Introduction: 3D Printed Eggplant Emoji Power Bank Enclosure

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Hand-made Christmas gift making is starting early in my house. This 3D printed project is perfect for phone addicts who need extra battery power... and people who can't imagine a conversation without emojis. It's simple and requires no skill. Other than a 3D printer, you don't need any specialised equipment, nor any particular painting talent.

Supplies

Power bank (mine is 95mm x 23mm)
3D printed parts
Craft knife
Sandpaper (80, 120, 240, 320)
Modelling putty (Plasto or Tamiya)
Strong plastic glue
Spray on top coat https://www.amazon.co.uk/Rustoleum-AE0040001E8-400...
Acrylic paints, brushes
Blu-tack

Step 1: Printed Parts

Those were printed in PLA, 10% infill, 1.2mm walls and 0.2mm layer height. You could always do 0.1mm for better quality, and skip modelling putty altogether, just sand and spray paint. Dimensions were designed to fit this specific power bank, you will have to adjust STL files to fit other power banks.

Attachments

Step 2: Cleaning

The tiny part and the body print very well, they don't even need to be sanded before modelling putty. The worst part is the top of the eggplant. Start by removing supports with a craft knife and sand it with 80grit sandpaper.

Step 3: Filler/ Modelling Putty

I'm using PLASTO modelling putty. It's pretty much the only filler available in the UK that works well with plastic. Tamiya is sometimes available online, but it's often imported from outside of Europe and therefore ridiculously expensive. PLASTO dries really fast, so squeeze a pea-amount of filler at the time and work quickly to smooth it all over the surface. Give it 2-3 hours to dry.

Step 4: Sanding

Once dry, begin sanding. 80-120-240-320 grit sandpaper until it's as smooth as possible. Rinse all parts with water to get rid of dust and dry it with paper towels. Use very strong plastic glue to connect the 'tail' to the top of the eggplant.

Step 5: Smoothing

To make it extra smooth, spray it with a top coat. There are specialised sprays for smoothing PLA, but honestly, this method is cheaper, works pretty much the same and is more available.

You could skip the top coat and use spray-on filler instead, but it's even more sanding and if there is a way to reduce the amount of sanding- I'm all in!

Best method I've found for spray painting small, weirdly shaped parts is to use a stick and a small amount of blu-tack. Simply roll the blu-tack until it's pliable, cover the tip of the stick (unused pencil and huge chopstick in my case) and adhere it to your parts. While spray painting it, you will be able to rotate the print as you spray and create a smoother part.

Step 6: Painting + Varnishing

It will take 3-4 coats of paint to get a perfect finish. Painting over a top coat is not the same as painting on raw plastic, it's a bit slippery, so your first paint layer won't look nice, but it will improve with more layers.
Once dry, apply varnish. I used some more top coat spray.

Step 7: Assembly

Lastly, assemble all parts, use a little bit of glue to keep the top and the body together and let it dry.

Step 8: Finished