One feature in my little gearbox that I've failed to talk about are what I'm calling the vital 'Orbital Plates' and the associated top portion of the gear box. These are actually very important parts of the design as these will keep the three separate geared plates in alignment and vertical.
The Deimos, Phobos and Mars gears are attached vertically with cages of dowel to various sized plates. (Well actually the Mars gear is strictly a 1/2 inch dowel up the very center...) These plates have about 1/8 of an inch clearance from one another and the outside recess of the top of the gearbox. Have a look at these photos and you'll see what I've decided to do.
I've made my own coasters or wheels about an inch across out of Alumilite casting resin to surround the two plates. I was hoping to find one inch nylon coasters but the local hardware store were kinda low on those. We'll see how they ware, but in my experience the Alumilite is pretty tough..
That takes care of the horizontal friction I hope...
For the vertical friction I've cut out and shaped 1/8 thicknesses of UHMW from Lee Valley. If you're unfarmilliar with this stuff, UHMW stands for Ultra High Molecular Weight and is perfect for frictionless bearings. It's a bit tough to cut, but not impossible. A good sharp xacto blade helps, but use some of that green High-Friction Guard Tape on yer fingertips if you want to keep them. I plan to next rout out 1/16th deep grooves for the UHMW to sit in and I'll attach with very small brass screws.
As for the rest, well it's looking like this:
Next : making the gear assemblies. The bearings hopefully arrive tomorrow!
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