Zero power making it from the mainspring to the pallet fork

[GregG]

1 hour ago, oldhippy said:

Normally you would hold one side of the balance staff in the chuck in your lathe while sharpening the other side with an Arkansas stone . This is the type I used and it's what you need.

https://www.hswalsh.com/product/arkansas-stone-type-triangular-size-92mm-x-10mm-ta75

Thank you for the link hippy.  My concern at this point is how to hold the balance in the lathe.  Chucks like on a lathe or a pin vise are good at holding simple cylindrical objects, like drill bits or a cylinder of whatever you're about to cut into.

But a balance is a complex surface and I'm having trouble envisioning how exactly it would fit into the lathe chuck.

[oldhippy]

I hope this explains it better.  I apologise for my crap drawing .

[GregG]

6 hours ago, oldhippy said:

I hope this explains it better.  I apologise for my crap drawing .

Thank you hippy.  I need to grab the top pivot of the balance and sharpen the bottom, but unfortunately, there is practically nothing to grab onto for the top pivot.  The chuck would essentially be grabbing just the conical portion of it, leaving all of the body outside, which I can see as a recipe for something snapping.

Concerning equipment, can this be done in a Jacot?  Lathes with the necessary parts seem to go for a minimum of $350, but I can find complete Jacot sets for ~$100.

Edited September 23, 2021 by GregG

[oldhippy]

If the jacot tool you are thinking of buying comes with the Jacot drum you should be able to sharpen the balance but if it only has the pivot holder then the answer would be no as the holes will not be big enough. Can you post a picture of the balance complete.  

[GregG]

1 hour ago, oldhippy said:

If the jacot tool you are thinking of buying comes with the Jacot drum you should be able to sharpen the balance but if it only has the pivot holder then the answer would be no as the holes will not be big enough. Can you post a picture of the balance complete.  

Can you elaborate on the difference, between the pivot holder and the drum?  If my understanding is correct, the side of the pivot that you're not sharpening fits into one rod of the jacot tool (I'm sorry I don't know the names of the parts).  That rod has a pin or a pair of claws that engage with the spokes on the balance wheel or gear.  The other side of the pivot that you are polishing rests in a disk with a set of divots.  You place the pivot into the divot whose depth is equal to the diameter of the pivot.  When you turn the first rod with the bow, the pin will engage the spokes of the balance and rotate it, as you burnish the other side.

The tool I'm looking at has all of the pieces I described above.  Is any of what I described the drum part of the tool, or is that something separate?

Edited September 23, 2021 by GregG

[oldhippy]

Here are the two parts. The one on the left is for pivots the drum on the right, the V's are used for you to rest parts in such as pivots and in your case the staff. These parts also come with watchmakers lathes. 

[GregG]

34 minutes ago, oldhippy said:

Here are the two parts. The one on the left is for pivots the drum on the right, the V's are used for you to rest parts in such as pivots and in your case the staff. These parts also come with watchmakers lathes. 

Thank you for the photo.  I ended up purchasing the tool for $75, and it appears to have three rods of the one on the right.  What is the difference between seating the pivots inside the holes as opposed to resting them in the V's?

Edited September 23, 2021 by GregG

[GregG]

And here's a photo of the balance complete.

 

[HectorLooi]

You have to remove the roller table and hairspring first to get enough grip on the arbor. You will need a staking set for this job.

[GregG]

1 hour ago, HectorLooi said:

You have to remove the roller table and hairspring first to get enough grip on the arbor. You will need a staking set for this job.

I'm not even sure what the function of the roller table is on this balance.  You can't see it from the picture, but the impulse pin is molded into the body of the balance.

[Klassiker]

4 hours ago, GregG said:

I'm not even sure what the function of the roller table is on this balance.

It is just a variant of the combined roller you are used to seeing, with the same functions. The roller table, through Interactions with the guard pin, only allows the pallet fork to move when the impulse pin is between the horns. This prevents accidental unlocking. You will need to accurately re-align the cut-out with the pin when you refit the roller.

[oldhippy]

Sorry for misleading you about the Jacot tool parts. Those I posted are not from a Jacot tool but from a watchmakers lathe. If your Jacot tool is complete you might find one of the rods that can take large pivots. 

That balance is different from the old Smith/ Ingersoll P/W. You might be able to remove the roller by putting your tweezers under it and try easing it off. When it comes to putting it back if you don't have a staking set but a pin vice you could use that as a stake, but be careful.  

[clockboy]

If you have a lathe it is very easy to make these that fit in the tail stock. I can testify that what OH has suggested it really makes a difference. I also have the tail stock tools OH shows 

 

 

 

[oldhippy]

clockboy he doesn't have a lathe. I wish he did it would make life easier.  

[GregG]

5 hours ago, oldhippy said:

clockboy he doesn't have a lathe. I wish he did it would make life easier.  

Well, if we want to start a GoFundMe page, I'm not opposed. XD

But unfortunately, this is one of those things where it's a balancing act.  I'm only a hobbyist, so buying a specialized piece of equipment might not be the best idea.  I have to balance how deep I want to go into this hobby with the rest of my life/responsibilities, closing on a house with my fiancée soon, getting married next year, putting money into the house to renovate it, probably kids in a few years, etc.  

The Jacot was only $75, not a huge investment.  Used watch lathes run about $500, new ones from China (of questionably quality, perhaps) are $1,000.  And if China is making them for $1,000, real Swiss ones are probably $5,000.

Back to the original point of the thread: is it possible that the mainspring is just old and worn out?  Most mainsprings I come across are large and have the backwards curl on one side.  The mainspring from this one is comparatively small.  It doesn't have the reverse curl; it's just a one-directional spiral.  And even in it's natural resting state, the diameter of the coil is only about double that of the mainspring barrel.

[oldhippy]

From that description of the  spring it doesn't sound right. A rough guide about springs and barrels can be split up in this 1 third for the arbor, 1 third for the spring and 1 third for space between arbor and spring.  

[GregG]

14 minutes ago, oldhippy said:

From that description of the  spring it doesn't sound right. A rough guide about springs and barrels can be split up in this 1 third for the arbor, 1 third for the spring and 1 third for space between arbor and spring.  

When I get home later today, I'll take out the mainspring and get a picture for you.  Probably worth it to get a new one if it's messed up beyond fixing.

[GregG]

6 hours ago, oldhippy said:

From that description of the  spring it doesn't sound right. A rough guide about springs and barrels can be split up in this 1 third for the arbor, 1 third for the spring and 1 third for space between arbor and spring.  

 

[HectorLooi]

Oh man! That's one tired looking spring! 

[GregG]

Probably should have led with that rather than investing in the Jacot XD

[oldhippy]

That spring needs replacing. A bit of uneven spacing between coils.  

[GregG]

6 hours ago, oldhippy said:

That spring needs replacing. A bit of uneven spacing between coils.  

How much leeway do I have in picking dimensions for a replacement?  I measured the dimensions with my caliper and micrometer.  I checked Cousins, and there are replacements that are close, but not quite the same.  Most notably the thickness, which I found 0.22 mm vs the actual 0.28mm.  That's about a 20% drop in thickness.

While we're at it, I have a similar mainspring in an Ingersoll watch which is also tired.  I'd get a replacement, but it uses a weird bridle type which I've never seen.  There's a protruding stud on the mainspring, which hooks into a hole cut into the side of the barrel.  What are my options to replace this?

 

[oldhippy]

First things first. The barrel you have posted where the spring has a stud. You can use the end as an attachment to the new spring. But you are going to need some tools such as a spirit lamp, needle files and a stake to make the hole and a small hammer. Have a look at this and you will see the idea on how it is attached.

When it comes to replacing the spring you should tell them what the movement is, this should help them to help you. Alway go for the nearest that is available. You need the width of the spring and always get the height of the barrel, the length as near as you can, better to be a bit longer then too short. Strength do not go for anything that is way over as it will damage the movement and it will gain so much the regulating it within reason will be impossible.

[GregG]

I don't want to derail my own thread with my own other problems so I'm going to stick to just the pocket watch for now.

Unfortunately I don't think Ingersoll had movement numbers (or at least I don't know where on the movement it's marked or how to look it up), so I can't search by that parameter. 

Here are the specs of the mainspring in mm:

Height 2.77
Internal barrel diameter 18.48
Arbor diameter 6.12
Thickness 0.254
 

I plugged those numbers into https://theindex.nawcc.org/CalcMainspringLength.php, and got an estimated length of 470mm.

On Cousins, the closest they've got is 

2.70 x .23 x 640 x 20 Non-Automatic

or

2.80 x .23 x 640 x 20 Non-Automatic

 

They also have 

2.80 x .25 x 500 x 17.5 SP End

but I have no idea what SP End is.  It's not present on that chart you provided, unless I'm missing something obvious on there.

[oldhippy]

You will have to go with this 2.70 x .23 x 640 x 20 Non-Automatic the others are to high. If you go to the site where I got the chart from they do have a few Ingersoll mainsprings. If you go to their homepage you can email them give as much info as you can ever photos. Have you tried other sites?  I don't know what an S P end is, I don't think I have heard of such a thing when it come to mainsprings.