Introduction: Flying Film Canister With a Twist!!
We made flying film canisters before, click here to see our Kid Friendly Film Canister Rocket, but we thought we'd try something more intense. In our fourth grade class we use "exploding" film canisters to demonstrate how an explosive volcano builds up pressure. In our eighth grade class we make rockets to discuss Newton's Laws of Motion. During our summer camps and presentations we made these Flying Film Canisters with a Twist because they are freaking awesome.
Step 1: Materials
For this activity you will need some 3D prints. Hey wait don't stop reading if you don't have a 3D printer. Just get a bunch of friends together. They can all flip their film canisters over at the same time. It is amazing when 24 students all flip their film canisters over at the same time. Fat Cat made this for days when friends can't come over or for a cool demonstration.
The first 3D print is a film canister holder. It simply hold 9 film canisters in place. This is needed to flip all nine film canisters at the same time.
The next 3D print is the insert that goes into the film canister. Originally designed so fourth grade students did not panic when doing the film canister rockets. The insert keeps the Alka Seltzer dry while snapping on the cap, preventing the chemical reaction.
You will also need -
9 x 35m canister with lid that snaps closed inside the canister. "Fuji Style"
Effervescent tablet like Alka-Seltzer. Generic works fine.
Safety goggles
Water dropper
Water
We do not suggest having kids use a film canister rocket without adult supervision. The rockets accelerate so fast that they could hurt someone.
Step 2: Place the Canisters
Take the film canister holder and set it down a firm surface.
Place the film canister firmly in the holes face down. See pictures for visual.
Step 3: Flip
Flip the film canister holder over.
The holder will now have all nine canisters attached.
Step 4: Break
Break the Alka Seltzer tablets into fourths.
Set aside to a dry location for later.
Step 5: Water
Add water. Here we show adding 15 ml of water with a pippet.
Using a Tbs. is a quicker way to add the water.
Step 6: Insert
Add a dry 3D film canister insert, tiny holes up.
This will keep the tablet of Alka Seltzer from getting wet for now.
Step 7: Tablet
Safety glasses on yet? Probably should have them on.
Add the 1/4 tablet of Alka Seltzer to every film canister. Place carefully onto insert.
Step 8: Snap
Snap the lids on. Press each lid firmly on. Make sure they snap.
This is the part that always got our fourth through eighth grade students and why we made the inserts. Without the insert the chemical reaction is happening already and the students could panic. When they did panic they would not close the lid all the way and the activity would fail.
The inserts work great for the nine canister demo or for each individual student doing their own canister.
Step 9: Flip
Are you safety glasses on? They should be!
Flip the nine film canister holder over. Shaking a little helps the reaction occur more quickly.
Back away!
Watch your film canisters take off FLYING!
Step 10: Why Orange?
We took our first pictures with white film canisters and parts. It made it really hard to see in the pictures. We ended up painting the film canisters in orange so we could take pictures especially when the canisters started flying.
Step 11: The Science!
There is a lot of science behind the rocket going up. Newton's Three Laws of Motion come to mind for us. One being that an object at rest will stay at rest unless acted on by outside force and an object in motion will stay in motion unless acted upon by an outside force (simplified version). The rocket would just sit there if there was no force from the chemical change that is taking place inside the canister. The build up of pressure is released out the bottom of the rocket which causes the rocket to move. The rocket would continue to move up but gravity is a force that stops the rocket from continually going up.
Second law of motion essentially says that the more mass an object has, the more force will be needed to get that object to move or stop moving (simplified). Force = Mass x Acceleration (f=ma). If we put more mass on the rockets the more force will be needed to launch the rockets. In our eighth grade science class we experiment with adding different amounts of mass.
Third law is action / reaction. For every action there is a reaction. If you push a wall the wall pushes back. Try it with skates on and you will see what I mean. Think of a balloon that is filled with air. Let go of the balloon and the balloon moves in the opposite direction the air is coming out of - action / reaction. The rocket has gasses shooting out the bottom of the canister downward (action) and the canister moves upward (reaction).

Runner Up in the
Make It Fly Challenge
23 Comments
10 months ago
Great idea but needs to be brought into the digital age…..I haven’t seen a film canister of any brand in years! Maybe Australia is different but outside of ‘professional’ suppliers no one sells halide emulsion film here. It’s next to impossible to find anyone who processes the stuff even if you could find it!…..so ? Tupperware space containers? Little snack containers? Dollar store little airtight containers?
Reply 10 months ago
You can find those film canisters on Ali. You get 10 for $4 shipped. I ordered the transparent version so that the kids can see the chemical reaction as it happens :)
Reply 10 months ago
Thanks, hadn’t looked there….should have!
But it’s sad that what was a common throw away, hence great for projects like this, is now a 40c a pop item from China. I liked the home grown free concept better. I am now trying to find a modern day version that is still ‘free’ and locally produced. If I find one I’ll post!
For more years than I care to remember I organised all my tiny screws and nuts in film containers. I mourn their passing.
I have done the ‘rocket’ thing with a rubber bung stuck to a base board and a small plastic soda bottle with appropriate chemistry inserted but it’s hard to engineer uniformity of multiple launches ….and water/acid charge in gelatine capsules to build in start delay tends to be erratic.
But never stop trying and dreaming…….and haveing fun!
Reply 10 months ago
I'm in Australia and you're right. We use these for school activities and we are working through a bag of them scavenged from one of the last photo developer shops in Belfast NI (they were gone in Oz by then). Sadly, I haven't found a convenient, reliable replacement as they actually work very well.
10 months ago
I use the film cannister popper in shows and activities all the time.
This looks like a great extension to the trick.
Thank you.
3 years ago
I wonder what the strength and speed of the reaction would be if you use vinegar...
Reply 10 months ago
If using vinegar, use baking soda instead of Alka-Seltzer. much better reaction and cheaper.
Reply 10 months ago
Is Alka-Seltzer not made of Sodium Bicarbonate?
Baking Soda is Sodium Bicarbonate.
Price would be cheaper, but how would you set up the experiment? Alka-Seltzer is in a packed form that can set up on the inserts. Is there a source of Baking Soda in a packed tablet form?
Reply 10 months ago
Fold the Baking soda into a "tea bag" made with a piece of paper towel etc.
Reply 10 months ago
There is a dimple in the lid of this type of film cannister. You can pack bicarb soda into the dimple, pressing it in. Then put a few drops of water onto the bicarb - this seems to set it in place a bit.
It takes a bit of practice. Add vinegar to the cannister, put the lid on and flip it over. It pops very nicely. Make sure you are not leaning over it. It hurts if it hits you. Protect your eyes properly, too. If you let a child do it, I suggest full face protection.
Reply 3 years ago
That could be an actual science experiment! Science Fair project idea ;-)
10 months ago
I teach at an elementary level summer camp. When I was practicing this experiment by dropping the tablet into the water, capping and then flipping, I was underwhelmed because I couldn't get the cap on fast enough to capture all of the gases from the reaction. Even though I don't have access to a 3D printer, the idea of the insert led me to using squares of window screening wedged inside to keep the tablets separate until the flip. Thanks for posting this hack.
10 months ago
Thank you for sharing - what a fun twist on an old standard!! :-)
Question 3 years ago on Introduction
Could you use dryice?
Answer 3 years ago
Not sure if the cold would crack the canister. I think it would work but be careful.
3 years ago
A spit of denatured alcohol and piezo igniter
Reply 3 years ago
What is that, that sounds so cool i guess
3 years ago
This is WONDERFUL!! This will be something my 10y.o. niece and I will do when she visits. =) Thank you for posting and offering a simplified version of Newton's Laws of Motion. This 40y.o. was wondering how I would simply explain this to a 10y.o. who's brain works as fast as mine.
Reply 3 years ago
Thank you! I appreciate you saying that!
3 years ago
I'm thinking Cola & Mentos !!!