Bergeon Platax Punches

Bergeon Platax Punches

I've been gathering watchmaking tools for a while as they are useful for making small things, and especially useful for fiddling with watches. I have a project watch that I want to work on and having the right tools is always a good idea. One tool I recently bought is a Bergeon Platax tool which is used for dismantling balances.

Unfortunately one of the punches that it came with was broken, so I decided to make some more. These are not easy things to make, as they have various holes in the end of 0.1mm, 0.15mm and 0.20mm.

I used 3mm silver steel for the punch body, and some EN1A rod to make the stop rings. I'm using the CNC engraver/mill to drill the holes in the end of the punches using carbide drills. I created a tcl script that writes gcode with appropriate feed speeds and pecking cycles. It took a few attempts to find something that works, but I seem to have that now. And a pot of broken drills... The results are pretty good:

That's mine on the right and the original on the left. This is the broken 0.20mm punch on the left. The hole is about 1mm deep, I've no real idea if that's the correct depth, but it seemed to work on the balance I had a go at dismantling. The silver steel isn't particularly hard, but then, if it wears out I can make another punch...

One problem is the accurate positioning of the hole in the end of the punch. I think I may have to build some sort of something that I can use for positioning the CNC spindle when making small things. Trying to do it manually by poking me head round the spindle just doesn't work very well.

You can see the hole here, and the fact it's a bit off centre:

I've also ground a used D bit down and used it to create the rounded edge to the hole that the original Platax has on its punches. I may have to do something more accurate for that too. Somehow.