DEWBOT III Arm

From DEW Robotics
Revision as of 11:57, 11 August 2009 by MaiKangWei (talk | contribs) (Original Arm Mechanics)

Jump to: navigation, search
Al Koenig, Ben and Kevin test the Arm prototype

Dewbot III ended up with an effective arm for scoring, but this arm had a difficult birth.

The Arm used on Dewbot III has three articulations:

  1. A hinge shoulder driven by a pneumatic cylinder
  2. A hinge elbow driven by motors and monitored via potentiometer
  3. A gripper driven by pneumatic cylinder

Original Arm Mechanics

The Shoulder articulation was used to deploy the arm for play from the robot's initial staring position. The pneumatic cylinder (Bimba xxx) was retracted and the shoulder folded back for the start of competition (this kept the robot within the FRC starting envelope dimensions). At the start of Autonomous Play, DEWBOT III's compressor came on and the Shoulder deployed to the forward position. The Shoulder could also be actuated during the game to allow bi-directional play (picking up ringers on one side of the robot and scoring on the other) or to manage center-of-mass when climbing ramps at the match end for bonus points. Bi-directional play was seldom used in practice.

Dewbot III's elbow was driven by a pair of Nisso-Denso motors (L & R) with a 4:1 "gear" reduction via 10 & 40-tooth timing belt pulleys. A 270° potentiometer provides elbow angle information.

The original Gripper was a

Improved Gripper

Alternative Arm Design