Brian Chamberlain
Software Engineer & Electronics Nerd

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RoboPup

Animatronic hand puppet robot running off the RaspberryPi and hobby servos.


This project is also on Hackster.io

Background

I wanted to build an animatronic hand puppet. The big challenge I faced was trying to sync up the movement with the speech. I still have this in storage and one of these days I will bring it back to life. I think it still has potential even after all these years. I'm sharing my results here because I think the platform is pretty good for animating despite the challenges I had achieving my end goal.

Diagram

RoboPup System Diagram - Page 1 system diagram

Build

This is what drives the servervos and gives the device the ability to speak. The Alamode board interfaces to the RaspberryPi and handles the precise timing for the servo control. robopup alamode pi hat

The Alamode board has Arduino compatible headers so I was able to add in the servo shield. This makes hookup easier. robopup alamode w servo hat

To make it possible to add audio for the project I found this nifty mini-speaker. It makes a great voice box. robopup speaker assembly robopup speaker enclosure

I cut a short length of PVC and cut an opening on two sides. robopup speaker v2

This is an early test jig for the mechanical arm that drives the puppet. What I discovered here was that the original hobby servos I had were not powerful enough. I swapped these out for ones that had more torque. robopup v1 arm

Here is a video of a early mechanical test

To join all the servos to gether I cut this metal bracket out of a sheet of 3mil aluminium. The paddles on the top/bottom of the servos drive the upper/lower jaws of the puppet. They are cut from 5mil. acrylic. This gives them some flex (but not much). I hot-glued the paddles directly to the body of the servo motors. This approach sorta works. The glue is not that strong but it holds well enough. If the upper/lower jaw servos are over-rotated the paddles will pop-off. You could think of this as a "saftey feature". robopup v1 motor mount

The foam and liberal application of gaffers tape helps protect the puppet. It also makes the paddels fit in the uppper/lower jaw of the puppet. robopup v2 motors

More tape applied for the final assembly. The iphone in this photo dates it pretty well. The iphone had a HEADPHONE JACK! robopup v2 motors w speaker

It's a pretty cute puppet. robopup closeup

Here it is doing a simple "laugh movement" test

Status: On Hold

The big hurdle for me with this project was trying to come up with a way to sync the movement and the audio. It seems possible but I lost some steam trying to make that work. If you know of any similar projects or have experience with this type of thing any advice is appreciated!

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