RepOlaRap

This is still in draft. I'm just putting down my thoughts and plan to edit it as I proceed with my prototyping:

The Polar RepRap, "RepOlaRap", currently only discusses an X+Y axis robot. I plan on attacking a Z axis once I have a working prototype to test the resolution, positioning accuracy and repeatability, and software complexity for the X+Y.

Structural parts from top to bottom:

Build platform, 14cm radius disk, 15mm thick

 - Hole + thrust bearing at center.
 - MDF?
 - counter top laminate on bottom for hardness, extending out partially to form belt constraint (?)
 - groove for belt placement around perimeter?

Top Bearing Race, ring, radius: 13cm outer, 8cm inner, 4cm thick.

 - 16x 6mm holes drilled every 22.5 degrees, alternating at 9cm and 12cm radius.
 - 16x 5mm stainless steel balls.

Upper Radial Arm Platform, 15mm thick

 - general shape is a disk 14cm diameter, with an offset half a diagonal square 20cm per side extruded outward.
 - MDF?
 - hole drilled for interface bolt from thrust bearing on Build Platform.
 - counter top laminate on top for hardness on area under bearing race.
 - Three cut outs:
    - Two for encoder device and wiring for absolute radial position of Build Platform.
    - One for radial arm bolt + thrust bearing.
 - Build platform motor assembly will attach to this.

Lower Radial Arm Platform, 21cm radius disk, 15mm thick.

 - Hole + thrust bearing at center.
 - MDF?
 - cemented/glued securely to Upper Radial Arm Platform.
 - One long cutout or groove, 1cm x 9cm, for encoder wiring.
 - counter top laminate on bottom for hardness, extending out partially to form belt constraint (?)

Lower Bearing Race, ring, radius: 16cm outer, 11cm inner, 4cm thick.

 - 16x 6mm holes drilled every 22.5 degrees, alternating at 12cm and 15cm radius.
 - 16x 5mm stainless steel balls.

Base, 46cm x 46cm square, 15mm (19mm?) thick.

 - Hole drilled at center for interface bolt from thrust bearing on Radial Arm Platform.
 - MDF?
 - Cut out for encoder device and wiring for absolute radial position of Radial Arm.

Image illustrating XY platform structure: