How to Make a Portal Gun

This is how I went about making my own Aperture Science Handheld Portal Device.

Ever wanted to run around a death chamber in an orange jumpsuit but never had the means to think with portals? Well now you can give it a go; perhaps. This is just one of the examples I hope to use to get into the Props and Special Effects industry *wink wink*. Rate it if you like it please.

Step 1: Starting Steps

To start this, I needed to do some research to get some good views of the Portal Gun other than the POV postion behind the device. These three pictures taken from the internet were the best examples I could find to get an idea of what the whole gun looks like. The first image is an artist's impression which is fairly accurate so I used it as my scale drawing.

Assuming the gun would be approximately 500mm in length, I scaled the first image up in Microsoft Word and then just drew lines to find measurements to get an accurate model. Then using the other screen shots, fill in the details.

Step 2: Tools & Materials

This project took the best part of a month and used a variety of tools, skills and materials. The most annoying part is that every aspect of the build is bespoke, apart from the paint so takes a far while to put together. So here's some of the main things:

Tools:
Drill press
Router
Lots of hand tools
Scalpel
Hot Glue Gun (lots of hot glue!)

Materials:
Various wood
Exercise mat foam
Folder plastic (like an A3 art folder)
5Litre paint can
Chicken Wire
Clay or plasticine
Wire coathangers
Newspaper & PVA glue
Various paints
Wood filler (this stuff is vital!)

Step 3: The Main Barrel

It all starts with the barrel of the device. This measures up to a cylindrical tube 75mm outer diameter and about 300mm long. A decent bit of wall thickness helps for stiffness but isn't critical. Home drainpipes are just around the right size if you can get some. I didn't want to spend the money so had to use a toy plastic tube which I had to thicken up with several layers of newspaper and glue plastered on. I also mixed some black paint into the glue to save some painting effort later.

Everything is then built onto this barrel, starting at the front. Cut out a suitable sized piece of foam and hot glue it around the barrel to build up the shape. I used an old exercise mat about 8mm thick which was easy to cut with a scalpel but also meant it damaged easily and deforms if in contact with the glue gun nozzle, so be careful! Shaping the front piece of foam is done carefully with a scalpel, it'll get tidied up later.

Step 4: Building Up

Now we're building up the profile of the model. This part was made from 18mm plywood shaped out with a router to get a 100mm disc. Drilled a hole in the centre of the disc and screwed a bolt to it so I could but the disc on the drill press, get it spinning and use a file to shape the radius on the disc. Then used the router again to cut out the centre and form a ring with an ID of 75mm (to slide over the barrel) and OD of 100mm all shaped nicely. If you have a big enough radius bit for the router, you can use that, or just painstakingly sand away the shape.

A ring is shaped out of foam from a kneeling garden mat which was thicker and stiffer than the exercise mat. Hot glue the two together and then hot glue the ring onto the barrel.

Step 5: Getting Tricky

The next section of the gun is a bit more work. It isn't a straight cylinder anymore but an oval which was about 130mm on the curves and 30mm on the straights with the 75mm hole in the centre of the top. Two identical shapes were cut out with a router from 6mm plywood and then wooden blocks tacked in between with nails to get the right thickness.

Slide it onto the barrel and hot glue it to the foam ring and the barrel. Lots of hot glue to hold everything together.

Step 6: Under Belly

This forms the skeleton of the underside which later gets a skin. The shape is the bottom half (well more than half) of the previous part, so the bottom curve and the straights, cut from 6mm MDF and repeated three times. A hole was drilled through all three and a dowel measuring the rest of the length of the barrel (about 160mm) poked through and more hot glue.

Step 7: Adding Detail

The wood sandwich is the basis of the windowed section of the gun. The wood is skinned with a thin plastic cut from an old A3 art folder (the folded black type with a handle and clasp). The plastic is easy to cut with a knife and is stiff enough to hold shape.

A rectangle of plastic long enough to cover the top curve and half as wide is cut out. 9 slits are cut so the plastic can fold alternately between stright and L-shaped to form the windows. Scoring the back of the plastic helps it crease nicely. Another strip of foam was glued to the barrel underneath the plastic to give the depth. All the folds are hot glued down so they stay put.

Step 8: Skinning the Underbelly

A suitably large piece of folder plastic is cut out to go around the curve, up the straights and over the top to form a ledge. Hot glue the whole lot together again.

The big cylinder at the back end of the gun is about 165mm in diameter and 200mm long, which is about the size of a 5 litre house paint can (which I found in a skip). After you've cleaned it out, cut a 75mm hole for the barrel to slide into. Again, it's not centre but is relative to the oval shape being in the centre of the can. I cut it out by drilling lots of holes in a circle and punched it out.

Step 9: More Detail

Two thin strips of foam were stuck to the side of the barrel and shell to add detail and little triangles of foam underneath the plastic window bits to fill in. You can use clay or plasticine instead. A hole is also cut out of the barrel for the clear window section to go in later.

A big disc of the kneeling mat foam was cut and tapered to the diameter of the paint can and stuck onto the bottom. Make sure to cut a hole in the same place on the foam as the can for the barrel to slide through. The top of the can (the back of the gun) was cut off to bring it to length.

This is where wood filler is invaluable. I used Ronseal Wood Filler which spreads on like a putty and sets hard. Go over the whole model and fill in any divots or gaps or uneven transitions with wood filler. This is crucial around the parts cut with the scalpel to smooth it out and lose the jagged cuts. Take time with this as it is where things will all smooth out and look neat. Sand it down with fine paper so it's nice and smooth for painting.

Step 10: Undercoating

I painted the whole thing with a few layers of brilliant white gloss house paint. House paint is thicker than spray or acrylic so covers up many sins and mistakes but it does take ages to dry. After it's dry, you'll have one model completely covered in a layer of paint.

Step 11: Making the Shells

This is a tricky and intensive part, at least it was the way I did it. The front handle shell was shaped from wire sheet, cut to shape, bent, and then cuts made at the front and back so the sheet can be bent over itself to form the curves. A few bangs with a hammer smoothed out the curves.

The large shell at the rear is made from chicken wire cut to shape and bent like before to make the basic shell.

I used pieces of paper to find the shape I need and made sure they fit around the paint can and the front section. I've added the patterns I used to make the shells. Sketched out mostly by eye. The front shell is on A4 and the back shell is on A3.

Step 12: Papier-mache the Lot

With the front shell, I built up the shape with plasticine to thicken the shell and add depth. The big shell didn't need it so was left as wire. Each shell is then coated in several layers of newspaper strips and a mixture of 50/50 PVA glue and water. You could use fibreglass resin if you wanted extra strength but the newspaper is just as good and readily available. Use small strips of paper to prevent creases and cover evenly with the glue mix using a paintbrush (just like in Art Attack). This is particularly crucial on the large shell to get a smooth curvy finish. Cover the handle shell on both sides but the big shell only needs covering on the outside.

Step 13: Smooth and Paint

The big shell wasn't smooth enough for my liking so I made up a Polyfilla mix paste (like they use for walls) and spackled the whole shell to fill in the dips and smooth the shell. Use a palette knife to spread the paste and then a wet knife to smooth things over, or just wet your hand and run it over.

Then paint both shells with the same brilliant white gloss paint used for the main body for a nice shiny white shell. You could save yourself alot of trouble if you have sheets of acrylic and a heat gun to mould the plastic into shape.

Step 14: All the Extras

These are the little details that make it look the part.

Picture 1 is the hole for big shell made from several strips of paper wrapped tightly round and glued. The paper coil is then staggered to get that chamfered look. More wood filler is spread to smooth it out and then a hole is cut in the big shell and the paper cylinder hot glued in.

Picture 2 show the arms that point over the front of the device. The arms are cut from wood and lap-jointed in place. The front of the arms sandwich the main arm and come to a point after some whittling (see Picture 3).

Picture 4 shows the cables made from some tube with coathanger wire inside to allow shaping and stiffness. The little black wire things are just that, made from coathanger wire. Each one is four identical lengths of wire with two bent into C shapes and then stuck to the other two lengths (see Picture 5).

Picture 6 is the little turbine like disc you can sometimes see inside the gun barrel when it's lit up. Just a piece of cardboard with foam inserts stuck on and the centre cut out. Then all painted two-tone grey.

Step 15: Finishing Touches

Unfortunately not many photos of these steps, but it's pretty obvious. The whole model is sprayed black and a hole cut in the paint can for the hole in the shell to poke through.

Holes are then cut in the front shell and top of the windowed section for the arm thing, tubing and black wire thing to poke through and all glued into place. The top arm on the windowed section is off centre in placement and is further over to the right.

Poke the other end of the tubes into the plasticine sweet capsules on the big shell and glue in. Then glue the shells to the main barrel. The hole cut out of the barrel is paned with a sheet of clear plastic inserted inside and stuck down and you're done!

Step 16:

This is the finished product now once everything is stuck down and painted on. I haven't had a chance to make it light up orange and blue as I didn't have an orange LED or an orange filter. Perhaps later I'll modify it with sprays for parafin and potassium chloride meths to make orange and blue fireballs instead.

Improvements to be made? Thanks for reading!