You know the one. Everybody's favorite weapon in Destiny. The holy grail of heavy weapons. The Gjallarhorn.
Since I couldn't seem to get one in game, I decided I had to make it in real life. With just a month left to go before RTX 2015 in Austin, Texas, I had purchased all the materials I needed to build a Suros Regime, but a video of Bungie's Gjallarhorn t-shirt launcher had me changing my mind at the last minute. I decided to put off Suros and build a Gjallarhorn replica from scratch, vowing not to 3d print any parts.
This is one of my longest build write-ups so bear with me.
I'll start by giving Bungie a huge thank you for sharing their amazing reference photos. These images were the foundation of this project. I began by scaling the photos on photoshop and printing them out to scale. Final length of the Gjallarhorn would be 48".
I decided to begin with the bottom half of the Gjallarhorn since I felt it was the most straightfoward section of the launcher to build.
I cut out the blueprint and traced it onto 1/2" MDF.
I cut out the basic shape with a scroll saw, glued it onto another sheet of MDF, and repeated the cutting process.
Scaling and printing the blueprints, gluing and cutting the MDF took a day to complete. With the rough base all cut out, it was time for some good ol' laminating. A couple layers of 1/8" sintra were hand cut with an exacto, the edges rounded off with a dremel, and smoothed out with 80-220 grit sandpaper. These layers were glued onto each side of the base.
Once glued together, I used a sanding drum and some 80 grit sandpaper to round out the hard edges of the grip. I used a mini belt sander to round out the top and bottom of the stock and forward grip, eliminating most of the right angles.
To add the long groove details to each side, I scored the sintra with an exacto knife and traced the lines with a needle file to add more depth. This got the job done for the most part, but my hand slipped in a couple areas and I had to fill in the mistakes with some spot putty and sand it over.
With the grooves carved in it was easier to lay down the raised details because the raised areas were usually adjacent to the grooves. I cut these out of 1/16" styrene and thin "for sale" signs (not sure what thickness). I softened the edges by sanding the styrene with a 320 sanding sponge and super glued these elements onto the sintra.
At this point I wanted to add the screws onto the sides, but couldn't seem to find any short enough at the hardware store; they were all a little too long to fit (that's what she said).
I decided to mold some hex screws and only use the tops of the resin casts. Since I was going to mold stuff, I figured I should prep some other parts I had to mold in the meantime. I made one of the fins for the front of the barrel in about 5 minutes with some 1/2" MDF and a belt sander.
I threw together some quick and dirty clay/lego molds for these parts and poured Rebound 25 silicone, since it's what I had on hand.
I cast the parts in Smoothcast 300 with a little bit of black dye.
It was quick and dirty, but it worked just fine. I sanded off the threaded parts of the hex screw casts and drilled some holes into the body. The screw caps were then super glued into these holes.
To make the wolf ornaments, I found some metal decorative shortcuts at a craft store and decided to sculpt over them in apoxie sculpt. I mounted the wings with epoxy putty on both sides, and spent an hour adding the wolf heads with apoxie. Loop tools were particularly helpful during this step.
Once the wolf head ornaments were sculpted, the front grip had to be attached. I cut out two identical MDF bits and drilled a hole for the pin that would allow the grip to adjust.
The grip was a length of balsa wood dowel from a craft store. I sanded down the base with the mini belt sander to give it an angle and sawed out sections of the top to convert it into a joint (420).
The grip is pinned in and it can now move up and down!
I made a shroud type deal out of some 4" PVC that I would fit the barrel of the rocket launcher into. A circular saw was used to split one side and holes were drilled into the other end to screw the parts together. The bottom was sanded flat with the belt sander.
That part will make sense in a little bit. For one of the wider bits on the Gjallarhorn I decided to heat shape it out of 1/8" sintra. First, I made a shaping buck out of MDF that would give me the proper shape for the piece.
I then cut out a rectangle of sintra to size and used a heat gun to form the sheet to the shape of the buck. This was done by hand, one side at a time. Gloves kept my skin from burning off.
There it is! All removed from the buck.
That little detail was glued onto the top and the empty gaps filled with bondo then sanded to a smooth angle. That big PVC chunk is starting to make a little more sense here. It was glued on and screwed in for sexurity. *Ahem, security, excuse me.
You'll see me use that heat shaping technique a few more times for this build. The chunky blocky parts on the side that I once mistook for ammunition were sanded down from blocks of MDF I glued together. They were rounded on the bottom to fit the side of the PVC perfectly.
Some 1/16" styrene was then cut to size and glued on/heat shaped one side at a time until it was seamless with the MDF.
Some more little details were cut out of styrene and the blocks were glued onto the sides of the PVC.
The barrel used was a 4" cast acrylic tube I bought from Tap Plastics, since hardware stores only had PVC measured from inner diameter rather than outer. This fit the bill perfectly, according to the blueprints. Some strips of sintra were cut and glued to the inside to provide a little depth and detail, and the lip of the barrel was shaped and sculpted out of apoxie sculpt. Once this dried overnight, it was sanded down until it was uniform.
The exterior of the barrel has a deceptive amount of detail. There are curved channels wrapping around the barrel that I didn't notice at first glance. I decided to layer these details with styrene that I cut out and heat shaped to the acrylic tube.
Once shaped, these sheets were glued on. The embellishment in the center is a cast sculpt from the talented Melodywise Cosplay. I sculpted some embellishments out myself, but when she showed me her sculpts I just had to get my hands on them.
For the long, floral ornaments wrapping the barrel I designed some patterns on photoshop, then transferred them to the vinyl cutter. Instead of cutting single sheets of vinyl, I stacked them before cutting to increase the thickness. These patterns were stuck onto a long strip of styrene, and this whole strip was molded with Mold Star 16 Fast.
At least 8 of these little decorative strips were cast out of Smoothcast 300, and hand shaped to the curve of the barrel while mid-cure, when it's most malleable.
Here's how they turned out! Cold cast even, because that's what's up.
Remember those little fins that I molded earlier? Here's how they came out. The bottoms were sanded down a bit and then glued to the front of the barrel.
Some final details were added in thin styrene, and the channels were filled with bondo and sanded flush to give it a more seamless, organic curve.
Now two weeks into the project, I was beginning to wing it. I wanted the top part of the Gjallarhorn to be lightweight but sturdy, so I opted to heat shape some more sintra and create a hollow top. Another buck was made out of MDF, much larger this time, and two sheets of sintra were cut out and prepped for shaping.
The first sheets shaped weren't perfect, but they sufficed. I would go back and grind down the imperfections later.
This piece of MDF that looks like a futuristic skateboard is the base of the top shell. This part makes direct contact to the barrel of the rocket launcher and holds the top together. The open gap is space for the PVC shroud to spill into. Cutting out that MDF also makes it a little bit lighter! As insignificant as that may be...
The sintra walls were glued on with metal corners and some thin styrene was cut out and glued to the sides to add raised detail.
I got a little hasty around here. Admittedly, I'm not the best sculptor, so I neglected to take many photos of the sculpting process of the wolf head. It was made from apoxie sculpt and some of the wings were thin sheets of styrene cut out and layered. The remaining open gaps on the top half were filled with MDF and/or bondo, and remaining details were added with MDF. The vertical ornamental strips near the center are urethane casts of a decorative piece of balsa wood I found at a craft store and molded. The final two embellishments on the back half of the barrel were also amazing sculpts from Melodywise Cosplay, since mine paled in comparison.
With most of the Gjallarhorn fabricated, everything was primed with filler primer to knock back little imperfections and bring out any other imperfections that I may have missed before priming. Those were filled with spot putty.
The last part of the ballerhorn that remained was the scope. The amazing Zander Brandt from Zprops came by and lent a hand towards making the scope. Like the rest of the launcher, it was made from MDF, styrene, and sintra.
Unfortunately, I also neglected to take many photos of the painting process since it was crunch time. Grey parts of the G-horn were masked using slip latex to act as weathering later on. The basic black and white portions were masked off and then painted. After the base colors went on, the slip latex was peeled off to reveal the grey undercoat.
The remaining parts of the Gjallarhorn were painted gold. By hand. Not sure what compelled me to do that. Golden brand iridescent bronze acrylic was used to hand paint the gold details. I then added some contrast using an airbush and knocked back the white using some dark acrylic washes, since the true color is a little off-white. The remaining red eagle emblems were then masked off with some help from the vinyl cutter and then airbrushed/hand painted.
Last step? Give the grip a nice leather wrap, build a quick MDF stand, and upgrade wolfpack rounds. The final Gjallarhorn weighs in at just under 15 lbs. Next thing is to convert it into a working launcher.
I should also mention that Weebly is tweaking the white balance on these photos. For images with truer color, check out the Flickr gallery.
Thanks to my roommate Chris for providing the practical smoke effects. And thanks again to Melody and Zander for their help!
Thanks for reading!