1930s Hermle Westminster School Project

[Tmuir]

I need to service a Westminster clock for one of my School projects.

I've only just finished stripping it down and cleaned it so I can now see what needs doing, and thought people here would enjoy some 'before photos' and hopefully in the not too distant fusture I will be able to provide some 'after' photos.

Fairly standard looking clock, it is a Hemle, but just stamped 'Foreign' on it.

 

I'm pretty confident of the manufacture date.

 

Now remember if it doesn't run, just add more oil.....

 

 

When I got the barrels open the mainsprings were completely dry, but there was oil on everything else. I'm wondering if the movement got the 'Dunk the complete movement in petrol, dry off and just oil what you can get to treatment' at some point in the past.

Pretty much all of the pivots need polishing, one pivot hole has punching up on it, although atleast half of the pivot holes will need bushing as does atleast one mainspring barrel and the anchor needs the pallets refacing. Lots of work but hopefully all achievable although the pallet refacing with offcuts of mainspring is something I've never done before.

[Lenj]

Nice old clock and a good project, gotta love the old dunkers, there is a video on YouTube and the guy is so proud of his work showing you how to do it..At least he does it outside, a tray full of petrol or gasoline as he calls it would make a nasty mess of your house if it caught fire..Always know when the have been dunked with the dry barrels..Are you doing anything with the case? Good you are going to use old mainsprings, I have made some great hands for School clocks that I have made from scratch..

Good luck with this project, it will be good to see the final finished clock..

Len

[oldhippy]

Bog standard chime. You need a mainspring winder for those springs. Any chance of a look at the pallets, it isn’t very often the pallets of these clocks need to be re-faced.  

[Tmuir]

Pallets are heavily warn.

I have had it confirmed by both my lectuers they need refacing. Im at work so dont have the photos handy.

Either way its better I learn to do this on a clock I own than a customers

[Pip]

I'm starting to be drawn towards these giant unwearable watches that you refer to as 'clocks' - there is something rather awesome about the scale of them and the different techniques involved.

[clockboy]

1 hour ago, Pip said:

I'm starting to be drawn towards these giant unwearable watches that you refer to as 'clocks' - there is something rather awesome about the scale of them and the different techniques involved.

Clocks are larger in size so in theory easier to work on. However clocks require unique tools such as a  good spring winder, a stand to hold the movement whilst testing and regulating. Re - bushing is also a common task required with the vintage clocks which does take a bit of practice to achieve success. Also getting a Westminster clock to work & chime correctly can sometimes be a real challenge. So you are correct clocks require different technics for sure but as with watches the work can be very rewarding. 

[oldhippy]

Years ago I switched to restoring and repairing clocks (there is a difference) In the past I have restored some wonderful time keepers. Making the parts was a challenge but such fun. Working on complicated mechanisms many with month duration. There is always something new, you never learn everything.

[Pip]

I'm a member at EFHC and am currently doing watchmaking but have been sneaking into the clock workshop and looking at the big tools. It won't be long before I'm in there officially I'm sure.

[oldhippy]

On 01/03/2018 at 7:16 PM, Pip said:

I'm a member at EFHC and am currently doing watchmaking but have been sneaking into the clock workshop and looking at the big tools. It won't be long before I'm in there officially I'm sure.

Good for you. I found clock movements far more interesting then watch movements. Much more goes wrong and far more to fix.  

[Tmuir]

The clock is now ticking and chiming, just need to finish regulating it.

I won't go through everything I did, but just show what I think are the more interesting things.

Firstly the Chiming barrel arbor hole had worn oval and need bushing.

First the barrel was set up on my large lathe and centered using a dial test indicator

It was then drilled out to 10mm and the hole was measured to ensure it was exact

A brass clock bush tube was selected that was 11.4mm outside diameter and 8mm inside diameter.

The thickness of the base of the barrel was measured and the height of the lip of the bush was machined 0.2mm taller than the thickness of the base of the barrel and the diameter was machined down to 10.05 to be a friction fit inside the barrel. A 1mm lip was left to sit on the outside of the barrel as this would not impact end shake and gave added strength.

The bush was then transferred to the watchmakers lathe to clean up and add a leading edge chamfer to make it easier to fit. Finally it was pressed into the barrel using an arbour press.

Once the mainspring arbor had been polished the bush was then broached to size using clockmakers broaches.

I needed to polish a number of pivots that were all 0.8mm in diameter. I know some people can just hold the wheel in a pin vice and using a pivot file and a block of wood polish the pivot, but I'm not that good.

I got some bar stock that fitted the tailstock on my watchmakers lathe and drilled it 0.8mm. I then turned a taper to the end and transferred it to my mill and milled just over half way through the bar so just slightly less than half of the 0.8mm hole was left.

I then set up my watchmakers lathe as a turns and using a pulley that I had made previously which has 3 screws 120 degrees apart screwed it onto the arbor and using a bamboo rod and finishing line made my bow so I could use my lathe as an oversized jacot tool.

The pivot was filed with a pivot file, finished with a triangle Arkansas stone and burnished with a pivot bunisher.

Hope this is of interest to some people.

 

[oldhippy]

Top rate job. I miss all of this type of work. Thanks for the photos.

[Lenj]

Great job, well done..