2023-11-08

Last modified: 2023-11-08 16:23:08

• Barrel gear
• Stepper motor clock

Barrel gear

I glued the barrel gear back on to the superglue arbor and proceeded cutting teeth. It flicked off again, I glued it on again, it flicked off again, I glued it on again, and it flicked off for a third time and flew across the garage and I don't know where it went.

In any event, there had been so many false starts that the teeth were all different shapes anyway, so nothing of value was lost.

However, I am confused about why it kept flicking off. This process was pretty reliable before, wasn't it? Is it because the weather is colder?

Maybe the answer is the same as when I was struggling with superglue workholding on the router: I should cut the teeth before parting off. It will waste a lot more material, but it's better to waste material than time. Need to remember that.

So I tried again using a piece of solid bar:

Great success.

Next up: a pinion for the escape wheel.

I turned a piece of 4mm silver steel rod down to 3.6mm (the major diameter of the pinion), and then cut 7 teeth on it using the existing cutter (definitely not suitable for this few teeth). Then I put it back in the lathe to turn the rest of the rod down to 1mm, but I had neglected to harden it, with the inevitable result:

This may be salvageable as it is longer than required, so the bent portion can be removed. The shaft is still about 1.3mm though, but maybe I drill out the inside of the escape wheel to match.

Also I crashed the gear cutter into the collet nut, and wore the sharp end off it. It wasn't quite the right shape anyway, I'll need to make some new ones. Would be good to work out what module I'm going to be using so that I can only make the gear cutters once. I'll need:

• one for the pinions
• one or two for the wheels
• a "shaper" for the inside of the inner barrel

Anyway, for now, the plan is to tidy up this shaft a bit, harden and temper it, and then try to cut pivots on the ends.

And maybe tonight I try to lay out a watch with module 0.4, and two layers (i.e. escapement on one layer and train on the other).

Great, I accidentally cut the pivot too small when I meant to cut it too large and creep up on the size. It's because I deliberately positioned the Z axis at about the top of the shaft, but instead of typing a number smaller than 0.5 I typed a number larger because I wanted to cut a larger diameter. Stupid.

I'm stopping for now, disheartened.

Also, I noticed that the Z axis backlash compensation makes the cutter move in the X axis. As in the actual cutter moves, not the table. I think the rotation of the Z leadscrew pulls the head left and right, should look at that.

Stepper motor clock

It has stalled again, having tried to reverse :(. And none of the gears in the train are tight. Why is this happening? The heatsink seems to be getting hotter than I remember, maybe it is getting too hot even with the heatsink, which increases resistance and means it doesn't have enough torque?