Happy New Year!

To start the New Year off with a bang I've discovered a fundamental problem with the Robotic Arm, but more about that in a moment.

The core components 'in a nutshell'

So far I have addressed each of the four core components of this project individually and started to pull together a encompassing C# program to get them to working together.  It was at this point I started to put the arm through it's paces with one of the kids Christmas presents - Marble Madness.

The issue I discovered is despite sending an identical set of commands to the arm the final position was not the same place each time, in fact some axis where hugely off!  The PC I/O is the same each time as verified when using the PC application which came with the arm, it's the actual motors themselves.

Now for the fundamental oversight; the DC motors are of course affected by the weight of the arm, battery condition and arm position i.e., asking a motor to spin for 1 second could result in 10 degrees movement in one instance and 20 degrees movement in another.

The view from the arms claw

The view of the whole arm

Running the tests in the above videos several times resulted in the arm completely missing the marble drop position.

Noooo, now what?!   Maybe I need to take a look at some servos or a step motor to increase accuracy.