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  • whimsyaly

God Arc Build

(This post is from September 19th, 2016)

Hello friendlies!!

Oh man, I’m just going to jump right into it.  PAX West 2016 was an amazing experience, and the God Arc for Alisa from God Eater that I worked so hard on was definitely worth the effort.  I wanted to provide a detailed write-up as to how I built the God Arc, because I couldn’t find one for myself when I was trying to build it!

Confession time…. I tried to take pictures, but didn’t grab as much as I wanted of the process because of the inevitable con-crunch.  So this is likely to be a wordy post, but bear with me!  I will also try to supplement the post with drawings to help explain things better.

Firstly, I would like to start by thanking my husband for all the help and support he gave me throughout this project.  Without his help with the 3D modeling, I would have been so lost.  

That being said, while there are a lot of 3D printed pieces on this prop, I just want to say that it could also be achieved without 3D printing.  Several other techniques could achieve the gun and disc portions, but we wanted to put our little printer to the test! But regardless of the 3D printed pieces, this walk-through will still be beneficial (hopefully ^.^;) to anyone wanting to build Alisa’s God Arc!

Project Time Stamp: 200 hours

Step 1: Scaling the God Arc

Scaling a weapon to fit your height can seem intimidating, but I think my method is pretty easy.  I had a character model/figurine of Alisa in front of me, but as long as you can find a full body shot of her next to the God Arc, you will be good to go.  My method is as follows for scaling all props:

Your height in inches/character height in inches = The % of scale

The model/reference prop in inches X The % of scale = Height of prop in real life

So for the God Arc for Alisa, I added 3 inches to my height because of the heels I would be wearing, and using the formula above I came up with this a total length of 104 inches, because who wants to deal with .4 of an inch. The scaling was 8.7%. In actuality, mine was actually about 100 inches, or just over 8 feet tall.  Which brings me to a very important note.  All in all, this thing weighs about 30 pounds.  Which isn’t bad, except spread out over 8 feet it was nearly impossible to pose with; I had to keep it on the ground the whole time.  There wasn’t really a comfortable place I could lean it over my shoulder without risking damage to the prop.  So in short, scale with caution.  While I love the sword dearly and am so proud of it, I do wish I could have added more variety to my poses.  

Step 2: Building the Core of the Sword

1)In an attempt to keep the sword as light as possible, we decided on balsa wood for the core.

2)Balsa wood comes in 4 feet lengths, which is not long enough on its own for the blade of the sword (keep in mind the balsa wood is just for the length of the blade, the hilt will be PVC pipe, more on this later…)

3)We solved this problem by ordering 4 pieces of balsa wood, then sandwiching them together to create a longer board that was 2 pieces thick. We wanted to increase the stability of the joins, so dremeled out a shallow groove and glued in popsicle sticks. 

 4) Glue all the balsa wood together with wood glue, clamp, and let dry 24 hours

 5) Cut out slot for the PVC pipe.

6) Glue PVC Pipe lengths together.

7) Glue/Secure PVC pipe to the balsa wood.   I did this by dremelling shallow slots in each    side of the wood and using 3D printed bridges to have multiple points of attachment. **PVC pipe should be equally spaced on each side of the wood.

8) Now, the rectangular balsa wood is not very sword shaped yet…. Time to plan out where you want to dremel out the shape of the blade.  Structurally, it’s important to have as much wood as possible between the foam, so I tried to make minimal cuts and ended up with the blade shape I wanted.  The length of mine was such that the very tip of the sword ended up being just foam, but it held up very well.

Foam Smithing

1) I used two thicknesses of foam to achieve the details I wanted in for the God Arc. Each of the following steps need to be repeated for each side of the sword.

2a) Using 8mm foam, cut out a piece the will fit the entire length of the God Arc.  Cut out the area that will be the slot in the upper half of the sword, matching it to the size that was cut out in the wood.

2b) Using 10mm foam, cut out the bottom half of the raised part of the God Arc that has the “teeth."

2c) Using 10mm foam, cut out the top half of the raised part.  The distance between part b and part c should match the size of the hole detail that is in the upper part of the sword.

2d) Using 8mm foam, cut out a rectangle that will cover the top of the sword, bridging the details on each side from part C

2e) Using 10mm foam, cut out the shape towards the bottom half of the sword that the disc will set on.

This image is a little further along in the process but it demonstrated the above steps well

-For part A above, it will be laid down over the PVC pipe.  Dremel out a shallow hole anywhere the pipe will be to get it as flat as possible.  Mine still bulged slightly over the pipe, but it will be covered with other pieces of foam eventually.

-Glue all pieces on for both sides of the sword! I used Barge contact cement because it is wonderful for EVA foam, but if you have something that you prefer please use that.  The order I listed under Step 1 is the order that I found it was easiest to glue the pieces on. **Keep in mind the bottom half of the raised detail with the “teeth” should match up on each side.**

-After the glue has set for a few hours, you can begin any clean-up or additional detailing.  For me, this involved dremeling a slight edge along the blade and teeth, cleaning and evening up the hole in the middle of the sword, and filling any gaps or holes in the foam with kwik-seal caulking.  


1) Prep the foam for painting! Use what works best for you, but this method has worked for me for several props now:

-Blast the entirety of the foam with heat gun quickly.  Don’t spend too long on one area or you risk burning/bubbling up the foam

-Coat all foam in 4-5 layers of Mod-Podge

-Coat all foam in 2-3 layers of Plasti-Dip.  Spray on is preferable for an even coating, but paint-on also works.  

2)I tend to skip a primer because the Mod-Podge and Plasti-Dip work very well.

3)Because this sword has so many large, flat surfaces, I bought mini paint-rollers from Home Depot and they worked like a dream!

-Tape off the area that needs to be black and lay down all the red paint

-Let dry completely

-Tape off the red and paint where it needs to be black

-Weather as desired


-Seal-- I used a paint on gloss varnish from Liquitex on the red areas, and a matte varnish on the black areas.

3D Printed Portion

1)Assemble all pieces using super glue.)

2)Bondo seams where needed

3)Sand until you are happy with it or until your fingers no longer work  

4)Prime with Plasti Dip


6)Attach gun to bottom of “T” of PVC using super glue.

7)Attach hilt portions to PVC with Super glue

8)Attach disc to each side of sword using a pinning method and super glue.

The Monster/Organic looking bits!

1)Cut strips of foam into vague tentacle/tendril shapes.

2)Use super glue to place the tendrils anywhere needed.  Layer and curve and squiggle them around to create a organic, creepy effect.

3)To add to the organic feel, we used Free Form Habitat Black from Smooth-On, a two part sculpting epoxy.  I watched Frank Ippolito’s video a couple times to learn how to use it, but it was really easy!

4)Before the epoxy cures, put in the eyes on the top of the sword.  We 3d printed these, and the epoxy grabs right on to the plastic and they are really secure.  

5)You have an hour of work time to sculpt the Habitat.  Wetting your sculpting utensil in water makes the Habitat really smooth.  I just used the rounded bottom of a Sharpie marker and dragged it along the Habitat to make grooves and ridges.  

6)The Habitat fully cures after 16 hours.  Dry brush to highlight and seal!

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