This has to be one of my favorite weapon designs of all time. When Jinx was announced for League of Legends, the shark cannon in her reveal video grabbed my attention immediately, but the change to do a purple/blue paint scheme placed this on my “must build” list. Fishbones needed illuminated eyes and a moving jaw, and became the first project built start to finish in my new studio.
I have to give a huge thank you to LoLKing.net for their spectacular model viewer. Having the ability to call up the models for this project on any computer I had available was invaluable during the course of this project. After some time studying Jinx and Fishbones, I set about making some full scale blueprints (which were later turned into posters as well!). Fishbones was to be 43″ long.
I started with the fun stuff, sculpting the head and jaws first. Both of these pieces follow my standard practice of building 2D cross sections, then filling the resulting cavities with sculpted urethane foam.
Recesses were carved out with a dremel and cavities in the foam were chiseled out to create the teeth areas.
Sections that needed raised details, like the teeth on the upper jaw, were first blocked out with small pieces of sintra, then skimmed with Apoxie Sculpt to make the beveled edges.
After a lot of sanding, I had these forms ready to go.
I made some quick 2-part brush on molds using Smooth-On’s Rebound 25. The first castings were done in urethane resin, and I was very happy to see the jaws meshed together perfectly.
The urethane castings worked great, but I wanted to try my hand at making some epoxy pieces with glass fiber backing. These have the potential to be much stronger and lighter than urethane castings, though they tend to take much longer to produce and also cost a fair bit more. The first step was to paint a gel coat into the molds using Smooth-On’s EpoxAcoat Red. The gel coat forms a detailed skin on the outside of your casting and is applied in a very thin layer to capture detail and reduce any trapped air bubbles. This was brushed on while the molds were separated.
Once the gel coat was semi-cured (wet enough to leave a fingerprint but not enough to stick to a finger) I added Free Form AIR to the deeper recesses of the teeth and eye areas. The later steps of this process involve layering glass fiber cloth along the inside of the sculpt, and sharp recesses like these areas are hard to get cloth to wrap around without trapping air bubbles. Free Form Air is both extremely lightweight and epoxy based, so it bonds to both the gel coat and the subsequent layers.
Finally, glass cloth and EpoxAcast 690 are added to the interior to give the part its strength and rigidity. Only one layer of cloth should be added at a time, and I prefer to use small squares of 10oz cloth, followed by larger squares of a heavier weight cloth in later layers. The molds are still in separate halves at this point.
Once both halves are semi-cured, the molds are bolted together and the seams are treated in a similar process: gel coat, then glass fiber and epoxy. The finished pieces are about half a pound lighter than their urethane counterparts. This may not sound like much, but every ounce counts!
Speaking of weight, Fishbones was on a very strict styrene-and-vacuum-forming diet for many parts of the project. The main barrel piece started out as a large block of tooling foam turned on my lathe…
…which was eventually split in two parts and vac formed from .060″ styrene to make a thin, lightweight shell.
The fins jutting out from the inner barrel were also vac formed in a similar way. The vac form bucks for these are sintra blocks. Thickened methacrylate adhesive was used to make the styrene halves of these parts into one hollow fin. This is some expensive glue, but it’s pretty much a tube of magic when it comes to bonding plastics together. The seams of both parts were treated with MA300 then clipped together to cure. After a couple hours the flange was trimmed off and the edge sanded flush.
Each of the fins is affixed with two bolts that secure it to an interior frame. This is a structural pipe that sits inside the lightweight styrene shell and provides support for all the plates bolted to the gun. In another weight-shedding endeavor I was able to hole saw another half pound out of this pipe, without sacrificing any of the structural rigidity of the part.
That strategy continued to the larger 6″ diameter tube that forms the front of Fishbones’ barrel. Initially things looked like this…
…but once I figured out that much of this would be covered by the armor plates on the gun, I chopped out a lot of material.
The larger armor plates were built from sintra sheeting. Large sheets were first heated in my vacuum former oven before being draped over tubes to take their cylindrical shape.
Each of the armor plates has a triangular-raised perimeter edge. For some parts I was able to make a long thin piece of triangle channel, then glue it to the plates, saving myself a lot of complex sanding later on.
Other parts required more complicated curves, so their raised edge was glued on as a flat bar then sanded down. I started off with my air grinder and a very rough chisel drum. If I were going for a wood texture, this would have been awesome.
This was followed by a dremel sanding drum and eventually hand sanding until all the parts were smooth.
The two contact points on the gun – the shoulder rest and the grip – were both made from solid blocks of sintra. The grip has a large 3/8″ bolt embedded 3″ into its center for additional support, and the shoulder rest has two solid wooden dowels that are used as anchorpoints that secure it to the gun frame.
I also milled out a small rectangular slot in the shoulder rest to house 3 AAA batteries which power the eye and mouth LEDs.
Now it’s time for the party piece: jaw articulation. I don’t have extensive puppetry knowledge so a lot of this was trial and error, and also a lot of imitating similar projects I stumbled across on Google. I sketched out a few dozen ideas and eventually settled on this mechanism. This is the left and right side hinge assembly and pushrods. The ball joints and threaded rod were purchased at a local Hobbytown, and the pivots themselves are laser cut acrylic.
This worked okay on the table, but some issues emerged when attaching it to the jaws. I had initially planned on using the hinge bolt as the pivot arm’s contact point, but repeatedly opening and closing the jaws loosened the bolt and the assembly failed. I added a second rigid pin to the jaw and head to prevent this from happening. Below, you’ll see both the threaded hole for the mounting bolt and the long thin threaded rod, which will be pushed/pulled when the mechanism articulates.
Here’s an interior shot, from top left to lower right. The large bolt holds the upper jaw in place. The smaller silver rod with the black nylon nut is the pivot arm for the upper jaw. The pushrod for this assembly sits just above it, with a brass rod covering the threaded bar to eliminate the spring rubbing against the threads and making an awful noise. The two return springs ensure the mechanism closes at rest when the trigger isn’t pulled back. Just underneath the right side of the brass pushrod assembly is the ball joint that attaches to the trigger; this pulls backward to pivot the large black plate and the attached pushrods. The second pushrod without the brass sleeve articulates the lower jaw. The hinge bolt for this assembly is the small hex head bolt and the silver threaded rod beneath it is the pivot arm.
There’s an identical mirrored copy of this assembly for jaw’s opposite side.
Here’s a shot from the backside, where you can see the cable for the trigger assembly. After adding the pivot pins, the mechanism works perfectly and is rock solid.
Cool looking though it is, nobody wants to see how sausage is made. I built a dummy rocket head to cover up the mechanism when the jaws are opened. These are vac formed styrene panels held in place with magnets. In case anything in the jaw hinge ever needs to be serviced, this can be easily removed for maintenance. In fact, the entire gun bolts together and can be disassembled into its component parts in case things ever need repair in the future.
The last major step before paint was to trim out the area for the eyes and sculpt the interior of the head. The eyes were pressure cast from Smooth Cast 325, and I used a small amount of body filler to make sure the mating edge was seamless.
On the inside of the upper jaw, there’s a sort of bone/rib type pattern. This was sculpted in Free Form Air to keep things lightweight.
I spent a lot of time with spot filler and sanding getting everything super smooth before paint. The larger sintra armor plates were painted with filler primer to make filling small divots in the sintra surface easier.
Time for paint! The paint job on this cannon took me about a week. Most of this is new ground for me, but I’m beyond happy with the results. The first pass was done with a Krylon satin blue enamel. Everything was given two coats and was allowed 24 hours to cure fully.
I used more Krylon, this time a gloss purple (the finish doesn’t really matter since I’ll be clear coating everything matte later on) to make a purple gradient across all the pieces. Gradient painting with spray cans isn’t easy and if this were a smaller area of paint I would have done it with my airbrush instead. The enamel base makes top coating much easier though, so I stayed with this technique. To get the best atomization of the paint, warm the can by running hot tap water over it for about 10 minutes before you spray your gradient.
After the gradient paint coat cured for another 24 hours, I started with the airbrushing. I used Createx Wicked Colors for all of the detail work from here on out. The first pass was some lighter blue on the tips of all the fins, followed by a nearly white-blue to outline the polygon edges coming out of these lighter tip spaces. In the picture with two fins, the left part is before edge-highlighting and the right is after. Airbrushes used on this were my Iwata Eclipse siphon feed for larger areas and my Iwata Hi-Line gravity feed for details
The armor plates were masked off in the center areas, as the purple gradient over blue was accurate to the game render. The perimeter lip had a very different paint scheme, which started off with a pass of matte cobalt blue as a new base color layer.
The inner face of the perimeter was tinted purple and the outer face tinted blue. I used the same edge highlighting as on the fins for the very top of the raised lip around the whole shape.
With the masking tape removed, here are the results!
The head and jaw were probably the largest amount of work, and I spent a lot of time tweaking the colors and gradients until I settled on something I liked. The technique was largely similar to everything listed above, but applied with a little less mathematical rational and a bit more artistic liberty.
That is, with the exception of the outlines on the teeth, which were all masked off and painted to give a hard, definite edge.
The dummy rocket head was also given a gradient treatment, incorporating a few accented shadows to better hide the seams on the rocket and shroud when the jaws open.
The last step was a coat of Krylon matte acrylic clearcoat #1311 over all the parts to give everything a uniform finish.
Illumination came next, with the eyes getting a little extra detail. In-game they glow yellow but I wanted a bit more here. It’s atypical for me to deviate from the reference material but this just felt right. I laser-etched a spiral pattern into 1/4″ clear acrylic and backed this piece with mirrored film. Three 5mm yellow LEDs provide illumination and the lines, combined with the mirror film, help to distribute the light evenly without any hot spots. Because of the lens effect of the eye itself, this pattern also appears to follow the viewer as they move around the piece.
There’s also two 5mm red LEDs in the tip of the nose that point inward and illuminate the mouth and dummy rocket. The effect when the mouth is closed is really neat.
I put off working on the belts until the absolute last minute, for reasons I can’t quite remember. The strap itself is made from 3/8″ EVA foam while the buckles are cut from sintra blocks. There was a lot more time with the airbrush here to make sure the shading lined up with the cartoonish appearance of the rest of the gun.
Bolt it all together, and you’ve got a finished shark cannon! (I tweaked the red in the eye recess after this shot was taken.)
This was a huge project and one of the most complex pieces I’ve built to date. It seems like every new project just keeps getting crazier and crazier. This is the first of many pieces to come out of my new studio, so make sure to follow along for more to come! Until then here’s some finished photos of Fishbones. Photos by my talented friend Dan Almasy.
If you’re interested in reading more details about the build, there’s dozens more photos with detailed descriptions of each step on my Flickr page.
Also be sure to check out the gallery for larger resolution photos of the finished piece.
Thanks for reading!
All of the products listed in this write up are the products that I used and can recommend. Some of them are provided as Amazon affiliate links, which help support Volpin Props.