Making a Paper Flamethrower

Today's project: make (or actually, figure out how big this thing is) a Team Fortress 2 pyro flamethrower out of Magic the Gathering cards and 110 lb cardstock. It would also be a good opportunity to document how one gets started on making one from scratch.

First, each weapon starts off with a side profile reference image. Each image is scaled to 1:1 scale for a 1:6 scale figure. Since there isn't much in terms of a reference length to use to determine the entire size of the object like there was for the saws, blutsauger and sniper rifle, this one was done by relative length. It appears the flamethrower in this case has a length approximately equal or exceeding the height of the pyro. The scientific method of "taking the figure and holding him up to the screen and zooming in until the size was about right" was used. For other cases such as modern firearms, my rule is to scale the handle/grip side profile width to 7mm and thickness to 4mm.
This is the scaled image. I used a really bootleg method of holding a sheet of paper to the screen and tracing the outline of the flamethrower. Sketching lightly helps, since it's an LCD. You'll get the following image with a light trace. The top and bottom traces were used as comparisons since I refused to believe the flamethrower was so long. The bottom, larger image was used.

Once the trace is made, the 2D side profile sketch is fleshed out in details, then dimensioned for reference. I try to minimize the need for inferred dimensions, but most of the dimensions get finalized on the fly as was the case for the hose and gas pump handle.

The process of making the parts begins with breaking down the model into primitives. The above picture shows the bottom tank, the weird muzzle thing on the tank, the pipe for the flamethrower, and the lighting mechanism. Each of these individual components can be classified into two groups: extrudes and revolves.

Revolves are my favorite. Roll paper around a stick until it's thick. Pipes, barrels and other round objects fall into this category. For conical shapes, I covered making those earlier with an excel file. The flamethrower is 90% composed of revolved objects.

Extrudes are the other, less fun part. These consist of boxier objects made thicker by adding thickening walls or additional laminations. Lots of tracing and cutting are involved, easily handled by unskilled slave/child labor. Since I have neither handy, I have to do it myself. The gas pump handle was done by tracing the outline, then transferring the shape to cardstock. Two halves were cut, with thickness added by putting some U shaped beams to make walls for the "box". There's a lot of structural support needed to keep the extrude from collapsing in itself in the centers for larger objects. I prefer using tubes with diameters of equivalent thicknesses.

Each part then gets some sanding to smooth out where sheets overlap and to make parts easier to paint. Since it's a bit freehanded, no two copies I'll make will be the same (assuming I can be bothered to make a second one). The finished model can be found in the following image.

Overall length of the flamethrower is about 12".

Celebrating the completion of the flamethrower with the pyro taunt. Since the flamethrower is done, I might make him next after the sniper gets his pants and vest. I should probably also get a photography area/box for my desk so less questionable objects are visible in the photos.

On a side note, the rocket launcher and sniper rifle are painted. The soldier is officially completed.