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2023-09-02

Last modified: 2023-09-02 15:38:57

< 2023-09-01 2023-09-03 >

Pin pallet escapement simulator

I've done a lot of fighting with Matter.js and I think I'm ready to throw in the towel. Probably I want to write my own physics system for it. I quite often want to make "schematic" simulations, examples:

So maybe I want a generic system that lets me specify constraints between parts and apply forces/torques to them.

Matter.js creates degrees of freedom where none exist (i.e. the constraints aren't actually respected) which makes it not ideal for the kind of work I do.

Here's a Javascript constraint solver: https://www.npmjs.com/package/constrained - maybe that would be useful.

Watchmaking

I made a little shaft for my little gear, on the mini lathe.

According to an example I found, it is very poor: https://www.awci.com/wp-content/uploads/2015/12/Pivot-Burnishing-Clockmaking-Dec2015.jpg

It is 10mm long which means if I actually make them this big it will be a pretty chunky watch.

The pivots on the end are 0.5mm diameter. At this size even measuring the pivots with the micrometer it feels like the micrometer is going to break them off. I could do with a tiny micrometer.

Also, the 0.4mm radius on the tool means it's impossible to turn a sharp shoulder. Probably I want to use HSS, possibly in the form of a hand graver.

The big 3mm diameter in the middle is not functionally necessary, except I can't hold the part in a collet without it. Probably I need some sort of miniature collet chuck. Also, ER collets are not ideal because they need to be supported at the back. I need a collet set that only closes at the front, and a bunch of different sized collets.

I don't know what shape the pivots should actually be. What are the bearing surfaces? It is hard to find examples online because basically all watch movements use jewels. Should it be conical? How do you set the end float?

This Clickspring clip shows a straight shaft going into a slightly-tapered hole. End float is set when you turn the shaft. Just make sure the distance between the shoulders is set correctly. My only worry with this is that the tapered hole will wear very rapidly.

https://www.youtube.com/watch?v=dAeAaedGffc

Mote info from 4:00 in https://www.youtube.com/watch?v=O8xIjsaDlN8&t=4m0s

6:19 shows a diagram - it looks like it's tapered from both sides? Seems unnecessary though

9:00 after the initial cut with the broach with flat sides, it is reamed again with a totally smooth broach to burnish the inside of the hole.

< 2023-09-01 2023-09-03 >