I am a recent college graduated with a degree in Mechanical Engineering and in the recent months I have been neglecting my video game addiction. I started to play the latest game in the Bioshock series and I fell in love with it. I won't give out any spoilers but it needs to be said that the game is beautiful, and the story was compelling. I haven't made many props but I wanted to build something from this game. With so many options it was difficult to choose just one project. After seeing the toy making contest I settled with making the Barnstormer RPG. A few modifications can provide a truly unique creation.
Step 1: Purpose/Goal
First and foremost I wanted to create an accurate replica of the Barnstormer RPG from Bioshock Infinite and I wanted to make this build as easy as possible. This is my first prop build and I wanted to get my feet wet. I am happy with the end result and but I always feel there is room for improvement. This build will walk you through the steps I took to create my prop and along the way I will offer tips and design alterations I learned along the way. I would recommend this project to anyone and I feel that this build will provide many simple prop making techniques.. Enjoy.
Step 2: Bill of Materials
|Bill of Materials|
|Parts List||Store||Part Number||Unit Price||Number||Cost|
|2'' PVC Coupling||Lowe's||23282||$0.69||6||$4.14|
|2'' PVC Clean out Adapter||Lowe's||23302||$1.22||1||$1.22|
|2'' PVC Clean out Plug||Lowe's||23306||$0.69||1||$0.69|
|4'' PVC Cap||Lowe's||23927||$7.71||1||$7.71|
|4'' PVC coupling||Lowe's||23284||$2.11||3||$6.33|
|2'' PVC Pipe 2ft||Lowe's||256099||$4.42||1||$4.42|
|3/8 Soft Referation Coil 10ft||Home Depot||1||$9.44|
|Leather Fabric||Joe Ann Fabrics||50% Coupon||$21.99||0.33||$3.63|
|8.5x11x0.25 Foam Sheet||Micheal's||$0.50||1||$0.50|
|Steel Gray Paint||Hardware Store||$5.98||1||$5.98|
*Dremel with various attachments and Accessories
Sandpaper various girts
* I bought my Dremel over a year ago and I have been looking for any excuse to use it. After this project I highly recommend it to anyone. The accessories that came with my Dremel allowed me to many aspects of the project.
Step 3: Size and Dimensions
This step is here to provide general layout and dimensions of the replica. I have provided several stills from the game play as well as a few pictures from the art book and game guide.
To start the build I wanted something to give a general basic shape of the barrel. For me PVC tubing was the natural choice it was cheap, readily available in many sizes. That being said the barrel OD is 3''. PVC pipe is measured by ID. Listed below is the standard PVC pipe and corresponding OD.
See chart for PVC sizes.
As you can see there is no pipe with the appropriate OD*. My solution to this was use 2"" PVC pipe and add a series of 2'' slip couplers/ Doing this I was able to increase the OD from ## to 2.875'' which is an acceptable first try for me.
I need to grid away the inner ring of the couplers in order to allow them to slip freely over the 2'' pipe.
*2.5 is not common size sold in most hardware stores.
The rail underneath the barrel is 1'' tall 2'' wide and 18'' long with a 1/2 chamfer on the bottom edges. The last 2'' are tapered at a 30 angle.
The rail cradles were made from one 4'' coupler. The coupler length is reduced to 2.5'' with a chop saw and then cut in half with a Dremel cut off tool. The edges of the of the cradles are then taped from 2.5'' to 1.5''. A 1/4 notch is cut out of the rail and the cradles are are glued in place. Bondo was later used to fill in the cracks and smooth the surface.
Once all the couplers are cemented in place I applied Bondo on the joints.
When the dried I used the Dremel and sanded the surface smooth and flush.
I attempted two methods for constructing the coils around the barrel.
Use Clear plastic tubing and fill the inside with orange and red LEDs. I would paint the tubing with a transparent orange. Then when triggered the LED's would light up and simulate a glow heat from the coils. The radius of the coils was too small I had trouble getting the coils to retain their shape so I moved to method 2.
I found some copper refrigeration coil form Home Depot. I did a little mental math and found I needed approximately 10ft.
The refrigeration coil is soft enough that it can be shaped by hand with relative ease. It will retain its shape and my opinion looks awesome. It's like a giant copper spring.
The coil starts precoiled in the box. I took the coil and slowly decreased the radius by wrapping it around the 3'' PVC pipe. At this point make sure to twist the coil in the correct direction. Once a 3.5 diameter coil is obtained you can then start to space out the distance between the coils.
The rear cap is made from a 4'' PVC cap. This was one of the more expensive pieces take additional time during the following steps.
Using a Dremel I cut off the curved end of the cap. I believe there are four slots but there could be three. Each slot is 3/4'' wide and 1 1/2 from edge. Using a Dremel I slotted a square hole to slip the 2'' screw end cap.
I created walls for the slots using 1/8'' plywood. I purposely cut them oversize so that I could sand them to size later.
I have the art book, the game guide and the game play itself. I found all three sources insightful but all had differences . The colors look different among all three sources. Even in game the lighting shows many different shades. This is particularly evident in the top front of the gun. In the art book it appears red. In game it appears a little like copper or dark brown. Do I make it out of a copper sheet or a brown cloth? My engineering mind kicked in. If this was a real gun do I want it to have a copper top to act like a heat sink and draw heat away from the barrel or a piece of leather to act as a heat shield and protect the player. It would allow the user to move this piece without burning themselves. I went with the latter. It would be expensive and difficult to use 1/4'' thick leather. To work around this I went to my local fabric and craft store. I choose a 1/4'' piece of foam and cut it to size then wrapped it with a leather like fabric. I feel this method was a easier and cheaper to work.
I did some basic stenciling to the fabric to simulate copper etching.
The "leathe'' pieces were attached using 1/4' long screws and finishing washers.
With this project I wanted to try another common prop making material polystyrene. The material is again relatively inexpensive if you buy a large quantity and very malleable when heat is applied.
This is was one of my first times using the plastic so I will make this suggestion to you. Cut several small pieces and try heating the pieces by several different methods; boiling, baking and heat gun. I like using a heat gun because I am able to focus the heat by moving the gun back and forth.
In order to shape the top cover of the gun I heated the plastic and molded it over a Nesquik canister. The diameter of the curve is 5''.
In order to make sure the paint adhered I lightly sanded all the plastic pieces then applied Gesso to the entire project. Gesso is a common primer and base for paint.
I then spray painted the entire gun with a gray steel spray paint. Looking at the color now, I would probably choose a brighter color, either a silver or light gray.
In order to shaped the pistol grip, I printed a scale model and taped it a scrape piece of pine. I cut the top and bottoms with a chop saw and used sander and slowly shaped the edges. I secured the grip in place with two screws.
The handle grip was made with another scrape piece of pine. At the time I did not have a working lathe so I attempted to shape it with a hand sander. I plan on fixing this piece in the future when my lathe is repaired. It should be a round handle with a 1.25 diameter.
Step 13: Future Changes/General Comments
I had originally plan on this being a spud gun but after reading many spud gun comments I found that people generally find them too dangerous for children. That being said I have not added a ignition switch.The entire gun can be pressurized and rear cap can be removed to add propellent but a sparking screw will need to be added.
After I change a few details I would like to create a military shipping crate complete with the Fink Industries stenciling. I also found a cigar box that it very similar to the size and shape of the RPG ammo box.
I will be adding additional dimensions in the coming days please leave comments where you would like additional details and photos and I will try to accommodate.
I look forward to hearing all comments and idea suggestions. Thanks for reading and happy building.