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Meet Stompy: An open-source, 18ft wide, 4,000 pound, 6-legged hydraulic robot that you can ride. Read more

Somerville, MA Robots
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This project was successfully funded on September 2, 2012.

Meet Stompy: An open-source, 18ft wide, 4,000 pound, 6-legged hydraulic robot that you can ride.

Somerville, MA Robots
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Project Hexapod in build mode, now accepting new team members!

Hi everyone!

It's been a long time since our last update, and we wanted to let you all know what's been going on. To make a long story short, we've moved out of our design and prototyping phase and into our build phase! Now that we're fabricating, we've decided to expand the team to include new skilled steel fabricators; if you're in the Boston area and are interested in joining us, check out the call for new members at the bottom of this update, or check out the application survey here. Now, on to updates!

At the start of the year, we worked pretty hard to build out both the hydraulic powerplant for the final robot and a CNC Plasma Cutter (that would then be used to cut parts out for the robot's legs and chassis). Both items took us awhile to complete, and took more energy than we were hoping, but we wrapped them up around May. Since then, we've been working hard to finalize our leg design, get the links analyzed for overall strength and manufacturability, and create manufacturing and quality control processes from scratch to ensure that we build as robust a robot as we can. If you're interested, you can check out an example of the kinds of work instructions and processes we're creating here.

We're happy to announce that we've taken on two new sponsors recently, which have drastically helped our design and process; the first was Tompkins Industries, a global hydraulic fitting and hose supplier. We worked with them to design and supply custom hose assemblies and hydraulic fittings for all of the parts in the hydraulic powerplant, and will soon be working with them again to design the hose runs and fittings for the legs of the robot. The second sponsor was AST Bearings, a global supplier of bearings and bushings of all different shapes and sizes. We were having a lot of trouble coming up with cost-effective ways of designing and fabricating joints with rigid bushing assemblies that had to be concentric across big weldments made up of a lot of individual thin plates; in order to solve that fabrication problem, we worked with AST Bearings to source low-cost spherical plain bushings for all of our joints, meaning that Stompy will be much easier to weld together (for both us and any novice fabricators that follow in our footsteps), will be much easier to assemble in the short term, and will require less maintenance in the long run.

As we mentioned above, we're now solidly in the build phase of the project. We've decided to start by building the lowest-stress parts of the leg first in order to get all of our fabricators on the same page; we're building the "calf" link, as we call it. This is the link that touches the ground, and is suspended from the rest of the leg via a four-bar linkage and shock absorber. This is what 8 calves (one to screw up, one for a 'spare' leg, and 6 to put on the robot) worth of parts look like when the parts come out of the CNC Plasma Cutter:

All 184 of those calf parts have to have dross removed from them, and they have to be ground down and cleaned wherever we plan on welding so that we don't get contaminated welds. We expect that the legs represent at least 1,100 person-hours worth of fabrication, all told, without including assembly onto the robot itself or building the chassis. Needless to say, there's a tremendous amount of work ahead of us, and we've decided to ask for help to get it all done in a reasonable amount of time.

If you're in the Boston area, have experience with steel fabrication, and would like to join Project Hexapod, we'd love to hear from you! We're looking for somewhere between 4 and 8 new team members who can step up and help us build this giant robot over the coming months. If you're interested in learning more, please check out our application for new team members here: http://www.surveymonkey.com/s/W23NKBD .

That's about it for now! We'll be posting lots of pictures of our build process to our Facebook page if you want to follow us there, and we'll be updating our blog soon with discoveries we've made during the build process.

Thanks everyone!

Comments

    1. Creator Tod Loofbourrow on January 23, 2014

      What's the latest with the project, guys? Word on the street is that you're a bit stalled. I hope that in this case the zeitgeist is wrong. Love to get the latest.

    2. Creator dgd3 on August 14, 2013

      Your answer is good.
      I'd not thought about the weight issue which is very valid.
      Do you have anything like a mini prototype to sort out controls and guidance? There is a lot of this already going on and sourcing skilled folks to work on this should not be a problem.
      Licensing, insurance and where to drive may end up being the biggest headaches.
      Ever since I saw backhoes as a kid I dreamed of having a walking machine.
      Keep at it!

    3. Creator dgd3 on August 14, 2013

      Oops!
      My suggestion is patented.
      U.S. Patent Application #08/804,318

    4. Creator Project Hexapod on August 14, 2013

      Dennis - that's a good question. The primary driver was weight and manufacturability - an excavator boom from a similarly-sized construction vehicle weighs around an order of magnitude more than our existing legs. Our legs right now weigh around 400 pounds each, and those booms can easily reach 5,000 pounds on small excavators (since they build their castings with 1"+ wall thickness cast iron), and 10,000 to 20,000 pounds on medium-size machines. Quite simply, we have no way to work with metal that heavy - whether we're talking about lifting it, moving it, or modifying it. Also, once you have legs that weigh that much, the body has to weigh proportionally more so that the vehicle doesn't get rocked severely from the inertia of the legs moving from side to side. Overall, instead of the robot weighing 4,000 to 5,000 pounds, the robot would likely weigh on the order of 30,000 to 40,000 pounds.

      We did investigate this option at the start of the project. Past the weight problem, we also ran into the problem of simply sourcing 6 identical digger arms - no used lot had 6 of the same exact machine, and no dealer would talk to us about just purchasing that one section of machine.

      As far as getting to leg sequencing and control software, that's one of the first things we did immediately after the Kickstarter campaign, by building out the full-scale prototype leg. You can see a review of our efforts on controlling a single leg here: http://projecthexapod.com/blog/update-5212013/ and videos of the simulation we've been using to work on leg sequencing were actually included in the Kickstarter video itself - we've had them for quite some time. The legs themselves are actually mechanically designed to not interfere with each other's range of motion.

      Thanks for the note!

    5. Creator dgd3 on August 14, 2013

      This comment has been removed by Kickstarter.