Black Rock Shooter TV Version Rock Cannon

The title says it all.

So this is my attempt to make this cannon.  I started with the figma figure and then to get the proper LED placement I got some pictures of the anime.

So with that I decided let's do this thing.  Now I wanted this to be around 4 feet long.  So I started my blueprints with that length in mind.  Problems I found is that the barrel of the gun has 3 different widths to it and I like to use cardboard concrete tubes to use in this construction.  but with that I would go from 8 inches to 10 thenn 12 inch diameter this thing would be huge and would not look right.  So after some digging around I made the front part of the barrel out of 7 inch diameter stove pipe.  I cut it down to 24 inches and then got it set up

Next I added some foam sheets that I had cut out the pattern in.

Now I doubled up some 1 inch hard pink insulation foam and made the front part of the cannon.

Now to make the wider part of the cannon I went back to my old standby cardboard concrete tube.  i added some cardboard to each end and then marked off and cut out each slot.  Then I added a layer of foam sheets with the slats cut out.

Now a test run fit.

Now on to next section more concrete tube a make shift template and fresh exacto blade and here is the result.

Dry fit test.

Now the arms.  So I'm trying to make this as lightweight as possible and I just picked up a handy dandy hot foam cutter so I figured let's try this bad boy out.  here are the 3 arms in rough cut.

So I sanded those bad boys down and added some thin plastic to the sides and top.  unfortunately I have no pictures of that.

So The back piece is made out of double cardboard and craft foam. 

Now for the handle and the insides.  I used a 4 inch pvc pipe for the back part of the handle because whoever designed this didn't think of real world practicality, (crazy an anime that is not grounded in reality)  so where the person holds the gun it needs to be at the tail end and the only way I could get it stable enough was to run a smaller pipe down the center of it and have it attach to the front metal part of the barrel.  So this way when you hold  it from the back it will stay straight and it will be sturdy.  So for the insides I cut 2 round MDF discs that would slide down the gun and fit perfectly into the front part and the back part would be wider since the tail end of the gun is more wide.  I'm so glad I figured that out before construction because I might have lost the rest of my hair on having that fail. Also for the 2 light up parts I drilled a total of 8 holes in the long pvc tube 4 in each section that light up so I could place the led's there.  I used a total of 12 leds 4 for the front 4 for the first light up part and 4 more for the final light up part.  i also had a on/off switch located at the back of the gun and I placed the battery holder near the the grip and out of site.  Phew here are some pics of it.

Ok after that I gave it several coats of primer paint and then I went with a flat black and then a spray of textured black paint before I sealed it with a satin acryllic sealer.  After that I added a thin piece of translucent plastic to the inside of each light up section to help diffuse the light and give it a nice glow instead of individual lights look.  I also crafted a front translucent piece with ridges and a pattern to give it a little better look.

Here is the final product she stands at 50 inches tall and weighs in under 5 lbs.  I'm pretty happy with it.  This one took a couple weeks to build but it did involve a lot of head scratching.

So there it is.  This is a fun project and I think I have made up to 4 of them now.