Skeksis Animatronic Creature Suit Project

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  • Chris Ellerby
    Chris Ellerby Admin
    This weekend I started working on the eyelids.

    I made a vacuum form buck using 3D printed rings that match the shape and dimensions of the mechanical rings that will hold each eyelid shell in place.  The rings were placed around 2 acrylic spheres that are the same dimensions as the final eyes.   The spheres were countersunk into the wood base by drilling a couple precise holes with a forstner bit.


    Then I 3D printed the interlocking rings that will hold the eyelid shells over each eye.


    I've modified the eyelid ring design to house a couple tiny compression springs that will keep the eyelids in their closed position by default.  The lids will then be pulled open via a servo/cable linkage.



    I also plan to try a torsion spring in the future as well, but compression springs in this size are far easier to source.

    I also spent a bit of time on the metal lathe on Saturday machining some slits into the steel shaft that allows the eye to rotate left/right.  The slit will allow me to use a retention washer on the end of the shaft to hold it in place rather than a collar, which will give me a lot more clearance for adding the mechanical linkage that rotates the eye up/down.

    Here is a photo that shows the collar that was holding the eye rotation shaft in place before I replaced it with the retention washer.  You can see how much space it takes up below the eye where I need to attach a linkage for up/down movement.

     
    I don't have a photo of the retention washers in action yet, but I'll post those soon.

    /Chris
  • David Boccabella
    David Boccabella Moderator
    Great Work Chris.
    I do like the spring idea. I was thinking of it myself for my eyes.  Re Eyes normally open/close  - if you think of a pair of scissors where the upper and lower lids activation arms cross over - you can still use a compression spring to achieve the 'normally open' look.

    As for the servo linkage - you can have the cable go in to the top arm, through the spring, and then attach to the bottom arm.

    Take Care..
    Dave
  • Chris Ellerby
    Chris Ellerby Admin
    Here is an updated image of the eye mech with the retaining washer replacing the shaft collar.



    This gives a lot more space under the eye for the linkage.

    /Chris
  • David Boccabella
    David Boccabella Moderator
    Nice - I see you raid R/C Hobby shops too :)
    I notices the bar that goes through the eye is not all the way across. Have you found that securing just one side is enough?


  • Chris Ellerby
    Chris Ellerby Admin
    The other side of the eye is exposed as it looks left/right, so the only place the eye can be supported is from the inner side.  

    It seems to be very well supported.  The thick 1/8 shaft and the shaft collar on the outside help to support it.

    Here's a couple shots with the eyelid rings in place, and the top eyelid linked up.



    /Chris
  • Chris Ellerby
    Chris Ellerby Admin
    Last week I took the Skeksis (temporarily attached to the harness) to my local maker space for a demonstration.  Also did an on-camera interview for Intel (curious how that will turn out).  With the Skeksis finally wearable, the range of performance is amazing.  Even as temporary plastic head on a metal skeleton it feels like it has some personality, and the large sweeping movements it's capable of are pretty impressive.

    You can't really see the harness in this photo, as it's hanging over the passenger seat back, but here's the Skeksis going for a ride.



    While at the maker space I was talking with one of my friends about the harness (which is working pretty darn great) and he mentioned another great harness would be a steadycam vest.


    These vests have traditionally been rather expensive in the past, but there are a lot of them on the market for pretty reasonable prices.  I really want to try one of these for a future project.

    That said, I'm pretty happy with the drum harness as it has 4 perfect attachment points for the Skeksis.  The only down side is it does not distribute weight to the hips as much as I would like, so most of the load is still on your back.  Though I have not been using the bottom strap yet, which will help with weight distribution.

    /Chris


  • David Boccabella
    David Boccabella Moderator
    Great work Chris.  Love the info re the harnesses - Finding ways to support one's creations and move is often just as important as the creation itself :)
  • Chris Ellerby
    Chris Ellerby Admin
    Tested.com released an interview with me today about the Skeksis project.  This is also the first video of the frame moving with the test head.

    https://www.youtube.com/watch?v=CDk8kJHJQZY

    /Chris
  • Joel Goodpaster
    Joel Goodpaster ✭✭
    Great interview!! Congrats, and as always, awesome work!
  • David Boccabella
    David Boccabella Moderator
    edited December 2015
    Hi @Chris Ellerby
    So nice to put a face to all of our comments and chats.  Great video and show. I definitely agree re the fine micro movements that living things have.. Working with fur-suits and characters I see that a lot. One solution for my old suit was to have a couple of LED's behind the eyes to simulate a 'blink'. It's simple but SO effective.

    One of the things I will be trying for my wolf suit is to have a fiber glass shell that form fits my face.. and then have Hall Effect sensors on it that would pick up the movement of small magnets attached to my face with sticky plaster (Band Aid?? not sure of the term in the US)
    By scrunching my eyebrows, widening my smile I can make changes in the position of the magnets and thus the fields. I'm using Linear Hall Effect devices so they are not On/Off.
    I was planning to use EMG (Electro Myogram) but the issues re sweat and conductivity made it impossible.

    Glad it was you doing the interview and not me. I get a terrible case of "Wongling my Turds" when having to speak in to a microphone.. Plus my accent sounds like an escapee from the BBC.

    Great work and SO glad to see it appreciated by a wider audience.
    Dave
  • Chris Ellerby
    Chris Ellerby Admin
    Redoing the eyelid ring design in OnShape.  Should be printing these out soon for testing.


    /Chris
  • Chris Ellerby
    Chris Ellerby Admin
    Here is the updated design for the full eye mech in OnShape.


    I'll be 3D printing the first test version of the new design this weekend!  (or possibly tomorrow night)

    /Chris
  • Chris Ellerby
    Chris Ellerby Admin
    edited May 2017
    It's been a while since my last update, but I've been quite busy on this project.  After many tests with the first prototype of the mechanical head core I've done a lot of redesigning.

    First, I've decided to design everything to be 3D printed rather than laser cut out of acrylic.  This will help me iterate through designs faster, while also making the finished product lighter and stronger.  And now that I'm not limited to flat-pack construction I can design things like recesses for captive nuts or additional supports.

    The second major change is that I've redone all the CAD work in OnShape.  I was pushing SketchUp too hard, and this is way beyond what it was designed for.  With OnsShape I have a long list of advantages.

    1. Everything is parameter based so I can easily change the dimension of one component and everything else adapts automatically.  Every element is defined with specific dimensions for its size and position, and any of those values can be updated later or be used as relational values for other elements.
    2. Proper parametric solid CAD is much more ideal for something like this, rather than architectural CAD like SketchUp.   Now I can take advantage of DFM (design for manufacturing) standards.
    3. OnShape supports versioning and branching so I can test new designs or iterate through changes more quickly.
    4. Assemblies allow for linkages and constraints, so I can actually see things move to check for range of motion, collisions, etc.
    5. The skills I'm building in OnShape are more future proof, since this is a professional CAD application.  I could easily transition to SolidWorks or other high end CAD software with my new skillset.
    I also changed the design of the eye mechanisms so they now share a single servo for left/right movement.  The new servo is placed centrally and linked to a sprocket under each eye mech via chain.  This means I can use the old eye left/right servos for other articulation.

    Here are some images of the redesigned components.



    Base plate and top servo housing.  Gold/orange parts represent the main component broken down to fit within the print volume of my Ultimaker 2+ Extended.  Final parts will be printed as single pieces on a larger format printer, but for my first few test assemblies this will work great.


    Underside of the base plate showing lightened structural supports.


    Jaw before and after being broken down for my print volume.


    Head assembly


    Head assembly back


    Head assembly underside


    Head assembly with skin overlay


    Head assembly with skin overlay and section view to check for clearance


    I hope to start live streaming work on this project again soon on my twitch channel. https://www.twitch.tv/vexfx  In the next couple weeks I should be able to start printing some of these pieces for testing, 

    /Chris
  • David Boccabella
    David Boccabella Moderator
    Wow Chris.
    Likewise you have been busy. I have been getting more into 3D printing myself however I use Fusion 360 for my dabbling.
    I was wondering what servo's you are going to use in him.. and also what are ging to control them.
    One of my current projects is a light weight face masks that have ultra low profile linear sensor to pick up eyebrows, lips, etc. I plan to put up some posts on this when I get the niggles ironed out.

    I suppose you are also just in time regarding Netflix doing a Dark Crystal series - you will have a Lot of fun at showings.
    Take care and many thanks for sharing..
    Dave

  • Chris Ellerby
    Chris Ellerby Admin
    edited May 2017
    I'm using the Hitec HS-5085MG Servo.  I chose it because it's small, has metal gears, it's strong (can move 59.7oz or 3.7lbs at 1 inch), and is pretty fast for its strength. 

    It's also a digital servo, so there are a lot of fun advantages and features there.

    To control it I'll be using a Pololu Mini Maestro.

    /Chris
  • David Boccabella
    David Boccabella Moderator
    Hi Chris.
    I know the Pololu units. Very nice with Scripting.
    I have not had much experience with the 5085MG.  I am purchasing one to compare against the HobbyKing HKSCM12-6 that I use. My biggest concern is noise as I have found many of the metal gears very noisy.
  • Arnie Cunningham
    Arnie Cunningham ✭

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