How to Make an Eye Mechanism - Design, 3D Printing & Assembly

Hi guys, 

I am working through the awesome Covarrubias tutorial on eye mechanisms, and I have two questions concerning the newer Autodesk 123d Design software. I thought maybe a more versed user could help.

1) Using the newer version of the software, has anybody been able to sketch on the face of the eyeball or the swashplate? I have figured out how to sketch on the faces of primitive objects, but I am unable to select the flat, straight surfaces of the swashplate and eyeball. These items come up in chapters 4 and 5 of the tutorial. I have a feeling it will continue to come up, and finding an alternative to sketching on these flat surfaces is proving challenging.

2) I don't know how to turn on/off components (the separate pieces, the swashplate, the eyeball, the eyelids, etc) like David does on the older software. So I "hid" my eyeball while I built my swashplate. When I was done with the swashplate I "showed" the eyball again, only to find that now it has a chunk taken out of the side of it. I think it must have happened when I made an extrusion on the swashplate at some point, because I "hid" the eyeball but left it in the same area as the swashplate. Anyway now I learned to move hidden objects outside the grid area so I don't mess them up while theyr'e invisible. But can anyone suggest an easy way to 'patch' the chunk I took out of my eyeball, so I don't have to rebuild it? Does anyone bychance know a good video that shows you how to do this? I attached a screenshot - the eyeball is the solid on the left, with a chunk missing in the side that looks kind of like a letter "c".

Thanks for any thoughts! 


  • Hi Ben,

    Wish I could help, but I've not used Autodesk 123d Design for a while.  I found it lacking in features and feeling a bit outdated, so I switched over to Onshape and never looked back.  Onshape is free, browser-based CAD platform (so you can use it from any machine, even tablet/phone), it's feature rich, updated frequently, and based on the same core parametric-solid technology used by Solidworks.  The only drawback is you have to make your work public, or use their limited storage space for free private documents.  The skills you learn by using Onshape are also more valuable than those learned by using Autodesk's 123d Design as it's more on-par with professional CAD software.

  • Thanks for the thoughts, Chris. Maybe I will switch once I work my way through the Covarrubias tutorial. I'm still chugging through it and don't have that much more before printing. 
  • I'm running through this course now and it's been great so far.

    I would suggest anyone doing it today use Autodesk Fusion360 and not Autodesk 123D. 

    Fusion 360 is almost exactly the same as what is being used in the course. It seems that they renamed 123D to Fusion360 and made 123D is a much more limited piece of software.

    Also Fusion 360 is free for personal, hobby, and small start-ups.
  • Thanks for the suggestion Lance! I ended up working through my issues with 123D and printed my pieces successfully. I am now programming the motors on the mechanism - which means I'm almost done! Calibrating the monofilament connections on the eyeball pulleys took a while, but mostly I've just been too busy working to make much time for this project in a while. Hoping to jump back on it again in the next few weeks!
  • Glad you got everything working Ben!  I hope you can share your results with us here.

  • Hi there, I am new in this forum.
  • Welcome to the forum Joan!

  • Hi there, I am not an expert. I am beginner in this topic. A few days ago I have attended workshops on 3d printing. From that day onward I become so interested in it. Therefore, I start collecting more info about the printing. While searching, I get to know about dlm, it has a wide range of applications such as aerospace, automobile, jewelry, medical, etc. I just want to know how we can do printing using Autodesk Fusion360.
  • Autodesk Fusion360 or any other CAD or 3D modeling software will work for 3D printing as long as they can output a file format that your slicing program (which prepares a model for printing) can read.  STL is the most common file format used when exporting a model for 3d printing.  

    DLM and other 3D printing methods that use UV light to harden a resin are a great way to produce high resolution parts, but those parts are then typically molded and cast in other materials.  This is because most of the materials that harden with UV light continue to be sensitive to UV light throughout their life, and can degrade over time.  There are UV curing materials that hold up better, but there is such a wide variety of materials for DLM printing that it can be a bit difficult to keep track of them all.  And they are all typically much more expensive than FDM printing materials.

  • I've got the piece mostly built and have moved on to programming the controller - but haven't had any time lately to work on this because of work. I'll post updates when I have it working. 
  • Can't wait to see it!


  • this guy works! I got a radio link at10 controller and have tested each of the motors. I need to channel mix the channels that control the 4 eyelid servos so I can use this in a real scene. I've been going through Gary See's stone mold making tutorial and Craig canon's animatronic head tutorial to build a head to add this eyeball mech into. I sculpted the head on Thursday and Friday and today I build a clay wall - tomorrow I'll finish the mold. I'll post more updates! 
  • Awesome, it's looking great!

  • Hey guys, I have a doubt.

    Is there any particular reason why a 6mm sphere was choose as pivot point element for the swashplate or not? I'm asking because I'm having a lot of trouble to find a exactly 6mm steel sphere. I found only with 5mm. Will it also work or might have a practical collateral effect that I'm not aware of?

  • Hi Gustavo,

    It does not have to be 6mm exactly, it just has to be small enough that the eye can pivot around it when the cables pull from their specific angles, and large enough that the eye has a surface to pivot on.

    When I built my version of this mech, I used 3/8" threaded brass balls, which worked perfectly.

    You can find 6mm brass bearings quite easily, so if you have the tools you could drill and tap those yourself as an alternative.

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