The Master Plan

Now that we had a vague idea of what we wanted to make,  we sat down and started talking about how we will make the project. The first thing we discussed is how should the arm look.The idea was to make it look as human-like as possible. This is the rough design that I drew

  For now the plan was to put some sort of a glove over the fingers and maybe stuff it to make it look like a real hand. We decided to use Aluminum for making the hand as it was cheap, light , strong and easily available. For the finger we had two options . We could use thin aluminum pipes cut into three pieces to make one finger. We could attach these pieces with hinges . The other option was to use plastic pipes cut at the right places so that they would bend like a human finger. Now in order to decide which option was best , we had to consider the way we were moving these fingers. The straightforward idea was to to attach a string to the finger and its other end to a servo motor. the servo will rotate, pull the string and the finger will bend.The problem with aluminum fingers was that when the servo will rotate back, they wont go back on their own. To do so they would need some kind of a spring to pull them back and that would put unnecessary load on the servo. The plastic pipe being elastic will go back on their own. So we decided to go with the plastic pipe fingers