How to Make a Portal Gun.




About: Im a model maker who makes film and game props in my spare time. If you like my work please visit my blog it has more work. email me at backwardsprops @ gmail . com (with out the spaces, stops...

This is how i made my portal gun for halloween 2011.

it is one of many way that you can make a portal gun. i made it this way because my experiances with these materials were higher than any other method. 

Ive entered this to the Hurricane Lasers Contest, if you like it enough could you please vote for me at the top of this page.. Thank you in advance. :D


Step 1: Materials

Blue insulation foam for the main shells of the gun.

the barrel and body were made from PVC pipes at 110mm and 70mm  and one clear 65mm tube. also a solid clear acrylic rod at 20mm

plastic acrylic sheet for detailing parts.

three black cables (thick electrical cable is fine) and wire to put inside.  or three wire core foam wrapping strips (like the hair curling things. i found mind at a general store or DIY store)

for the electronics i had two bright blue LEDs and two red LEDs (shoud be orange but i didnt have any) a three way switch, an assortment of wire and a 9volt battery.

emulsion paint, filler primer spray paint, plastic primer spray paint, lots of white spray paint and black spray paint.

car body filler (most commonly called bondo) i used P38 polyester filler.

Glue! lots of glue ranging from two part epoxie and super glue.

also masking tape.

Step 2: Tools.

the tools used for this project were:

belt sander, jigsaw, hacksaw blade and lots of craft knifes.

losts of different grade sand paper: corse to very fine.

soldering iron for the wiring.

lots of clamps.

Step 3: Shaping the Two Shells.

stick the layers of blue insulation foam together and draw on the out line of the shells.

Then roughly cut out the side profile then the top.

Then use a belt sander to bring the blue foam closer to the shape of the back and front shell.

then draw a thickness of the shell and carve out the inside of the shell to hold the rest of the gun.

then paint the shell with the white emulsion to seal the foam from the filler and the paint which will eat the foam if not sealed.

Step 4: Barrel

cut two rings out of the acrylic to create supports for the smaller PVC tube with in the larger.

then trace the cut out shape on to the larger tube and cut it out.

place the smaller tube inside using the ring supports, making sure there is enough of th smaller tube out front of the larger to create the barrel of the gun.

then trace the same shape on to the smaller one and cut it out, matching up the cut outs.

glue it all together.

add a PVC coupler to the rear for the handle.

fill the gap between the two tubes and sand it all smooth. then carve in the vent shape at top front of the opening of the hole.

Step 5: Barrel

place a hook connector made out of acrylic on the top of the fron barrel section.

spray the plastic barrel with plastic primer then normal primer to get a uniformed finish and sand down lumps and uneven sections.

do the same with the front and rear shells. if there are any uneven sections/ dents in the parts fill and sand again untill you get to the finish you want.

test fit the barrel in the two shells to make sure it all fits together.

cut out and construct the claws out of acrylic.

tyhe last pic shows me showing the claw for size comparrison.

Step 6: Barrel

cut out three rings for the barrel end.

first ring is a larger thicker ring for the rear of the barrel. chamfer one side to the thickness of the second ring.  (see photos)
the second and third rings are the same size but the third is chamfered to the front of the barrel.

paint and fill to make them smooth and space them evenly on the extended barrel (smaller tube inside larger barrel)

then paint the whole lot with black spray paint. i used matt but it can be gloss.

Step 7: Finishing the Shells.

spray the shells with filler primer and sand them to a smooth finish.

insert two hook mounting points into the front shell.

add the three small wire emmiter points onto the rear shell. the emmiter points were made in the same was the shells were.

spray them both flat white.

then add some decals for the portal branding. this can either be done in hand painted through a stencil or cut out of vinyl stickers.

then spray a gloss coat over all the shell and logos to give it a great shine and to seal the decals.

Step 8: Lighting.

wire the LEDs and resistors to the three wat switch with the top position being blue the middle being off and the bottom being the orange.  

when all has been connected wire the battery socket and the lighting system is done.

take the solid 29mm acrylic bar and sand with a rough paper to make a diffuser. this is what the light will be placed at the end of to give the glowing portal chamber.

inside the clear 65mm tube the light bar is held by two more acrylic discs and on them are some detailing (in the pictures i have used two large format printer spool ends.) but use whatever you have to hand.

wrap a small amount of tape (preferably black) around the clear tube with the light bar inside at the end points where the support discs are. make sure the discs are wide enough apart that when in the main gun tube they are just inside the tubes and not visible.

Step 9: Assembly.

place the clear tube assembly inside the main barrel of the gun and glue it in.

glue the LEDs onto the rear of the diffuser and affix the switch somewhere inside the handle assembly where it will be easily reached by your thumb when holding the gun.

glue the front shell the the barrel assembly so the peak of the front shell is at the same level of the front barrel.

drill two holes behind the hook mounting points. into which glue the wires.
on the top of the barrel behind the hook mounting point drill a hole for the wire.

in the wire emitter points on the back shell drill holes where the wires will be placed.

glue the back shell onto the rear of the gun and drill down through the top hole in the rear shell. (20mm) for another section of the solid bar to be placed to bring the ligth up to the top of the gun. (make sure the main diffuser bar comes back to the same point as the top down bar reaches the lights so that all the light will be used.

once all the glue has dried and set glue the wires into the rear shells and let them set.

now add the front claws onto the mounting points and posision them correctly.

Step 10:



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    97 Discussions


    1 year ago

    My username Spelled backwards is xXThe_Nerd_KingXx


    2 years ago

    great job with this prop!


    2 years ago

    hehehe your not supposed to look down the front end of the divice


    2 years ago

    Hey! Thanks for the tutorial! Im a little confused as to how to connect all the wires to make them light up, I have an on/on switch, 2 large orange LEDs and 2 large blue LEDs and a 9V battery, how do I wire them so the on/on switch will toggle between the orange and blue LEDs while the battery is plugged in? Im not sure what your switch and LEDs are encased in but mine are just stand alone.


    2 years ago

    what's the estimate cost for this project in USD? i've got a budget of $30

    1 reply
    backwards lambthesquidguy78

    Reply 2 years ago

    I'm pretty sure it was more than $30 but I guess you could use techniques from this to make one for $30

    I don't know the actual cost as it over 4years ago that I built it


    2 years ago

    hi can you explain what you did in detail and how you connected things and made a shell out of some insulation foam? because otherwise I will be stuck with my equipment and it will turn out that I used my money for nothing and that will not be accepted.

    1 reply
    backwards lambAarav2007

    Reply 2 years ago

    I'm not sure what you want? This whole post is how I made it in detail

    I carved the insulation foam with a hacksaw blade , craft knives and sand paper. I glued three layers of foam together, like is stated in the steps about the shell. it is all connected together with glue I glued the shell onto the tubes. Theres not much more I can tell you other than the steps that are in the instructable.


    3 years ago

    nice project, ii intend to to do it some time


    3 years ago

    Hey! I really like your project, and i want to try it, can i ask you the density of the foam that you used in that project?


    3 years ago

    these really are amazing! I don't think I could create one in any short amount of time that I would have the patience for. And the same question as GLaD0SA, do you sell these?

    1 reply
    backwards lambLightTrainSTEM

    Reply 3 years ago

    I don't know, I have no idea how patient you are or how fast you build. You could Defoe make one relatively quick if you find a faster way to build the shells they were the most time consuming thing.

    And no I don't sell them.


    3 years ago

    Where did you get the claw things on the front? I was also wondering if you sell these.

    1 reply

    3 years ago

    Where do you get the PVC pipes :o?! I only get 75mm ore 63mm pipes, not 70 and 65 :/... Thank you for this instruction ;)!

    4 replies
    backwards lambHimbeerT

    Reply 3 years ago

    hi, i got mine from a plumber friend but if you google you will find lots of online sellers, or you could try a plumbing hardware store. they dont have to be exactly the measurements i used something close will be fine.

    The sizes i used are UK sizes the ones you quote are conversions from inches 75 is 3 inch and 63 is 2 1/2 inch.

    backwards lambbitzndprops

    Reply 3 years ago

    The three front rings on the barrel were made from layers of 5mm Perspex. The large rear ring is 4 or 5 (I can't quite remember) layers with a sanded edge to give it the chamfer and the other two smaller rings we 3 or 4 (depending on how many you make the large one) layers of 5mm Perspex and one of them had a sanded side to give it the chamfered edge to meet the barrel of the gun. Hope that helps.