Tooth replacement - I might need help

[LarryAC]

I've never tried to replace a gear tooth and this one might be too small and challenging for a first effort. The thinest file I have barely fits between two teeth and I don't have a lathe so it will be all by hand.

This is the 2nd wheel in the strike train. Before I hack away at the wheel, does anyone think there is even a remote possibility of successfully bending that tooth back and soldering it in place?

Assuming the answer is "no", I plan to cut a keystone slot in the rim below the missing tooth and hand filing a narrow rectangular slug that will fit in the keystone and project up past the existing teeth. Then, after soldering it in place, and with probably more patience than I have, slowly file away at that slug until I get something resembling a new tooth.

Has anyone actually successful done this by hand with one of these smaller gear wheels?

 

[shutterbug]

You won't be able to bend it back, but you can replace it. Look up "dove tail" here on the site and you'll get lots of help in how to do it. It's not as hard as it looks, and is a good skill to put in your arsenal. You have the idea, just an "iffy" approach.

 

[Willie X]

I would order some smaller files first.

I often use a 'safe barrett file'. It has a long double taper and the "safe" means that it won't cut anywhere except the flat face.

Willie X

 

[Dick Feldman]

My first approach would be to find a suitable replacement.
What kind of movement is that?

There is a second alternative which I feel is a less than quality repair.
This came from a post on this board dated Mar. 10, 2023 "Quite Unique Tooth Repair"
Others think this is just fine but if a clock came into my shop with this, I would feel obligated to correct it properly.

If you do not feel capable of doing a proper repair, a third alternative would be to send the wheel to someone that is qualified and can do a proper job.

As I mentioned in the Mar 10 thread, the cause of the tooth damage should be cured along with the bad tooth/teeth. Otherwise the problem will likely reoccur in another place on that or other wheels. Faulty click assemblies cause this sort of problem. Teeth do not just fall off. In addition to the bad teeth you have, there may be secondary damage like a bent arbor on that wheel, there may be other wheels with bent/missing teeth and/or bent arbors.

This is how I feel,
Dick

 

[LarryAC]

The movement is an Ansonia A26 from a mantle clock. This is just a project clock for me to learn techniques.

There were bent trundles on the adjacent pinion that I replaced and the arbor with the pinion was slightly bent. The break in the tooth was very shinny while the rest of the clock was pretty grimy, so I think it was done by the person I bought the clock from who I’m know had intended to work on it, but had zero experience.

I’ll see if I can find. “Safe barrette file”.

if I had another spare wheel, I might try the “alternative” fix suggested, but I don’t and the point of the project is to try and learn the proper methods.

 

[Dick Feldman]

Bent trundles, bent/broken teeth are commonly caused by excessive shock rather than someone simply forcing a wheel train. That excessive shock normally is caused by a spring breaking, a click assembly failing, a mainspring becoming unhooked, etc. Double check the integrity of the click assembly as that is probably the most common cause of bad teeth.

A good source for a replacement wheel might be David LaBounty
About Time - David LaBounty
Will Walker (WOW on this board) has a lot of spare parts movements as well.
You may want to send Will a PM through the board.

To me, it seems you have the right intentions.
It might be a good time to enlist a mentor.
A lot of good lessons can be learned quicker from personal contact.
Even a less than quality mentor can teach good lessons.
Your message board profile does not give your location.
A good way to find a mentor is to use the NAWCC.
Click the link below and follow it to a nearby chapter and chapter officer.
Local Chapters - National Association of Watch & Clock Collectors, Inc.
You can ask that officer for a suggestion for a mentor.

Best of luck,
Dick

 

[Carl Bergquist]

I count 43 teeth, what is the diameter? Just might have something in my scrap pile.

 

[LarryAC]

Dick, Thanks for the advice. I hadn't thought about finding a mentor. I'll look into a local chapter. I live in Claremont in Southern California. I've also updated my profile. Also, both clicks were sticky and gummy and the springs very weak. I had to loosen them up to be able to safely/easily dissasemble the movement. I'm inclined to agree with you that the spring might have let go while he was working on it, or perhaps that's why he ended up with the clock in the first place.

Carl, thanks for the very generous offer. It's 1.245" or 31.64mm dia., and I too count 43 teeth. I am inclined to take a shot at repairing this wheel, though I'm not highly optimistic I'll be successful. Let me give it a try and if I just make it worse, I'll send you a PM.

 

[LarryAC]

I got the first step done tonight. I got a little far to the left with the left cut and I can't get the corner of the right cut pointy, but this step wasn't that hard to accomplish. And the bottom is a little angled off. Maybe not the prettiest keystone cut but I think this will work.

It turns out I found a "safety" barrette jewelers file in my collection of small files that worked perfectly to finish up the bottom and sides of the cut. Thanks Willie for the suggestion.

I have a couple of sheets of 18g brass coming n tomorrow.

 

[Dick Feldman]

Good work!!!

If you do not have a jeweler's saw maybe put one on your Santa Claus list.
That will be a help with that and other projects.

Best,
Dick

 

[TEACLOCKS]

How to make a dovetail for replacing a wheel tooth

Following a recent thread on wheel tooth repair I thought it might be useful, and enjoyable, to show a few techniques I use when repairing/dovetailing a tooth on a French wheel. These teeth are very small and can be challenging to replace. I've enjoyed doing this, I hope it offers something to...

mb.nawcc.org

 

[Dick Feldman]

Another trick that may be handy is to use a piece of modeling clay to make an impression of a good portion of the wheel. As you file/shape the new tooth/teeth, you can hold the repair area over the clay impression to gauge your progress as you shape the new teeth.
Best,
Dick

 

[Brunod]

Don't worry if the dove tail doesn't fit perfectly, you can hammer it if needed. As long as it fits and doesn't fall out, the tin will act as glue to hold the part in place.
These wheels are 1cm diam.

The first one was done by hand with saw and file only. If you don't have a lathe, you might hold the wheel in a drill and use it as a lathe to finish the round shape and flatten the sides.
Now I also have this tool : a round topping tool.

Enjoy !

 

[gmorse]

Hi Larry,

I’ll see if I can find. “Safe barrette file”.

Even if the file is bought as having 'safe edges', it's often necessary to stone them off to a really sharp profile if you need to achieve good crisp corners. The very fine Vallorbe escapement files are good for this work, but are pricey, and the thought of grinding off part of a file costing that much can be daunting, but the results are worth it.

Regards,

Graham

 

[shutterbug]

Be sure to solder the new piece in well. You cut a little deeper than necessary, but the new piece should add the strength back into it if soldered well.
Edit: Someone re-posted this tutorial that will help you.

 

[LarryAC]

Thanks for the both of the links to the tutorial, and the suggestions on the file and next steps with fitting the slug and soldering.

I do have a jewelers saw and and various fine blades. I just need to get better at using it.

The barrette file I have is about 20 years old and is much higher quality then the junk set I bought off of amazon a few months ago. But I noticed it does not have sharp edges which is why I could not get that one corner sharp. I took a stone to it and sharpened the tip on one side and was able to improve the dovetail cut on the gear.

Brunod, amazing work and a very amazing machine.

 

[LarryAC]

I think I did it! Here's the final product. I have a little more polishing up to make it look nicer and it's not perfect, but it's my first try and the important point is the strike train wheels now runs perfectly and smoothly.

 

[bwclock]

I think I did it! Here's the final product. I have a little more polishing up to make it look nicer and it's not perfect, but it's my first try and the important point is the strike train wheels now runs perfectly and smoothly.

View attachment 757571 View attachment 757572

Nice job! Amazing what some initiative, a bit of perseverance and some simple hand tools will allow one to accomplish. Congratulations,
Bruce

 

[shutterbug]

Not bad at all. My first one looked worse But you might have to narrow the peak of the tooth in order for it to work smoothly with the connecting pinion. They connect to each other right at the transition from straight to peaked.