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Jacot tool and pivot file burnisher question


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Hi

I got my hands on an old jacot tool and want to learn about cleaning pivots. Most all jacot tools on the net and u tube have a pulley  and string to drive it pretty self explanatory. 

The one I have on one side is the slots to rest a pivot on the opposite a bar that comes out with flat sides and a point not in the center but off center on the top of the bar.

Looking around e bay and pictures on the net I don't have the only one they seem to be much less common but they are out there.

My problem is I can't figure out the setup. Could someone show me how the balance would be mounted and spun, or point me in the right direction ?

I have looked around quite a bit before asking and just can't find any info on it.

Thank you, Tom

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The burnisher removes a small amount of material. But that is not it’s purpose. It’s purpose is two-fold. It folds over the surface grains of metal which makes them smooth and achieve a polish. So thi

There were numerous funny little lathe-type tools made for refinishing pivots over the years, usually with one pivot supported in a cone center and the pivot to be polished sticking through a hole in

That all sounds pretty spot on. The Bergeon burnisher works much better haha. Especially for conical pivots, I think you'll find the Vallorbe is only good for large pocket watches (the radius is too l

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Thessler,

The Jacot tool is essentially a dead center lathe. The off center looking part (center) on your lathe is actually aligned with the groove in the drum. One end of the staff (the pivot) goes in the center and the other end rests in the groove in the drum. The Jacot tool in your picture is missing the drive pulley assembly that is on some Jacot tools. The drive pulley assembly should rotate around the dead center and generally has two drive pins sticking out of the pulley. The drive pins will engage the balance wheel (if it is attached) and turn the staff. The pivot to be burnished rests in the appropriate groove so the burnishing file can be run over the pivot. If the part to be burnished does not have a wheel attached to it, then driving dogs (which are shaped like fish) are attached to the shaft. The pulley is generally powered with a bow that is strung with thin fishing line.

A high quality Jacot lathe, such as a Steiner, is generally in an encased set and should come ready to run. If you go to the OTTO FREI site you can pull up a picture of a complete Jacot Tool Set. The tool you currently have needs the additional components in order to work.

david

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Yes, you are right... here is a similar one http://www.ebay.com/itm/Antique-watchmakers-jacot-pivot-lathe-with-brass-frame-steampunk-instrument-/322344296852

but I've looked through all my books and don't see one in use. Is it possible that you use the bow directly on the wheel staff? 


I made a YouTube video on using this tool.




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Hello Tom:

Here's my setup. I bought a low RPM electric motor and a controller and just mounted the thing on a cheap wood carving board that I bought at Wallmart. Additionally, I bought the pulley and O-ring from eBay as-well-as the motor, the controller, and some rubber feet. The clamps is milled out of aluminum but they could just as easily be made out of wood - there's very little pressure on this operation.

If you want more specifics I 'll be glad to provide them.  Check out the video and let me know.
 

Thanks!

Tom
 

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The pic Stuart references is the exact tool I have. It is not missing parts, the more common ones with the pulley have an extra shaft. Very similar tool but not the same.

The only thing I can figure is as Stuart suggested,  wrap the string around the balance shaft.

I'm guessing that's the  real good way to bend and snap off pivots. Maybe that's why the other style is more common.

Thanks for the thoughts, Tom

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Thessler,

There used to be special drive pulleys for that purpose but they are no longer made. The pulleys had a clamping bar on one side with a square notch. The shaft would be placed in the notch and tightened to the shaft with screws. There were a couple of problems with this method. The first problem was if the exact pulley was not used for a given staff, the pulley would be off center. The second major problem is the tool was bulky and pretty much unsuitable for smaller wrist watch staffs. I never heard of winding a string around the balance staff itself to drive it. It does not sound like something that would work.

david  

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20 minutes ago, david said:

Thessler,

There used to be special drive pulleys for that purpose but they are no longer made. The pulleys had a clamping bar on one side with a square notch. The shaft would be placed in the notch and tightened to the shaft with screws. There were a couple of problems with this method. The first problem was if the exact pulley was not used for a given staff, the pulley would be off center. The second major problem is the tool was bulky and pretty much unsuitable for smaller wrist watch staffs. I never heard of winding a string around the balance staff itself to drive it. It does not sound like something that would work.

david  

It's called a split ferrule and can be seen illustrated in De Carle's Practical Watch Repair at the beginning of the chapter on turning.

I have a few in various sizes including a couple that are small enough for some of the larger wrist watch balance staffs but have never used them for the reasons David has stated above. I guess that at a push they would be ok for roughing out the staff on a turns up to the point where the wheel could be riveted on allowing the use of a pulley wheel with a driving pin and then then turning the pivots, but if you were unlucky to subsequently break a pivot you would have to cut the rivet off again to remove the staff and start again. I can't see pivots surviving the lateral loading that the bow would exert on the ferrule.

Wrapping the bow around the actual staff would I'm sure be a recipe for disaster.

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I think the best bet would be to make a small pulley to rotate on the dead center of the Jacot tool. It could be turned from a piece of brass rod with a small hole drilled in the center to ride around the outside of the dead center. The groove in the pulley can be cut with a V shape cutting tool. I think that would be the easiest way to get the tool up and running.

david

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Thessler,

Take a look at the Jacot tool sold by  OTTO FREI. I am pretty sure it is a Steiner. The cost of a new Jacot set is about equal to the down payment on a house so it would be a good idea to find a used one.  Once you can see what a complete set looks like, you can take a look at  used ones  for sale on Ebay. Also, check with Uncle Larry's Watch Shop.

david

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Thessler,

Take a look at the Jacot tool sold by  OTTO FREI. I am pretty sure it is a Steiner. The cost of a new Jacot set is about equal to the down payment on a house so it would be a good idea to find a used one.  Once you can see what a complete set looks like, you can take a look at  used ones  for sale on Ebay. Also, check with Uncle Larry's Watch Shop.

david


I lucked in on mine, a real beauty


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Working with a Jacot tool you use a bow, which I see is included. I also see in the other piece of paper what looks like a watch mainspring thickness gauge, which is not part of a jacot tool.  The rubber bands you don’t use them with the jacot tool

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