Reassembly of the Tudor (ruby edition)

Tudor 'ETA 2784' main plate

Reassembly of the Tudor begins!

It has been sitting under a dust cover in the form of a bunch of tiny, but clean parts. I began to miss wearing it more than I thought I would. Free time is at a premium with my current schedule, and during school hours the course projects take priority (duh). That's why I finished the current ones up, so I could get back to this.

A couple tiny rubies.

Servicing a watch isn't just about taking it apart, cleaning it, and putting it back together. Parts wear out and need replacing (if you recall from earlier blog posts, burnishing a pivot and replacing the mainspring), cleaned jewels, pivots and moving surfaces need to be oiled and greased. Applying oil is a bit of an art, and a skill developed through a bit of repetition. Too much oil and in the wrong spots can cause your watch to run improperly or just straight up damage it.

Most of the pivots in a mechanical watch interact with a tiny ruby. When oiled properly the action between the pivot and ruby has very low friction and runs efficiently. Servicing your watch is partially about cleaning and oiling these pivots because over time the oil will degrade and get dirty. When this happens it becomes harder for your watch to run and the degraded oil and dirt will wear down your watch, best to keep them freshly cleaned and oiled on a regular interval-not after you've detected a problem.

A cap jewel next to a penny

I've spent a bit of time practicing oiling, especially on cap jewels, which I find particularly challenging. The battle with cap jewels isn't just applying the oil, but it's how you handle and manipulate them. If someone walks past you too briskly, it may fly away. If you grip them too tightly with your tweezers, it'll fly away. If you breath on it, it'll definitely fly away. Basically, you need to refine your micro-telekinesis skills, hold your breath, and hope that you can apply the oil before you need to take a breath (or somebody walks near you). And when I say fly away, I mean take off like the golden snitch, you literally need to be a wizard to find it.

That's way too much oil

When oiling a cap jewel you need to apply the right amount pretty much on the first try-some situations may offer some forgiveness but that's uncommon. Above, you'll see my oiler with a tiny drop of oil on the tip. That is an example of way too much oil (for this specific jewel).

That's a better amount

The oiler comes to a needle like tip (literally) and there are a few techniques to determine how much oil you pull and let go of. Each jewel necessitates a different amount of oil, there's no good way to know how much is the right amount other than doing it a whole bunch of times with the trusty 'trial and error' methodology. 

Oiled cap jewel

Here you see an oiled cap jewel, well it might be hard to see the oil, it's kinda tough to photograph. The goal is to get a nice blob that occupies around 50% (give or take some depending) of the surface of the jewel. It needs to be a nice uniform circle. The cap jewel actually rests on top of another jewel that the pivot of the balance wheel interacts with (cap jewel because it gets worn like a cap..?). You need to drop this jewel EXACTLY ON TOP OF THE CAP JEWEL and the capillary action of the oil secures them together. When dropping them you have to do it right so the oil doesn't mush out everywhere, which is my bane right now. You just do it enough times until A) you actually get it perfectly, or B) you become a god tier watchmaker that can one shot oiling every jewel on every watch (goals).

Helpful diagram of what's going on

Helpful diagram of what's going on


Since I'm still a novice when it comes to perfect oil application I decided to do the cap jewel oiling first in terms of reassembly. I knew it would take a bit of my time (I lost count of how many attempts it took), but I was able to make some good headway with reassembly.

Missing some jewels

There are shock absorbing jewel settings on the dial side of the main plate and in the balance assembly. Above you see a balance cock sitting on a balance tack with the balance wheel hanging by the hair spring.

For the sake of brevity (it's actually just past my bedtime) I'll save more of the reassembly for a later blog post; and in additional news, my latest model (and shameless plug) the Orion: Field Standard is available for pre-order. So at least check it out and tell a friend, it helps me pay the bills.


Until next time!