“Gertie,” here, is a work-in-progress from Alameda resident and Pixar character technical director Alonso Martinez. The design stands conventional delta robot kinematics literally on its head, using the parallel linkage as a nimble, flexible “foot,” rather than as an arm equipped with an end effector.
Gertie Concept Sketch - January 28, 2014
The robot's mechanics and electronics will eventually be encased in an egg-shaped silicone shell that can bend and flex organically with the armature's movement as it jumps around.
Base with Actuators Detail - February 16, 2014
The torsion springs create a so-called "series elastic actuator" to recycle energy between jumps. Here the base is shown from below, with the legs splayed and the springs in their high-energy state.
Duplicate Bases - February 21, 2014
Two identical base / actuator / upper leg sets positioned side-by-side. Here the legs are in their closed position, and the springs are in their relaxed or low-energy state.
Gertie Concept Renderings - February 24, 2014
The outer shell is planned to be smooth and featureless except for a prominent molded-in "eye." See-through rendering, right, shows "top-heavy" layout with LiPo batteries positioned uppermost.
Rendering vs. Reality - February 24, 2014
Gertie uses a Raspberry Pi for a brain, positioned low in the base. Here the HK47902TM servos have been replaced by Turnigy 306G-HVs, and the socket horns / extrusions with one-piece 3D printed upper legs.
Tie-Rod Detail - January 3, 2014
Here as elsewhere, the red parts are 3D-printed fused filament plastic. These lower linkage members are made from off-the-shelf R/C hobby ball joints coupled by 3D printed rods. Two are required for each actuator.
Custom Buttons - February 24, 2014
Hacked Staples "Easy" buttons with custom 3D-printed JUMP! inserts will transmit wireless commands to Gertie using Arduino Pro Minis connected to low-power 2.4Ghz nRF24L01 tranceiver ICs inside.
The video embedded up top was uploaded in November 2013, and though the sound isn’t great, it’s definitely worth watching to get a feel for how brilliantly this idea succeeds in creating expressive movement — even in this early prototype stage, Gertie is like a cartoon character brought to life. The concept renderings and photos immediately above show a later version of the same design. Martinez plans to premiere the first complete Gertie prototype at Maker Faire Bay Area 2014. If you’re going to be in northern California the weekend of May 17, don’t miss the chance to come by and see what’s
hopping jumping off going on.