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====== What I want to accomplish ======
  * Build a machine to polish glass surfaces very smooth,
  * Wring some smooth glass surfaces together,
  * Characterise a wrung glass join.

THE MACHINE:

{{:projects:glass_sphere:work_logs:pasted:20190105-101443.png}}

Wrong machine.

{{:projects:glass_sphere:work_logs:pasted:20190105-101349.png}}

The idea is to ensure that each portion of each surface of both parts touches every other part:

{{:projects:glass_sphere:work_logs:pasted:20190105-101554.png}}

Using the [[http://ericweinhoffer.com/blog/2017/7/30/the-whitworth-three-plates-method|Three-plate Whitworth method]] I should be able to create very smooth and flat surfaces.

====== What I've done ======

I built a few rotating platforms. The first one was too weak, using a geared DC motor. I was using water and various grit compounds:

  * Toothpaste,
  * Titanium dioxide,
  * Bicarbonate of Soda.

When the two test float glass pieces got wet and smooth-ish they would bind together very strongly, stalling the motor. I needed to build something with more power and some inertia to overcome the spiky friction.

My second pass was a bit better:

{{:projects:glass_sphere:work_logs:pasted:20190105-102330.png}}

Using a scrounged office chair base, an old drill, some 3d-printed gears and a concrete round from bunnings. Shown here with some pottery on top, because it also worked as a pottery wheel. I used a variac to slow the drill down to a good speed. I ran into heat problems in the drill, and the office chair base was not as stable as I would've liked.

I ended up picking up a cheap pottery wheel off gumtree (classifieds website). I'll be using that in the future.

=== Videos ===

{{youtube>Bv8tEChs2u8?large}}

====== What I want to accomplish next time ======

  * Build the reciprocating part,
  * Test the process with my pottery wheel.
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