Black Widow Infinity War Eskrima Stick
Black Widow Infinity War Eskrima Stick
3D
Published 2018-01-08T11:57:11+00:00
2018-04-28 Important Update
The original design is solid enough as a display prop, but it feels a bit "wobbly" as a cosplay prop, so after using these props for a day (nothing broke and I did twirl the staff and sticks around, but didn't hit anything with them), I decided to give another look at solidifying the design. I came up with a three quick to print parts that replace the connector ring parts and really help make solidify the build without any glue.
I printed mine in clear PETG, because the new design fully wraps the LEDs inside. The new look is a bit more diffused, but actually appears brighter from a distance. I have added a comparison photo where the new version is on top.
PETG is soft and slippery, so I didn't tap the holes at all and just bolted the screws on. The old design relied a lot on the screws being tight for rigidity. The new one just uses them to keep the parts together and the rigidity comes from contact between the parts. Tolerances are fairly tight, so depending on your printer, you may need to sand the insides of the male segments a tiny bit to get everything to fit.
If your build has 9 joints, you'll need 7 of the TubeConnector parts and one tip and hilt part (double that for two sticks or a staff).
Original Post:
This is my interpretation of a weapon recently seen used by Black Widow in trailers & photo shoots for the Infinity War movie. The full build includes WS2812B NeoPixel strips, Arduino Pro Mini.
Disclaimer: this is a cosplay/display prop and it is not designed for actual combat.
Some Youtube videos showing my first prototype:
https://www.youtube.com/watch?v=tbSOtF_mO4Y
https://www.youtube.com/watch?v=YY8wmjXqZDc
The software was mostly ported from my Kryptonite Sword project, but I will be making a custom version soon. Ask for help in the comments, if you start working on the electronics and need wiring instructions & software. Here's the source code repository:
https://github.com/jmunkki/eskrimastick
Alternatively, a USB power bank can be fitted inside the hilt and a TV backlight LED strip can be used for lighting. This will give you a nicely lit up weapon, but no animations & active features. This item is highly modular, so you can upgrade to a full electronics build later on, even if you start out with no LEDs at all.
In addition to the 3D printer parts, a number of small screws will be needed. The design was created for M5 x 5mm socket head (Allen) screws, but M5 x 6mm screws can be used as long as you are very careful not to short out the NeoPixel strips. If you don't like metric, you can try 3/16" long screws in 10-24 thread size. The rings where the screws attach are not threaded, so a thread tap is recommended, but not mandatory. The "TapHelper" part can be used to help align a thread tap with the holes in the rings that need to be tapped.
There are places for small M3 screws and nuts in the electronics enclosure, but those can be replaced with just a drop of superglue and the second one is optional (as seen in one of the photos).
Aside from a little bit of superglue at the first joint ring, no glue was used or needed. You can stiffen the joints with superglue or epoxy as needed.
Electronics components:
- Arduino Pro Mini (8MHz, 3.3V)
- 18650 battery with overcurrent & discharge protection
- Approximately 1.5 meters of WS-2812B strip @ 60 LEDs/m
- A 2x2 WS2812B NeoPixel LED circuit board for the tip (with a round hole through the center of the board).
- 12mm rotary encoder (short shaft) with a switch
- 6x6x5mm microswitch (for the tip)
- Two resistors (I used 50kΩ)
- Wiring & connectors
Here's a TinkerCAD design for the circuit: https://www.tinkercad.com/things/2A92gsdHCTD-eskrima-electronics
* OR *
- 1.5m long USB-powered LED strip for a TV backlight
- Tube-shaped USB power bank that fits inside the hilt
There are also a parts that can be used to join two of these weapons into a staff. You will not be able to access the rotary controllers for menus while the two sticks are connected, but the tip buttons will still work. The XL version overlaps the handle a bit more and has a tighter clearance. I found that while the original design works great on a fresh print, it will start to feel a bit loose after the parts have worn down a bit. Either one will work. The XL version has an "inside brim" built into the model for more reliable printing, which will need to be cut or sanded off (it's just 0.2mm high).
A short segment of 1.75mm filament can be placed in the tip lens part to activate the microswitch, but a bit of plastic tube from a Q-tip will also work great.
Here's a referral link to Hobbyking. If you sign up, I get points, which can be used for store credit, so not actual money, but I'll be able to use the credits for filaments and other hardware. I bought the M5x5 screws and the Hobbyking Silver PLA filament from there and can recommend both (while you are at it, pick up some of their flexible filaments, at least the black):
https://hobbyking.com/en_us/customer/account/create/referral/3MDCXNTAWMCAXNT/
The segments consist of a male and female part that twist together rather tightly. The first female part should be printed as strong as possible as it is least supported. The tolerance between these parts is intentionally rather tight, so print just one pair first and if it really is too tight to close properly, replace the male segment part with the male part for the tip, which has a looser tolerance, but is otherwise compatible.
The standard build has 8 joints (4 x 8 screws = 32 screws). You can add or remove segments to make the weapon fit your size. The one in the photos & videos has 9 joints and is 67 cm long.
Most of the print shown uses cheap silver color PLA with some parts printed with silver & black acrylic spray paint. Pick a strong material with excellent layer adhesion.
The tip lens is clear PETG. The red part of the hourglass knob is fire red Ninjaflex and the black part is just generic TPU (semiflexible filament). There's a simpler, more movie-accurate knob as well.
Depending on wether you are going for the full Arduino build or not, you should pick the "electronics" or "no electronics" version. Pay attention to which parts your chosen build requires (and how many).
Most objects have a single correct print orientation that you may have to find before printing. I randomized the layer start positions in Simplify3D when printing the ornamented handle. The SegBigFoot model is a version of SegFemale with a modeled-in brim on the inside of the part. I recommend this version on FDM printers, because it gives you better bed adhesion and the brim doesn't even need to be removed (it shears off or is not visible when the parts are assembled).
Most of the parts are printable even on a relatively small printer. The ornamented cover will require a print height of approximately 170mm. The other large parts (electronics housing & triangular spine for the LED strips) print flat and will easily fit onto a 200 mm print bed. If you are not adding electronics, the cover is the only truly large part to print.
Here's a link to a text document where I've tried to count how many of each part you need to print. I hope the numbers are correct and that they will help you.
http://cameraid.com/misc/IWEskrimaPartCounts.txt
| Date published | 08/01/2018 |
| Material Quantity | ~250 grams |
| Complexity | Easy |
| Support Free | YES |
well I have had some success printing and practicing assembly of the parts. I am printing in primarily PETG. strong and just the right amount of flexibility. I also have made a few small design changes in some of the parts I am printing. First the ring printed very nicely in blue T-Glase and looks fantastic over the silver. I also wanted to diffuse the light and make the center look like the twisted cable in the online photos. Space was in deed an issue. Enter Adafruits Mini Skinny neopixel strips. https://www.adafruit.com/product/2964 They are tinny . I printed a smaller triangle base the would hold the strips and had a center hole fro the tip wire to run down the center and a clear tglass twisted cable tube for the whole thing to fit into. The twisted cable section interlock and fit 2 universal joint sections each. The T-glase reflects and refracts the light very nicely . it gives it a good electricity sparky look to it. that reminds me. do you thing you could incorporate this light pattern into the program, maybe in blue https://www.tweaking4all.com/hardware/arduino/adruino-led-strip-effects/#LEDStripEffectSparkle . ok thats my update so far , back to printing parts.