Robotic Arms

Like your arm, but on a robot. It might not be shaped like your arm. There are a lot of types.

Types:

• Anthropomorphic (aka Articulated): Shaped like your arm and with a human looking hand. Typically mounted upside down, with the base (would be your shoulder) on the bottom, and the elbow sticking up into the air. The MeArm is one example but these are common and what you probably think of first. e.g Dexter
   
• Spherical / Polar. With a base that rotates, and an slide that can be angled up or down, and in or out. It moves by changing Azumuth (rotate the base), Declination (angle the slide higher or lower), and Range (slide in or out from the base).
   
• Cartesian / Gantry: With slides and axis that move in 3 dimensions: X, Y, and Z. Commonly found in 3D printers and CNC machines. These are the easiest to control, and probably the most common.
   
• Cylindrical: With a central pole that it moves up and down upon, and rotates around, and then a slide that reaches in or out from there. It's dimensions are Height, Azumuth, and Range.
   
• SCARA (Selective Compliance Articulated Robot Arm.) robot: Like a cylindrical robot, but instead of a slide, it has an elbow joint going out to the side. Put the top of an articulated arm, turned on its side, on a cylindrical base. They sometimes have two elbow joints, one left, one right, connected together at the end. These are becoming very popular.
   
• Delta: 3 actuators of some form (usually slides, sometimes levers) move three rods which meet together at the end. By moving each of the rods up or down, the point where they meet can be changed. Seen in some 3D printers. The rods can be replaced with cables in a Wirebot.
  

Terminology:

End effector

Like your hand. With metal fingers, pinchers, gripper, vacuum, or many other things that can effect the world.

Kinematics +

How it moves. Believe it or not, this gets really really complex.

Actuators, Motors

See also:

• https://www.youtube.com/watch?v=W_f1JcTgQuc Excellent design made simple with really large pulleys.+
• https://www.youtube.com/watch?v=gPYjo-W2ctU A 3 cylinder soft arm molded with ink pens. Can turn to any angle and any amount.+
• https://www.youtube.com/watch?v=uPx8xwRpfFk Molding an adjustable soft pneumatic gripper.+
• https://docs.google.com/document/d/1dQq4EfBD3MWvAWnioHKCsFHYMW_WQ9pfJITspgXiqNc/edit Mostly a collection of links, organized by outline.
• http://walter.readthedocs.io/en/latest/ Amazing build with good documentation and source code.
• https://github.com/ColbySchexnayder/mearm/wiki a very simple, but almost useful, truly open source robotic arm.

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