Poking around reddit for costume ideas for Awesomecon 2025 I came across a design for building BD-1 from Jedi: Fallen Order. I hadn’t printed anything this large before but I loved the idea of animating it with lights and sounds. After printing a couple of the inital parts I started looking at how others had remixed it to make it unique.

My next stop was off to grab some parts from microcenter to get the animation working. I decided on an adafruit propmaker board since it could do sounds, neopixels and had motion sensitivity. I loaded up Circuit python and began testing turning lights off and on. With the head printed, I realized I couldn’t fit my hands inside to get access to things easily so I needed to make some changes. Splitting the head into a cover and adding magnets gave me the room I needed and while I was at it, I embedded the amp power pack from here.

For printing the body I went with ABS filament to give it some strength and used PLA on areas I thought I could get away with it.

Playing with the adafruit board I found I could reuse some of my OLED screens I bought for the lightsaber chassis. They were pretty much plug and play like the Proffie boards. I switched up the amplifier side plate to pressure fit the OLED screen and made a hole in the head cover to run wiring.

Once he was mostly printed I gave him a shot of primer. Unfortunately I had the ankles on backwards, I was able to break them off later without too much damage but I had to reprint a couple of the toe pieces.

Painting BD-3 started out easy enough with some rattlecans I sprayed him an ivory color and decided on forest green accents. The masking I used for the green bled through though so I had quite a bit of touch up work to do. Fortunately I wanted a weathered look anyways so I fixed as much as I could by hand after.

Once paint dried I began test fitting electronics, adding led’s and trying to figure out how best to mount the pixel strips.

I ended up with about 36 pixels in the back of his head in two rows and one neopixel for each eye. I also found a nice acrylic lens on amazon that fit his larger eye. For led animation I couldn’t decide on one color so I created a sequence to run through colors and pulses. I tracked down a couple sound clips and added them to run randomly. After a while it started to drive me crazy so I switched that to his more common beeps and added the touch sensitivity for the louder clips. I made a voltage divider with 10k resistors like on the adafruit site and read out the battery voltage on the screen so I know when to charge him. I also added a kill switch to the main body with the speaker and ran those wires back to the head where the adafruit board sits.