To start of this years prop making I decided to begin with an ambitious project to build a full sided Fatman from Fallout 4. Despite looking simple at first glance, the Fatman is quite complex and so I first made a blue print using reference images form the game. Thanks Bethesda for your in game model viewer 🙂

Since this is a big project the write up is also quiet large. As not to fill the page with a hundred build pictures I have only selected some of them to show progress. I have also split up into 2 parts. This first part will cover the construction of the main body of prop. The second will cover the construction of the mini nuke cartridge and painting. They will all be available as a slide at the end.


To give it some strength but to also keep the weight down, I planned to construct it from foam ex (foam PVC) with a lot of hollow sections. Some for the details would be made from 3D printed parts, various metal nuts, bolts, grub screws, screws and acrylic rod.

I started with the back and cut out the sections of the blueprint to use as templates and started to build up the structure. Some details such as the vent and rods were added. The rest of the details, such as knobs and screws would be added later.


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I moved on to creating several different assemblies that would attached to this and make up the Fatman. These were designed to slot together to provide more strength to the structure.


The shoulder rest on underside was made from a hollow box mounted on top of another. To created the sloped sides I used some body filler with a flat metal applicator. When dry, any low spots were further filled and then sanded to create a flat surface.

I then created the first version of the front grip. More on this later

 20170226_150247.jpgAlthough the prop  wouldn’t fire I wanted the trigger to move. I began by making the section of the body that would hold the trigger and grip, leaving a gap for it to slot into. I then worked out where the trigger needed to sit and how I wanted it move. With this done I inserted a rod though the trigger and then milled out 2 trenches to form a cradle for it to sit in. When I was happy with the movement I used some plastic to keep it in place. A spring was the attached to the top of the trigger and body of the weapon.

 The the grip was made from foamex and styrene. The textured panels on each side were also made from foamex. When cut out I attached a template to one side and used a blunt object to trace the lines onto the foamex. Then using files and sandpaper I defined the lines. These were then attached to the sides.



The trigger/grip assembly and shoulder rest were then all joined together by a strip that runs under the main body. The end of this was formed into an ‘A’ shaped loop using a heat gun.



This is the front grip assembly which slotted onto the end of the drive shaft and main body. The grip was made from foamex which flexed a little too much when handled. To make sure it wouldn’t snap after the prop was finished, I remade it using my 3D printer.



To create he holes that run from one side to the other of the  ‘boat hull’  front section, holes were drilled in the sides and small plastic tubing was inserted. This also added some strength to this front section since it would be hollow. The circular indents on the top and bottom were cut out using a sanding drum mounted in a drill press. A piece of foamex was then placed on the inside. This would be further built up when attached to the other sections.



All the assemblies were then glued together with a lightweight wooden dowel being used for the ‘drive shaft’, which provides a lot of  strength to the body of the Fatman.  Further supports were added down the length of body to provide even more support. To cover this and to provide a base for the rail to sit on, several strips were glued on top. This was then followed by the rails.


Before adding any more parts, the whole thing was sprayed and any unwanted gaps were filled. This was repeated until I was happy with the finish.


Details were added using styrene, 3D printed parts, acrylic rod and screws. The cylinder with the tube coming from the top was a printed part with styrene strips glued around the edge. I did this for all the knobs as well as the gears that go into the opening near the back.  These could have been part of the print , but I enjoyed finishing of the basic forms myself.


The ‘skirts’ or ‘baskets’ on the top sides of the Fatman were made from 2.5cm styrene. This is able to keep it’s shape well with holes cut in it and is easy to bend when heated. When done, these would slot into gaps I have left in the body of the Fatman. The blueprint was used as a template for these. I had to account for the the fact that the side view doesn’t accurately show the height and some to slot into the gaps.


The sides were first cut out on my band saw and were attached together using double sided tape. Using the template as a guide I first drilled a hole in each section I wanted to remove. This allowed me to put my scroll saw blade in and cut out the pieces I didn’t want. The raised sections were added using more styrene and 3d printed screw details. To finish I filled any gaps I didn’t want and used files and sand paper to tidy up the edges.


In order to curve them, I bent a section of sheet aluminium to provide a solid base to shape the plastic around. This worked on for the two smaller back pieces, but not for the front. Heating it a bit at a time and with all the small holes, this lead to some warping which was a lot of work to straighten out. Next time I may shape the plastic before cutting the holes or try and work out how to heat the whole thing. This is all part of the learning process. These were then slotted into the gaps in the sides. I must thank my fellow Prop Tart Facebook members for their tips on forming plastic. More practice and experimentation will be needed.

A plastic tube was used as a base for the gas tank. The lines around the tube were created by using my lathe; I just managed to fit it on. The tray which the tank sits on was cut out and formed around the tube. I had the same trouble with this warping and had some real trouble getting it flat to the tube. As you can see below this had to be screwed on and looked a mess. I did manage to fix it with some filler and filing it to shape which added to the build time. I worked out the length for the restraining straps with extra to attach it to the body and assembled them form foamex and syrene. After this the straps were heat formed around screwed in place. The dome on the end was 3d printed and glued on. The cap on the other end was also formed from foamex.


I used acrylic rod for the piping  which was slowly and carefully heat formed. Doing this too fast could cause the bends to flatten or bunch up ruining the look.


The images below show a little more of the build process and details. Part 2 will cover the construction of the sled and painting, along with some more thoughts on the build.

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