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InMoov - Advanced Eye Mechanism

by Dakota76, published

InMoov - Advanced Eye Mechanism by Dakota76 Sep 22, 2017


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Fusion 360

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This is an advanced eye upgrade for the InMoov robot. It features eye lids and independent movement of each eye. The design files include a drill mount for sanding and painting eye balls.

Demonstration videos @: https://www.youtube.com/channel/UC-TVs2NgcdnF-nCaefCc6zg

Note: this is a difficult build as clearances are small and some specialized tools may be required for assembly.

You Will Need:
6x SG90 servos with related hardware and horns
2x 2-56 threaded ball joints
2x 2-56 threaded 12" long pushrods
4 pushrod to servo horn couplers
2x cameras
monofilament or braided fishing line in 6 to 8lb test
Forceps - The non toothed type used for stitches (used to aid installation of fishing line and hinge rods)
small phillips head screw driver (mounting servos and servo horns)
riffler files

I will be adding a assembly manual with instructions as soon as time allows. Extra points for building before instructions are released. lol

Preliminary instructions: (You may want to print these for easy reference!)

  • These instructions are preliminary and by no means complete!! *
    Parts require filing for proper fit as they were designed tight to adjust fit by hand.
    hook servos to control board and center them before assembly

1.) Print all .stl files with a maximum layer height of .1mm for best results. (recommend printing eyeballs first so you can sand and paint them while everything else prints) File rough edges with riffler files and chase all .072" holes with a .07" drill bit except for servo screw holes on servo frame.
2.) Sand and paint eyeballs to your taste using the eyeball cordless drill finishing mounts with a metric screw in the mounts for drill chick. I painted my irises at a .5" diameter as this is the diameter of average human irises (some like the large iris of the original InMoov eyes)
3.) Optional Mount cameras (camera specs will be in official instructions when released) into back of eyeballs. Fix in place with a tiny bit of CA glue. Also fix wires off to side as pictured in eye photo being careful not to add height as the cameras barely fit without hitting gimbal.
4.) Using a hacksaw or jewelers saw, cut and chamfer ends of two 8mm, four 6mm and four 5mm pieces from the non threaded end of one of your pushrods. The 8mm are used for eyeball gimbal to servo frame attachment, the 5mm are used to mount the eyeballs to the eyeball gimbal, the 6mm are used to attach the eyelids to servo frame.
5.) Using small bit of pushrod from last step, attach the gimbals to servo frame with 8mm length rods. You will need the forceps to hold rots for insertion into holes without damaging them. Next mount eyeballs to gimbal using 5mm rods taking note of camera orientation for correct image. Next install ball part of linkage on the beam between eyelids on both pairs. then install eyelids to servo frame using the 6mm rods.
6.) install servos, horns, printed servo horns and, linkages as pictured. bending of connecting rods is necessary to make connections.
7.) Use 6-8LB test monofilament fishing line or similar diameter braided line in four 12" sections. this will leave alot of excess but will be easier to work with in this length. Using forceps to help, use Rapala knots (google it) to tie the four sections of string to each of the side holes in eyeballs. Fish the 4 lines up through the holes in the servo frame. Wrap the lines around printed servo horns of upper servos a couple times and affix them using servo horn holes.
8.) Position completed mechanism behind mask and glue in place. (I recommend hot glue so it can be removed later if needed for maintenance or upgrades as I refine the mechanism)

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Hello. The links to order the parts are broken. Can you give more specific information about the cameras. I would buy them. I don't understand where to place the pieces: "finished eyes mount". Thank you from France for your sharing.

In my case is 65 mm or 2,5 inches (Distance between centers of eyes).

Hi there, just wondering what the distance is between the centers of the eyes... is there somewhere I can find the dimensions?

Anyone working on this project try using a tig welding rods for the joints and servo rods. Ones I found worked like a charm and much less expensive or even free if you know anyone that uses a tig welder. Stiffer than copper yet less ridged than the steel du-bro rods.

Hello Dakota,
Your design is still great and I know you are currently working on a design to have the eye lids operate independently for a total of 8 SG90 servos.
Is it possible as part of the redesign to relocate to middle lower servos that operate the eyelids currently to a location that has the whole of the servos above the current center mounting place.?

Those who use the designs from Monnerby: https://www.thingiverse.com/thing:992918
and the remix of that by Dix238: https://www.thingiverse.com/thing:1581955
currently can't use this great design as the relocated jaw servo obstructs the installation of the two middle servos for the eye lids.

If it is even possible to do this, it would be most appreciated.

What were the dimensions of the camera module that you used?
I'm looking for something that I can get locally.


Modified InMoov head
InMoov - Low Back Skull / Neck Joint - Modification
by dix238

Hello Ray,
Sorry about the late response. There is enough free space to allow for this with a bit of creative engineering. I have been swamped in work and unable to work on this project much. I will likely print those mods and alter the design to accommodate them as well as make the eyelids independent for winking as time allows.

I may need to team up with someone in my area that is currently working on InMoov who can assist with printing those mods and assembling them in a skull so I can focus my limited free time on measurements and design work. it would be great if I had samples of all the head mods so I can make my design compatible with all of the variants.

Thanks for your interest and input on this project!

Hello Dakota76,
Not sure where you are in the world, but if i can help I will.
I'm located in Country Victoria Australia.

I've added a photo of my latest build with 4 of the servos fitted for the eyes and the Jaw servo fitted as well.
As you can see from the photo, there is a ton of room in there.
In a previous version using this skull layout I was able to fit 3 Raspberry Pi 3 computers in there :-)

If there is any test prints photos or measurements you need let me know and I will do my best to help out.


Just a bit extra, here is a link to the video I made of testing the eye mech using a remote control.

The neck is Barts design and not yet released.
Bart has mostly been working on Legs: https://www.thingiverse.com/thing:2316843

Damian legs (InMoov)
by Bartods

Hey Dakota! Thank you for sharing your awesome design!
Any chance you'd share the code you are running on it? Thanks for your kindness!

Hi Hepari,

I am using VSA (visual show automation) software and mini maestro servo controllers for my project not MyRobotLab as I am more interested in the mechanical workings of InMoov for now. If my build progresses to the point where I use MyRobotLab I will share my files with the community!

Thanks ~ John

Dakota, how did you add your video next to the files? I want to add a video or my hands... https://youtu.be/kPr9rbcnG-Y

Nice movements, I will check this out when I get to that part, (still working on my hands)

Can it blink? or move the eyelids individually?

Hi Willy, the eyelids are linked in groups of upper and lower so all it can do at this time is blink and track up and down. There is enough room in the original InMoov skull to add an additional two servos to make winking possible. That would raise the servo count to eight servos. If there is enough interest in this configuration I will make it an optional feature in the future.

Hey Dakota. Im sure you already know from my posts on your inmoov thread, but I would also be interested in a redesign for winking. I really hope you have the time to release such a setup!

I myself would like that upgrade, if we got the space and the cost is just for two more servos... I think it is amazing the work you doing. Hope that upgrade is available when I get to the head of mine.
Your Robot would be the only one capable of this task, if you do.
Thanks for the great design.

Very nice mod. Would you consider sharing the Fusion360 file?

started printing and assembling - do you have the script for testing with the polulu controller. and a template for bending the linkages ? thank you for sharing.

Hi, The software needed to run sequences and scripts is Pololu Maestro Control Center and can be downloaded from Pololu.
This video from Pololu describes setting up servos to run sequences and scripts very well https://www.youtube.com/watch?v=DAQUcXFBGTI

Sorry I do not have a rod bending templates at this time. Posted pictures to aid in assembly. Will look into designing a rod bending jig for this project when time allows in order to aid in assembly.

Thanks ~ John

Hi John,

Do you think it could be possible to use copper wire instead of rods with the same diameter ?

Thanks and congrats for your work

Hi Peloche,
The eye mechanism was designed to use pieces of the pushrod for hinge material for all moving parts as well as linkages. If the diameter of solid copper wire or even brass wire is the same I see no reason why it wouldn't work as the forces involved here are small. The rod diameter is .072".

Thanks ~ John

Very fast reply John thanks and on top of this the rod diameter ! it's perfect ;-)))

So 1" = 25,4 mm
D 0,072" = 25,4 x 0,072 = 1,828 mm
R = 1,828 / 2 = 0,9144 mm
S ((0,9144 x 0,9144) x 3,14) = 2,6 mm2 and we have in Europe existing solid copper wire section of 2,5 mm2, it should comply no ? ;-))

Hi Peloche,
Your math is correct as far as diameter. The metric equivalent of 13 gauge .072" wire is 1.8288 mm thus making the cross section of 2.5 mm2 solid wire a good choice. You will no doubt need to do a bit of cleaning of the holes for all the joints/hinges as they were designed to be very tight which would make it easy to bend the copper while trying to push it into the holes. The steel of the original design would not bend easy with a lot more force applied.

I may try solid copper wire on my next build as it will also be easier to bend making it possible to 3d print a wire forming jig which would simplify the wire bending that is currently being done by eye. It is a more malleable material than the mild steel used for RC linkage wire but shouldn't be a problem as long as the servos are not driven past the mechanical limits of the eye gimbal causing the copper to bend out of shape.

Let me know how it turns out with the copper wire please. I am interested to see if it has suitable strength for the job.

Thanks ~ John

Ok thanks John for your advices.

Concerning the solid copper wire strength we can keep the insulation and remove it only at the ends of the link, it should be a bit stronger.

For the time being i'm very busy and couldn't get time enough to print your mechanism, i did receive the SG90 servos but didn't find yet threaded ball joints and pushrod to servo horn couplers with an acceptable price (what you get at amazon.com for $9,48 in amazon.fr price is EUR 37,79 …

As soon as i'm ready i'll tell you the result but hopefully somebody will complete it before.

Your idea of 3D printed template is a very good idea, settings will be easier for everybody.

Thanks John,

Nice looking design, I'm printing it now. Can you provide a link to where you got all of the couplings. I'm having trouble finding the servo horn couplers. Thanks

Thanks for the link for those parts. It would be great if you could post some pictures detailing how the eyeballs are attached. The eyelids are pretty straight forward. Thanks

I have added a few photos from Fusion 360 that may help with this. I will go back and look at my Preliminary instructions too. May not have been clear on placement as I rushed this whole project out before refinements. Also note that you may need to file the gimbal core down a bit to round it out until the eyes run smoothly on it. I will be updating the file for those with it rounded better for less finish work with riffler files or sandpaper. Thanks ~ John

Sorry, I should have asking to add some to pictures to show how the eyeballs are attached to the servos.

Take a look at the newly posted pics. Hope they help. Did a lot of rod bending which is why I said linkages would be the hard part of this build.
Thanks ~ John

Those pictures helped, thanks.

You do very nice work.

Thanks! I will be spending some time refining this design. Right now the linkages are a bit of a chore to get right and that's what I will focus on improving in the future.

Bummer, I just figured out I can't use it, I don't have enough room in Fred's head for the servos in the current arrangement.
I have a lot of room above and below the eyes, but next to none behind the eye's.

I'm guessing that you use the servos:
1) Upper eye lids
2) Lower eyelids
3) Left Eye X movement
4) Right Eye X Movement
5) Left Eye Y Movement
6) Right Eye Y Movement.

I like the Idea of using the fishing to operate one of the axis for the eye's.
Do you think is is possible to relocate the servos to above and below the eyes and use the fishing lines for most of the axis? or would it be too fiddly?

Do you have a modified head arrangement? This fits nicely in an original head layout. You are correct about the servo usage. Servos can be moved based on your modified head layout.

I'm new to InMoov.. Are the modifications to your InMoove head common? If so I could modify the design to fit other popular arrangements.

To my knowledge, Fred Inmoov is unique.
The head I have is a slightly modified Monnerby head.
Where Fred differs, I have installed 3 Raspberry Pi3 as well as a 16 channel I2C servo Driver Hat.
This leaves very little room behind the eye's.
As it is unique, it is most likely not worth your time changing it for one robot, The current arrangement you have would suit most Inmoov robots out there.
Is there any chance of you uploading the cad files, I may be able to tweek it my self.
The only other mod that might me useful to others is for different camera types, The inmoov site list two camera's and there are a few who use the Raspberry Pi Camera.
I'm also new to the InMoov, but like you it doesn't stop my from experimenting.

Keep up the good work..

Modified InMoov head