The blade is made from a thick 1in OD polycarbonate tube and an Adafruit mini skinny NeoPixel strip (1-meter, 144 pixels). The amount of pixels will be determined by the desired blade length. We suggest using sourcing a good quality tube from online shops like UltraSabers.com and TheCustomSaberShop.com.
The tubes from UltraSabers.com are available in medium and heavy grade polycarbonate. These ship with press-fitted resin casted tips and include an inner plastic light diffuser. They're available in different lengths that are pre-cut.
Tubes from TheCustomSaberShop.com are less expensive but bare. These require DIY inner diffuser and tip. They're not as thick as the heavy grade polycarbonate tubes from UltraSabers.com. These can be pre-cut in size of your choosing, up to 40in length.
The Adafruit Mini Skinny NeoPixel strips use NeoPixel Mini 3535 RGB LEDs on a flexible PCB. We found these smaller NeoPixel LEDs can fully illuminate the tube and evenly diffuse light. These do not require a second strip! We see benefits in using Mini Skinnys because you save cost on parts, less wiring work and longer battery life! Standard size RGB LED strips can be used but may require two strips to fully illuminate the polycarbonate tube.
A strip of corrugated plastic sheet, sometimes referred to as Coroplast, is used to create a backing for the LED strip. This will make the strip more ridged and easier to insert into the polycarbonate tubing.
We used a 20in x 30in semi-translucent sheet that was 4mm thick with 4mm wide corrugations. To fit within the inner diameter of the polycarbonate tube, you will need to measure and cut the sheet down to two strips. These strips will need to be the length of your desired blade. For longer blades, use clear tape to join multiple strips together.
Stripping The Strip
Most NeoPixel strips ship with pre-soldered wires and a weather protective sheathing. The wires and sheathing will need to be removed in order to fit the LED strip into the polycarbonate tubing. Carefully use a box cutter knife to remove the hot glued tips from both ends of the the flexible PCB strip. Use a soldering iron to remove the wires, we'll replace them with a 3-pin JST-PH cable.
Connect the wires from the 3-pin JST cable to the end of the NeoPixel strip with data in (as noted by the arrow goin to the right direction). Reference the labels on the strip and photos for matching polarity. We suggest using a set of third helping hands to assist in holding wires in place while soldering. 5V (red) is on the left, Data-In (white) middle, Ground (black) on the right.
Pulling and twisting the cable will eventually wear about the strands of wire. To reduce the amount of stress from excessive handling, use hot glue or a silicone-based adhesive over the solder pads.
Test NeoPixel LED Strip
Double check your wiring to ensure the polarities are correct. The 3-pin JST connector can be plugged directly into the NeoPixel port on the Prop-Maker FeatherWing. Power the Adafruit Feather on by plugging in the lipo battery. Use the button switch to activate the NeoPixel strip.
The number of pixels and length of strip is dependent on your desired blade length. We created a 24in and 32in blade in our builds. The numbers below are from a 144/meter Mini Skinny NeoPixel Strip. Use flush cutters to cut in between the copper pads on the flexible PCB.
- 24in – 85 x NeoPixel LEDs
- 32in – 114 x NeoPixel LEDs
Strip Stick Sandwich
We'll sandwich the Mini Shinny NeoPixel strip in between two strips of corrugated plastic. I suggest using double-sided nitto tape to secure the LED strip to one of the plastic sticks and then wrapping the second stick on top with clear tape. The second stick provides stability and light diffusion necessary for even illumination.
Double-sided nitto tape has a strong adhesive that is good for sticking things together. Cut several strips and spaced them out. Evenly distribute the strips of tape across the length of the plastic strip.
Peel & Stick
Carefully remove the protective film from the top layer of each strip. Position the LED strip over the plastic stick and slowly lower onto the tape. Inch the strip onto the tape by pressing it down. Try to keep the strip straight and true.
Place the second plastic strip over the LED strip and wrap clear tape around to secure them together. Hold the two strips together while apply the tape. Try to keep the edges straight and true.
Power on the circuit to test out the LED strip. The connections should be capable of hand handing and a bit of movement but take care and treat it delicately.
Install LED Strip
Insert the LED strip assembly into the polycarbonate tubing. The light source is thin enough for it to wrap around the other side and illuminate the tubing. There is a slight variation in the brightness at close inspection but looks fully lit for the most part.
The LED strip assembly needs to be secured to the tube or else it will fall out. To keep it in place, use clear tape or hot glue to seal the bottom of the tube. A bit of light leaking near the bottom tube is fine and will actually add a slight lighting effect to the FeatherWing.
Install Blade to Emitter
The polycarbonate tubing is press fitted into the blade emitter. Insert the 3-pin JST cable through the top opening of the emitter and carefully press the tubing. Firmly grasp the tubing and emitter while forcing them together. You may use... the force to do this (couldn't resist!).
Constructed NeoPixel Blade
At this point we can test out the LED strip again. Take a moment to make tweaks if necessary. I found the light diffusion in the blade construction to be interesting. Originally I used two strips of high density, 5050 NeoPixel strips. I was surprised to find a single Mini Skinny NeoPixel strip could decently diffuse the tubing. There is a slight variation in brightness on the backside but it's not that noticeable. Feel free to experiment with different strips, DotStar LEDs even! I constructed two blades with different lengths and can swap between the two!