Monday, May 30, 2011

More gripper arm work

Tonight I spent some time on the gripper arm.  I would really like to have this working for the event this weekend but I keep encountering more and more issues.

As you may recall from previous entries, getting the right sized actuator and reducing the size of the linkages.  So the good news is that it fits the doorway.  The BAD news is that the servo that opens and closes the claw barely does.

The pictures may not be a great illustrator of the problem, but the servo comes right into contact with the hinge.  You can also see how tight it is on the left side, clearing the door.

Now recall, if this just had to pivot straight out of the body, no problem.  But, R2 is round and in order to compensate for where straight ahead is, the arm has to open at an angle.  I had to do the same thing for the CPU arm several months ago.

My first thought was to see if I can replace the servo with a smaller one, such as a micro one.  The servo that this gripper uses is a very unusual, "medium" sized Chinese model.  It has the same spline (round gear cog the servo arm slides onto) as a regular servo.

I have an idea or two about, perhaps, getting a micro server to fit in there.  As you can see, how the servo hangs from the claw...

I could remove the servo completely but the "wow" factor of the claw opening and closing is really sharp.

Well, more in a bit...a few more ideas to try!