Lenzkirch Alarm Clock Escape Wheel Tooth

[Klassiker]

Greetings everyone,

I am currently working on this Lenzkirch mantelpiece clock with alarm function.

On inspection of the parts, I noticed that one of the escape wheel teeth is damaged. I don't think a replacement is going to be easy to come by.

The profile is still complete, so it may run OK (for a while at least) as it is, but I would like to attempt a repair if possible. I don't have any milling or fly-cutting equipment, so any work would have to be done by hand. Do I have a realistic chance of doing a serviceable repair, and what is my best option? My thoughts so far:

1. Somehow fill the metal back in, then work it back to the original profile. Would require a filler with a lower melting point than the brass, and some very precise filing. A soft solder would be easy to work, but not offer much in terms of durability.

2. Make a new tooth, file away the old one, make a cavity in the rim of the wheel, and set the new tooth precisely in place (with shellac?). Would require some accurate jigging, and even more precise filing, but the tooth would be solid brass.

3. Make a complete new wheel. I don't think I have the tools, skills or the time to attempt this.

4. There is a dead simple, quick and cheap solution that I haven't considered, but a clever forum member will suggest. (Please let it be this one!)

Looking forward to your ideas and advice, especially if you have attempted something similar in the past.

 

[Tmuir]

I've not seen it done on an escape wheel before but have seen it done on otherer wheels in clocks.

You cut out a wedge shape, like a dovetail in woodwork and soft solder in a new bit of brass and file it to shape, but for an escape wheel there is very little tolerance for error.

Another option might be to try with a square file file down the tooth across the side of the wheel until you have removed all the broken part but still left the small amount of good tooth and soft solder in some brass sheet that fits the profile exactly left by the square file and using what is of the original tooth as a guide file the new bit of brass to profile.

But wait until someone like Oldhippy jumps in with advice.

[Klassiker]

21 minutes ago, Tmuir said:

Another option might be to try with a square file file down the tooth across the side of the wheel until you have removed all the broken part but still left the small amount of good tooth and soft solder in some brass sheet that fits the profile exactly left by the square file and using what is of the original tooth as a guide file the new bit of brass to profile.

I like that idea! Thank you! I will wait to see what Old Hippy and the others say, but that already tops anything I came up with.

[clockboy]

If it does not run then as “Tmuir” has said the tooth has to be repaired. Not an easy job but there is no alternative if a replacement wheel is not found.

[watchweasol]

Hi Before boldly going at it with a file, which maybe the preferred option or replacing the tooth, Make a master copy image of the wheel on some paper stuck onto thin plastic or card. That way if things go pear shaped there is always an escape route and you have the profile to work back to. 

[Klassiker]

Well, cleaned and lubricated, it seems to run fine as it is. Amplitude is slightly more than 180 degrees on a full wind, and ist's still ticking after a day and two nights. As it is not mine, and I'm not sure how much use it is going to get, I think I will not take any risks. If I change my mind I will let you know and post my progress (or otherwise).

Thanks for all your advice so far.

[HectorLooi]

The dental lab that I use uses 3D metal printing to construct their crowns. The process involves scanning the object and the printer uses a laser to fuse very fine metal powder into the object you wish to print. I was skeptical at first but all the crowns I've issued are still in the patients' mouths.

The metal it prints out has no visible porosity unlike traditional casting methods. The metal is a non precious alloy, similar to stainless steel.

I wonder if anyone has adapted this technology to print watch components.

[Nucejoe]

There was a video posted on the making an escape wheel , CORPELA (if I correctly spelled his name) and his skilled team had to make special bits.  I,d say it is high skill machining.

I don't believe acceptable result can be expected  by hand filing or anything of the sort.

Perhaps 3D printing.

Regs

 

 

[Michael1962]

When I was an apprentice fitter we used these products with amazing success. Ok, it was on industrial equipment, but maybe it has a place here as well?

I wonder if one of these products would be able to be used?