Runaway Regina Pocket Watch

[Stevelp]

Hey everyone, this one is a bit of a head scratcher me.  I have a 16S Regina pocket watch that was brought to me for a little TLC.  After servicing and replacing the 4th wheel due to the extended pivot being broken, it runs very strong.   I put the watch on the timing machine and got some puzzling results.  The amplitude looks very reasonable and beat error is a touch high but I will take care of that later.  The odd part is the seconds per day not registering and the timegrapher resets every 5 seconds or so. The trace that I do get so see seems nice and flat, looking like its only loosing a few seconds per day, but after setting the hands on the dial and actually keeping track of time keeping, the watch is extremely fast.  I moved the regulator all the way back to slow it but not near enough change.  I then moved out the 4 mean time screws and it is still fast.  I then have added 4 of the heaviest timing washers that I have on hand.  Still fast.  I have an identical parts watch that I transferred the hairspring from and still the same thing.  After all that, the watch with hands on it runs 25 minutes fast in 24 hours!  Ive never been down the rabbit hole quite this far to get things adjusted.  What would be the appropriate next step to check?  Would an incorrect mainspring strength affect things like this or would that just be an amplitude issue?  The amplitude quite strong, just curious if that could be a possibility?                         

[LittleWatchShop]

If you have a modern smart phone, could you take a super slo-mo video of the balance in operation?

[Paul80]

Remember that I am a novice and an idiot so this is probably not your problem but assuming it ran ok ISH before you worked on it, could it be the fourth wheel you changed, maybe it was off a different model and it has a different number of teeth.

I know  I am talking out the back of my hat again as I am often told but its worth a look, do you still have the old 4th wheel, give the teeth a count.

it will give you something to look at while waiting a more knowledgeable reply.

Edited January 19, 2023 by Paul80

[LittleWatchShop]

1 hour ago, Stevelp said:

Would an incorrect mainspring strength affect things like this or would that just be an amplitude issue? 

I too am an amateur...I worked on a Waltham PW recently that was slow until I put a new mainspring in it and now it runs great.  So, yeah, mainsprings can impact performance.

[Stevelp]

Thank you both for your quick replies!  I will try to get a video of it later today and get that posted.   Paul, your points are very valid!  The 4th wheel pivot was bad enough that it ran very poorly so I don't know how it ran when it was in working order.  I did compare both wheels under the microscope before I did the swap and they are both the same.  Ill maybe take some measurements and see if all of a sudden the mainspring is incorrect.  I'm kinda hoping as I'm running out of ideas!

[JohnR725]

If you had an older watch much older watch then the problem would be the timing machine doesn't know the frequency. Much older pocket watches ran at slower frequencies in the timing machine will time them but you have to manually set the machine this watch looks new enough that it should be running in 18,000.

Then you could try manually setting the machines 18,000 because for whatever reason is probably confused. Also if you don't have a graphical display the numbers will not be correct either the machine is just guessing with whatever it's trying to pick up. The graphical display has to look right then the numbers have to agree with the graphical display and then visually all of three should look the same and then their right. Sometimes if you've super low amplitude you can have goofy numbers on display there's a variety of other things that can happen

when you change the fourth wheel if the teeth are not quite right that might be an issue perhaps usually it's more of if you put the wrong gear in the hands will revolve that the wrong rates the balance wheel still should oscillate at the proper frequency. You also want to look very carefully at your hairspring make sure it's not touching the balance arms not touching anything at all and maybe even hold the watch your ear and listen and see if it sounds like it's ticking or clanging no it was at that hairspring is bumping in the stuff the timing machine will have issues with that to.

 

[Stevelp]

I wasn’t able to spend to much time with it this evening.  I took a slow mo video of the balance but am having trouble with the format and not being able to add the file to my post.  The spring looks nice and level and does so seem to be rubbing anywhere or have any coils sticking together.  The movement has been demagnetized as well.  One thing I did notice through the microscope is the spring is quite tight between the regulator pins and doesn’t have that little bit of freedom to bounce between the pins.  Could this be possibly contributing?

[Nucejoe]

In case variant calibers of Regina 16s were made, the new 4th wheel might belong to faster beater variants.

Compare the damaged and replaced 4th wheel, ie; count the gear and pinion leaves on the damaged and new 4th wheel.

Rgds

[JohnR725]

2 hours ago, Stevelp said:

quite tight between the regulator pins and doesn’t have that little bit of freedom to bounce between the pins.  Could this be possibly

Flat hairsprings need breathing room yours does not look flat it's over coil and the pins are supposed be as tight as possible but still allow the spring the slide through.

12 hours ago, Stevelp said:

25 minutes fast in 24 hours! 

I really need to improve my reading skills. I can't see the entire balance wheel check your balance wheel carefully make sure that you have pairs of screws. In other words it is a screw on one side there has to be one on the other side in the exact same position if you're missing one screw you would be running fast although usually it's about 16 minutes fast.

The other thing to check is make sure your balance wheel is  round. In other words it's really easy to squeeze the arms on a bimetallic balance wheel and bend them in and that would also speed you up. For instance looking at the picture above I snipped out something it looks like the arm is bent in but will hard to tell a picture like this

[Stevelp]

So a bit of an update!  I looked into all the great suggestions listed above.  All screws have pairs and the balance is nice and round.  The parts watch that I have had a bit of a bent hair spring so I decided to straighten it out the best I could and try it as it’s pretty much the last thing I could check at this point.  Sure enough it is much much slower!  I’m guessing the hairstyling must have been changed in a previous lifetime.  I found this strange as both hairsprings have the same amount of coils and seem identical, but obviously not!

[JohnR725]

19 minutes ago, Stevelp said:

Sure enough it is much much slower!  I’m guessing the hairstyling must have been changed in a previous lifetime.  I found this strange as both hairsprings have the same amount of coils and seem identical, but obviously not!

I'm not sure if this came up in the discussion above but hairsprings have to be matched to the balance wheel. Modern flat hairsprings are individually vibrated to each balance wheel therein. Watches with over coil springs the Springs are made first because they need a very specific characteristics for the over coil it's easier to pre-make the spring. Then the balance wheel is matched to that spring. So basically you could have 100 hairsprings a look identical but they're not there will be some very tiny differences that will show up with dramatic timing differences because they have to be matched

on the other hand if you're running slower how slow? In other words  within reason you can lighten the balance wheel. You still have to keep a pair of screws but find a pair that looks lighter than the rest other words physically smaller hands on how much weight you need to have to lose and take off to screws and see what happens. Slower is better because it means the balance wheels heavy you just need the lighten it if you can get the right screws to lighten the right amount.