3D Modeling & Printing

Moira’s right-hand gauntlet, the Decay Biotic Grasp, was modeled in Autodesk Fusion 360. The bodies were constructed mostly in the sculpt workspace using the original game model as a sketching base. The model was then split into several different components and tweaked to serve several purposes:

• Simpler finishing and painting (minimizing the need to mask)

• Considerations for physical fit on the wrist/palm

• Provide space for electronics and vinyl tubing

• Separating the parts that would be resin cast (everything in purple)

The exploded views show the final component separation for both the main wrist piece and the palm emitter.

All of the model parts were 3D printed in PLA plastic and test fitted.

Resin Casting

All of the purple bodies in the model transmit and diffuse light evenly.

After 3D printing and fully finishing the surface to a 400 grit smoothness, they were molded with silicone rubber (Smooth-On Mold Start 20T). They were then resin cast with Smooth-On Smooth-Cast 325 with a small amount of So-Strong purple and a very small amount of So-Strong white. The transparent purple provides a color tint and the opaque white allows the piece to uniformly diffuse LED backlighting.

Finishing

All 3D printed parts were finished using this method:

• 220 grit light pre-sanding/scuffing

• XTC-3D double layer

  • First layer ultra-thin

  • When tacky-cure, apply another thin glossy layer

• 400 grit full surface sanding

Painting

The black gloss surfaces were all airbrushed using this process:

• 3 coats Vallejo Gloss Black primer (74.660) with Airbrush Flow Improver (71.562)

• 2 coats Vallejo Model Air NATO Black (71.251)

  • If there is a red accent on the black, let the black dry overnight then:

  • Mask the accent shape

  • 2 coats Vallejo Model Air White (71.001)

  • 2 coats Vallejo Model Air Rot Red RLM23 (71.003)

• Allow the acrylics to fully dry (at least 24 h)

• 3 coats Rustoleum Gloss Clear

  
  

The metal surfaces were all airbrushed using this process:

• 3 coats Vallejo Gloss Black Primer (74.660) with Airbrush Flow Improver (71.562)

• 2 fine dust coats of Vallejo Metal Color Aluminium (77.701)

The matte white/grey gradient surfaces were all airbrushed using this process:

• 3 coats Vallejo Gloss Black Primer (74.660) with Airbrush Flow Improver (71.562)

• Gradient of Vallejo Model Air Insignia White (71.279), White Grey (71.119), USAF Light Gray (71.276), and Grey Violet (71.259)

  • If there is a red accent, let the color dry overnight then:

  • Mask the accent shape

  • 2 coats Vallejo Model Air White (71.001)

  • 2 coats Vallejo Model Air Rot Red RLM23 (71.003)

• 2 coats Vallejo Matte Varnish (62.062)

Electronics

The LEDs are all RGB-programmable LEDs (Neopixels), controlled with an Arduino microcontroller (Adafruit ItsyBitsy). It was necessary to use RGB since magenta is not a “real” color on the spectrum, but is instead a construct of the red and blue cones of our eyes being stimulated at the same time. As such, single-color magenta LEDs do not exist, and also cannot be created through filtering (as was done with the Regeneration Grasp). To simulate magenta, the LEDs emit both blue and red at the same intensity.

All the Neopixels (including the palm emitter) are wired to a single controller, and are powered by a 5V, 10000 mAh power bank that sits further up the arm. Wires are threaded through the tubes to connect the battery to the gauntlet and connect the various lighting elements to the single controller.