The Escapement (part 1?)
The power for this kinetic sculpture comes from the weights which are attached to the drums behind each of the large drive wheels already mounted. What stops the wheels spinning round is the escapement.
This takes the form of a smaller wheel, whose teeth connect to the drive wheels. What stops that smaller escapement wheel from spinning even faster, is the way in which it is held back by stoppers which press against brass pins which are mounted on these escapement wheels, which only lets them rotate 1/6th of a revolution at a time.
Each escapement is made of a solid wheel which engages with the drive wheel, a spacer behind (to ensure the escapement wheel is at the same distance from the frame as the drive wheel), and the escapement wheel itself - whose key aspect is the series of pins which are used to stop it from spinning uncontrollably.
So, first, the solid wheel. Same technique as before, hand cutting on hegner, and making it circular using the vertical belt sander. This time, I checked the drill for its orientation to the table though !
Then the outside and inside of the escapement wheel. The teeth around the outside will be used by the mechanism which allows it to rotate only one pin at a time.
The escapement wheel also has four more brass pegs, which actually protrude opposite to the rotation-limiting pegs (6 of). They are used to allow the sculpture to be wound up. They support a ratcheting mechanism, whereby when the drive wheel is applying torque to the escapement wheel, it tries to spin it, but if you rotate the drive wheel in the opposite direction, then you do not have to spin the escapement wheel - such is the nature of a ratchet. To tell the truth, till I made one of these on my first model from this designer, I didn't realise how it would work, so don't worry if you don't either. But its rather clever, and is used in a number of his designs (clocks as well).
So, having also cut the ratchet teeth, these are the two sets of components needed to make the escapement. The escapement wheel has already got its brass pegs in place.
Now for their assembly. I had to thin down the wheel, so the back of it is looking a bit ropey - I've not bought the expensive ply of just the right thickness, but the front looks fine.
The spacer is stuck to the back, and the ratchet wheel, part of the ratchet mechanism is stuck to the front, all three items are mounted onto a 9/32 brass tube (which will rotate on the 1/4 inch brass rod).
So, once assembled together, on the mounting rod, a single escapement assembly looks like this. You can see the ratchet assembly which is what couples the front to the back.
And here is what they pair look like in situ.
Next - more cogs and the bits which engage with the pegs on the escapement.
