Great stuff, as usual!

Happy new year!

 

I'm working on an Omega 354 at the moment. It's not cased and was bought as a test movement and the first thing I noticed is this:


You can see that the hairspring is canted over and is touching the centre wheel, which makes the effective spring length very short and the rate very, very fast. I'm not worried about damaging this spring in making this test as it is in a pretty bad anyway.


So, I've seen a few movements where the spring is damaged and it seems to be from careless handling and removal. Here is the spring on the right and an unused one (not cleaned either) on the left. The one on the left has the true spiral shape from the collet (the brass ring in the centre) out to the stud with a small correction applied on the outer coil so it sits in the regulator pins. The one on the right from this movement is hopelessly out of shape at the centre and at the outer coil. It's also not planar which might be obvious in the outer coil and so, it's sitting incorrectly and touching the centre wheel.


So, for those who tinker with watches, I thought it might be interesting to show how I'm inserting and releasing the balance and cock from a movement as it looks to me like this has been pulled out roughly, caught on something and been permanently deformed. This is the way that the BHI teach this. It may be completely obvious to everyone but, something to share and, of course, it's not the only way to do it, just one way.

To insert the balance/cock, put a little wind onto the train with a turn of the crown and that means the fork can be locked into one position. Here, I'm showing it over to the left in another movement, not a 354.

Holding the balance by the cock, position it so that the ruby jewel is more or less where the green circle is and lower the balance pivot into the lower shock jewel. This means that the cock will be somewhere over the centre of the movement.

The idea is to then rotate the balance clockwise as indicated by the red arrow so that the ruby jewel engages with the fork and the cock is lowered down into position. But, I don't do this by rotating the cock which would make it easy to catch something as you're holding the cock by the tweezers. Instead, rotate the whole movement holder anti-clockwise to achieve the same effect. It's easier to hold the cock steady when you're not trying to turn it.


To remove the balance, lift the cock a little and rotate the whole movement holder again to disengage the balance from the fork and allow the whole thing to be removed. Obviously, don't put it down on the bench with the cock at the upper as it can damage the lower pivot, instead, roll it over onto it's back when the wheel contacts the bench and it drops into the jewel in the cock to be stored with the cock on the bench and the wheel uppermost. I suspect we all do this latter part anyway. Let's hope so

I've found this the safest way to do insert and remove the balance and the risk of damage to the spring is minimized. Perhaps this weekend, I'll write some stuff about how to size a balance spring - bit theoretical but might be interesting.

Oh, and Happy New Year!

Cheers, Chris

 

Hi Chris,

Interesting method of installing the balance, and if it works for you by all means use it, but to me that's actually backwards.

When I look at a movement to decide which way the balance should come out or go in, I look at where the balance cock is in relation to the balance jewel in the main plate. In the watch above, like the majority of watches in my experience, the balance cock fits to the "right" of the balance jewel, so I put some wind on the mainspring, flip the pallet fork to the opposite side of where you have it, insert the balance into the jewels, but with the balance cock out in the air and to the left of the balance jewels if you can picture that. I then rotate the movement CW and drop the balance cock right onto it's final location.

If the balance cock fits to the left of the balance jewels, I would do it the way you show and turn the movement CCW under the balance, but in both cases the balance cock starts off the side of the movement, not over the middle.

I'm not terribly fond of holding the balance cock over the middle of the movement, in particular with modern balance springs where the balance doesn't hang down very much compared to older movements. This can actually cause stretching of the spring due to the possible height difference to clear the balance cock over the middle of the movement compared to how much the balance hangs on the spring. By starting it with the balance cock off to the side of the movement, I can keep the height of the balance cock lower and not ever stretch the spring.

There are exceptions - with co-axial watches you have to do it as you have described and start with the balance cock over the middle of the movement, and since those balances don't hang down much, it can be a pain to get those into the watch since the balance is pulling up all the time due to this height difference. I know you are working primarily on vintage watches right now, but if you do some modern stuff and see that the balance stays very tight to the underside of the balance cock, you might want to consider reversing your procedure to see if that makes things easier.

Cheers, Al

 

Thanks Al.

Good feedback there and it does sound like your way is a complete reversal of mine. The way I'm using means when I slide the balance in, I'm sliding it with good visibility of the second wheel and fork and that gives more control of the clearances for me. If not, I'm looking through the cock or the bridge but, I can see advantages in reversing it as well. I've also tried that but it seems more difficult to me. I will experiment with both though.

It sounds like you're also rotating the movement and not the cock and I think this is where someone has damaged the spring as trying to rotate the cock gives less control. Well, that's my theory anyway.... Could just be they were very clumsy!

Cheers, Chris

 

Hi Chris,

Yes I certainly rotate the movement (rotating it about the balance jewels, not the center of the movement) when moving the balance cock in place.

I guess this goes down a little to the way you were taught, but just to expand a bit for everyone on what I talked about above, I'll show some photos of what the balance looks like from a vintage and modern watch. Here is a Cal. 321 balance hanging on my balance tack:



As you can see the vertical distance between the underside of the balance cock, and the balance itself is quite large. Here is the same view of a balance from a Cal. 3301 (F. Piguet based chronograph) that I'm servicing right now:



The vertical distance is a lot less on this one as you can see. This is common with modern watches, since most modern watches use generally smaller balances than in the past, they are often smooth (or at least don't have a full compliment of balance screws), and I also think the alloys used in the springs play a part in the differences of how these hang compared to each other. So as I mentioned above, sometimes you have less vertical clearance to start with the balance cock over the middle of the movement than at other times.

Looking at that 3301 again, here it is just before going into the cleaning machine, and you can see the top of the balance cock has a portion of it machined away:



The reason for this becomes clear when you look at the assembled base movement - there is a train wheel (specifically the second wheel) that requires clearance so the balance cock must be machined away. In this watch, the balance cock would have to enter underneath that second wheel, so must be swung in from left to right.



In addition, although it might not be completely evident here, this is a tall (thick) movement when it comes to the minimum parts needed just to make it tick. So other than some calendar parts on the dial side, the only things you can really remove from this movement before it can no longer run is the small automatic bridge and rotor. So in addition to the barrel and wheel train bridges, all the chronograph parts and that upper chronograph bridge must be in place for the watch to run. The height of all these bridges means that trying to put the balance in with the balance cock over the middle of the movement is difficult, since the height of the movement is greater than the distance the balance hangs. As I noted with the co-axial watches, you have to start with the balance cock out over the center of the movement (the roller table goes under the pallet fork on these - yes it's as strange as it sounds), and trust me I am not really fond of installing the balance on the 3313 version of this movement...I feel like I'm going to distort the balance spring each time I do one of those because of the height issues and having to turn the movement one direction, then back the other to get it into place. It's one of the awkward things encountered on these F. Piguet based movements that make some watchmakers shy away from them, at least according to the people at Omega that I've spoken to about these.

Anyway, as I said if the method you use now works for you that's good, but just note that in some cases you may need to start it from the other way, and it does make life easier in some specific cases.

Cheers, Al

 

Came back to this watch and have been trying a couple of things. That spring above was a long way out of true in many places and was also conical to some degree so has been badly treated.

I thought this was beyond my ability to recover so, sourced a new balance spring for a 354. I was lucky to get this. Fitted this to the balance and with the regulator right over to slow, the best result I could get was this:

This is very fast and is even more when the regulator is in its neutral position so, the spring is too strong for my balance. Springs are specified with a stiffness (strength) and you choose these to suit the mass of your balance and its radius of gyration. So, out of interest, sizing a spring for a balance goes like this:

Let's say the mass of the balance, m = 0.75 grams
and the Radius of gyration, k = 9.0 mm = 0.9 cm

Then the balance "Moment of inertia", I = m.k^2 = 0.75*0.9^2 = 0.608 g.cm^2

I can't do the "squared" in this editor so, I have used ^2 for that. That is a big balance with a diameter of about 20 mm which is far larger than the balance I have here but, the logic is the same. You size the spring for a given train count (19800 in this case) to fit this balance and there's a specific equation for that but, basically, the spring stiffness varies linearly with the balance moment of inertia - that is, if you double the balance moment of inertia, you need to double the spring stiffness.

The situation I have here is that I have a given spring but my balance inertia is too small so, I need to adjust either the balance mass (by adding mass at the balance screws using timing washers) or increase the radius of gyration which I can do temporarily by unscrewing the screws a little. It's clear that adding the washers will also increase the radius of gyration a little as well but, ignoring that effect:

There are 86400 seconds in a day and with the regulator in the middle, I'm about 450 seconds fast which is 450/86400 = 0.52% fast. So, I can increase the mass of the balance by 0.5% which is significant or I can increase the radius of gyration by about 7% (because it's a squared effect).

It's not easy to do the latter in a permanent way but, let's try it as a temporary solution. I loosened all the balance screws by a half a turn and end up with this where it might just be possible to see all the screws are not tight to the wheel. There's a lot of mass in these screws so, it might just increase my balance radius of gyration and so the inertia sufficiently.


Pop this back in and now with the regulator fully slow, I have this:


It's still not enough as the regulator is hard over on slow and leaves me nowhere to go but, it shows that there would be a way forward with this spring. I can get the timing washers out but, I'm not sure I have any small enough and don't really want to add mass to the balance if I don't need to.

So, with some encouragement (from Al) I put this spring back in its container and go back to the original spring. I'm starting with the one on the right and aiming for something close to the one on the left.


First thing I do is try and get the centre closer to where it should be as it's clearly not in the middle of the spiral and get to this:

That's a bit closer and in the range that I would normally be able to correct it - difficult to get all of this right when it's not mounted so, this is an exercise in getting the spring to where I feel it's adjustable and then tweaking it when it's fitted.

Next, that outer coil is hopeless out of plane and looks like this:


So, I work to get that closer to in plane with the rest of the coils and end up with this:


This is in a range I can tweak on the movement so, I work on the outer coil in the other plane and get the spring to look like this. I also slightly straighten the collet relative to the spring as it was not quite at 90 degrees which you can see above. Still, I don't think the collet is exactly centred as it looks fine left to right but still a bit high vertically - it's hard to judge this so, I'll solve that when I put it in the cock and can use the features of the cock to help me.

I still don't have perfect concentricity of every coil but, it's workable with and I can put it on the cock and see how it lines up. Again, there's a bit of tweaking to get to this but, it's now close to lining up with the jewel and it's between the regulator pin and boot.


I give it a few more tweaks in the centre and especially in the outer coil where I'm trying to get it centred between the regulator pin and boot for the regulator range of movement which goes right down to the lower of the picture and a bit higher than where it is. Then it's mounted on the balance and put back into the cock and everything back into the movement. Now, my result with the regulator in the middle of its range (not at it's slowest point) is this


This is fine but, over six positions, I have a 50 second variation which is too much for me. That's not an issue as I can work on it now to solve that as it's back to the range I would usually deal with. There is still a little "coning" of the spring but it works well in all positions.

Overall, it's not bad but, I could do better. It's just a case of deciding where to stop and for this movement, apart from reducing the delta, I probably won't do anything else. It's quite intense work this as the spring is only about 5 mm in diameter....

Cheers, Chris

 

Great stuff Chris! Happy to have some news of your work.

I tried also to correct a hairspring on an Omega bumper. Really tricky because, as you said, it is really small! I succeed to get somethink correct... untill I screw it up trying to get to much from that movement!

So watchmaking is sometimes like casino: if you want to win, you have to stop before you lose!

(Of course, I do not pretend to compare my amateur trials to your professional work.)

 

Some news as it's been a while....

I now have an assessor for my Unit D14 watches. This has to be an approved BHI member or fellow and his task is to assess the ten watches I submit for the first year unit D14. These are to be six mechanical and four quartz with a minimum series of faults introduced and they need to be complete for the end of June. I work on them in my workshop, submit them and receive feedback plus a pass/fail mark. They have to be full services and not just a partial job.

I have been very fortunate as an existing watchmaker that I know is willing to do this for me. It's not that easy to find someone as it takes time away from the bench and that's not what you want to be doing when it's your business. Anyway, this Watchmaker makes it clear that he is always interested in improving knowledge and training within the industry and very kindly offered to do this. I will ask him if I can use his name here.

So, the watches to be submitted will include the following:
1. A cased ETA 6498
2. A cased ETA 2892-2
3. A cased Omega 354 automatic
4. A cased Omega 601 manual
5. A cased Omega 5600 stopwatch (the one I replaced the balance staff on above).

They don't all need to be cased but, it's going to be difficult to keep them clean if not. This gives me a fair selection, I feel and includes some modern and some vintage. Am not sure about the 5600 stopwatch and am on the lookout for some quartz that I can rebuild.

A bit more later/tomorrow as I'm working on the quartz testing and writing up the service of the 2892.

Cheers, Chris

 

I need to do some quartz watches and am on a short course with the BHI in February relating to those so, although not many people have a great interest in quartz, I’ll run through the tests and equipment I’m using. They present their own challenges and the testing is a little more complex than for a mechanical watch.

I’ve looked at various quartz testers and the Witschi ones are certainly the best and most comprehensive but at $3000-$5000, they are a major expense that I had trouble justifying. So, I opted for the Horotec Flashtest and ordered it from Cousins at about a tenth of that price. The one thing I really needed that it wouldn’t do was the “lower working voltage” test but, I decided I could quickly rig up a variable supply voltage to accomplish this. In fact, that’s not as easy as I first thought because of the very low voltages and currents involved so, luckily, when the Flashtest arrived, it came with a sticker on the front saying it had been upgraded to include this feature – it appears to be new stock and although Cousins have this, I am not sure that all suppliers do. This has saved me some time.

One simple thing the Flashtest doesn’t have is a way of holding the probes but, I solved that with a soldering helper that I already had and so, this is the set up – not very impressive but, it does 8 of the 9 tests that I’ll list below. The Witschi testers will do extra tests such as graphically showing the motor pulses but these are not essential as far as I can see.


This is a list of tests I see that are typically made with quartz analog watches and I’ve shown the minimum requirements for the BHI. It’d be interesting to see if everyone makes these tests every time and any comments on the expected results. I’ve put some typical expected results but these are calibre specific and not all general sources agree. It’s based on a 1.5V nominal battery watch.



Here’s the test watch, a Loruz quartz which contains a Seiko VX42E calibre. Unfortunately, I can run the tests on this but, it’s not really designed to be stripped and rebuilt as many of these cheaper quartz calibres aren’t.


More later.

Cheers, Chris

 

So, the first test is the only one that the Flashtest won’t do. The idea is the tester listens to the watch and determines that the quartz crystal is vibrating at approximately 32 kHz. If the watch passes test 2, then it confirms that test 1 would be passed. If the crystal is not vibrating, then the watch won’t work.

Test 2 is using the tester on the left hand area to sense the stepper motor (that drives the watch train) pulses. Due to the way quartz watches typically work these days, the IC is set up to apply inhibition to the output from the quartz crystal and this is all set up at the factory. But, it means that this test needs to be run for 60 seconds, typically, to remove the effects of that inhibition and get a correct reading. Here, during the 60 seconds:


And here after the 60 second test period. The stepper motor is working fine and the rate is +0.16 seconds per day.


The third test is to measure the movement consumption while the movement is running. For this, the tester is supplying the voltage via the probes and the display shows a current consumption of 1.47 micro Amps. Seiko specify approximately 1.60 micro Amps so, this is fine. This is a good indication if the movement needs servicing (stripping, cleaning and oiling of the train) as any drag in the train will increase the current consumption and reduce the battery life. Doubling the current consumption due to dirt and drag on the train will half the battery life from the required 3 years to half that.


The fourth test is the same as the third but with the crown fully pulled out to stop the watch so the stepper motor is grounded and not drawing power. Here, it’s showing 0.21 micro Amps and this is as expected as the motor is not being driven anymore. Seiko have no spec for this but this is within a typical spec.


The fifth test is the same as the third but with the crown pushed in so the watch wants to run however, the train is blocked so the motor pulls more current in an attempt to free the blockage. Here, there’s an increase in current consumption to 2.19 micro Amps so, it’s trying and in fact, I struggle to block this train properly.


The sixth test also shows how the movement is performing and the likelihood of needing a service. This is the lower working voltage limit and the tester again supplies voltage but that voltage is slowly reduced until the movement stops. This would be easier with the mirror set up on the better testers but, it’s possible here as you can see the train turning. When it stops, that is the step below the lower working voltage. Seiko specify an “operating stopping voltage” of 1.1 V and that’s the result I get here (top left in the display) so, for me as the steps on the tester are 0.1 V, the lower working voltage is 1.2 V. The higher this is, the less time the battery will power the watch before it’s voltage drops below that needed to power the movement.


The seventh and eighth are checks of the battery itself and I’m only showing here test seven which is the battery voltage without load. As this is a new battery, you’d expect it to be 1.59V and it is. Test 8 is simulated by holding down the right hand button so, I never got a picture of that.


The last test is another movement check and is the resistance of the coil. No specification from Seiko here but, to be fair, I doubt you can buy just a coil for this calibre. The value of 0.91 k Ohms is a fair value and clarifies that there is no insulation problem or short circuit.


I find this interesting in a different way to a mechanical watch but, these are just tests to determine problems. After this, if a service is needed, it’s a case of dismantling the movement.

Cheers, Chris

 

Chris, I really enjoy these narratives. Wonderful that you are making the effort to keep us informed of your progress, very interesting and always well-illustrated. Your engineering background clearly gives you a great advantage.

Whilst I have a technical interest (only as an observer, as a collector and enthusiast) in the limited range of movements that are in my zone of interest, your studies show how widely trained and capable a watchmaker has to be nowadays. Presumably many will specialise in one (or just a few) areas – but there will be those that exercise all these skills.

Again, many thanks. Please keep it going and good luck!

 

Thanks Tom

I find it helps to write some stuff down as it stays in my memory better that way. And, it's not like being at college, you're doing most of this on your own from various sources (many of which don't quite agree) so, I'm always happy to see any feedback, corrections or better ways of doing things.

Ideally, I'd specialise in mechanical watches but you need to know the quartz as well and I suspect most Watchmakers deal with both. Now, clocks are another thing entirely and many Watchmakers have no interest in them. I want/need to know the basics but, it's not an area I want to really work in. That adds another 50% to the course, I'd say.

Cheers, Chris

 

Hi Chris,

One test I don't see listed is the EOL indicator - typically I would check the voltage that the EOL kicks in to make sure it's at the level specified by the manufacturer. Note that on some watches you have to wait a time before that feature will kick in, so you can't just lower the voltage and see it kick in right away. This is important because if that is not working (circuit problem - I've had it happen) then the battery can go dead and leak with the owner not getting any warning of it.

For those with quartz watches, as soon as you see the EOL kick in (typically the hands moving every 4 seconds or something similar) get the battery changed as soon as you can. You don't want it to leak, as that can ruin the movement.

I also don't see the drive level specified anywhere - this machine may not tell you that. That is telling you how much of the chopped pulse (in watches equipped with asservissement) is being used. In a watch in good condition, I commonly see 50%, and in one that may have some problem it can be more, right up to 100%. Not only is it another data point that helps confirm the state of the movement, if I see an otherwise fine movement with a high percentage of the pulse being used, I know to look for some problem that is not showing up in the other tests.

The rest are pretty typical, and some are sort of "automatic" with the tester I use and are all displayed on the screen at once. Also note that the inhibition period is sometimes not 60 seconds - I see 10 seconds and 20 seconds sometimes as well but it depends on the movement.

Also note that not all quartz watches have a switch to disconnect the motor, so some will simply keep the power flowing and block the train. I see these less and less as time goes on, but some cheaper/older movement do work this way. People will often pull the stem out to hack a quartz watch thinking it saves the battery, but in some cases it's the opposite - it draws more power.

For the numbers to use, whenever possible I refer to the tech guides of the company. For example your tolerance on the overall consumption on this watch is 1.6 uA, where an Omega 1538 the max would be 1.2 uA, so your 1.47 would be too high for the 1538 (clearly much different level of quality, so that's not surprising). If I can't find the information on a specific movement, I will use one of a similar construction that I do have information for as a comparison. So I'll look at the number of jewels (if any) and the material for the wheel and plates, as well as the overall size, and pick something as close as I can find.

Like you, I have zero interest in fixing clocks, and despite how similar they may sound to a watch, what a clockmaker and watchmaker do on a daily basis are quite different. But quartz has it's charm, at least for me. Unfortunately I typically get cheap fashion watches from my wife's work colleagues to fix - I do it more for my wife than for the money, because the money isn't there really on those jobs.

Mind you some watchmakers make a living flipping batteries, but they do incredible volumes, and are in a location that is plentiful with walk in traffic.

Cheers, Al

 

Thanks Al, I will add the End of Life indicator to my list of tests as this is one I have made previously. No, my machine will not tell me the drive level but, I will investigate that as it's not a test I have made. I've not played with one of the Witschi yet but, will next month.

As you say, these are pretty much the standard tests but interesting that pulling the crown out does not always apply a ground but instead blocks the train on some older calibres. I have not seen this written anywhere so, that is definitely good to know. Many of the standard values seem to vary between reference documents so, I was lucky with this Seiko that I could find an actual spec which gave 1.6 uA for consumption. I seem to have access to most specs for ETA and it would appear that they will be useful. I did look up, some time ago, the spec for my wife's De Ville and think it was 0.8uA but of course, that's a very small 2 hand movement.

Most quartz I've seen are pretty cheap and with throwaway movements but, out of interest, I have a Seiko Kinetic Auto Relay although I'd class that as being a more complicated quartz so am leaving it alone for the moment. Any recommendations on straight forward quartz that can be serviced so I can get in some practice? I'm thinking ETA 955.1x2 or 955.4x2 as these have a proper train plus are available new and used for very little.

Thanks, Chris

 

I have an omega mega quartz that I bought nos in 2008. It has only had the battery changed since I bought it. If you would like to have a look at it then I would be happy to let you have a look at it. It is not an expensive watch but it is my favourite watch.

 

That's really generous, thanks. I have loads of quartz watches to try out though so, it won't be necessary. What I need is a movement (or four) to strip and service and I'm picking up an ETA 955.1x2 as one of them. Will be on the lookout for some actual watches as well because that's just a movement but there must be plenty on eBay.

The issue with something like the Seiko is you can remove the two screws (in red) and the the bridge (in green) comes off. Obviously, it's just a plastic bridge and you can see the wheel pivots in there. It's not really designed to be serviced and won't work for me to show the BHI.


On the ETA, you get a proper bridge held by it's own screw - it's called "Train wheel bridge, jewelled" and is item 110 below so, you can strip this movement, clean it and reassemble with oiling as shown. They are obviously a lot simpler than a mechanical but still interesting.

Cheers, Chris

 

Hi Chris,

Can't recall - have you serviced a quartz watch before? If not, then just a few tips - your course material may cover these, or maybe not.

I never clean the rotor or stator in the cleaning machine. The stator is usually of a shape that can be bent pretty easily, and if that happens the watch may run backwards, or may alternate between running forwards and backwards depending on the extent of the bend. So out of an abundance of caution, I hand clean that part.

The rotor is a permanent magnet, so if you run it through the cleaning machine any small fines of material that might be in your cleaning solutions that can be attracted to a magnet, will end up on the rotor. In other words it can come out with more debris on it than it went in with. Also the material of the rotor can be fragile and easily chipped. This is one time when the use of Rodico or other similar material is permitted by most brands. You can also clean it in a bench jar of appropriate solvent (like One-Dip, Hexane, etc.) and use a small brush to clean it in the solution, and the press it into pith wood, and then use some Rodico. It really depends on how dirty it is.

For oils, I use Moebius quartz oil. It depends a bit on the watch, as some have plastic gears in them, so those are self lubricating enough that I don't oil them (also concerned how the oil might affect the plastic), but on a watch with steel pivots either through a metal plate, or with jewels, I use this oil.

Standing the wheels up (rotor specifically) can be a challenge the first few times. On a watch like the one above, it's not too much of an issue, but on a chronograph like say the ETA 251-262 you have I think 7 pivots you have to line up all at once to get the main bridge on, so that one can be frustrating the first few times.

Have fun!

Cheers, Al

 

Hi Chris,

I came across this thread while trying to find out what movement the D15 exam uses. Something that uses etachron, which I've never encountered so far. You are a courageous man, skipping the entire first year

Last year I took (and passed, yay) D1, D2 and D4; this year I'm doing D5, D6 and D15. I'd love to do some of the BHI courses you did, but I'm on the other side of the globe, in Singapore. I'll leave D14 (record of repairs) for next year, since I haven't been able to find a local assessor. Maybe I'll see you next year at Upton Hall for final exams!

Cheers!

Rob

 

Hi Rob

Nice to hear from someone else who's doing this and well done for passing D1, D2 and D4. I wasn't sure about doing the two year, rather than three year course but, when I looked at the first year, it was those three exams and I was feeling confident :facepalm2: that I could do D1 and D4 with the intermediate units. It will be a bit of a struggle but it means I bypass D2 and just do D5. Just so others knows what we're talking about without going back to the first page of this thread, I'm taking these this year:

Unit D1: Theory of Clock and Watch Servicing
I've got confidence in this as I looked at some past questions and I think I have the knowledge, especially after working through the course.
Unit D4: Servicing and Correcting Faults in a Quartz Watch
I've done very little quartz but y I have a grasp of the tests and excluding the slightly different aspects as noted by Al, above (thanks!) I believe this is mainly covered by the mechanical watch work I've done. Have a course on quartz next month as well. I'll be interested to hear your thoughts if you have time. What calibre was used for this - I suppose some ETA?
Unit D5: Constructing Clock and Watch Components
This is the one that still concerns me but you passed the slightly simpler (?) D2 so, I'm impressed! Again, I'll be interested to hear your thoughts if you have time.
Unit D6: Drawing Clock/Watch Escapements
I'm an aircraft Engineer and this one holds no fear for me as I've been drawing for a very long time... I must say, that drawing them certainly made the whole escapement function and tolerances much clearer for me and it was really worthwhile.
Unit D14: The Practical Servicing of Quartz and Mechanical Watches
As you say, it's not easy to get an assessor but, I've been lucky to find that help. Next year you'll need D17 as well so, a lot of watches.
Unit D15: Servicing and Correcting Faults in a Manual Winding Watch Movement
On the mechanical course, they use an ETA 6497 as I probably noted earlier so, I'd expect one of these. If you're sitting this in Singapore then I suppose they send out the test movement with some faults and you work on it locally.

Just in case it seems odd that Rob is not sitting the exams on site, the BHI offer the option to sit them locally for everything except the last year exams (Rob, correct me if I'm wrong). The last year for both of us should be next year and D16/D18 must be sat at Upton Hall in UK so, I'll be seeing Rob there.

Unit D16: Servicing and Correcting Faults in an Automatic Watch
Unit D18: The Theory of Complex Watches and their Repair, Restoration and Conservation

Keep in touch and definitely interested in how you get on.

Regards, Chris

 

Hey Chris,

To be honest, I didn't even know it was possible to skip year one. Not that I wanted to skip it, though The year one material is completely revised and is vastly more pleasant than the next two year texts, which can be a dense mess at times. That material is also being revised, but will take quite some time to complete.

D1: There is a large amount of overlap of the old year 2 text and the revised year 1, so you may be ok there.

D4: They sent a cased ETA 955.112 watch with some issues introduced, and a box of spare parts. You get six hours to service it. This was the most troublesome exam for me, since many things went wrong, and it took me 5.5 hours to finish. Good thing I don't do this for a living! To my surprise, I scored much higher than expected, the highest mark of all three exams even.. You definitively should practice several times on a similar movement, but since you're doing a quartz course you'll be fine! And you have a beautiful quartz tester -- I had so much trouble with my hacked up DMM method. And an even more beautiful cleaning machine, I'm mucking about with jars in an ultrasonic cleaner You'll be done in two hours!

D5: I don't fear this one, though it is more challenging than D2 due to a jewel setting. For D2, I had to make something resembling a rack tail:



D6: I actually kinda fear this one It takes so long to draw a lever escapement correctly, I wonder if I'll run out of time. I use QCAD on Linux, and haven't touched 2D CAD/drafting since I was in school 25 years ago. I always despised the drafting class with those stupid pens and templates.

I'm doing all this in Singapore yes, except for the last two exams. Finding an invigilator can be very tricky, since the BHI is very serious about the exam procedures. I'm lucky to know a lecturer at a local university that helped me. Even when you do the servicing exam, the invigilator has to be present in your workshop for 6 hours.. The invigilator has to be a teacher at a respectable school/uni, a justice of the peace (yeah right), or an MBHI/FBHI. Apparently there are none of the latter in Singapore, so that left only option 1 for me.

Cheers!

Rob