This is a light-up desk toy of Mei's little robot Snowball from Overwatch. It's a static model designed for LED lighting. He comes in standing at just under 5" tall. It is powered by an internal 18650 battery that should provide roughly 8 hours of continuous runtime (at 2200mAh) depending on the LEDs and resistors you choose, and can be charged with a USB Micro B connector, which should allow continuous operation while charging.
Included in this download is a ZIP folder with all the parts separated out individually, and organised into folders for ease of browsing. Parts that need multiple copies printed are marked as such with the number of copies required.
Also included in this download are a pair of Adobe Illustrator files designed for laser cutting parts, one for an alternate base stand in 1/8" acrylic, the other for cutting out the face mask for Snowball from a sheet of tinted plastic transparency (this part is optional as a tinted mask can cut down the brightness of the eyes, and you may prefer it without this addition).
For the parts named as 'Diffusers' in the eyes and the thrusters, I recommend using clear PETG so the light can shine through. The rest of the parts can be printed in PLA just fine.
If available, printing this model with an SLA machine would also be a fantastic option, really helping with the small details and post processing.
Hardware you will need for the full electronic assembly:
Obviously many of these parts can be picked up individually from local hobby or hardware stores, but links were provided for convenience
Rough assembly guide showing how the parts fit together
Modelled in Fusion for Ease of Assembly, Printing, & Painting.
The model was designed in Fusion 360 with 0.5mm tolerances between parts for ease of assembly. The model was also carefully planned out such that supports are not necessary for printing when the parts are in the correct orientation (the included "Snowball Parts Arrangement.stl" file demonstrates that correct orientations of the parts for support-less printing).
- Updated 3/7/2019 - Updated the size of the screw holes at the back of the head for the charging chip, made them small enough that an M2 screw should more easily bite into the plastic. The original holes only made a loose connection, I ended up gluing down my charging chip. Now the file is "Head Main v2", and also updated in the Parts Arrangement file.
Prepped for Painting
Completed and on my Desk!
The electronics inside are fairly simple, comprising 3 parallel arrays of of 5mm strawhat blue LEDs. The LED's are designed to fit snugly into their respective recess in the back of each of the "diffuser" 3D models, but can be tacked in place extra secure with some hot melt glue.
Adafruit's Micro Lipo Charger chip provides a pad that can be bridged for 500mAh charging rates, this should be bridged with a tiny dab of solder to improve the charge rate. The protected 18650 I'm using has a 2200mAh capacity, so charging will take just under 4.5H, but you will also be able to trickle charge the battery at about 200mAh with the lights running, so you can keep the toy constantly 'On' sitting at your desk and it should be full charged when you want to take it with you.
Recommended are thin gauge wires, 24AWG or possibly thinner. Packing the electronics inside can be a tight fit. There is enough space to fit everything, but you may need to give your top and bottom halves a squeeze to close up the body.