Introduction: Robot Caterpillar Tank Treads, Johnny Five Style - 3D Print

Picture of Robot Caterpillar Tank Treads, Johnny Five Style - 3D Print
When I was but a wee little inventor, I saw a movie that forever imprinted itself into my soul. This picture told the gripping tale of mans' ever loosening control over its own technology; a film that dared ask the question "What makes us alive?" This masterpiece of the cinema was, of course, Short Circuit 2.

During November of 2012 I was fortunate enough to play as an Artist in Residence at the Instructables HQ, and was given full access to a room full of Object Connex 500 multiple material 3D printers! I had always wanted a toy version of the robot from Short Circuit, Johnny Five, and I found myself with the means to print one at my fingertips.

Later on I will be adding components to this robot until I have a completed, functional model. I was more concerned about getting the base to actually function than with it being an exact replica of the Johnny 5 robot, so I did wing it a bit with the design (aka: artist license.)

Bonus Trivia: The original design for the J5 robot was created by a concept artist named Syd Mead. Mead is best known for his design work for the movies Blade Runner and Tron, and he is considered a god among the concept drawing community. I highly suggest taking a deeper look into his work.

To begin, I drew a handful of rough pencil sketches just to give myself a an idea of how the treads could work and eventually moved the idea over into 123D beta 9.  A copy of the model was printed, and the pieces of track snapped together just as intended.

The treads where printed using one of the Objets more interesting features, the ability to print combinations of separate types of materials at the same time. The light blue areas of track are mostly a rigid white material with a pinch of rubbery black. This gives the print a solid structure with just enough flex to be snapped together. The rubber treads are more rubber than rigid, making an outer surface that gets much better traction than its light blue counterpart. Since the two materials are printed together they are permanently bonded.

When it came time to make this hub for the track I tried to build around my initial tread design, but the geometry just wouldn't work out. I ended up starting from scratch by drawing a hub first and a track made to fit around it. The new parts were printed out, assembled and tested. Happily, the mechanics flowed like they were made for each other! I tweaked the tolerances by .05 mm or so and printed a few dozen links.

The base is held together with short 0-80 thread machine screws that go through one side of the enclosure and attach to holes on the opposing side. Although these holes are included in the model, and the printer did render them, I still found it necessary to use small drill bits to adjust tolerances and remove support material.

Motors are secured in place with mounts built into the two halves of the base. To get the motors to fit perfectly I ended up making a model of the gear motors from dimensions taken with a digital caliper. The motor mounts were then designed around that virtual motor.

Thanks for checking my project. Keep an eye out for more Johnny Instructables as I make progress on the build. Feel free to ask me questions, give suggestions and leave feedback.

Attached files:
I started this model in 123D beta 9 but have moved it to Inventor Fusion. Both sets include DWG and STL format files.

Tread Set includes files for a single segment of tread, a drive single hub, and a free spinning hub. Since each piece of track is the same, more copies of the track segment are printed to make the entire length. The drive hub is designed to fit on a the end of a small gear head motor, but could certainly be modified to fit other types. The free spin hub is made to fitted with an axle and simply roll along with the track.

Johnny9 Base Set holds the files for the the complete drive base as seen in the pictures.

Small Brass Gear Motor files are for the motor only and are intended to be used as reference


AlanR103 (author)2017-01-24

Hello, I've printed some treads but the stl is so small that I had to scale it up to 1500%, is it right?

gravityisweak (author)2014-11-18

How is the rest of him coming out! This is sweeet!

hektora (author)2013-09-26


arpoky (author)2013-05-01

This looks just like a TIE Mauler!

Tomdf (author)arpoky2013-05-04

Whoa, your right, the tracks are almost identical. That wasn't my intention, but I bet it would be easy to modify the model to make a working Mauler.

arpoky (author)Tomdf2013-05-15


bfk (author)2013-05-14

Short Circuit (1&2) are one of my all-time favorite films. Your files are headed straight to my printer... Thank you

Phiske (author)2013-04-22

Johnny 5 is alive!!!!! Almost anyway. Very cool!

M.C. Langer (author)2012-12-29

Awesome!!! I love Johnny 5 and you gave me some interesting ideas. Thanks for sharing! :-)

J-Five (author)2012-12-22

Now are you make rest of him?

Tomdf (author)J-Five2012-12-22

Oh you know it! I got it all planned out in my head, I just need to transcribe it to reality.

Thanks for the comment :D

hwaranghaw (author)2012-12-16

can you please include more detailed orthographic drawings?

Tomdf (author)hwaranghaw2012-12-16

I made that particular drawing with photoshop and screen shots from Inventor Fusion; adding further detail would be a bit too time consuming, I'm sorry. I'm guessing that you are looking for more dimensions?

To get all the dims you could possibly want, you could download the preview version of Inventor Fusion ( and use it to open and measure the model.

In the mean while I'll try to learn how to automatically generate more detailed isometric images.

quantya (author)2012-12-07

Very Nice!!!
I tried to made it but I can't find the project of the treads, can you put the 3D draw.

Tomdf (author)quantya2012-12-07

I'm not sure what you mean by 3D draw. Name a file type and I'll see if I can get it for you.

quantya (author)Tomdf2012-12-07


Tomdf (author)quantya2012-12-09

These should be what you are looking for


(You'll need to print multiple copies of the single tread model.)

quantya (author)Tomdf2012-12-10

Hi, I can't open or save the file, can you put the file not how link?

Tomdf (author)quantya2012-12-13

Howdy, I've added the hub and track .stls. I hope that is what you are looking for, I'm not sure what more I can do.

clazman (author)2012-12-07

I am impressed with the "rubber" treads. By the way they aren't rubber alone. It is a material that was patented as "Santoprene" a number of years ago. It is a plastic/rubber matrix. The rubber material is a ground "cured" rubber that is mixed with a plastic material. The result is a plastic material quality for processing (extrusion/molding) and a "rubber like" end product (once the plastic cools and hardens). It takes out of the equation the problem of the heat required for vulcanization (curing) of the rubber which can be difficult, if not impossible, to include in the manufacturing process of a plastic item. The vulcanization has already been completed prior to mixing with the plastic. A prime example is the soft rubber like pads on many plastic consumer products, i.e. toothbrushes.

Tomdf (author)clazman2012-12-07

Hey neat! I hadn't heard the name of that stuff before, but I bet I've seen it hundreds of times. Although, I'm fairly certain that santoprene is not what is being used in this model. The Objet printers use a UV light to cure their materials rather than a thermal extrusion process. The "Tango Black" material as it's called simulates rubber, but I have no idea what that it is actually made of. I even checked the MSDS: "exo‐1,7,7‐trimethylbicyclo[2.2.1]hept‐2‐yl acrylate"

I almost recognize the word "acrylate", sounds kinda like "acrylic."

clazman (author)Tomdf2012-12-07

Thanks for the kind response. Tango Black is a UV cured material. As a consequence it may be better than the Santoprene I mentioned. I imagine that Tango Black cannot be remelted being comparable to a thermal set compound. Therefore, it would be better suited at temperatures that would melt a plastic/rubber compound like Santoprene which, unfortunately is one of its cons. None-the-less I think I will contact a few 3D printer concerns to get their opinion. It should be possible for Santoprene could be extruded into the proper diameter so as to be remelted like any of the materials now used.

Tomdf (author)clazman2012-12-09

That sounds completely possible. I personally haven't seen anything like that for thermal type 3D printers, but I'd sure like to buy a spool.

fretted (author)2012-12-03

Johnny9 Base v22.zip6 MB
invalid for certificate trust list

Tank Treads v2.zip527 KB
invalid for certificate trust list

For some reason this is all i get from the zips

Tomdf (author)fretted2012-12-07

Hrmm, I've been able to get them to download from the site. If you are still having trouble, send me a message with your email and we can try that.

fretted (author)Tomdf2012-12-09

Oh they download fine but i get a message that says cert is faulty i don't know i gave up trying thanks though ! to all !

clazman (author)fretted2012-12-07

It sounds as though you have a firewall that is causing this. It is protecting you. You should, however, be allowed to accept this certificate. I am using Norton, for example, and it will, at times, delete a file that was just downloaded (very frustrating). I temporary fix is to turn off Norton anti-virus. Just a thought.

Edgar (author)2012-12-07

Went to my Blog:

Tomdf (author)Edgar2012-12-07

Awesome! ty :D

Edgar (author)Tomdf2012-12-08

Keep it up! :)

Edgar (author)Tomdf2012-12-08

Keep it up! :)

Edgar (author)Tomdf2012-12-08

Keep it up! :)

Edgar (author)Tomdf2012-12-08

Keep it up! :)

Higgs Boson (author)2012-12-05

If only I could afford a 3-D printer...

gbeltrao (author)Higgs Boson2012-12-06

It would be cool to have one but you do not need own one - there are companies in the web that can do the job for you! You just need to e-mail them the 3D models, specify the material, pay and they'll print and ship it back to you.

Higgs Boson (author)gbeltrao2012-12-06

I did not know that. That will come in handy in the future.

Tomdf (author)Higgs Boson2012-12-07

It is handy, and it is fun to browse what other people have designed. It can be a bit pricy though. Realistically, this tread base would cost around $80-100 from most of the 3D printing services that I know of, and the motors are $8 to $15 each.

The truly industrious thing to do would be to finalize and print the design, make silicon molds of the prints, and use those molds to make resin copies. These would be much cheaper and stronger than the printed version, and they could be smashed into the wall without regret :p

you can just upload to and they can even do metal!

Mike GeniuS (author)2012-12-07

This is exactly what i've been looking for, though when I construct mine, i'm going to scale up to a much larger size. I was going to try a walking platform, but this should work much better, due to the heavy weight of my design. I will post my design when I'm done. Thank you for posting this. My Robot thanks you, too!

Tomdf (author)Mike GeniuS2012-12-07

You should definitely check out the build that simon_m74 linked below. Just look at these things! Such grace, such beauty; they bring a tear to my eye.

whtboybig (author)2012-12-06

If only i could open the files

Tomdf (author)whtboybig2012-12-07

What kind of trouble are you having?

simon_m74 (author)2012-12-06

Very cool!

Check out what I am working on with a team...

I know you will like it!

Tomdf (author)simon_m742012-12-07

Oh wow that is freaking amazing! I could get lost in all the info there, learning how it all functions and was made. That must be incredibly fun to be a part of.

Beenay25 (author)2012-12-03

That, sir, is a work of art!

Tomdf (author)Beenay252012-12-07

Why thank you sir :)

Geoffrito (author)2012-12-06

I once made an almost identical tread design using pieces of Sintra PVC foamboard cut on a CNC router... the end result was very similar, but I ended up fitting and gluing around 300 pieces together to get there (and snipping and filing wire brads to use as pins...).

Jealousy aside, this is very cool!

Tomdf (author)Geoffrito2012-12-07

That sound brutal to build, but fun to in a way. How did the track turnout, do you have any pictures?

rr3 (author)2012-12-06

Great Instructable! I just ordered a Solidoodle. Any suggestions for printing the treads using that?

About This Instructable




Bio: When I was young I took all of my toys apart just to see inside. Eventually I learned how to put them back together.
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