Let's Make Robots!

Wobbly - The 3D Printed, Walking Automaton

Walks down slopes using gravity, makes his owner smile.
Wobbly_-_STL_and_Source_Version_1.1.zip1.3 MB
Wobbly-RoundedArms.zip384.38 KB
Wobbly-ArmStopAndRocketPack.zip1.69 MB

Wobbly is a 3D-printed, gravity-powered, walking automaton. He basically walks down slopes.

The files for printing him are in the attached files here at LMR, and are also on Thingiverse here: http://www.thingiverse.com/thing:170932


27 Oct 2013 Update:

After some feedback, I've added some extra parts for Wobbly. He no longer needs Blu-Tack or the coin.

I've added "Arm End Stopper" parts which are tight fitting rings that go onto the shoulder axel to hold all the pieces on. (This replaces the blobs of Blu-Tack that were there.)

I've also added a removable "Rocket Pack" accessory that hooks onto his back. For me, this is heavy enough so that I can ditch the coin. However, if you need some extra weight, the Rocket Pack contains a slot for placing a coin. So, you can add more weight if needed.

Also, I've added new Rounded Arms. These are actually the ones in my photos/videos. I had previous uploaded a slightly older version by mistake.

Here's how Wobbly looks now:

Note, I've provided 2 versions of the Rocket Pack part.

One is for printing with the "right way up" with the hanging hooks at the top. Because the hooks are high up and require over-hang... I wasn't sure if they would be easy to print for everyone. (The Up seemed to handle it fine, generating support, etc. But I wasn't sure if it would work for everyone.)

The other version avoids this over-hang by printing the rocket pack upside down (i.e. hanging hooks at the bottom). For this version, I've changed the coin holder so that it's not a full container. It is instead two slanted walls (forming a V-shape) that should hold the coin in using gravity. I thought having a bottom on the coin container might create overhang too. So, you can try this version if you like! The only thing with this version is that it might not work with very small coins (as they might fall through). [Note that this version needs support to print!]

I think that's all the updates I'm going to do to Wobbly for now (until I get more requests/feedback).

(Time to jump back onto some other projects!)


25 Oct 2013:

I decided to do this project for a few reasons. I've been messing around with some "swinging" style bipeds (Duckling and the still in progress Gutsy). I started looking at related designs including Robosapien and saw Jamie Samans's "Robosapien Companion" a page about mechanical walking automata that used a similar movement.

That had me wondering about these kinds of automata and made me want to make one.

Then, this week, I attended my first meeting at the Australian Antiquarian Horological Society (I thought Horology skills might be useful for robot making), and the presentation this month was on automata - which was perfect for me, and again reminded of these automata.

So, I did more research and found this walking wooden automata on YouTube (http://www.youtube.com/watch?v=UJLH5GYyVhY) which also included a link to a build instructions.

With the instructions as a starting point, I decided to try creating a fully 3D-printable version of the walking automata.

The result is Wobbly. I modelled him using 123D Design, and he was printed on my Up Plus.

Wobbly is made up of 8 3D-printed parts. (The left and right parts are identical. He's symmetrical.) He can be assembled and disassembled easily. The parts just slide together.

The arms were designed to use friction to hold him together. However, I found he got loose pretty quick... So, I used Blu-Tak to hold him together. (Using glue is a more permanent alternative, and finding some tiny O-rings would be a nice neat, flexible option.)

Getting Wobbly to walk well turned out to be an exercise in mechanical debugging! I tried him at various gradients, tried pushing him in various ways, studied his stance/positions closely, etc... In the end, I realised that he needed more weight on the back to keep him standing upright while on the slope.

To do that, I blu-tacked a big coin onto his back! That did the trick! :)

If I revise the model, I will add a coin holder on his back, kind of like those Penny Racer toy cars from when I was young. I was also thinking about changing the shape of the body to create more weight on the back. (E.g. Giving him a tail? Or turning the entire body into a T-Rex shape instead of a humanoid shape.)

The result is what you see in the video! He can walk down slopes, powered only by gravity! :D

He is still somewhat temperamental though. The slope needs to be the right gradient, and you need to give him the right nudge (not too much, and not too little). If the conditions are good, and the gods are smiling, then he walks down the slope beautifully. (If not, I find that thumping the ground a few times sends enough vibrations to get him moving again.)


So, Wobbly is not really a robot... but he is an ancestor of the robots that I'm working on.

Also, I thought he might be something that members of the LMR 3D Printer Club might want to play with.

The STL files are on Thingiverse already. But here at LMR, I'm also putting the source 123D Design files in case anyone wants to play with them (and improve/customise the design).



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Wobbly got remixed and was at Hack Omaha III. Makes me so happy to see him out in the world! :D

Video of Wobbly race: http://www.youtube.com/watch?v=LDomJnFO1Vk

Remixed Wobbly: http://www.thingiverse.com/thing:189879

I saw the remix, didn't see the races, very cool seeing Wobbly out and about! -Stephen

Just wanted to post a pic of my Wobbly fresh off the printer. Have no clue if he'll actually walk but no matter I like what he looks like.. He's nearly 0% fill so may be too light to even think about walking without the rocket pack that I'll print in black next.

The only other thing I did a little different was use one of the leg/arm spacers and give him a little neck.

Thanks for sharing the files!

-StephenProtowrxs Wobbly

He came out great! :D The neck looks really good too (and the extra height will probably help with walking)!

Thanks very much for posting the picture. Let me know if he's able to walk!! :D

I need to proceed with the old version since it's almost done. But I will print the new version as soon as I get time for the 3D printer.

Sounds good! The only part that's changed is the arm (were the new one has a rounded edge). So, there's not much difference to what you've printed. :D

The other parts (the "arm end stopper" and the "rocket pack") are new bits to add onto the existing model.

Wobbly is going to have a brother!


love it ... showed my 4yr old son it and he loved it ... looked for more online and found some ... and my son had a lot of laughs looking at similar ones.

strange that i never seen anyting like these in a toy shop ... as i bet kids would love playing with them .

could remove the coin that u have as a weight and attach a battery disguised as a carrier bag put leds in his head for eyes and then u could combine non electric with electric   ....  

That's so cool, Lumi!!! Now I'm even more keen to see him! :D

+1for your suggestion. Now I know what I have to do tomorrow :-)))

Awesome little guy!

And +1 for the suggestion above! :)