Wednesday, 30 May 2012

MiG Cockpit Chronograph adjustment & photos

This is my MiG Cockpit Chronograph that I use as a general desk clock. I actually haven't wound it for a while, and recently discovered that the chronograph function is a bit off. The chronograph will have trouble engaging and when it does it sometimes stops the balance.

These clock are quite popular on eBay, but do prepare yourself for between $60-$90 depending on the quality and functionality. They all have similar construction, with back and side screws holding the back case to the bezel and main plate.

These next two photos aren't showing you anything specific - they're just a gratuity. You may notice that I'm quite fond of the this movement's aesthetics, since this clock also features as my blog's background.

The problem lies with the central arm in this next picture. It is over-engaging the seconds wheel by applying too much pressure.

To fully get at the responsible arm, first the cock that holds the seconds wheel  and a transmission wheel must be removed.

You can see that the pivot screw for the arm and the adjustment screw in the next photo.

And just to make it a bit clearer this is the arm being discussed:

The screw on the far left adjusts the depth of the swinging wheel in relation to the chronograph wheel and the seconds wheel.

Re-installed, regulated, and now it all runs smoothly. I'm not going to pretend that this post is about the cleaning and assembly of this clock, it's all really about the following money-shots:


Elgin 379 Pocket Watch Restoration

This is an Elgin 379, size 18, open-faced pocket watch with a Silverode case. I purchased this from eBay in non-running condition thinking that it would be a quick fix by the description. And of course, I was wrong. Apart from the aesthetic work on the case, the balance was in a bit of a state, and I had to replace the staff, repair the balance, replace jewels and some pivot-less wheels. This job ended up consuming 2 non-running 379s, and as I write this post the watch is running nice and strong right in front of me.

To start, the case has seen better days. There are deep scratches and small dents a-plenty. The following photos give you an idea of the starting point. This might not be a big deal for some, but at the time of writing this I am without a functioning bench motor (no polishing wheel) - the Dremel will have to suffice.

 The movement plate and bridges are in exceptional order, this photo was taken just before I began disassembling it:

I really love bimetallic balances from the start of the 20th-century. There is an incredible amount of craftsmanship and skill that goes into the manufacturing and adjustment of these components. Even though the technology in this type of balance wheel has long been superseded, there are still plenty of fine examples around. Unfortunately, this is not one. There's rust on the balance spring, the balance arms are slightly deformed and the top pivot on the staff had snapped off.

After replacing the balance staff, I placed the balance in my truing calliper. Straightening the balance arms to something approaching 'true' took quite a while, the last thing I wanted to do was apply a little too much pressure and then have to track down a suitable replacement part online..

Another problem: cracked jewels. On almost every wheel - and strangely all on the bridge (not the mainplate). Luckily these jewels are nothing special and I've got a pretty good supply of replacement pocket & wrist jewels floating about my parts draws.

The chatons that the jewels are set in can be a little stubborn. Even though they are 'held' in place by screws,  they may as well be friction fit chaton/jewels. I don't have a jewelling set, so the watchmaker's favourite tool (staking set) steps in to lend a hand.

After I mended all the tiny problems with the plate and scavenged replacement wheels and springs, the choicest bits went into the ultrasonic cleaner.

Now for the assembly. With full plate movements like this, the order that you assemble the movement in is quite important. I'm reluctant to generalise, but with most 'conventional' mechanical wind movements (at least those featured on this blog) the obverse and reverse of the movement can normally be assembled in whatever order pleases the watchmaker. However, the keyless design on this pocket watch (keep in mind that this watch was made as watch keys were just becoming obsolete) requires assembly and some corresponding manipulation of the arm beneath the mainspring barrel before the going train is installed. Unfortunately I forgot to get photos of that crucial step, but you can see the spring arm I mention just to the right of the mainspring barrel in the photo below.

With the gear train installed. After this step, the plate gets dropped on. Well, actually, it needs to get slid onto the movement at an angle whilst a pair of tweezers guide the end of the lever into the balance roller's well (ahaahahahhhhH!).

At this point the balance required more adjustment to make sure that it didn't rub against the balance cock. After I gave it an extra fraction of a millimetre to operate within, it started to tick wonderfully.

 The vastly improved, but not quite perfect (if I'm honest) case back.

I had two dials to choose from, and this was in the best condition. When you own old watches with enamel dials, you have to be resigned to the hairline cracks. This just has a few more than usual. From here on I'll just say that they add to the character of the watch.

Tuesday, 29 May 2012

Enicar AF1010(B) Restoration

This is an Enicar AF1010(B). I've had this watch for about 12/18 months now. The watch is a classic design, beautifully finished, Swiss hand-wound movement, but it has been a perpetual nightmare since I bought it. There are some unconventional design aspects for the movement, and replacement parts are hard to find.

I've lost pieces, broken pieces, and had to resort to purchasing a parts movement. Hopefully it has all been worth it. The following photos are the final assembly for what I think is now my best Swiss hand-wound dress watch.

Here is one of my parts containers, you can see a couple of bridges, wheels, an escapement, springs, clicks, yoke, and so on.

The parts are being prepared for the ultrasonic cleaner, in a newly designed cage I've made from a cutlery holder.

To start, I've got a photo of the obverse of what is a fairly conventional hand-winding movement.

Flipping the movement over, the first part to go in is of course the centre wheel.

The AF1010 holds the centre wheel in place with a small bridge. The nice thing about this movement is the quality of the jewelling. I should temper that praise by saying that Enicar are also guilty of a little jewel inflation on this movement... I'll point that out in a few photos from now.

Back to the obverse of the movement again, with the cannon pinion pressed onto the centre wheel.

Next, the clutch yoke and set lever spring a set.

I haven't got a clear individual photo of the minute wheel, but you may notice that it has a couple of jewels seemingly pressed into the wheel's face. There are four jewels around the minute wheel, contributing to the jewel count of the movement. I do not believe they serve any purpose other that to increase the jewel count. Enicar are certainly not the only manufacture guilty of this, but you would hope that a watch like this could be sold on its own merits without the need to stamp "25" on the movement instead of "21".

A weak point in the AF1010 design is the set lever bridge. The arm which engages the set lever and provides the satisfying 'click' whenever the position of the stem is changed (the winding postion versus the setting position) is either poorly manufactured or not designed to take the stress of the action its subject to. I have tried to get a replacement bridge, however, it does appear that this is a common fault that gives the part a relatively short life span. Even with a broken set lever bridge, the watch can still function - the clutch will still engage the winding pinion and the set wheel when the stem is activated. There is just no firm feel to its position and a 'click' firm seat the clutch.

UPDATE: I've purchased a replacement set lever bridge from an Australian supplier on eBay - $13 (not including postage). Now the movement is fully functional, at least until the new poorly designed/manufactured set lever bridge breaks.

Back to the reverse of the movement, with the winding pinion and the clutch installed.

And now for the mainspring barrel assembly.

A puzzling and ever so slightly annoying feature of the AF1010 is the click screw. The click screw is also a bridge screw, with a very long thread and a slightly larger screw head than the other bridge screws. If I'd have designed this movement, I would have had screw that did hold down two items, this can lead to confusion and possible damage during disassembly.

Now, the following photo shows the crown/transmission and winding wheels already attached to the winding bridge. After I took this photo I had to remove both of these wheels to place the third wheel and the seconds wheel, as they need to sit below the winding bridge wheels. I also sheered the screw holding down the crown wheel, luckily I had a spare from the parts movement.

Aligning the train bridge is eminently frustrating with this movement. The third wheel and the escapement have cap jewels which are pressed into a small fittings on the bridge. As far as I can tell, they are not designed to be removed and offer no shock protection. So trying to seat the pivots becomes a very time consuming operation. If you don't demonstrate that highly necessary virtue needed by all watchmakers - patience - then you'll break off the top pivots on both the third and escapement (again, luckily I had the parts movement).

I got there in the end. The balance is installed and it runs like a metronome. For the more astute reader, you may notice the the balance cock has a shock spring on the balance cap jewel, whilst on the obverse of the movement the balance cap stone does not have shock protection. The reason for this is, again, due to the parts movement required to bring this troublesome watch back to life.

Installed in the case ready for the hands.

Despite all the trouble this movement has given me, it certainly feel like it was worth it.