D.Va Keychain

If you're a fan of the video game Overwatch, you'll know how much personality the characters have through their amazing designs, animations, and voice-acting (there's a fascinating video by Extra Credits that discusses some of this in greater depth).

For me, the 19-year-old Korean gaming prodigy Hana Song, who goes by the name D.Va, is one of the most engaging heroes, with her super-competitive nature and sassy remarks. She pilots a flying pink mecha-tank that bunny-hops around and fights giant evil robots in her home country. What's not to love?

This white rabbit keychain is almost identical to the one attached to the pistol D.Va uses when she comes out of her mech. So it's a bit of a homage to D.Va, and to Overwatch, which is heaps of fun to play.

D.Va's pistol with the pink bunny keychain.

I started this project by looking online for things from the game which I could 3D-print at my uni's Fab Lab. The Overwatch fanbase and cosplay community have been quite active in modelling up props from the game, with some people even extracting the 3D character models and converting them into .stl files.

I eventually chose this 3D file by Tokytome because it was the most accurate version of D.Va's keychain that I could find. I highly recommend this file, as it's modelled with a lot of consideration.

I printed in white PLA with a 0.2mm layer height on a FlashForge Finder, which did a great job of it. The print time was around 90 minutes. This was faster than I expected, based on previous experience with 3D printing, but it's only a small print.

The support material was easy to remove, and I did most of it with my bare hands. Some of it remained on the underside of the print, though, so I double-sided taped some 400-grit anti-clog sandpaper to an old chopping board and wet-sanded the surface with a circular motion. I used some small metal files and wet-and-dry sandpaper to wear down the 3D-printed texture on the outside of the print. I began with the metal files, then 400, 800 and 1200-grit sandpaper.

To ensure the sandpaper was flat, I used a piece of popsicle stick as a sanding board. This worked really well - much better than the emery boards used for nails, which fell apart when they touched water. I had previously used a metal file as a sanding board, but the edges tore up the sandpaper.

 Also pictured is a 3D-printed hotshoe cover for my Sony a6000 camera, which fit really well after sanding.

The emery boards didn't work at all.

The sandpaper tore up when I used a metal file as a sanding board.

After 1200-grit wet-sanding.

The next step was to stick the two halves together. I chose 2-part epoxy resin for this, as the underside of the prints was still textured with small cavities due to the nature of 3D-printing, which would help to create a strong bond. Epoxy is also easy to work with once cured, as it gets pretty solid. At this stage, I picked out an eyelet from my box of random bits of hardware for the chain. I decided against using a ball-chain because the ones I had were too flimsy, and I was already in possession of the parts required to make a standard chain-style set-up.
As the eyelet was too big for the original hole, I filed down the interior of the print for the thread of the eyelet to fit into.

I applied the epoxy resin to both parts and wiped off the excess with a wet paper towel. To ensure they lined up correctly, I tightly wrapped masking tape around each ear and put a rubber band around the whole thing.

While I waited for this to set, I cleaned up the rusty chain with WD-40, isopropyl alcohol, and a cotton rag.

A day later, I took off the rubber band and masking tape. The edge of the print where the two halves met, had some gaps which came about when sanding. I filled these in with some 2-part epoxy putty, and carefully scraped off the excess with a knife. I waited another day for the putty to set. Gap filler from the hardware store could do a similar job, but I chose the epoxy because it is less powdery. If the keychain were to take some abuse in future, the epoxy would do a better job of keeping its shape.

Once the putty had cured, I sanded the edges to even it out as much as possible. I sanded the rest of the print with 1200-grit to clean it up after handling it so much, and did a final clean with a wet cloth.

I wrapped some tape around the eyelet, and attached it to a wooden dowel for painting. I used white Rust-o-leum acrylic spray paint/primer, which I had lying around from a previous project. I used this instead of hot pink because 1) I had no hot pink spray paint. 2) The 3D-print was white, so if it got scuffed, it would be less noticeable. 3) I'm a fan of Alice in Wonderland, and the white rabbit is a significant character in the story.

The spray paint left a really nice surface texture, which was a bit like a painted wall. I stretched out the painting over four days, sanding with 1200-grit between each coat, to remove small bits of dust and other lumps on the surface of the print.

I then sprayed it with some cheap clear enamel, which was a mistake. I should've found some acrylic clear-coat instead, as the enamel reacted badly with the white acrylic layer and turned the surface a little yellow. Luckily, it didn't discolour by much, and the discolouration was even.

 Needs cleaning.

After cleaning it up.

Shoeboxes are excellent spray booths for small items. You can just close it up for storage.

After the white acrylic coats. Notice the cool texture.

The discolouration evened out after a while.

I let the keychain sit for a few days while the enamel layer dried. Enamel is pretty nasty stuff to work with sometimes, as it might feel sticky days or weeks after spraying. It really needs a few weeks to fully 'cure' and become a hard layer.

I decided not to wait so long, because I really wanted to see the keychain in use. So after these few days, I attached the chain and keyring, and put it on my bag, which was in need of repair (I'll probably write about how I fixed the bag in the near future).

Overall, I'm really happy with the keychain, as it's almost exactly like the one in the game. The surface texture is quite smooth, and doesn't give away its material origins like a lot of 3D-printed objects do. Despite all this, I want to try again. Partly because of the enamel clear-coat screw-up, but also because I'm just a really big fan of D.Va.

Next time, I might use pink filament for the print, or try casting it in resin to get a solid, single piece that I can make duplicates of in different colours.

Nerf this!