EB 8021 Servicing

[jdm]

Here's the 1st part of a service walk-throughout of this 10.5''' pin pallet mov't which was barely running.
It's built with some unusual characteristics for this class, like the ratchet wheel on dial side, the abundance of parts, and the use of four tally upping jewels beside the shock protection, perhaps an attempt to compete with Swiss lever mov'ts by boasting 23 jewels. I apologize for the mediocre quality of the pictures or any inaccuracy. I didn't find a service sheet, but that is not big deal really.

Starting from the dial side we remove two tiny screws and the top calendar plate.

Here we need to be cautious with the finger spring. You can place some rodico on it and lift where it's curved. Then remove the finger and the brass plate.

Lots of more parts are now revealed, off it goes the date ring, date wheel, hour wheel, and the rocking bar

Not less than three pinions on the bar, and that is without a quick-setting mechanism. Sorry I did not picture the setting spring, which is not difficult to remove safely.

Having full access to the click we can now let the mainspring down. The next "dangerous" item is the click spring, again use caution.
After  the click we remove the setting wheel, cannon pinion, and the small plate holding two cap jewels, the lower anti-shock, according to the part list they are different from up and down sides don't mix them up. By noting the four no-function jewels around the date wheel machining we're done with this side.

After pulling the stem out and storing the sliding wheel we can then flip the main plate, remove the upper anti-shock device and the balance. The massive cock it's a bit fiddly to lift.
Also be aware that the dial screw can be completely removed, it's a good a idea to do that to avoid these falling at some point.

Removing the pallet bridge and pallet I didn't noticed immediately but a pin had snapped. Maybe that happened in the washing jar, but the pin was nowhere to be found ?!? Fortunately a spare pallet fork was available to order. It should be also possible to make a a new, I hope to be able to cover that in a future posting.

Remove the train bridge. It's possible that the barrel bridge is to be done first, but I had no problem anyway.

Remove seconds, third and the escape wheels.

In the best Swiss style there is no screw like another.

After removing the barrel bridge we start seeing oil having left around.

The thick center wheel bridge is removed with the wheel, lastly is setting lever screw and lever. I don't know why I pictured the sliding wheel with them.

Opening the barrel we see that the last repairer, decades ago. liked to use a lot of grease in there.

I don't guess on a mainspring's condition by its uncoiled shape, but just get a new one when possible.

Washable parts go into my special machine, which is a small jam jar. First bath is horological ammonia solution, rinsed with petroleum ether, followed by distilled water rinse that is repeated until no floating particles can be seen against the light. Last rinse is with IPA.

To be continued.

[Jon]

@jdm Nice walk through.

Unfortunate about your pallet pin snapping somewhere in the process!

Wow...I didn't think they were that delicate. Saying that, I don't put jewelled pallets through a cleaning machine, just as a precaution, so I'll now also be hand cleaning pin pallets.

You were sure right about liking to grease the mainspring to the max whenever it was last done. No wonder it was pooling on the top of the barrel as well.

Looking forward to the next instalment, once you've got the replacement pallet 

[Kraai]

you can try to squeeze the pen out and then break off a bit of an equally thick drill bit and squeeze it in

[jdm]

As the usual things are taking longer than expected so her's a 2nd part before concluding.
First of all I need to correct two inaccuracies, the inactive jewels are in fact six, as there are also two under the setting wheel, that make the actual jewel count to be a very common 17. And I mentioned something like a "sliding wheel", when the correct name is setting pinion, because it does not slides in this mov't.

Main plate ready to work on

I found worth of note the interesting construction of the three large posts fitted into pentagonal broached holed holes of the main plate.

With everything cleaned and inspected the first that we assemble is the center wheel on the main plate, with its bridge and screw. That is 4 parts to begin with. Lubrication is only HP-1300 on the pivots.

Next is the train with the escape, third, seconds wheels, bridge and two same screws, 6 more parts. As the usual a bit of patience and attention is needed to line up the picots. Lubrication is 9501 on the pivots that can't be reached. otherwise it's placed on the concave jewels from the outside. Test that all spins free, I've got it running 4 seconds with a puff of air.

We then reassemble the barrel (not pictured). To insert the barrel arbor I had to adapt a bit the hook and that was a bit difficult because I had transferred the mainspring already, so perhaps is better to do that with the mainspring still outside.

For this section we need to install first  the setting lever and its screw, stem pinion (which has no orientation), and stem. You can use a bit of rodico to hold the setting lever. Then the barrel, bridge, and the two screws pictured, that is 11 more parts. HP-1300 on where parts rotate or move.

We continue with the cannon pinion, setting wheel, rocking bar complete with three pinions, and the screw, 7 more parts.
The two smaller pinions are the same and there is no orientation to take care of. Once a bit of HP-1300 is place on contact area, the pinions should stay in place when you set the assembly.

The setting spring and screw (2 parts) are not difficult, set the screw lose and leave the tip of the spring over the raised section, then position it and tighten the screw. Check that motion is transferred alternatively to barrel or setting wheel depending on the crown position.

Follow with the click, its screw, spring, and screw, 4 more parts. I used keep the long leg of the spring secure with rodico before pushing in the short leg and fitting the screw.

To be continued.

 

 

 

 

[jdm]

Last part of this walk-through.

Pallet, pallet bridge, and screw make 3 parts. This is a replacement pallet, and it has a large end-shake. I did not investigated further at the moment, as I wanted to see if it runs reliably in first place. I touched two of escape teeth with 9010.

Cap jewels plate and its screw, 2 more.

Balance, cock and screw consist actually of at least 10 parts, even if I haven't take them all apart.

Balance jewels, end stones and springs make 6 more parts. For the occasion I bough the KIF Trior tool (largest size) which made installation significantly easier and safer. Lubrication is just  9010 under the end stone.
Time to check that is running strong in all positions before moving on. For the record I got about 180° amplitude with the default lift angle. Beat error was 2.5 ms,  pattern barely acceptable, and large positional error.

Last are the date wheel, hour wheel, inner plate, date jumper, date ring, outer plate and its two screws. The date finger spring can be inserted conveniently and safely from outside. 9 more parts. I used HP-1300 on all arbors and contact parts.

 

There are actually 2 last parts to fit, that's the dial screws (not pictured). It's probably a bit easier to fit them them as the very first thing.

I have been counting parts to get to a total is 67 or thereabout, or 90 if we count the jewels separately. Not a small number for an economical, unsophisticated mov't.

I hope that this no-pretense document can be useful somehow, thank you for reading so far.

 

[jdm]

Due update. with running parts in place the mainspring was slipping when winding. No big deal because the construction of this movement make access to the barrel possible with just two screw. 
I'm posting this because one can think that a brand new mainspring is a sure recipe for working good, no isn't so, in my case the end needed a small correction,.

[pubudeux]

This is a great, thorough walkthrough and really interesting to read.

Was the skidding mainspring a contributor to the low amplitude? Did you investigate the pallet endshake further?