This Instructable is going to show you how to build Hexabot, a large six-legged robot platform that is capable of carrying a human passenger! The robot can also be made fully autonomous with the addition of a few sensors and a little reprogramming.
I constructed this robot as a final project for Making Things Interactive, a course offered at Carnegie Mellon University.
Typically, most of the robotics projects I've done have been on the small scale, not exceeding a foot in their largest dimension. With the recent donation of an electric wheelchair to the CMU Robotics Club, I was intrigued by the thought of using the wheelchair motors in some sort of big project. When I brought up the idea about making a large-scale something with Mark Gross, the CMU professor who teaches Making Things Interactive, his eyes lit up like a kid on Christmas morning. His response was "Go for it!"
With his approval, I needed to actually come up with something to build with these motors. Since the wheelchair motors were very powerful, I definitely wanted to make something that I could ride on. The idea of a wheeled vehicle seemed kind of boring, so I began thinking about walking mechanisms. This was somewhat challenging since I only had two motors at my disposal and still wanted to create something capable of turning, not just moving forwards and backwards. After some frustrating prototyping attempts, I began looking at toys on the internet to get some ideas. I happened to find the Tamiya Insect. It was perfect! With this as my inspiration, I was able to create CAD models of the robot and begin construction.
During the creation of this project, I was stupid and didn't take any pictures during the actual construction process. So, to create this Instructable, I took the robot apart and took pictures of the assembly process step-by-step. So, you may notice that holes appear before I talk about drilling them, and other little discrepancies that wouldn't exist if I had done this right in the first place!
Edit 1/20/09: I discovered that, for some reason, Step 10 had the exact same text as Step 4. This discrepancy has been corrected. Step 10 now tells you how to attach the motors, rather than telling you how to machine the motor linkages again. Also, thanks to Instructables for saving a history of edits, I was simply able to find an early version with the right text and copy/paste it in!
I constructed this robot as a final project for Making Things Interactive, a course offered at Carnegie Mellon University.
Typically, most of the robotics projects I've done have been on the small scale, not exceeding a foot in their largest dimension. With the recent donation of an electric wheelchair to the CMU Robotics Club, I was intrigued by the thought of using the wheelchair motors in some sort of big project. When I brought up the idea about making a large-scale something with Mark Gross, the CMU professor who teaches Making Things Interactive, his eyes lit up like a kid on Christmas morning. His response was "Go for it!"
With his approval, I needed to actually come up with something to build with these motors. Since the wheelchair motors were very powerful, I definitely wanted to make something that I could ride on. The idea of a wheeled vehicle seemed kind of boring, so I began thinking about walking mechanisms. This was somewhat challenging since I only had two motors at my disposal and still wanted to create something capable of turning, not just moving forwards and backwards. After some frustrating prototyping attempts, I began looking at toys on the internet to get some ideas. I happened to find the Tamiya Insect. It was perfect! With this as my inspiration, I was able to create CAD models of the robot and begin construction.
During the creation of this project, I was stupid and didn't take any pictures during the actual construction process. So, to create this Instructable, I took the robot apart and took pictures of the assembly process step-by-step. So, you may notice that holes appear before I talk about drilling them, and other little discrepancies that wouldn't exist if I had done this right in the first place!
Edit 1/20/09: I discovered that, for some reason, Step 10 had the exact same text as Step 4. This discrepancy has been corrected. Step 10 now tells you how to attach the motors, rather than telling you how to machine the motor linkages again. Also, thanks to Instructables for saving a history of edits, I was simply able to find an early version with the right text and copy/paste it in!
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Signing UpStep 1: CAD Model
Using SolidWorks, I created a CAD model of the robot so I could position components easily and determine the location of holes for the bolts that connect the legs and linkages of the robot to the frame. I didn't model the bolts themselves to save time. The frame is made from 1" x 1" and 2" x 1" steel tubing.
A folder of part, assembly, and drawing files for the robot can be downloaded below. You'll need SolidWorks to open the various files. There are some .pdf drawings in the folder as well, and these are also available to download in subsequent steps of this report.
A folder of part, assembly, and drawing files for the robot can be downloaded below. You'll need SolidWorks to open the various files. There are some .pdf drawings in the folder as well, and these are also available to download in subsequent steps of this report.
mti_robot.zip2 MB
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http://www.youtube.com/watch?v=0jMmebn49EM
and those motors are for wheel chair motor? I'm from Indonesia , and I must think where can I find the motors.. please reply.. thank you very much
You may be able to find these motors on ebay.
http://www.metal-supplies.com/12201/index.html
Rubber treaded feet with absorbers was the first thing that came to mind for me too while watching the video
http://www.amazon.com/UB12180-Sealed-Lead-Acid-Batteries/dp/B001DL7D1O
circuit board for connections
Build it bigger and with armor plating, you'd get the military's attention!!
In light of that, here is a forum thread on connecting relays to an Arduino: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1196698219
Keep in mind that you really don't need to use a very complicated circuit to control the hexabot. I used a microcontroller and more complicated circuit because it was required for the class I was taking, but realistically all you need is a couple high-current rated switches to turn power on and off to each motor.
I do see some room for improvement in the legs. Why not hook up small shock dampeners in the legs, between the tubing and the feet? Something like the air shocks that hold open the rear hatches on SUVs should do the trick. I think one of those in each wheel, with of course a plastic foot on it, would even out the ride considerably, and make the whole process a bit more effective (not to mention easier on your spine!).
Even as it sits, it's an awesome project. When I get old, screw a wheelchair, I'm building one of these. XD