CAD files for Dingo robot

See https://grabcad.com/library/dingo-robot-quadruped-2 for latest files

Some build notes:
- The black piece which acts to transfer the motion of the lower servo to the lower leg should be printed in two parts, then have a bearing inserted, then be glued together.
- All parts in contact with the motors MUST be printed in ABS for temperature resistance. PLA parts will soften due to the heat the motors produce (although this may be avoided using the fans). So all orange parts are ABS as well as the black hub which holds the servos for the upper and lower leg. Note that the upper leg is in contact with the servos via the bolts which attach it so should also ideally be printed in ABS to avoid any issues.
- All heat set inserts should be pushed in with a soldering iron tip. See here https://www.youtube.com/watch?v=hwq15qH-4x4