Introduction: Make a Vortex Ring Cannon and Get a Frisbee for Free
This is an Instructable that happened by accident.
The bottle was meant for a diferent project but I was asked today if I could make a smoke ring cannon within an hour for a party...
What you need for this:
# A big PET bottle, like those from a water dispenser in my case.
# A good cutting knife - these serrated "forever sharp" knifes wrok great.
# Sturdy sissors or tin snips.
# A very strong foil - I used the outer lining from a cheap wine (the ones that come in a box ;) ) but a big bag for chips or similar should work too.
# Double sided and electrical tape, the later can be substituted for duct tape.
If you can handle sharp knifes you should be able to it.
Younger explorers might want to ask for some help from their parents for the cutting of the bottle.
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Step 1: Cut the Bottle
The tricky part is the first cut.
That is why I said a serrated knife is good.
If your bottle is anything like mine than you want to cut the bottom somewhere between the last ring and the actual bottom - mark it with pen if you want to keep the bootom as a frisbee - they fly great!
Once you managed your way all the way around you trim the bottle to get a smooth finnish.
It certainly helps to put this last cut (using strong sissors or tin snips) at a rounded edge - I used the one on the ring.
This helps to get the foil in place and give a longer life.
If you do it all good you should get from the above to something like this:
Note the rounded edge from the ring!?
Step 2: Tape It
Before you start playing with the tape some words:
Make sure you removed all sharp edges left from the cutting on the bottle!
If in doubt use fine sandpaper.
Clean the ring part with some methylated spirit if the bottle was from the scrap.
Use quality tape and avoid for example stuff to put pictures in an album.
I used "Mirror Tape" the stuff used to put glass mirror tiles on the ceiling or wardrobe.
Leave the protective film on the tape for now so you can press the tape down firmly!
Now it is time to put the foil over the big hole we created.
Remove the protective film and place the foil on the top - make sure it does not touch the tape before you have it in place!
Pull from opposite sides on the foil to get some tension in it, then pul down on over the tape and press in place with your fingers.
Repeat this all the way around.
I use a 90° pattern to start with and then pull between the already fixed points - you want it firm and even like a drum.
Time to cut the excess off.
Depending on what foil you used be careful that you don't tear it, some chips bags tent to this quite easy.
After it should like like this:
For the final touch, and mostly because these foils never reall stick to anything, we add a layer of electrical tape or duct tape around the area.
This is to keep pressure on the double sided tape, which otherwise will loose the grip on the foil.
When it looks like the below image you are ready to shoot!
Due to the neck acting as a barrel the created vortex ring is really fast and really small in diameter.
It takes some good aiming but you can blow out a candle from several meters away.
Even more fun is to surprise people by shotting a ring at them from behind - see their reaction when a sudden bang of air messes the hair up LOL
Step 3: Last Words....
Before you say that it would work better with more travel on the membrane:
I tried with old elastic band and barbage trick but it does not work properly on the small diameter of the exit on the bottle.
Instead a sudden blast like you hit a drum with your hand does the trick much better.
If you have access to some flexible material like latex sheets it might work even better.
I have no way of making a good amount of smoke and recording the ring - it moves far to quick.
So unlike the usual smoke ring cannons you have a fast travelling ring.
If you have the means to record the rings properly I would appreciate if you post a link to the video in the comments.