A Drawing of the Arm Upright Assembly

A Drawing of the Metal Posts in the Assembly

The Basic Arm Upright Assembly

Goals

• Gear the Motor that controls the Lifting Arm to a good speed.
• Acheive a hieght that will allow the robot to score on all three spider leg heights.

Design Process

This assembly was relatively simple to design. Our only concern really was creating the proper gear ratio to control the Lifting Arm with. With our calculations, we determined that the proper gear ratio to achieve the desired arm speed was 27:1. We used three stages at a ratio of 3:1 to achieve this.

This is the only assembly on our robot that uses #35 chain. The first two stages of the transmission use #25 chain, but the third uses #35 chain. There is a lot of stress on this part of the robot when the arm is fully extended and holding a tube. We didn't feel that #25 chain would be strong enough. Also, as a way to keep the stress on the shoulder joint down, we used a 50 pound gas spring.

This shows a good view of our placement of the Gas Spring to aid in lifting the arm.

The Assembly on the Final Robot