balance wheel

Darrel22 · September 18, 2020

I have a eta 2824 movement that i am learning on and i have assembled the balance wheel , Its not been easy i locate the impulse jewel and then tried to line it up to the fork and hope for the best .

If what balance wheel moves and the watch is ticking does that mean i have installed it correct ?

Nucejoe · September 18, 2020

Yes.

You next go for its regulation.

HSL · September 18, 2020

It's friday night over here and what is better than having an small party with wine, chips and a small check.
Just because it is ticking it might not be ready to be adjusted.
Since this question is freqently occuring in different shapes I will just make a small guide which can help you decide if you done the minimal checks. Maybe it will avoid this beeing an 50 + page post

There are some initial checks one can do while servicing a watch after the repair, here I use a ETA 2824-2 as an example.

First of all, I assume you cleaned the movement properly. After and before cleaning always check the status of the jewels in the bridge. Just as an assurance use a peg wood and clean the holes in the jewels again. Most of your focus should be on the lower pallet fork jewel and the Inca block lower block. If you want to adjust end shakes you can do it with these two ones.
Check for cracks or worn holes. These steps should be done when changing parts, the original one did after all fail for some reason.

Next you can check the pallet bridge upper jewel, here too you check for cracks in the jewel and the condition of the hole. The holes on the jewels should always be round and nice. If it looks dirty or not take a extra run with the peg wood
just in case

.

Check the pallet fork. Look carefully at the pallet jewels impulse faces, they should be in a mirror finish. If there are scratches buy a new or change the pallet jewel. The action depends on your skill level.
Check the upper and lower pivot, they should be perfectly cylindric and straight. Even the slightest dent from wear will affect the performance. If the pivot isn’t straight it will stop in certain positions depending on the bend.
Check the safety pin it should be straight and level, perfectly centered.
Check the fork, here you examine it for wear and tear.
Check so both the entry and exit pallet is firmly in place.
The pallet fork must be perfectly clean.

Check the balance staffs pivots they can’t have any wear or be even the slightest bent, the same applies here as with the pallet fork pivots.
Check the impulse pin it should be clean with a polished finish. Check it is firmly in place.
Check the safety roller isn’t t loose.

Now Put only the balance complete and bridge into place.

With a gentle push on a spoke on the balance you now try if the balance will swing freely.
If it is not you first look if the lover balance is touching the small collet on the Inca block.
If there is a clearance between the balance and the collet then you have to check the lower cap jewel for wear, if it is good then you have to adjust the lower Inca block seat a bit downwards, avoid using any shims under the balance bridge.
You can’t adjust the upper Inca block since the regulator arm is tightened with it.
If it runs freely check the end and side shake with brass tweezers. You should have only minimal movements of the balance. If you visually see the balance wiggle more than the rims height then it is a big chance the balance pivots are to worn and the balance staff has to be changed. One gets a feeling of the correct end and side shake with time.

Next you should examine so the hairspring is flat al the way around. If it touches the bridge, the plate or some of the studs the performance suffers greatly and the graph on your timing machine will look like snowfall in January.

From the side you now can check the position of the impulse pin, if you look from the side where the arrow in the picture is you should see the rest position of the impulse pin. It should be in between the two banking pins, on the 2824-2 it is the sides of the bridge which are the pins.
If you put the hairsprings collet approximately as it is in one of the previous pictures you now should be able to put the impulse pin centered with the regulator arm to the right, a fine tuning can later be done on the time graph.

While you are at it you could look if the hairspring is in the middle of the index pins.

If not, you could use a tool like the Bergeon 31081 to adjust it into position.

You remove the balance and put the pallet fork and bridge in place. Check the end and side shake.
The pallet should move with ease when you move it back and forth.
Check the clearance of the safety pin, it should go totally free and not touch the Inca block below.

When the pallet fork and bridge cleared your examination, it is once again time to put the balance bridge into place.
Give it a push on the spoke and observe the balance and pallet fork action.
If the safety pin is too long the balance would stop at almost center position of the impulse pin.
The same goes if the safety pin is to low then it should hit the top of the impulse pin.
If everything is good, take the balance and pallet fork off and assemble the rest of the movement.

Like the chefs on TV I already have one assembled. I put some tension on the mainspring by winding it a couple of turns. This gives me a chance to see so the pallet fork has a snappy and nice action.
I almost always leave the fork to the right banking position.

There is probably lots of theories too in how to put the balance back, since I know in which position, I left the fork it is easier for me to put the balance back. I have a clear line of sight so I can push the index pin approximately in the pallet fork. I adjust the lower balance pivot in place.

With a small twist I put the balance down onto the two guide pins. I slightly adjust the upper pivot so it gets into position. Most of the times the balance swings into action.
The movement is now ready to be adjusted.