Barrett Technology 

Summer Internship 2011

Construct, program and run a cable life-cycle analysis test system, design and prototype a novel control accessory for the Barrett Hand that will eventually be sold as a product, as well as others. Build CAD models in Solidworks and perform detailed analysis of complex electromechanical systems.

The rig should simulate as closely as is reasonable the operation of the cables in the WAM, while taking accurate measurements of cable tension, position, and stretch. It should be able to run safely, unattended for days, logging data, and shutting off automatically when a cable breaks with the possibility of operator notification.

The cable tester should consist of two motors, mounted rigidly to some sort of rail. The motors will drive pulleys so that a cable stretched between the two will be held at a controlled tension while being worked back and forth over the pulleys with a predetermined profile. The motors should be able to tension the cable to at least the same maximum levels as a typical WAM® Arm. The motors will need to be water cooled in order to be able to apply high tensions for extended periods of time.

The cable tester was designed to make use of the existing L-bar material from the previous cable elevator project from 2010. The entire physical infrastructure of the cable tester is fabricated from the L-bar used previously. The body of the cable tester is a 700mm length of aluminum 6061-T6 L-bar which serves as a mounting/interface plate for the two motors, gearbox and pulley support bearings. There are essentially five systems which comprise the cable tester infrastructure.