So this is was by far the most complicated prop. The client wanted an Etch-A-Sketch (remember them?) that could write messages by itself. Yep, a haunted Etch-A-Sketch. Possibly one of the biggest challenges. How to do it? Well two obvious ideas came to mind, CG and practical effects. CG was the cheapest option, but I didn’t think it would look nearly as good. So I put forward the option of practical, and the production team went with it, good lads!
It was a fairly straight forward process, so to break it down;
- I sourced my components,an Arduino microcontroller, two stepper drivers, two stepper motors and a button.
- Machined a coupler which I mounted to the back of the Sketch’s control rods.
- 3D printed some pulleys.
- Coded v1 (some basic movement)
- Assembled it all together.
- CODE AND DEBUG!
- Decorate to make it look like it was owned by a kid.
- Duplicated the decoration on hero version.
Below is a quick test video
As you can see in the early version I had some issues with the Y axis, this was due to the belts not being tight enough, so when it reversed direction it wasn’t traveling far enough. This countered by adding a bit of extra code, although if I had the time I would have created a jockey wheel. Just at the time my 3Dprinter was being a little tetchy.
This was a fun prop to work on, and I’m so glad the production team gave the go ahead for me to do the practical version.