Revisiting my first project - Things I learned and new stupid things I did this time!

[ColinC]

Back in February I attempted to disassemble and reassemble my first watch. I learned a lot but it could hardly be called a success.

This week I decided I would see if I was up to the task of getting it running again.

My first attempt was just to disassemble and reassemble - I started with a watch that looked pretty simple and was running (probably not well  but at least it ran and could be set). I chose to work on an AS1130  - with hindsight this is a nice easy movement to work on but I found it was quite rare and expensive / difficult to find spare parts or donor movements.  If I were to choose again I think I would choose an ETA 2390 - there appear to be plenty of these (or the ETA 2409 - roughly the same but with a date wheel) - available at bargain prices ( <£20)

I managed to get it back together but afterwards it wouldn't run for more than a few seconds before stopping again.

This is probably where I made my first mistake - I convinced myself it was a problem with the balance / balance spring - so after much messing around I eventually slipped and destroyed the hairspring in an attempt to diagnose / fix.

I then, made another uniformed choice and purchased a new (NOS) hairspring for this watch.

When the hairspring arrived I realised I needed more stuff - or more precisely I learned that you should order a "Balance Complete".  The watch and hairspring have remained in my cupboard until this weekend.

This weekend I spent about 10 hours on this watch - most of that was spent in a trial and error effort trying to fit the hairspring I had bought to the balance.

I started by removing the stud from the old hairspring .  I have learned from previous experience not to waste your time trying to reuse the pin (Old pins that have been trimmed are so small and difficult to handle and because the narrowest part has been trimmed off they are next to impossible to get back into the hole).

I then attached the stud to the end of the new hairspring using a new pin making sure I had the stud the right way up.

I think I have now discovered what happened with that other watch I posted about where I couldn't get the balance to swing fast enough - I guess someone there broke the balance and then bought a new hairspring and then just put it in without calibrating / finding the balancing point before selling it again on eBay.

It took many iterations of moving the stud further and further down the hairspring and twisting the collet so that the impulse jewel was roughly in place before I found the right point.  I had to resort to attaching the seconds hand to the movement and timing how long it took to go around 1 minute and once I had got it down from 70 seconds to roughly 60 seconds I could then use the time grapher to help me narrow in on exactly the right place.  I am not sure if there is a better way of doing this without a very expensive "Hair Spring Vibrating Tool" .  In this case, I found the vibration point was about 2.5 loops of the coil in.


The watch now works again ( but I still need to clip the pin and the remaining excess hairspring ( I used nail clippers to shorten the hairspring but want to get a proper set of cutting tweezers to do the job safely when I get close to the delicate stuff)

Edited December 17, 2023 by ColinC
correction

[watchweasol]

Hi well done for getting this far, Cutting tweezers would be better than nail clippers unless you can get some good ones with straight jaws.

[nevenbekriev]

Hi, good job so far.

Of course, there is much easier and faster ways to do the job.

Vibrating the hairspring is easy to do by the help of another watch with the same BPH. You can use this watch as reference, as one use the vibrating tool. Of course, it is not the same like with vibrating tool, but is not so much different. And, You will not be able to find vibrating tool for another BPH but 18000.

You just grasp the haitspring with tweezers where You think the point must be and hold the balance above glass surface in a manner that it hangs on the spring but the down pivot reass on the glass. Then, You must make the balance oscillate. You can do that by moving the tweezers up-down 'in beat' with the oscillatios, some time will be needed to learn to do it. Or just use finger to give twist to the balance... Then, watching the balance and hearing the beat of the reference watch, You will see if the balance oscillates slowlier or faster than reference and move the point of grasping in or out, untill reaching the same frequency. Then, use the timegrapher to fine find the point of pinning in the stud.

The pin on the picture is put the wrong way. You can use nail clipper safely this way: put mark on the pin on the wider part after it is put well in the hole (together with the spring) Then take the pin out and cut where the mark is. Then pin the spring in the stud and cut the other end, together with the rest of the spring. You must be sure that this is the correct lenght!!!

[ColinC]

1 hour ago, nevenbekriev said:

The pin on the picture is put the wrong way.

Well spotted!! Actually that was an earlier photo where everything was the wrong way!!  The spring was upside down!

I have at least 1 more watch where I need to do something similar so thanks for the explanation of how to do it in a less random way!

I have let it run for a bit now and it seems to be my most successful project to date - I don't think I have ever got the amplitude of a 1950s watch over the magic 270° before