Assorted diddy engineering.

Cheers optimus.

Back to mechanical things, here's another recent task I had. The escapement in a clock/watch is the part that regulates the speed which the whole thing 'goes' at. The oldest form of escapement is the verge dating from the very beginning of mechanical timekeeping. Developments in the 18th century superceded it but it was still in use into the third quarter of the 19th.

In a watch the verge staff is quite fragile and easily broken by mishandling. I've only had to make a few so I'm no expert and this one was quite a challenge as it is very small for a verge. There are several methods but this is the one I was originally shown.

Steel of the appropriate diameter in a collet in the lathe and a pivot turned on the end to suit the bottom pivot hole.



Flats are then filed.



Half of that section is then filed and rounded off to leave a 'flag'. The next area above this is turned down, I leave a wafer thin wall so that the cutting tool doesn't snag on the flag. The 12 on the collet obviously refers to the size, the raw material in this case being 1.2mm diameter.



I remove the wafer section by filing and the shaft is turned down to diameter about as thick as the flag.



The working surface of the flag actually needs to be roughly on the centre line of the shaft. A wooden support is used while the top surface of the flag is reduced. Previously I have always used files for this but as this one was so small after some experimentation I found it easier to scrape the material away with a graver.



Here is that flag basically finished. As you can see I've nicked the shaft slightly - I did say I was no expert. These would have originally been made by people who did nothing else but make verge staffs and so would have turned them out perfectly and quickly.



The its time to do it all over again with the top flag. This is formed at ideally a little more than 90 degrees from the other one. No more than 100^O though. An indexing ring on the lathe headstock helps will filing this at the right angle. Its trickier to file too as the other flag gets in the way and catching it with the file means a bent staff and likelyhood of starting all over again. The flags are also chamfered on the back edge and mirror polished on their faces. Much use is made of the wooden support for this.



With the flags done the next section is turned to the right size to suit the hair spring collet. Enough material is allowed for above this and the staff parted off.



With the staff round the other way in the lathe the seat for the balance wheel and the top pivot is made.



There is lots and lots of trial fitting to get things just so. Here you can just see the top pivot of the verge in its hole. It needs to sit just below the surface of that recess into which a piece of steel is retained as a thrust surface, allowing for a tiny amount of endfloat.



Here's the view from the other side. The arrow is pointing at the upper (second) flag, the staff passing behind the brass section which is jutting out into a hole at the top in this image, the blue steel piece being the thrust surface at this end.



The balance fully assembled with with the staff and hairspring looks like this. You can see why they are fragile. In this case the distance measured with a micrometer from the tip of a flag to the back of the shaft is just under 0.5mm. 'Scuse the bit of hairy dust.



And then with it all assembled and the movement running you can barely see any of it.

I love this thread, makes the impossible seem possible

I like the fact that I cannot believe how small these are and how you produce something so tiny and yet they were designed and made many years ago when 'technology' was supposed to be less advanced.

Great work as usual Seth.

John.

Id been thnking of doing some work experience in this sort of engineering. I'm studying aero engineering at the mo.

This thread has made me want to do it even more. Truly inspirational. Thanks Seth.

Impressive as ever.

Kin ell!

Makes me feel like a cack handed Neanderthal!

Keep it up Seth, it's fascinating.

Superb stuff as ever.

Working on big lumps of iron everyday, I sometimes find it difficult to comprehend such miniture work

Nothing Superhuman really bigrod. Well, not like Sylar anyway....

Here's something I've been doing on and off for a while. Mostly off than on to be honest but I've decided to get it finished sooner rather than later so have picked it up again recently. I repair watch cases as part of my normal work but making one from scratch is something that I wanted to learn. I was fortunate to have a couple of conversations with a man called Martin Matthews who sadly passed away a year or so ago and was a fourth generation watch case maker using tools and techniques passed down through his family. An excellent film was made of him making a case around the year 2000, a copy of which I have, and it shows most of the processes involved.

I don't collect watches as such but obviously acquire bits and pieces from time to time, one of which was a nice, good quality movement by a well known London firm which is not totally standard but incorporates a couple of nice features. Financially it would not be worth paying to case (it's only worth a few tens of pounds), but for me it would make a nice watch if I could give it a home. It would also originally have been in a half hunter case, one with a sprung hinged cover over the dial, with a small hole in the centre. You can tell this because of the double headed hour hand. So making a half hunter case would add to the complexity and challenge of the project and if successful, be a better 'show piece' for potential future business.

After taking some dimensions and making some drawings I started with some metal, learning and adapting techniques as I went Making a case is mostly about making rings First up the central case band to which the movement is fitted. When trying to bend this rectangular section around the nose of my 'die' it was trying to twist out of shape so I cut a groove of the appropriate size to try and keep it more square.



Obviously I could wrap it right around in the groove but once it was most of the way there I could finish back up at the top.



Ends were cut and make to sit together. for soldering.



Difficult to see but its now a sold ring with the joint soldered.



Then, having intentionally made it a little small, it can be pushed/knocked/hammered over the die to make it round and flat.



The do it again with another bit of wire.



And then again with another bit, this time some 'D' shape wire, around a larger die such that the fat rings just fit inside it.



That assembly was then all soldered together to make the complete band ready for turning. The inside needs to fit the front and the back of the movement plates snuggly and then the outside has steps on to which the covers will fit.



With the inside and the front turned, the movement fits in, being located by the two pins, holes for which were drilled.



The back was still in the raw, but you can see towards the bottom where the movement retaining screw should go.



With the rear steps turned, I cut the semi counterbore in the case to suit the screw recess in the movement.



The movement can now be fixed in with the screw.



Two more rings made, (ie wrapped around steel die, soldered, made round and flat,etc) the thinner one to eventually be for the inner back cover, the fatter one the front bezel that holds the glass.



Here's the front now equipped with the bezel.



I have got a bit further with it but need to sort out some more photos before I can continue with this.really. So more anon.

I love seeing how you fabricate the complex shapes from simple sections of bar and sheet Seth. Fabulous stuff.

Thanks chaps.

Tallsam, I've tended to just mention tools here as and when I've thought of something worth showing. Most of the work tends to be with basic hand tools, I suppose with the odd thing to help out with workholding etc. The small lathe is just that.
Markb, Not sure if you'rre referring to the case there but to be honest I haven't managed to work out how they were mass produced. It may be that the case bands were made using some stamped sections before turning but I can't really see any joins on them. So I had to come up with my own method, using those three rings soldered together, as making from solid wouldn't really be a sensible solution or at all economic should I be asked to make one in gold at some point in the future.

Here's part two of the case making, bringing it up to where I am now. I made some case backs a few years ago and perhaps stupidly wimped out from pressing the dished sections instead hammering each one from flat sheet. They came out OK but I knew I would get a better finish by stamping them by some means. So I bought a cheap bench mount arbor press and set to making a punch and a die to form the inner back.



That worked OK.



Then the smaller of the two rings mentioned in the post above was shaped to fit inside, soldered and then the excess material cut/filed off.



This was a bit of a hit and miss method in terms of getting the ring flat to the dish so I wanted to do the outer back and the front covers a better way. First up to make another punch and a die to suit.



I used the metal die on the left at first to press the outer back but it wrinkled a bit much and wasn't great, requiring a bit of hand finishing over the punch. My last 'proper' job was desigining press tools so I have got a vague idea of what does what and how but its a while since I did that. I was pretty sure that a larger lead in radius on the die would help and so made the nylon one, with a bore right through so I wouldn't be restricted by depth. The punch was also slightly reduced in diameter to allow for the extra metal thickness of the front cover.



Things lined up on the press.



Much happier with that result.



With these I reckoned a method I had seen used by Martin Matthews would enable me to remove the excess material much more reliably. I've got some bits of oak from when a tree in our garden was trimmed so I stuck a branch of appropriate diameter in the lathe and turned it round.



Then using a hand graver, formed an end similar to that on the punch. (the bore tool was just used as a rest)



Et, voila. The metal dish pushes on nice and tight and flat.



A bit of work with a parting off tool and...



So that's where I'm at now, two dishes and two more rings.



There's only one ring there though because the other is chucked in this lathe.



Since turning the various steps on the central band I became aware that I was using my watch lathe probably beyond its capapbilities for power. So I have cleaned this larger, almost home made, one up which I was given by a family friend a few years ago. It's not as precise as the watch lathe but a perfect size for the case work and had the bonus of coming with adapters to take the same chucks as the watch lathe. Now I've got to turn both these rings to suit the two covers and solder them on. To be continued...