#015: Gear Cutting

featurephoto18
Standard

We have been practicing and learning our last micromechanics challenge, gear making. Although not a common demand for the modern watchmaker, gear making is a very useful skill for restoration, and essential for making an actual watch yourself – something I am definitely interested in.

There is nothing terribly complex about gear cutting but it does require lots of preparation and focus, utilizing lots of expensive equipment and all of the bed space of a Schaublin 70.

The set up for gear making, hiding behind the milling head is a centering microscope.

The set up for gear making, hiding behind the milling head in the tailstock is a centering microscope.

 

As you can see, it can be a bit confusing, spatial awareness is very important, one knock of a lever can completely throw off the centering, ruining a gear that requires any precision (the 6497/8 and larger wheels are a bit more forgiving).

The process is simple although somewhat laborious, as with most things in watchmaking preparation and set up time take up the majority of time/effort. When making a gear we prepare the stock to specification, center the microscope, cut the teeth, t and finally part it off.

 

Cut to specification, this section is ready to have teeth cut into it.

Cut to specification, this section is ready to have teeth cut into it.

 

cuttingwheel2

The cutting acttion, very logical and straightforward.

 

Ready to be parted off.

Ready to be parted off.

 

The result: A handmade 6498/7 hour wheel, this has not been finished or deburred yet.

The result: A handmade 6498/7 hour wheel, this has not been finished or deburred yet.

 

In my eyes the biggest challenge in gear making is focus, because of the high number of actions required when cutting teeth, it can be easy to get distracted and forget to turn the dividing head properly which can in the best scenario skip a tooth, in the worst it can ruin the gear. Brass is a simple job, one shot for each tooth, steel as always is a different animal and like other harder materials requires multiple passes to remove material. In this instance steel involves multiple cuts per tooth, greatly multiplying the time and possible room for error – and overall difficulty.

 

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>