Poltergeist : From the German for “noisy ghost”.
A metaphysical entity which announces its presence with rapping, banging and general mischief making.
It wasn’t easy, but I’ve got one shut up in this box. I call him Piecax. Sometimes he will lie quietly and make you think he’s gone, then startle you with frenzied knocking. Other times Piecax will have fun by echoing you. Find his favourite number and he might play you a spooky tune. Watch the video to see Piecax in action.
Thanks and credit go to JKestner whose Knock Block gave me the inspiration for this project.
Step 1: The Box
I did this first so I wouldn’t be waiting for varnish to dry once I’d built the circuitry.
I started with a cheap softwood box from a craft shop. I clamped a rotary sander upside-down in a vice and rounded the corners and smoothed the sides, starting with a coarse sanding sheet and finishing off with fine. A final rub over with very fine paper and I had a smooth rounded box but a bit of a boring colour.
To bring out the grain I gave it two coats of walnut woodstain and then for the gloss, three coats of yacht varnish. The first coat was diluted with thinners to make it soak into the wood and give it more hardness and a good base for the other coats.
A quick raid on my sons' lego sets and I had a casket fit for a ghost.
Step 2: The Electronics
* I'll re-write when I get a chance. *