Question about balance problems

[saswatch88]

hello all i have 2 questions about balance assemblies 

1. How do you true a balance wheel, i have a caliper and i have seen videos on how to use them but none of them explain how to make the balance wheel true if you find that it is not. Iam guessing you use the caliper to do this but iam not sure.

2. If you find that a balance wheel has too much end shake, or even too little how do you fix this. I read that for too little you can burnish the pivots but for too much what do you do? can you bend the cock a little bit to make a tighter fit? change the jewels? in DeCarle's book its explaines how to check end shakes but not how to compensate for them.

[nickelsilver]

In general you just use your fingers to true the balance. There are special tools you see illustrated in books like Fried or Levin show, basically rods with slots in the end that allow twisting split balance arms. I have a few and in 20 years have yet to use one. The balance pivots are safely inside the tips of the truing caliper and the staff is supported on the conical area, and you can use a surprising amount of force on the balance to get it true if needed. The calipers should have a little finger or "thingy" of some sort that you can bring up near the balance rim to use as a visual guide. Many are missing this.

On many watches moving the balance jewels to adjust endshake is simply not possible. If the staff is too long the pivots can be shortened slightly, a jacot tool is good for this, you would use the lantern end of a runner so the pivot is supported by the cone and then touch up the end with a fine degussit or arkansas stone, then refinish it and round it with a small burnisher. Only a very small amount can be taken off, as the cylindrical portion of the pivot can quickly become too short, and the conical portion can bind in the hole jewel.

If the staff is too short, you can bend the cock slightly. You can also do this if the staff is too long. The key word is slightly, and it's more tedious than it sounds as the balance should be removed and the cock screwed to the plate to do it.

What is seen very very often are what one of my teachers called "chicken tracks", which is little pips of raised metal on the plate where the cock seats or on the bottom of the cock itself. A graver or even screwdriver corner is typically used to do this. Depending on where they are done shake can be either increased or decreased, by causing the cock to tilt. "Chicken tracks" is the name because they kind of look like chicken tracks, and because the watchmakers who use this technique are chickens, not doing the job properly.

[saswatch88]

1 hour ago, nickelsilver said:

In general you just use your fingers to true the balance. There are special tools you see illustrated in books like Fried or Levin show, basically rods with slots in the end that allow twisting split balance arms. I have a few and in 20 years have yet to use one. The balance pivots are safely inside the tips of the truing caliper and the staff is supported on the conical area, and you can use a surprising amount of force on the balance to get it true if needed. The calipers should have a little finger or "thingy" of some sort that you can bring up near the balance rim to use as a visual guide. Many are missing this.

On many watches moving the balance jewels to adjust endshake is simply not possible. If the staff is too long the pivots can be shortened slightly, a jacot tool is good for this, you would use the lantern end of a runner so the pivot is supported by the cone and then touch up the end with a fine degussit or arkansas stone, then refinish it and round it with a small burnisher. Only a very small amount can be taken off, as the cylindrical portion of the pivot can quickly become too short, and the conical portion can bind in the hole jewel.

If the staff is too short, you can bend the cock slightly. You can also do this if the staff is too long. The key word is slightly, and it's more tedious than it sounds as the balance should be removed and the cock screwed to the plate to do it.

What is seen very very often are what one of my teachers called "chicken tracks", which is little pips of raised metal on the plate where the cock seats or on the bottom of the cock itself. A graver or even screwdriver corner is typically used to do this. Depending on where they are done shake can be either increased or decreased, by causing the cock to tilt. "Chicken tracks" is the name because they kind of look like chicken tracks, and because the watchmakers who use this technique are chickens, not doing the job properly.

ok so in my case i had the watch working a minute ago after adjust the endstones, but trying to push the crown back i dropped it like an idiot and now it no longer runs in the dial up position, it runs perfect dial down, slows a bit on the sides, then stops as soon as dial goes up. the wheel looks to have a little too much vertical wobble but doesnt seem to hit anything. so i dep think i have too much end shake but could i be looking at a bent pivot now too.

[nickelsilver]

Sounds very much like a damaged pivot.

[saswatch88]

great just my luck. well iam gunna see if i can straighten the pivots and give them a polish if it doesnt work then luckily i have a spare wheel with a good staff. but the cock does need to be bent because the end shake was too much even when it was running

[rodabod]

My heart sinks when I see marks underneath the balance cock. They are also called “pigs’ ears” sometimes. Very common on anything pre-1960. 

[saswatch88]

no sign of pig years. i bent the balance cock a bit and i got it running but may have done it a wee bit too much for now it stops occasionally. i may have to adjust it a bit higher with a shim. at least now i dont have to remove the balance wheel again, because main that is the one thing i hate doing