ORBIS DARTS RIG
https://orbisdarts.com/#rig

Three USB cameras on 3D-printed arms round a steel-tip board, and a ring light behind them.
Plug the cameras into one computer, open https://orbisdarts.com/play/, choose the cameras in
Settings > Camera & detection, and press Calibrate.


WHAT TO PRINT

Camera mounts (tested)
  camera_mount.stl         x3   Prints on its side, no supports. PLA is fine.

Ring light (NOT TEST-PRINTED YET: print one bracket and two sections first and check the fit)
  ring_segment.stl         x17  Prints upside down on its flat top. 2 walls, 10-15% infill.
  ring_segment_wire.stl    x1   The same with a hole for the strip's lead. Fit it at the bottom.
  ring_key.stl             x18  Joins two sections at the back.
  ring_bracket.stl         x3   Clamps onto a camera arm and holds the ring. Prints on its strut.

Every part fits a 220 x 220 mm bed.


WHAT ELSE YOU NEED

Cameras
  3   USB camera modules: OV9732, 1280x720, 100 degree lens without fisheye distortion,
      38 mm square board
  9   Neodymium magnets, 10 x 3 mm discs, glued three to a mount's foot
  12  M2 self-tapping screws, four to hold each camera board
  1   Bristle board with a metal band round its edge, standing proud of the surround:
      the mounts clip onto it with their magnets and hook a lip over the playing face
  3   USB ports on one computer running Chrome or Edge (a powered hub if you are short)

Ring light
  3 m  COB LED strip, 8 mm wide, 24 V, neutral white 4000 K, CRI 90 or better,
       10 W per metre or more.
       The ring takes about 2.8 m.
  1    24 V power supply, 2 A or more, with a plain on/off switch. Avoid dimmers: most
       of them flicker on camera.
  36   M3 x 8 screws for the keys
  6    M3 x 12 and 3 x M3 x 10 screws for the brackets


ASSEMBLY

Camera mounts: glue the magnets into the foot, slide the camera board in from the back and
screw it to the front wall, and press the USB lead into the channel down the back of the arm.
Put the mounts round the board at 12, 4 and 8 o'clock (120 degrees apart, never facing each
other). The lip over the playing face sets every mount at the same height.

Ring light: slide a bracket sideways onto each arm, all three the same way round, and tighten
its locking screw. Join the sections with the keys, stick the strip into the throat under the
visor, lift the ring onto the three brackets and screw it on from below. Then calibrate.


SOURCE

camera_mount.scad and ring_light.scad are the OpenSCAD models the STLs come from. Every size
is a setting at the top of the file. ring_light.scad expects camera_mount.stl beside it.


LICENCE

These files are licensed under Creative Commons Attribution-NonCommercial-ShareAlike 4.0
(CC BY-NC-SA 4.0): https://creativecommons.org/licenses/by-nc-sa/4.0/

You may print, change and share them, with credit to Orbis Darts (orbisdarts.com). You may not
sell them or prints of them. If you share a changed version, share it under the same licence.
