I've always been a big fan of K'nex, ever since I was a little kid. Then, when I discovered this website, I felt like I had hit the jackpot. This is a "robot" that I built out of knex, it's designed to play the piano. This version can play up to a 16 note sequence in a 12 note range. I call it "Zeeanobot" (Zach's Piano Robot), corny, I know, but I couldn't think of a better name. I spent a lot of time on this, and I'm very proud of it, so please be nice. Just to be clear, I have not tried it on a real piano, I built it to play my Yamaha DGX-230. You may need to modify the design slightly to get it to work on real pianos or other keyboards.

Please note that this is my first real instructable, so I'd appreciate any constructive criticism. Thanks. (So far the response has been mostly positive, so thanks everybody! I put a lot of work into designing and building this so I'm very proud of it. I'm glad you like it too.)

The first video is a mechanical view of Zeeanobot, showing how it works.

The second video is Zeeanobot playing a simple proof of concept song.

The third video is a duet of Katy Perry's "Hot and Cold". Ignore the errors on my part, they're not the point.

The final video is a duet of "Heart and Soul".

Step 1: Materials

Materials Required:


6 x Black Rods
25 x White Rods
100 x Blue Rods
104 x Yellow Rods
23 x Gray Rods


20 x Gray 1-Prongs
60 x Gray 2-Prongs
4 x Brown 2-Prongs
41 x Red 3-Prongs
28 x Interlocking Gray 4-Prongs
1 x Green 4-Prongs
54 x Yellow 5-Prongs
20 x Interlocking Blue 7-Prongs
18 x White 8-Prongs


63 x Blue Spacers
48 x Gray Spacers
2 x Small Blue Gears
8 x Medium Red Gears
2 x Big Black Gears
48 x Chain Links
37 x Tan Clips
1 x Motor
1 x Piano (Optional)

Step 2: Build Right and Left Base Modules

Build two of these, a right one and a left one. They're exactly the same except for the two yellow rods on the right side of the left module. See the picture for more details.

NOTE: I didn't have enough yellow rods, so I used the gray rods that are the same length as the yellow ones. I needed to make several substitutions, so the colors may vary.

Step 3: Build Fingers

You need to build 12 of these. The double construction, is essential. It gives the fingers the necessary strength and stability they need to function properly.

Step 4: Build Hands

You need to build two of these. Then pivot the movable pieces so the Gray 2-Prong clips are resting in between two yellow rods.

Interlocking Gray Connectors --- Gray Spacer --- Blue Spacer --- Gray Spacer --- Blue Spacer --- Gray Spacer +++ Yellow 5-Prong Clipped On --- Yellow 5-Prong Threaded Through The Hole --- Blue Spacer --- Yellow 5-Prong Threaded Through The Hole --- Repeat From +++ 5 More Times --- Yellow 5-Prong Clipped On --- Interlocking Gray Connector

Step 5: Build Programmable Armatures

Build two of these. To program the robot, you will insert pegs into the White 8-Prong connectors, but don't worry about that now, I'll explain more later.

Gray 1-Prong --- Tan Clip (n-) --- Medium Red Gear --- Medium Red Gear --- Tan Clip (-n) +++ Yellow 5-Prong --- Blue Spacer --- White 8-Prong --- Tan Clip (-n) --- Repeat from +++ 5 More Times --- Yellow 5-Prong --- Gray 1-Prong

NOTE: (n-) and (-n) indicate the direction of the peg on the tan clips.

Step 6: Build Rear Supports

Build two of these.

Gray 1-Prong --- Blue Spacer --- Gray Spacer --- Blue Spacer --- Gray 1-Prong (Threaded Through The Hole) +++ Blue Spacer --- Gray Spacer --- Blue Spacer --- Red 3-Prong --- Repeat From +++ 6 More Times --- Gray 1-Prong

Step 7: Attach "Fingers" to "Hands"

Attach six Fingers to each Hand. The Yellow Rods on the Fingers go into the top slot of the Yellow 5-Prong connectors on the Hands. The Blue Rods on the Fingers go into the 45 degree slots on the Hand's Yellow 5-Prong connectors.

Step 8: Attach Hands to Base Modules

Pretty self explanatory. Just note that the end of the Hand that has all the spacers on it, is closest to the camera. Also note that the Gray Rods may bend slightly, that's how it should be.

Step 9: Attach Programmable Armatures to Base Modules

Slide the Programmable Armature onto the Gray Rods of the Base Module. Then attach the "Hand's" Yellow Rods to the Yellow 5-Prongs on the Programmable Armatures.

Step 10: Attach Rear Supports to Programmable Armatures

Now slide the Rear Supports onto the Gray Rods of the Base Module. Then attach the Rear Support's White Rods to the Yellow 5-Prongs on the Programmable Armatures. You should now have two complete Base Modules. If not, repeat the earlier steps to complete the second module. They should look like the 4th picture on this page. They should be nearly identical at this point.

Now hook the two Base Modules together using the two Yellow Rods on the Left Base Module.

Step 11: Construct Left Drive Train

You need just one of these.

Tan Clip --- Red 3-Prong --- Gray Spacer --- Gray Spacer --- Tan Clip (n-) --- Red Gear --- Red Gear --- Tan Clip (-n) --- Gray Spacer --- Gray Spacer --- Blue Spacer --- Blue Spacer --- Gray Spacer --- Gray Spacer --- White 8-Prong --- Gray Spacer --- Tan Clip (n-) --- Black Gear --- Tan Clip (-n) --- Gray Spacer --- Gray Spacer --- White 8-Prong --- Tan Clip (Snapped On, Peg Facing Out)

NOTE: I had to use Gray Gears in place of the Red Gears because I didn't have enough, but they're the same size and have the same number of teeth, so they're interchangeable.

Step 12: Construct Right Drive Train

You need one of these.

You can clearly see how the front Gray Rod is arranged so the configuration below is for the Gray Rod with the Black Gear on it.

Tan Clip (Clipped On, Peg Facing In) --- Gray Spacer --- Blue Spacer --- Red 3-Prong --- Gray  Spacer --- Gray Spacer --- Tan Clip (n-) --- Red Gear --- Red Gear --- Tan Clip (-n) --- Gray Spacer --- Blue Spacer --- White 8-Prong --- Gray Spacer --- Gray Spacer --- Tan Clip (n-) --- Black Gear --- Tan Clip (-n) --- Gray Spacer --- White 8-Prong --- Gray Spacer --- Blue Spacer --- Tan Clip (Clipped On, Peg Facing in)

Step 13: Construct Center Drive Train

You need one of these.

NOTE: Depending on which motor you are using, you may need to make some slight modifications. The motor I used is big and gray, but I don't remember what set it came with.

You can clearly see how it is arranged in the picture, however, there is one correction that I've made since I took this picture. See the notes on the picture for more details.

Step 14: Connect the Left, Center, and Right Drive Train

Okay, I know this is hard to see, well its also pretty hard to describe, but I'll do my best. The second picture makes it clear how to attach the Center Module to the Right Module.

Step 15: Attach the Drive Train to the Base Modules

If you've done everything correctly up to this point, it should be very clear how the Drive Train attaches to the Base Modules. Now, add two Chains, 24 links each to connect the Gears on the Drive Trains to the Gears on the Programmable Armature. You should now have a near complete "Zeeanobot".

Step 16: Construct and Attach Support Structure

This part will probably require some customization but I'll post the one I built for my Yamaha DGX-230.

Step 17: Programming and Fine Tuning

Programming Zeeanobot is simple. You just put White Rods in the White 8-Prong connectors. This way, when you turn on the motor, it spins the drive shaft, which is attached to the Programming Armature via a chain. The White Rod that you put in the Armature then pushes up the finger, which pivots around an axle on the Hand, thus causing the front of the finger to push down on one of the piano keys. The White Rod will then pass in between the top part of the fingers releasing the key. If you find that the White Rod doesn't make it through the two Yellow Rods, move the Gray Clip on the Hand away from the Programming Armature.

You may have some synchronization trouble at first (between the left and right modules). You can fix this by taking off the Chains and lining up the holes of the White 8-Prongs on the left and right modules.

Step 18: Play Beautiful Duets

If you've made it this far, congratulations. Hopefully it hasn't taken you as long to build as it took for me to design. I happily accept any constructive criticism or improvements on my design or my instructable. I plan to refine this 'ible' over time, clearing up some of the confusing parts, but for now it will have to do. I'll be happy to answer any questions you may have, so just leave a comment.

All that's left for you to do now, is to start learning some great duets.
<p>you really should</p>
You should enter this in the first time authors contest. I'd think you'd win grand prize. ☺
<p>This is interesting!!!!</p>
Haha now I don't have to do piano anymore!!!!
I'm probably the first comment you've had in a while.........................................can you use the smaller chain links? I'm all out of regular.
And that is realated to this instructable in which way other than its knex?
It makes noise?
S'pose so&hellip;<br>Still pretty unrelated :^/
if u trow a real grenade at them i bet they both explode XD
am i the only one kidda scared about this?
Cool Mech, 5 stars
It is very good u should be proud, may i ask how long did it take to make
It's hard to say. I worked on it a little bit at a time over the course of several months. But thanks, I am proud of it.
I'm going to try and make it (a modified design) in under 48 hours, I think i can.
&nbsp;Sry for the double post but do you play the saxophone?
Yes I do, as well as the piano and the viola.<br />
Viola?! Nice<br /> <br /> I play the sax to. I have have alt, tenor and a bari. =D<br />
&nbsp;Bassoon!!!!! get some!!!!
<br />
finaly a cool instrument i play <br>
I really like this! I want one! <br>If only it was a bit more in time.. Haha
i would like to build this exept i only have 6 red gears do you no any way i could make it work? Great instructable 5*
You can build just one of the modules(hands), but you'll only have a 6 note range. To do that you only need 4 red gears.
were are the videos?
&nbsp;Can I suggest re-designing it so that it uses gears with chains on them for the programming? That would allow much more complex rhythms&nbsp;
Its funny that you say that, I spent a lot of time trying to use gears and chains as a means of programming, I just couldn't make it work. I'm sure someone will improve on my design sooner or later, and maybe they'll figure out how to make it able to perform longer sequences. I sure hope so.<br />
&nbsp;Look at my other comment, I managed to program a knex robot using a chain&nbsp;
Yea, no doubt yours is cool, and a good design. However, you really couldn't apply it to my robot, well maybe you could, but I don't see how without major modifications.<br />
I did make one that could write, with two chain units for up/down left/right. It sort of worked, but the writing was unreadable.
&nbsp;You got that Idea from mine! &gt;:(
&nbsp;Thats how my robots work! check em out! :<a href="https://www.instructables.com/id/KAP-V-Knex-Programmable-Automated-Vehicle-MK2/" rel="nofollow">www.instructables.com/id/KAP-V-Knex-Programmable-Automated-Vehicle-MK2/</a>&nbsp;
This is very awesome! It is one of the best K'nex models I have seen.
&nbsp;Brilliant just Brilliant 5* dude i sub too.&nbsp;
@27ace27<br /> <br /> Yeah, I found it similar to music box mechanics. I might actually build this if i can find the pieces, this is the most genius knex build ever, very unique too. Not just another gun or rollercoaster, ball machine etc, this is epic.<br />
I don't know why, but the videos are not being embeded on the page I'm viewing.&nbsp; This is not your problem; I just wanted to let you know.<br /> <br /> Other than that, this is probably the best K'nex Instructable, and one of the best Instructables of any kind, that I've seen.&nbsp; You actually wrote out how to construct the components!&nbsp; You used proper English!&nbsp; You've got clear pictures!&nbsp; And the project itself is just, well, I'm stunned.<br />
It's not the first knex instructable with clear pictures, proper english, and &quot;how to construct the components&quot;.<br />
Didn't say it was the first, but it is the first that &quot;I've seen.&quot;&nbsp; Which includes the obvious qualification that it's the first I have looked through with those qualities, having the obvious requirement that the topic has to be interesting enough.&nbsp; The card shuffler, for example, was a cool project, but not as well documented.<br />
I saw that the parts of the card shuffler were somewhat disassembled while here he just dissects it into chunks kind of like what I do, and doesn't disassemble it if it's too inconvenient.&nbsp; I don't think a first time knexer could build this just from what he has.&nbsp; I could, but that's a different story.&nbsp; <br /> <br /> I'm not ripping on his ible, but I&nbsp;don't see how the card shuffler wasn't as well documented as this.&nbsp; Or I might be missing something from your point of view.<br />
The card shuffler's &quot;documentation&quot; was only in the form of image notes.&nbsp; Those are not accessible, not printable on steps, and cannot be viewed at the same time as the image (since they get in the way).<br />
On the PDF files, it has the image notes built into the ible.&nbsp; You can just print the PDF out.&nbsp; <br />
Can you remind me if the PDF&nbsp;(not customized, just the default) is available to non-paid users?&nbsp; I know it isn't available if you don't have any account, but I thought PDFs were one of the &quot;value added&quot;&nbsp;features pulled back last year.<br />
I'm not &quot;pro&quot; yet. I plan to, but I'll abandon this user account and create a non-anonymous account when I do. I'm butting in here to say as a cheapskate member I'm able to download the pdf files.<br />
Thanks for the info!&nbsp; Are you able to customize the PDF content?<br />
I just clicked on the pdf icon for this instructable. Comes up with al the boxes ticked, I can deselect them. The download button says download a custom pdf. All I can say just give it a try. As a non pro member I can use the allsteps feature on one day and next day I can't. The only feature I miss as standard member is the ability to past into the comment edit box. Makes it harder to share pertinent information, links.<br />
You should still be able to paste using the normal Ctrl/Cmd-V.&nbsp; If you cannot do that, please post a bug report.&nbsp; If the editor is really short-circuiting normal functionality, then there is something really wrong which needs to be fixed.<br /> <br /> Thank you very much for the information about the PDFs, and the inconsistent all-steps!<br />
Yeah, I realize that. &nbsp;But both of us are pro, so your argument doesn't really apply to you, me, or any pro user. &nbsp;This is true for non-pro users.&nbsp; But I think there was a way to get the PDF files without being pro.&nbsp; Just get someone to get the URL of it for you.<br />

About This Instructable




Bio: You don't have to be a kid to love k'nex!
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