Don't Roll a One

Several years ago we had one of those Hallmark-type animated musical tabletop Christmas village decorations – a little snowy town scene with a rotating turntable that would blast Andy Williams’ “It’s the Most Wonderful Time of the Year” for 30 seconds or so. It broke and I got rid of it, only to discover that it was apparently one of our youngest’s most treasured core holiday memories. I couldn’t find the specific model and didn’t even remember the manufacturer.

Never Tell Me The Odds

There were several problems with this plan. I knew nothing about electrical engineering and between all the usual holiday panic combined with end-of-year school events plus work crunches, time was tight. I did have a lot of prior experience making wargaming terrain and access to 3d printers, though. I wasn’t worried about the physical shape of the thing, but rather all the moving, noisy, powered bits.

After some encouragement from friends, I decided to fuck around and find out.

A Plan Is Just a List of Things That Don’t Happen

3d printers take a long time to run but you can let them cook while you do other things. I roughed out a basic layout in Blender using stand-ins for foamcore and XPS sheets. In a nice bit of serendipity, I had taken 3d scans of my family’s gingerbread houses (and other bulky, sigificant art projects) for the last couple years using Polycam. I scaled them, edited them to make manifold meshes, and got them printing out on the FDM printer while I printed two tiny Dodge Chargers and another snowman 3d scan on my resin printer. Because trains are tired but Fast Five is wired, my Christmas turntable would feature 2 cars pulling Santa’s gift bag like the vault from that film’s final chase scene.

While all that was going on, I turned to YouTube for wiring tutorials and from there learned about Tinkercad.com, which is an S-tier learning tool and I’m not sure why it took me so long to learn it existed.

To save time, I scavenged a battery pack and motor from one of my kids’ less-used CrunchLabs projects. Luckily most of the components I needed shipped quickly and fairly soon I had the sound board and motor hooked up to a breadboard, only to discover that the 2 AA batteries I could easily wire into the project couldn’t run the motor and the sound card.

There was also the matter of gears. Even underpowered, the motor would turn my prospective roundabout into a helicopter. I looked to https://geargenerator.com/beta/ and from there I bought my first paid Blender plugin, Precision Gears. It worked perfectly the first time and I was able to easily print an internal gear for the turntable.

“I stripped an old USB cable to provide a steady 5v” was not a sentence I ever thought would apply to me, but here we are. By this point, LED lights had arrived as well and I was feeling confident about its eventual functionality, if not its eventual completion.

I couldn’t light the gingerbread houses because I had printed them without spaces, hollows, or channels for lighting. I had to edit and reprint them as manifold “shells” (MVP here were Cura’s tree supports), then drill holes to run the 0.75mm fiber optic strands. That part sucked real hard – many drill bits died to bring me those tiny holes.

The Easy Part

When I wasn’t waiting on electronics deliveries, I was cutting foam. The basic footprint was roughly 9″x12″ foamcore top and bottom surrounded by carved XPS foam. The hardest part was threading all those fiber optic strands through the houses into the hollow box below. The scariest part was hot gluing the fiber optics to the LEDs and then gluing the box shut. That was the point of no return – if a circuit shorted out or a light came loose, I’d have to cut into the project to repair it.

Otherwise, a mix of mod podge and craft paint with some grit and flocking provided a fast, easy, and protective basecoat. I used superglue and baking soda to give some icy road texture and then it was time to add the snow.

I’m Dreaming of a White Xmas

I tested out some different snow materials on scrap cardboard, and decided that lightweight spackle (one of go-to crafting materials) dusted with baking soda looked nice, was easy to spread, and provided some much-needed gap-filling and smoothing without multiple layers. The drying time was long but I was on time for once.

Some glitter sprinkled on top for that classic Christmas decoration magic, some protective spray to hold all the dust down and hopefully prevent the baking soda from yellowing, and it was done.

The best way to learn is to have a goal and get excited about it.

This is formatted like it should be a quote but it’s just a sentence, sorry.