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1.     Introduction

Having not made much of an animatronic before apart from Peter the Pumpkin - pt4 (ready to Share the Scare) I jumped in with an idea for this. I made a blog post detailing my progress Animatronic Fun: Snippets and continued on from there. Unfortunately several things stopped me progressing and with the deadline tomorrow I'd like to give you all an update of progress without giving away my idea...and hopefully I can progress it later to full effect .


2.    Issues With Progress

Progress for me was hampered with a combination of things:

  • an unexpected large workload on my day-job
  • a lot of household maintenance required - painting and carpentry for Christmas visitors
  • car repairs
  • my fault in ordering cheap servos from Ebay


[This product is likely a counterfeit TowerPro ]


3.    Pieces Made

My animatronic definitely grew in size from initial ideas and I soon found I required a large baseboard to mount the servo housings on. My 3D printer has been working flatout making bits. The concept is to move various parts of the animatronic using fishing line that has been passed through spiral metal spring sections. This way the action pull can be remote to various sections of the animatronic allowing several sections to move independently. All of the parts have been designed using OpenSCAD and I am really starting to get to grips with the concepts of that scripted design style.


{gallery} My Gallery Title

Some post holders which accept round wooden dowel to make a higher platform. Only needed seven more after the initial test print worked well.

Baseboard with two of the dual servo holders and the raised section for the animatronic. Also shows the coiled spring sections that the fishing wire can be guided in.

A dual servo housing minus servo that has been pulled apart !

Top end of the animatronic without any external covering. There is a head section to go on here as well.

The lower part of the animatronic with guide wires for left/right and forward/backward control of the lower section. This uses two servos. The other two main servos are for the similar control of the upper body. Small servos are to be fitted for the arms and eyes.

The top shoulder section, this drops the 50mm diameter main body down to 25mm for the arm sections.

4.     Control Electronics

I've bought a simple 16-channel Servo breakout board and plan to use that with an Arduino to control the servos, add some movement and choreograph the output. I initially planned to use the Arduino MKR1010 but later decided to use the Digilent BASYS MX3 which I had recently roadtested and had so much fun with BASYS MX3 Trainer Board


I was doing reasonably well until I found that two out of the four servos I had purchased were garbage and didn't work. I'm assuming the other two won't last long either. And unfortunately I'm allowed a certain amount f money out of the housekeeping money to make my projects and in this case I had exhausted it with those badly chosen products, hence no replacements are available this month . I tried taking the servos apart and repairing them but could not determine what was faulty. I then started to consider using a stepper motor to create the oscillating rotary action I required. If anyone can advise on some mechanics to do this I'd be most grateful - I was thinking that the servo could run continuously without endstops and the mechanics would create the oscillations I need.


I found the Digilent BASYS MX3 to be very useful for controlling the servos as it has two channels and it was that that I started to use before I realised the servos were broken.

5.    What Has Worked

Every project has some good parts and so far so has mine. My knowledge of using OpenSCAD to draw the parts I require has come on in leaps-and-bounds and I am pleased with the material choices  have made including how I attach the fishing line control wire to the servo pulleys. Also I was pleased with how the PLA 3D prints accept paint:


6.    Next

As mentioned, I'm going to keep a bit quiet about this project for now. Instead I look forward to seeing what my peers have created in this Project 14 challenge. Once Christmas has passed I should be able to purchase some new servos and carry on with this project for the fun aspect....I'll post an update