Tutorials » How To Make An Eye Mechanism - Design, 3D Printing & Assembly

edited November 2013 in Animatronics
Even though I don't have a 3-D printer...yet, I am really enjoying this tutorial. David is awesome, and I look forward to implementing what I learn.


  • check out http://www.kraftwurx.com/ to print your files. They are good i have used them in the past.
  • Thanks! Can they print working servos?
  • no you still have to buy or build those.
  • Sadly, 123d Beta 9 is no longer available for download.
  • Hi Jamie, try http://www.autodesk.com/education/free-software 
    also I designed an eye mech  with freeCad http://www.freecadweb.org/
    We apologize that Autodesk canceled the beta program of the software.

  • It's too bad the software is no longer available.
    The video was great but this was to be my first try at a Cad program and I still need something to follow along with.
    I was really looking forward to printing up some of the eye mechanisms to use in my props.
  • Try fusion 360
    As of now its free and it's almost identical to 123d beta but has lots of added features... Eventually they will start charging for it but as of now its free!!!
  • Thanks for the update but it doesn't look like my system is supported as it requires 64 bit Windows 7.  May be time for a new computer!
  • Hi everyone, 
    I bought the tutorial and i'm trying to follow along with using Fusion 360. The program is pretty close to the one in the tutorial but I've run into a problem. I'm stuck in the beginning and not sure how to take off these lines that separate the eyeball. When I put the mouse over it, it acts as an individual piece instead of a whole. This is also my first time using any kind of 3D modeling software so I apologize if this seems like a silly question.

  • Dave,

    Absolutely fantastic tutorial.  I have been knee deep in Autodesk 123D Design trying out some of the tips you suggested.  Copied over your servo model... Thanks.  I have incorporated it into a test project.  Really nice.

    Looking into Fusion360, as you recommended above.  This technique offers an alternate path to the old school way of fabricating.  I think it will fit well in my toolkit.



  • David,
    Do you have a link or item number for the eyeball lens?  I've checked All Electronics but can't find it.
    I've got the new computer up and running Fusion 360 and have the first component finished.
  • Hi All -

    Total noob here lookin to make his first eye mech. Question - I modeled a latex mask (WED clay to hydrocal plaster mold to latex) and I used bouncy balls as eyes that were 4 inches in circumference when making him in clay. I assume I should make my eyes match those measurements? Anyone know how that would adjust the measurements used in David's awesomesauce tutorial?

    I am a total virgin at this stuff and math was never my strong point. Why didnt anybody tell me that I would use math later on in life?! I thought that was just a myth! ; )

    Any help would be appreciated. Thanks in advance! 
  • Christopher VaughanChristopher Vaughan ✭✭✭✭✭
    Hi Ivan it is extremely difficult to back fit the eyes into the sculpture after it is already made. Lots of patience and sand paper will be required. to redesign the eye mech you should start with the measurements off the sculpt from center of the eye to center. You should also make the spacing in x,y,x adjustable by adding 1/4" 20 rods between each eye platform. Pretty much a back fit will not work without heavily modifying the design, you can however use the techniques he teaches to acquire a new design for the eye mech. 

  • Hi Chris -

    Thanks for the reply. So when you say"...center of the eye to center." If humanoid do you mean center of eye to center of face, like the center of nose bridge? And then that would be the base eyeball size measurement?

    So far I have created the initial eye to be 13.17% bigger since that is the difference between his "average human eye measurement" and the bouncy ball size. So instead of using 1.125 as the base eyeball measurement, I went with 1.273. I planned on doing the same to the lid measurements - printing out the 2 balls with lids and seeing how they fit in mask. 

    Do you foresee any issues with that approach?

  • edited July 2014
    I loved this tutorial, and have adapted the mechanism to work with the sensor "eye" balls on my 1/4 scale R/C Tachikoma from the Ghost in the Shell: Stand Alone Complex. I have images from the build for the mechanism here: https://www.flickr.com/photos/[email protected]/sets/72157645574540515/

    A full build log is available on the Replica Prop Forums here:
  • Anyone know how to copy paste components (like he does in the beginning of swashplate chapter) in autodesk fusion 360?
  • Scratch that. figured it out.
  • Ok - how about the e flite/heli max hardware? Seems like that ball link and piston arm are pretty specific to this build. Im trying to find them online. Has anyone found these anywhere?
  • Although I am aware I may be speaking to myself, I realized there was a parts list listed in tutorial. Anyhow in the off chance somebody else reads this - I just got a majority my parts in and I noticed that either my ball links are too small or my pushrod o-ring end pieces are too big. I ordered what I think are the exact parts listed in materials. Pushrod: http://www.heliproz.com/EFLH2218-Servo-Pushrod-Set-BMCX/productinfo/142218/ BAll link: http://www.heliproz.com/HMXE8559-Flybar-Pivot-Assembly-Novus-CP/productinfo/HMXE8559/ Anyone happen to know which I should try to reorder elsewhere? I think I have seen larger ball links in a local hobby store, but I am worried the holes I made on eye lid would be too small? Any thoughts on how I should address? Thanks in advance!
  • I order most of my linkages and hobby hardware from Tower Hobbies.   Look around, things are often hidden among a large list of parts.
  • I am working my way through this amazing tutorial.  I designed in fusion 360 and printed on my Printrbot Simple Metal.  I am very close, just waiting on a few more servos to arrive to complete construction. 

    @David Covarrubias , I was hoping you could give some recommendations on alternative transmitters. It appears that at this point the Futaba 12Zap is discontinued.  I was hoping to find something with similar features necessary for the eye mech like servo grouping/mixing.  I am also hoping to keep the budget in the $200-500 range.  Any advice would be much appreciated.    Looking forward to getting into the Arduino class when it comes out, wish I could have been there for the live sessions.

  • I've been using the JR X9303 for a few years, and really like it.  It's not their latest model, so probably harder to find, but their latest equivalent model would be good.

    For future projects I'll probably make my own transmitters/receivers using Arduino and Xbee.  That way I'm not limited to 9-14 channels like you find on most hobbyist transmitters.

  • That sounds great Chris....I actually have the original eye mech I did for this lesson running on arduino....for the lesson I went with standard rc as to not confuse people and sidetrack the lesson but using a arduino makes it cheaper if you can program
  • edited June 2015
    Answering a few of your questions..... Unfortunately tech keeps changing. ...one big change is that many of the cool micro rod ends have been replaced on new helicopters by ball links molded right into the copter parts....also radios change every year....the standard duBro ball links with 2-56 threads work well but are bulkier so you might need to beef up the lid rings in future designs...also for radios, any 12 channel can work...there are some low cost open source rc radios out there that can probably do the job perfectly....
  • You only need as many channels as you have servos, but if you want to create mixes, make sure the radio can do it.....
  • Chris, David,

    Thank you for the tips and quick response.  I was out of the country so I missed the Arduino for animatronic course but I've been using Arduino for some other projects.   So I may dive into that and work it out.  Would be worth honing my programing skills at the same time...  So I assume you can program proportional movement of the lids to move with the eyes similar to a mixing transmitter, right?  Can't wait to get this thing moving :)   

    I had no problems finding all the parts and links etc on ebay from various hobby sources.
  • Good to know, I can't find the micro parts at any hobby shop anymore and could definitely use them for other things every now and then....
  • edited February 2016
    David, Chris,

    After banging my head against the code for a few weeks. I finally asked for a bit of help with my adafruit servo hat and Voila! She's up and running.  Thank you both.
    Here's a little test video.

  • Awesome, glad you got everything up and running.  Looks great!

  • They look great!!!
    Did you go larger on the eye size or is that a wide angle lens effect?
    I'm digging the oversized cartoony feel!!!
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