Mark Pauline just completed work on the new actuator for the Spine Robot that solves the scoliosis problem encountered at the robot’s debut during the Explosion of Ungovernable Rage show last October 2010.
On this image gallery page, click on the Spine Robot January 2011 link under Galleries for a larger view of the new actuator.
“It’s a 2 axis push-pull winch configuration with a urethane spring tensioner to take into account the differing radii on the tendons as they move. The cables are terminated in sefac spiked terminations that are clamped into the winch spools. In operation, the ropes are spooled from the bottom or top of the winch. The one side passes through a urethane spring tensioner. An 18² sprocket powered by a 1000 ft lb high torque hydraulic motor spools and unspools the rope, moving the spine roboti.
For the SRL show on Oct 30th 2010 (Explosion of Ungovernable Rage), a hydraulic actuator was hacked together from another SRL machine, The Finger. It had several serious drawbacks. One was that it used rubber bungee cords to power the return of each axis. This created about 5000 lbs of compressive force on the spine segments when the system was at rest, causing them to bind and creating a ³scoliosis² twisting effect. “, says Mark Pauline.
Mark’s been keeing a running log documenting the building and maintenance of the Spine Robot here.