STARtech Glow Round for Air Cannons

About: My name is A.J. Petersen. It is my mission in life to introduce Protection Suit Technology to the world. I am going to do this through a line of suits. An ever-growing un-halting monument of technology and ...

STARtech is a creation of mine. You can find a few extra pictures and a video on my website (look in the WeirdWorks section of the site!) =)


STARs are specialized rounds I have created for loading into air cannons.

They contain a very simple electronic assembly that makes them glow very brightly at night. When loaded into an appropriately sized air cannon and fired into the night sky, they look like stars, hence STARtech!!

***This particular instructable deals with STARtech rounds that work with 1.5" schedule 40 PVC barrels. Though any size needed can be made with a little creativity!!

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Step 1: Tools and Materials


DREMEL for smoothing the finished product.

RUBBER MALLET for soft but firm "encouragement."

LARGE DRILL BIT creating the cavity inside the round.

WIRE CUTTER for trimming wire.

NEEDLE NOSE PLIERS for fine work with the smaller electronics.

PLIERS for clamping the round while you hollow it out.

GLUE GUN for creating the round and sealing it up afterward.


TUPPERWARE CONTAINER for holding the Plaster of Paris mold.

ELECTRICAL TAPE for wrapping the CAST round before making the mold.

DEPLETED CO2 12 Gram this is the object you will be casting the round from.

GLUE STICKS you will need 6-8 at least to complete one round.

A23 battery. This is a tiny 12 volt battery more powerful and cheaper than other batteries out there. You can get a pack of two for $1.19 at some stores. Or just snag one out of your garage door opener!

SPDT Mini Slide Switch turns the round on and off.

LED you can get one of these at any radioshack, pick a color you like. For my STAR I chose blue.

ELECTRICAL WIRE you will only need a tiny length to connect the SPDT switch to the LED.

VASELINE acts as a release agent in the casting process so you can get the round out easily.

Q-TIPS helps spread the Vaseline evenly so you don't have any irregularities in your casted round.

PLASTER OF PARIS mix with water and pour into the tupperware container. This will be your mold for pouring hot glue into.

Step 2: Electrical Component Scheme

The A23 Battery fits into the "N" Battery holder (Radioshack). One wire will be attached to the 12 VOLT RESISTOR, which is connected to one end of the LED. The other wire from the "N" Battery holder will be connected to the SPDT on/off switch. The other end of the LED is connected to the SPDT on/off switch, creating a complete circuit. 

The electrical component goes inside the round. So you really need to make it as small as you can. Pretend that the "N" Battery holder is a little man. The LED is his hat. The on off switch are his shoes. They go on opposite ends and stick straight out.

** You may want to buy duplicate parts as it can be very difficult and frustrating working with small parts like this. You may want a magnifying glass, and tweezers and maybe a friend to help you out.

If you're like me though, sufficient swearing and endless patience should get the job done just fine!!

Step 3: Making the STARtech Round

The round casing is made of hot glue. You will need to make a cast first. You will be using the Depleted C02 12 Gram and plaster of paris to do this. The glowing electronic component goes inside the casing.

First, you need to wrap the end of the 12 gram with a lot of Electrical Tape. This will create a stopper that will help the round fit in the barrel better and catch more air, creating more force.

Test to make sure you have the right amount of electrical tape before you make your cast.

Insert the cast round into the plaster of paris with the round end pointed downward. If needed, you can attach a wire at the tip to hold it in place while the plaster of paris hardens.

It will take a few hours for the cast to harden.

Wiggle it very carefully and use the pliers to lift the 12 gram out.

After the 12 gram is out you might want to leave the cast in the sun for a while to make sure it is dry.

When you are ready, heat up your hot glue gun while you coat the inside of the mold with vaseline.

Fill up the mold cavity with hot glue until it almost reaches the top. Wait for it to cool. It will be very hot. When it is just starting to harden, stick a q-tip or a screw into the cooling round. This will be a handle to help you lift the round out of the mold. (or you can just break the mold to get it out and make another casting after) You are going to hollow out this area anyway.

Once the round is out of the mold, hollow out the center about 2/3 of the way in carefully with a drill or a small knife.

Once there is enough room, insert the Electronic components. Make sure the LED goes in first, and the On/Off switch is sticking out the back.

Seal it up with hot glue.

Sand or trim and make sure the round still fits in the barrel.

Step 4: Load and Fire

Load the round, and fire it straight up into the night sky!!

The round should be pretty sturdy if you connected the components well and the casing is thick enough. It's best to fire in a grass field or at the beach anyway just in case.

It's a pain to open it back up to fix something that got knocked loose so be careful where the round lands!!

THANK YOU FOR CHECKING OUT MY INSTRUCTABLE!! If you liked this, please check out my website,


I will do another test video soon and upload it here, stay tuned!!

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    20 Discussions


    5 years ago

    why not try mixing in glow in the dark paint instead? it would save a lot of time in hollowing it out and save money in materials


    5 years ago on Introduction

    No offense, but the cannon seems to be pretty weak...have you thought about just increasing the psi? The STAR ammo is very cool though. I've been working on my own that is very similar actually

    Josef Lister

    6 years ago on Step 4

    May I ask what happens when the AA runs flat. Do you have to open it up, replace it and cast it again. Do you just make a new one or is there another way to remove it? Thanks, I think its a really good idea. Its like a tracer round but for a potato gun :-)


    7 years ago on Introduction

    do you have a 'ible for the cannon. i would love to make on of those


    7 years ago on Introduction

    You could use a plastic pipe for the outside and the inner wall. It would hold together better and allow you to easily replace the rubber tip or to fix the internal circuits


    9 years ago on Introduction

    Seconded that hot glue isn't a great material because - friction = heat = melted glue on your barrel.  Barrel lube is almost necessary if you use this regularly!

    I made one out of a super-high-bounce ball that PERFECTLY fit the barrel taped to a glow stick tail.  Wasn't bright enough.

    A good material to use would be the 'compressed' polystyrene ible - melt styrofoam in a solvent (gasoline, mineral spirits, whatever)...mold into your shape while its still pliable.  It hardens DAMN strong.

    1 reply

    Reply 8 years ago on Introduction

    make it out of hot glue, but wrap it in clear packing tape- problem solved


    9 years ago on Introduction

    This is going to sound like a joke, but couldn't you use a Condom for a mold? I don't know if it would melt, or what.


     why not just use a piece or barrel pipe with a end cap in it for the mold, other than that cool, i might try to put a removeable led throwie in it though

    2 replies

    9 years ago on Introduction

    Thanks for all the comments everyone!

    I was wary of using hot glue when I first had the idea, but then I took a second to really think about it... If you drop hot glue on paper, it doesn't catch fire does it? That's because paper burns at about 450 degrees (or 451 if you like that Novel).

    So I did some research, and found out that my hot glue melts at about 400 degrees Fahrenheit.

    I dare you to get a little slug like that to get up to 400 degrees while it's being propelled out of a smooth plastic barrel by cold air at about 130 MPH!!

    It's very tough, cheap, and no, it will not melt. =)


    9 years ago on Step 4

    Wow thats great. Better than sticking a glowstick in a potato.
    Too bad I retired all my cannons. Maybe I'll have to build one now


    awsome rounds, suggestion for someone below....put some lubricant to prevent sticking.

    have i seen you on spudfiles?

    1 reply

    9 years ago on Introduction

    1) this sounds like fun
    2) i really need to own some (any)  land so I can do things like this
    3) hot glue, wow, props on that, i would have used clear drying epoxy

    That's not a robot!! I'm a robot!!

    Seriously though, that is a Prototype Mock up Exoskeleton I'm building in my garage. I've been working on it for a long time but am slowing down a bit because it's expensive.

    You should check out my website if you want to know more about it. Click on WeirdWorks and scroll down, it has all the progress pictures and some back story.

    Glad you like it, thanks for the comment!


    9 years ago on Introduction

    Thank you! I'm glad I could help you! I've actually been thinking about making the rounds with a different filler material like you said. So far I've only done wax, which is great. I was thinking some sort of ready to pour plastic that would harden on its own.

    I have a case of hot glue refills to go through first though! haha.

    Your method sounds very inventive and cool Tommyhzy!! You should do an instructable on it! Many people just assume that frozen liquid can't be used as a projectile but they never think about air cannons do they? So cool that you found a ready made casting with the yoghurt containers!!