Robotic manipulator

[Todo: add intro]

serial robots

Purely mechanical serial robotics can expose the problem of unintended differential bearings. When the control of the second joint from the root is threaded through the first joint by e.g. a conical gear turning the first joint will cause the second joint to move too when no measures are taken. [Todo: add mechanical equivalent circuit diagram to make this more clear] [Todo: discuss methods for preventing or compensating that]

Examples:

• K. Eric Drexlers robot arm design [add reference]. It mitigates the "unintended differential bearing effect" by using flexible nanotubes and a very high gearing ratios.
• Another design by J. Storrs Hall [1] [Todo: analyze and shortly discuss]

Parallel robots

• steward plattform
• parallel mechanics form industrial designs and DIY 3D printers

General

• stiffened classical robot arms
• designs avoiding sliding rails
• designs avoiding ball bearings
• small angle designs