel wheel screw and put power into the mainspring, while pallet fork removed, the train wheels stops for a while and runs again 

 Thats where the  " HOT SPOT "   comes into action, actually when the fault faces & engages with the adjacent component of the train including the yoke/springs. for all we know the rough spot can be on tip of a yoke spring.

Good luck 

[Khan]

So what you are saying is that the barrel possibly is touching the very long yoke spring beneath on the dial side ? 

Edited November 18, 2022 by Khan

[Nucejoe]

5 hours ago, Khan said:

So what you are saying is that the barrel possibly is touching the very long yoke spring beneath on the dial side ? 

 No, This is not what I was talking about( though its a possibilty) .  In general a fault can be anywhere. 

 Stopping and running again as you add power to the barrel, INDICATES A FAULT WITH GEARS/ PINIONS  OR CAMS or ARBOURS. 

but gears and cams engage with yokes,  so I examine the yokes as well  and polish them where I deem needed. 

Rgds

 

 

 

 

[Khan]

Okay, so I inspected further and figured this out: 

When I tighten the top screw for the flat wheel on top of the barrel (image 3), the barrel tilts downwards on right side of the image 1 and make resistance with the bridge of centre wheel (image 2) and the bridge above barrel. When I don't tighten the barrel screw, the barrel lays flat. And the barrel screw aren't bent either. Now I just don't know where the fault is

Edited November 19, 2022 by Khan

[Nucejoe]

 Further investigation is needed to reveal whats causing the barrel to rub on center wheel's bridge, most common causes are as follows.

1-  Incorrectly seated barrel lid, The lid should be seated flush level in the barrel , if tilted or not flush ,it can rub on the barrel bridge or center bridge or center wheel. if seated too deep in the barrel it rubs on the mainspring. 

2- Bent bridge( barrel bridge or center wheel's bridge )  or bent center wheel.

Turn the barrel while observing the center wheel, if the wheel is bent it wobbles as it turns, unbend it to streighten the wheel.

 

 Streightening a bent bridge is kinda hit and miss game, I would just shim the bridge to free whatever rubs, cut a shim out of real thin aluminum foil to place  in between the bridge and mainplate so to raise the bridge, you need to find which bridge to raise and the location the shim should be placed. 

3- Damaged barrel teeth .

Good luck pal.

 

[Khan]

Hi Nucejoe 

Appreciate your time for giving ideas. 

I figured out that the barrel tilts when putting power on the barrel by turning the screw, when pallet fork installed. It actually runs freely and smooth (with and without Chrono on) when pallet fork not installed and turning the screw head on top. I noticed that the barrel tilts when I push on the left side of the barrel top wheel, see last picture. So this barrel wheel gets wavy when tightened with top screw. What could be the reason? 

Edited November 20, 2022 by Khan

[Nucejoe]

Hi khan,

52 minutes ago, Khan said:

 I noticed that the barrel tilts when I push on the left side of the barrel top wheel

Its due to excessive side shake on barrel arbour, which in turn is caused due to worn bushings in the mainplate or barrel bridge or the arbour itself is worn thin. 

I remove just the ratchet wheel and check the barrel arbour's side shake, you should feel almost zero side shake. 

Good luck pal.

 

 

 

[Khan]

Hi Nucejoe 

The barrel bridge seems to have too big bushing compared to arbour diameter. I wonder why so much difference. There is also wear beneath the barrel bridge where the barrel touches - will it help with some grease to minimize resistance? I can tilt the barrel by moving it vertically with a tweezer around barrel teeth and also by moving the arbour horizontally on top. But when the mainplate is installed, then the arbour top doesn't move horizontally but moves/tilts when moving vertically around barrel teeth. I also replaced the mainspring with a better one as the old one was not aligned good enough when laying on the table. 

[mikepilk]

What acts as a bearing for the top of the barrel arbor ?  There looks to be a large gap between the arbor and the barrel bridge.  

[Nucejoe]

27 minutes ago, Khan said:

 I can tilt the barrel by moving it vertically with a tweezer around barrel teeth and also by moving the arbour horizontally on top. 

 

Hi Ammar,

You have spotted the fault, completely worn out or missing the mainplate bushing. 

Your local watch maker might source you the bush.

Rgds

[mikepilk]

7 minutes ago, Nucejoe said:

 

Hi Ammar,

You have spotted the fault, completely worn out or missing the mainplate bushing. 

Your local watch maker might source you the bush.

Rgds

That's what I thought - the bushing was missing. But looking at pics of similar movements, they look the same. Here's a pic from WatchGuy's site :

Hence my question of what supports the arbor top.

[Khan]

Should there be a bushing anyway? 

Can't see one in the parts list. 

I also wondered by there would be such a big gap between the plate and arbour. Both interfaces looks smooth and healthy to my eye. 

Edited November 21, 2022 by Khan

[Khan]

I just talked to Christian from watchguy.co.uk - he told me that if there is side shake, it needs to be re-bushed.

[mikepilk]

I don't know this movement. I didn't realise the pic is of the chrono layer, and there is a bridge to go on top. The top barrel bearing is in the top bridge, where you need to check for wear

 

Edited November 21, 2022 by mikepilk

[Nucejoe]

10 hours ago, mikepilk said:

So the bushing is in the plate which is to be mounted on this, 

I call it the mainplste buz it is to hold arbours of  escape and sweep wheels. 

 

4 minutes ago, Nucejoe said:

I call it the mainplste buz it is to hold arbours of  escape and sweep wheels. 

 

In other words, I called mainplate what you say is the top bridge.

[Khan]

I think I have a solution. 

I placed one dial adhesive dot below barrel bridge to raise it - Close to where barrel was hitting the bridge. I now have a straight space between the bridge and barrel and the barrel runs straight horizontally. I checked all this without the Chrono parts. With balance and power on, the amplitude was around 230 so not bad at all. BUT when turning dial side up, the watch stopped. I assume the hairspring stud was touching the balance wheel which was running wobbly possibly caused by worn pivots. So I'm out for sourcing a new balance. I bet the 7005 balance must fit? 

Edited November 21, 2022 by Khan

[thor447]

4 hours ago, Khan said:

I bet the 7005 balance must fit? 

Seiko parts manuals show the same balance complete for both 7017A and 7005A movements.  All of the following movements share the same balance complete assembly (P/N - 310020)

Balance cocks will obviously differ.  The only one I found that shares the same balance cock as yours (P/N - 171033) is the 7018A.

[Nucejoe]

 Have you checked the balance pivot for wear?    And if shimming the bridge creates new problems then shimming isn't  the right approach. 

We are still not sure of the exact cause of the wobble in the barrel nor that of the balance. 

Rgds

 

 

[Khan]

Surprisingly, the barrel isn't wobbling now. I guess the alignment of the barrel bridge by the adhesive dial makes the connection between arbour and barrel bridge more stabilized. 

How do I analyze if there is wear on the balance pivots? I can take a image later in the evening. 

[Nucejoe]

1 hour ago, Khan said:

How do I analyze if there is wear on the balance pivots? I can take a image later in the evening. 

Best to examine pivots under high magnification. 

The magnification in previous picture you posted should suffice, we will at least see if a pivot exists.