Dragon. My animatronic project.

Joel GoodpasterJoel Goodpaster ✭✭
edited November 2017 in Animatronics

I've posted some questions and comments before, but this will be the first real post about the full project.

I have been working on a dragon head and neck (so far). And, like a lot of other people, mine will be a long term project. I'll try to update as often as I can. 

On to the project, and my progress so far!

This is the neck. 2 vertical, and 2 horizontal hinge points, and a 3 axis plate to mount the head to. All of the hinge points, and the universal joint plate, are cable driven and counterbalanced with springs. The rotating axis is driven by a servo and gear drive. Still a lot of assembly to do!



Here are the 4 main cable drive units. 12V, 60 RPM gear motors, with feedback pots. I may have to use 30, or even 20 RPM motors depending on the load.


Closer look at the drive, with the cable and sleeves  in place.


This is my miniature "input rig" I will use to directly input motion, or create a motion file that the Arduino will read and execute.


And last one for now. My 1st (bad) attempt at sculpting. I really need to ditch the styrofoam head and make an armature.  But, I'm learning!  This was more a test to see if I could do it this way.    Um... nope. lol


I always welcome comments, questions, advice, constructive criticism, or even just a chat.  

Take care all!
Post edited by Joel Goodpaster on

Comments

  • Joel GoodpasterJoel Goodpaster ✭✭
    I got some 30 RPM angle gear motors for the vertical movements on the neck.  After a bit of design, I came up with this cable drive which is very similar to the straight one I had. Had to use some sheet metal for the base since the mounting holes were on the face where the output is. Now, to center drill all the cap screws for the adjusters (like a bicycle brake cable adjuster). 


  • Chris EllerbyChris Ellerby Admin
    Looking awesome!

    What is the attachment piece on the cable connecting it to the 3d print in your last picture?

    I love working with cable mechs, but the attachment points for the housing or the cable are always a point of frustration for me.

    /Chris
  • Joel GoodpasterJoel Goodpaster ✭✭
    I used a 1/4-20 x 1" cap (allen head) screw with a plain nut. The cable fit great in the hex, and the lightly knurled sides make it easy to turn.  I center drilled the cap screw, which was a huge pain.  I think, in the future, I am doing to slot down the side of the screw instead of trying to drill it.  Kind of like this...
  • Chris EllerbyChris Ellerby Admin
    That's a creative solution.  Let me know how your other idea works out for you!  

    Another challenge I've been trying to address with my cable mechs is that having the controllers, cables, and character all permanently linked makes working on and transporting them a real headache.  I'd love to find a way to be able to easily disconnect the cable at either or both ends.  Ideally with some type of connector that does not limit mobility of the cables or introduce any slop.  

    /Chris
  • Joel GoodpasterJoel Goodpaster ✭✭
    edited August 2018
    You've got me thinking about the disconnect. I have a really good idea on how it could be done. I'll see if my Fusion 360 skills are good enough to get the basic structure.  

    I've also had time to work on various parts of my project, and figured I would work on my (severely lacking) video skills.  

    First a quick test of the gear motor/ cable drive.  I'm currently working on coding the Arduino so I can control the 4 actions.

    https://www.youtube.com/watch?v=sce-zP-eXlY

    Next, I tried my first go at silicone. I just made some test skins to get the 'feel' for it, and to have something to practice my painting on. My technique is not great, and I need to pay more attention to details. But, it is all learning... :wink:  

    https://www.youtube.com/watch?v=7cyiEKu04uc&t=1s
  • Chris EllerbyChris Ellerby Admin
    Great work Joel, love seeing this kind of stuff!

    /Chris
  • Joel GoodpasterJoel Goodpaster ✭✭
    edited September 2018
    Chris, you mentioned being able to disconnect cable for transport.  I was thinking about using something like this. The pulleys are on bearings, and the 3 pins provides 'some' alignment reliability. This was just a quick design, and the tolerances are probably off, but my basic design works.  It should be aluminum due to the stresses on the bearing shaft.  For a pull/pull setup, I think it would work.  I have ideas for other drive types, and for single cables, just need to get some Fusion time. lol
    If anyone is interested in the file, I can throw it up on GrabCAD or something.
    Last edit...promise.


    Post edited by Joel Goodpaster on
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