The Evolution of the Spitball Cannon
by MechEngineerMike in Workshop > Science
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The Evolution of the Spitball Cannon
In step 1 ive listed a small description of my thought processes which have helped me create the five versions of my spitball cannons. In this instructible i will only include plans for versions 1, 4, and 5.
In this instructible, I will give the instructions as clearly as i can however, i am making this instructible after having completed all of the cannons, so the pictures will Not include the cannons under construction. However, i feel that the designs are pretty self explanatory when you get a good look at the finished product.
Always be careful when firing these cannons! They work though internal combustion processes of flamable gasses caused by electric shock discharge. Be afraid. But above all, just be responsible. Dont shoot at people, animals, or priceless vases.
In this instructible, I will give the instructions as clearly as i can however, i am making this instructible after having completed all of the cannons, so the pictures will Not include the cannons under construction. However, i feel that the designs are pretty self explanatory when you get a good look at the finished product.
Always be careful when firing these cannons! They work though internal combustion processes of flamable gasses caused by electric shock discharge. Be afraid. But above all, just be responsible. Dont shoot at people, animals, or priceless vases.
History of Cannons
Since i was young i have been interested in potatoe cannons and such, and i always knew i wanted to be an engineer.
I started out experimenting with different ignition sources like tazers, camera flash shocks, and grill ignitors to ignite various fuels inside my various size cannons. The biggest of which had a 2" diameter barrel and was 5' tall. It shot completely over a nearby cornfield.
Then it occurred to me that I was continually trying to build one bigger and bigger and better. So I decided to try and design one out of the smallest parts. So Spitball Cannon version 1 (SC1) came along. It was so much fun blasting the little thing at friends (dont do it though) I continued to try to improve it for efficiency, hand comfort, effectiveness, cool looks, and safety.
I also tried to accomplish the same task (shooting a spitball) by other means. SC2 was made to shoot from pressurized air. Originally I intended to fit it into a large magic marker to conceal it, but it ended up being too big, too ineffective, and it didnt make a cool blast!
SC3 was made to fit the hand better, store ammo in it, use a tube to inject fuel into it, and look better, but the combustion chamber was too small to work reliably. So i combined concepts from SC1 and SC3 to create SC4. At this point i thought that this design could not be improved very much more, (at least not cheaply or easily). SO it sat for a year......
One day i happened to pick it up and play with it for a while on the same day i chose to spray paint some furniture. After having the gun fresh in my mind, i picked up a spray can spraying tool handle and PING, the lightbulb lit up in my head. Thus the creation of SC5, the "big shot".
Moral of the story is that there is always another way of doing the same thing. It just took time, setting down the project and coming back later. Research is also important to help guide you on your way; why not learn from other's mistakes and build off their success (just remember to Aways give credit where its due).
I started out experimenting with different ignition sources like tazers, camera flash shocks, and grill ignitors to ignite various fuels inside my various size cannons. The biggest of which had a 2" diameter barrel and was 5' tall. It shot completely over a nearby cornfield.
Then it occurred to me that I was continually trying to build one bigger and bigger and better. So I decided to try and design one out of the smallest parts. So Spitball Cannon version 1 (SC1) came along. It was so much fun blasting the little thing at friends (dont do it though) I continued to try to improve it for efficiency, hand comfort, effectiveness, cool looks, and safety.
I also tried to accomplish the same task (shooting a spitball) by other means. SC2 was made to shoot from pressurized air. Originally I intended to fit it into a large magic marker to conceal it, but it ended up being too big, too ineffective, and it didnt make a cool blast!
SC3 was made to fit the hand better, store ammo in it, use a tube to inject fuel into it, and look better, but the combustion chamber was too small to work reliably. So i combined concepts from SC1 and SC3 to create SC4. At this point i thought that this design could not be improved very much more, (at least not cheaply or easily). SO it sat for a year......
One day i happened to pick it up and play with it for a while on the same day i chose to spray paint some furniture. After having the gun fresh in my mind, i picked up a spray can spraying tool handle and PING, the lightbulb lit up in my head. Thus the creation of SC5, the "big shot".
Moral of the story is that there is always another way of doing the same thing. It just took time, setting down the project and coming back later. Research is also important to help guide you on your way; why not learn from other's mistakes and build off their success (just remember to Aways give credit where its due).
Spitball Cannon 1
I have my own workshop but it is not necessary to build these, just really helpful.
SC1 is the easiest and cheapest to make
Tip on materials: Cannon 1 can be built entirely from stuff from dollar stores
Tools
Dremel tool or electric drill, or drill press, or something else to drill with.
Electrical tape (use your favorite color)
Safety glasses should always be used (Always! you only have 1 set of eyes!)
Materials
Medicine bottle any size
(bigger results in more reliable shooting, but less compact overall size and a little more dangerous product)
A long lighter
A plastic ink Pen Tube
STEP 1 Ignitor preparation
Tear apart the long lighter, we want the Piezo electric ignitor. It is almost always a black small rectangular solid with 1 or 2 wires coming out. Also save the little bottle of lighter fluid and any extra wire in the lighter.
If it only has one wire, use some spare wire, and wrap some exposed copper wire around the exposed cylindrical metal surface on the ignitor. (this is the negative lead, required to make complete circuit)
Now tape the wires to the ignitor so that they wont be easy to tear off. (we want a durable product)
STEP 2
Now use your drill to make a hole in the center of the bottom of the medicine bottle. Make sure the hole is SMALLER than the pen tube. You want it to fit Snugly so it doesnt fly out.
STEP 3 wiring
Now we want to poke two small holes into the medicine bottle to stick the wire leads through. I recommend using a pushpin and make the about a centimeter apart. Put the wire through the holes and look in side the bottle, You want them to be at a distance where the spark can jump from one wire to the other. Press the ignitor to check if they are the proper distance. WHen your satisfied, tape down the outside of the bottle around the wires, holding them in place.
STEP 4 firing
Ok this step applies to all cannons. What we are doing is using the little ignitor spark to ignite some fuel inside the CLOSED medicine bottle. I recommend AXE or other body spray, OR your ttle can of lighter fluid from the long lighter you destroyed.
1. make sure your barrel is loaded. (load it breach stile in this case). Without the spitball your gun may shoot a fireball or not shoot at all, either way, not a desireable affect.
The process of combustion is VERY sensitive. TOO much or TOO little fuel can prevent the explosion. Understand that the process requires oxygen.
I spray AXE into the bottle for a half a second, just a whiff! Then i blow gently for half a second into the bottle.
Now SEAL it off as quick as possible. Dont aim at anyone. And press the ignitor about 3 times.
If it does not work, try opening your bottle and blowing into it briefly and trying to shoot again.
if that doesnt work, open your bottle and blow into it VERY hard, to vent it out, then start again.
SC1 is the easiest and cheapest to make
Tip on materials: Cannon 1 can be built entirely from stuff from dollar stores
Tools
Dremel tool or electric drill, or drill press, or something else to drill with.
Electrical tape (use your favorite color)
Safety glasses should always be used (Always! you only have 1 set of eyes!)
Materials
Medicine bottle any size
(bigger results in more reliable shooting, but less compact overall size and a little more dangerous product)
A long lighter
A plastic ink Pen Tube
STEP 1 Ignitor preparation
Tear apart the long lighter, we want the Piezo electric ignitor. It is almost always a black small rectangular solid with 1 or 2 wires coming out. Also save the little bottle of lighter fluid and any extra wire in the lighter.
If it only has one wire, use some spare wire, and wrap some exposed copper wire around the exposed cylindrical metal surface on the ignitor. (this is the negative lead, required to make complete circuit)
Now tape the wires to the ignitor so that they wont be easy to tear off. (we want a durable product)
STEP 2
Now use your drill to make a hole in the center of the bottom of the medicine bottle. Make sure the hole is SMALLER than the pen tube. You want it to fit Snugly so it doesnt fly out.
STEP 3 wiring
Now we want to poke two small holes into the medicine bottle to stick the wire leads through. I recommend using a pushpin and make the about a centimeter apart. Put the wire through the holes and look in side the bottle, You want them to be at a distance where the spark can jump from one wire to the other. Press the ignitor to check if they are the proper distance. WHen your satisfied, tape down the outside of the bottle around the wires, holding them in place.
STEP 4 firing
Ok this step applies to all cannons. What we are doing is using the little ignitor spark to ignite some fuel inside the CLOSED medicine bottle. I recommend AXE or other body spray, OR your ttle can of lighter fluid from the long lighter you destroyed.
1. make sure your barrel is loaded. (load it breach stile in this case). Without the spitball your gun may shoot a fireball or not shoot at all, either way, not a desireable affect.
The process of combustion is VERY sensitive. TOO much or TOO little fuel can prevent the explosion. Understand that the process requires oxygen.
I spray AXE into the bottle for a half a second, just a whiff! Then i blow gently for half a second into the bottle.
Now SEAL it off as quick as possible. Dont aim at anyone. And press the ignitor about 3 times.
If it does not work, try opening your bottle and blowing into it briefly and trying to shoot again.
if that doesnt work, open your bottle and blow into it VERY hard, to vent it out, then start again.
Spitball Cannon 4
SC4 is better than all of the ones before it
It shoots more reliably while fitting into your hand nicely. It can be made more reliable and powerful by choosing a larger medicine bottle. It requires the same tools and materials and some steps as the previous cannon.
For your benefit, so you dont have to keep switching pages i have copied and pasted the instructions from the last page and added the extra materials and steps in italics.
Tools
Dremel tool or electric drill, or drill press, or something else to drill with.
Electrical tape (use your favorite color)
Safety glasses should always be used (Always! you only have 1 set of eyes!)
Materials
Medicine bottle any size
(bigger results in more reliable shooting, but less compact overall size and a little more dangerous product)
A long lighter
A plastic ink Pen Tube
Two 1/2 in. PVC plugs (from LOWES or ACE hardware, like 40 cents each)
One 1/2 in. PVC 90 degree coupling
Thick glue like silicone or rubber cement
STEP 1 Ignitor preparation
Tear apart the long lighter, we want the Piezo electric ignitor. It is almost always a black small rectangular solid with 1 or 2 wires coming out. Also save the little bottle of lighter fluid and any extra wire in the lighter.
If it only has one wire, use some spare wire, and wrap some exposed copper wire around the exposed cylindrical metal surface on the ignitor. (this is the negative lead, required to make complete circuit)
Now tape the wires to the ignitor so that they wont be easy to tear off. (we want a durable product)
STEP 2
Now use your drill to make a hole in the center of the bottom of the medicine bottle. Make sure the hole is SMALLER than the pen tube. You want it to fit Snugly so it doesnt fly out.
STEP 3 frame & wiring
First you size up the ignitor, noting where the wires are in comparison to the PVC frame. Now drill a small hole (around 1/8in. dia) into the 90 deg PVC and run the wires into it.
Now this can be tricky. Get out a plug and your medicine bottle cap. Use a marker or pencil and trace the little part of the plug around in the center of the medicine bottle lid. Now cut out that hole so you can push the plug through the cap snugly!
Next you need to drill a small hole ( around 1/8 in. dia) in the center of the plug you just put into the cap.
Now pull your wires from inside the 90 deg PVC through the plug hole, and push the plug into the 90 dec PVC
Now glue the medicine bottle lid to the plug and 90 deg PVC, and set your wires up how you want them to create a spark and glue them into place. The idea is that we want an AIRTIGHT combustion chamber. let your glue dry.
To check for airtightness, attach the combustion chamber to the cap and blow through the barrel. If a lot of air goes through it easly, find where it is leaking and GLUE IT UP.
STEP 4 firing
Ok this step applies to all cannons. What we are doing is using the little ignitor spark to ignite some fuel inside the CLOSED medicine bottle. I recommend AXE or other body spray, OR your ttle can of lighter fluid from the long lighter you destroyed.
1. make sure your barrel is loaded. (load it breach stile in this case). Without the spitball your gun may shoot a fireball or not shoot at all, either way, not a desireable affect.
The process of combustion is VERY sensitive. TOO much or TOO little fuel can prevent the explosion. Understand that the process requires oxygen.
I spray AXE into the bottle for a half a second, just a whiff! Then i blow gently for half a second into the bottle.
Now SEAL it off as quick as possible. Dont aim at anyone. And press the ignitor about 3 times.
troubleshooting
If it does not work, try opening your bottle and blowing into it briefly and trying to shoot again.
if that doesnt work, open your bottle and blow into it VERY hard, to vent it out, then start again.
Make sure to check that your spark is still firing.
It shoots more reliably while fitting into your hand nicely. It can be made more reliable and powerful by choosing a larger medicine bottle. It requires the same tools and materials and some steps as the previous cannon.
For your benefit, so you dont have to keep switching pages i have copied and pasted the instructions from the last page and added the extra materials and steps in italics.
Tools
Dremel tool or electric drill, or drill press, or something else to drill with.
Electrical tape (use your favorite color)
Safety glasses should always be used (Always! you only have 1 set of eyes!)
Materials
Medicine bottle any size
(bigger results in more reliable shooting, but less compact overall size and a little more dangerous product)
A long lighter
A plastic ink Pen Tube
Two 1/2 in. PVC plugs (from LOWES or ACE hardware, like 40 cents each)
One 1/2 in. PVC 90 degree coupling
Thick glue like silicone or rubber cement
STEP 1 Ignitor preparation
Tear apart the long lighter, we want the Piezo electric ignitor. It is almost always a black small rectangular solid with 1 or 2 wires coming out. Also save the little bottle of lighter fluid and any extra wire in the lighter.
If it only has one wire, use some spare wire, and wrap some exposed copper wire around the exposed cylindrical metal surface on the ignitor. (this is the negative lead, required to make complete circuit)
Now tape the wires to the ignitor so that they wont be easy to tear off. (we want a durable product)
STEP 2
Now use your drill to make a hole in the center of the bottom of the medicine bottle. Make sure the hole is SMALLER than the pen tube. You want it to fit Snugly so it doesnt fly out.
STEP 3 frame & wiring
First you size up the ignitor, noting where the wires are in comparison to the PVC frame. Now drill a small hole (around 1/8in. dia) into the 90 deg PVC and run the wires into it.
Now this can be tricky. Get out a plug and your medicine bottle cap. Use a marker or pencil and trace the little part of the plug around in the center of the medicine bottle lid. Now cut out that hole so you can push the plug through the cap snugly!
Next you need to drill a small hole ( around 1/8 in. dia) in the center of the plug you just put into the cap.
Now pull your wires from inside the 90 deg PVC through the plug hole, and push the plug into the 90 dec PVC
Now glue the medicine bottle lid to the plug and 90 deg PVC, and set your wires up how you want them to create a spark and glue them into place. The idea is that we want an AIRTIGHT combustion chamber. let your glue dry.
To check for airtightness, attach the combustion chamber to the cap and blow through the barrel. If a lot of air goes through it easly, find where it is leaking and GLUE IT UP.
STEP 4 firing
Ok this step applies to all cannons. What we are doing is using the little ignitor spark to ignite some fuel inside the CLOSED medicine bottle. I recommend AXE or other body spray, OR your ttle can of lighter fluid from the long lighter you destroyed.
1. make sure your barrel is loaded. (load it breach stile in this case). Without the spitball your gun may shoot a fireball or not shoot at all, either way, not a desireable affect.
The process of combustion is VERY sensitive. TOO much or TOO little fuel can prevent the explosion. Understand that the process requires oxygen.
I spray AXE into the bottle for a half a second, just a whiff! Then i blow gently for half a second into the bottle.
Now SEAL it off as quick as possible. Dont aim at anyone. And press the ignitor about 3 times.
troubleshooting
If it does not work, try opening your bottle and blowing into it briefly and trying to shoot again.
if that doesnt work, open your bottle and blow into it VERY hard, to vent it out, then start again.
Make sure to check that your spark is still firing.
Spitball Cannon 5, the Big Shot
SC5 is way better than all of the ones before it
It shoots very reliably while fitting into your hand very comfortably. It requires all of the same tools and the same source of ignition as the previous models. However, building it requires a lot more work with more materials.
This model's trigger presses the ignitor AT THE SAME TIME as it releases gas fuel into the chamber, which increases the Firing rate by a lot.
It also increases the firing rate by Changing the way it VENTS. Before, you had to remove the entire combustion chamber to blow out the exhaust. Now, there is an oral syringe with a hoze running directly into the combustion chamber. SO after the shot, you just pump the syringe a bunch to vent it through the BArrel! hahaha!
Ive also improved the Firing rate by improving the Loading rate. Ive attached extra pens to the top, so that after a shot, you can just change the barrel out!
Ive tried another method of faster reloading, which is shown in the picture that looks like a gatling gun barrel. YOu just twist the barrel and it is reloaded. But unfortanatly that design is VERY hard to seal the barrel shut, and a lot of power is lost!
To be honest, i dont know how to improve the design any more at the moment, OTHER than devoloping an easy way to make CARTRIDGES (im working on it!)
If you have any ideas i'd love to hear them.
I am really proud and would love to profit off of this design, BUT toys like this arent monatrially vaulable or marketable. SO i will share it with all of you and I expect that people will love this!
Some general instructions are on the next page. General because too many details kill me, and i still feel that with adequite pictures, people interested enough will be able to produce their own.
More importantly, detailed instructions take away from people's imaginative potential. If you want to make one, and you dont know how, you will likely come up with a NEW way of doing the same thing. BUt that is the subject of another instructible.
and for some reason i cannot make image notes on any pictures from here on out.
It shoots very reliably while fitting into your hand very comfortably. It requires all of the same tools and the same source of ignition as the previous models. However, building it requires a lot more work with more materials.
This model's trigger presses the ignitor AT THE SAME TIME as it releases gas fuel into the chamber, which increases the Firing rate by a lot.
It also increases the firing rate by Changing the way it VENTS. Before, you had to remove the entire combustion chamber to blow out the exhaust. Now, there is an oral syringe with a hoze running directly into the combustion chamber. SO after the shot, you just pump the syringe a bunch to vent it through the BArrel! hahaha!
Ive also improved the Firing rate by improving the Loading rate. Ive attached extra pens to the top, so that after a shot, you can just change the barrel out!
Ive tried another method of faster reloading, which is shown in the picture that looks like a gatling gun barrel. YOu just twist the barrel and it is reloaded. But unfortanatly that design is VERY hard to seal the barrel shut, and a lot of power is lost!
To be honest, i dont know how to improve the design any more at the moment, OTHER than devoloping an easy way to make CARTRIDGES (im working on it!)
If you have any ideas i'd love to hear them.
I am really proud and would love to profit off of this design, BUT toys like this arent monatrially vaulable or marketable. SO i will share it with all of you and I expect that people will love this!
Some general instructions are on the next page. General because too many details kill me, and i still feel that with adequite pictures, people interested enough will be able to produce their own.
More importantly, detailed instructions take away from people's imaginative potential. If you want to make one, and you dont know how, you will likely come up with a NEW way of doing the same thing. BUt that is the subject of another instructible.
and for some reason i cannot make image notes on any pictures from here on out.
Building SC5
here is straight mechanical info.
Tools
Dremel tool or electric drill, or drill press, or something else to drill with.
Electrical tape (use your favorite color)
Safety glasses should always be used (Always! you only have 1 set of eyes!)
Materials
Medicine bottle, LARGE size
A long lighter
A few plastic ink Pen Tubes
Thick glue like silicone or rubber cement
A plastic spraypaint handle trigger ( sold at lowes...~$5)
A can of body spray that fits into the can sprayer (mine was from dollar store)
A couple feet of 1/4 in. dia plastic vinyl tubing
2 brass connectors that fit inside 1/4 in. tubing (sold near tubing, you can buy them individually too)
extra lengths of insulated copper wire , i like 12 gauge stranded
One oral syringe (the bigger the better, ask for some at pharmacies)
Now take your syring and fit it into different sizes of PVC pipe until you find a size that fits, mine fit 1/2 in. pvc
a foot of 1/2 in. PVC pipe
one 1/2 in. PVC coupling
one 1/2 in. PVC end cap
zip ties, (my color ones pictured came from the dollar store.)
three small washers (fit onto cap to make it taller, look at 4th picture)
STEP 1 Ignitor preparation
Tear apart the long lighter, we want the Piezo electric ignitor. It is almost always a black small rectangular solid with 1 or 2 wires coming out. Also save the little bottle of lighter fluid and any extra wire in the lighter.
If it only has one wire, use some spare wire, and wrap some exposed copper wire around the exposed cylindrical metal surface on the ignitor. (this is the negative lead, required to make complete circuit) Leave a foot or so of extra wire for each lead.
tape the wires to the ignitor so that they wont be easy to tear off. (we want a durable product)
STEP 2
use your drill to make a hole near one side of the bottom of the medicine bottle. Make sure the hole is SMALLER than the pen tube. You want it to fit Snugly so it doesnt fly out.
STEP 3 frame & wiring
First, note that your spraypaint handle has hinges and opens up. You will need to open it and cut out a section that will fit the ignitor, such that the ignitor will be pressed when the trigger is pulled, but it will not move out of place. This is the hardest part of the project. Use tape or glue as needed.
drill a hole in the top of the handle and run the wires out through the top.
Look at your pvc pipe and see where you want it to be on the handle to look cool and be comfortabe on the back. Now drill a small hole (around 1/8in. dia) into the pipe so you can run the wire through it. Also MAKE NOTE that you are going you force your syring into the back at the end, leave room for it.
this can be tricky. Get out a small piece of pvc pipe and your medicine bottle cap. Use a marker or pencil and trace around the pipe in the center of the medicine bottle cap. Now cut out that hole so you can push the pipe through the cap snugly!
you need to drill a small hole ( around 1/8 in. dia) in the center of the PVC cap, this is for the wires. Also drill another larger hole to SNUGLY fit some 1/4 in. pipe through, this will be for the ventilation from the sryinge.
pull your wires from inside the PVC pipe through the cap hole, and push the cap on the pvc onto the coupling with the medicine bottle cap inbetween the coupling and the cap. See image 3 for help.
glue the medicine bottle lid to the cap coupling, and set your wires up how you want them to create a spark and glue them into place. The idea is that we want an AIRTIGHT combustion chamber. let your glue dry.
To check for airtightness, attach the combustion chamber to the cap and blow through the barrel. If a lot of air goes through it easly, find where it is leaking and GLUE IT UP.
Onto the body spray can. You need to glue the three washers onto the top of the lid. This will correct the spacing between the lever and the lid.
NOw you need to glue a brass tube connector around the nozzle. I actually cut off the back lip of the connector and shoved it into place, then glued it.
For the combustion chamber you will just need to add a hole in the bottom to fit snugly the other brass tube connector. Having these connectors will allow you to detach the combustion chamber if you need to.
STEP 4 firing
my favorite part about this.
just pull the trigger about three times fast.
Dont aim at anyone.
troubleshooting
If it does not work, Try pullng the tube off the connector on the combustion chamber. Then pump the syringe to air out the chamber.
if that doesnt work, open your bottle and blow into it VERY hard, to vent it out, then start again. Make sure to check that your spark is still firing.
Tools
Dremel tool or electric drill, or drill press, or something else to drill with.
Electrical tape (use your favorite color)
Safety glasses should always be used (Always! you only have 1 set of eyes!)
Materials
Medicine bottle, LARGE size
A long lighter
A few plastic ink Pen Tubes
Thick glue like silicone or rubber cement
A plastic spraypaint handle trigger ( sold at lowes...~$5)
A can of body spray that fits into the can sprayer (mine was from dollar store)
A couple feet of 1/4 in. dia plastic vinyl tubing
2 brass connectors that fit inside 1/4 in. tubing (sold near tubing, you can buy them individually too)
extra lengths of insulated copper wire , i like 12 gauge stranded
One oral syringe (the bigger the better, ask for some at pharmacies)
Now take your syring and fit it into different sizes of PVC pipe until you find a size that fits, mine fit 1/2 in. pvc
a foot of 1/2 in. PVC pipe
one 1/2 in. PVC coupling
one 1/2 in. PVC end cap
zip ties, (my color ones pictured came from the dollar store.)
three small washers (fit onto cap to make it taller, look at 4th picture)
STEP 1 Ignitor preparation
Tear apart the long lighter, we want the Piezo electric ignitor. It is almost always a black small rectangular solid with 1 or 2 wires coming out. Also save the little bottle of lighter fluid and any extra wire in the lighter.
If it only has one wire, use some spare wire, and wrap some exposed copper wire around the exposed cylindrical metal surface on the ignitor. (this is the negative lead, required to make complete circuit) Leave a foot or so of extra wire for each lead.
tape the wires to the ignitor so that they wont be easy to tear off. (we want a durable product)
STEP 2
use your drill to make a hole near one side of the bottom of the medicine bottle. Make sure the hole is SMALLER than the pen tube. You want it to fit Snugly so it doesnt fly out.
STEP 3 frame & wiring
First, note that your spraypaint handle has hinges and opens up. You will need to open it and cut out a section that will fit the ignitor, such that the ignitor will be pressed when the trigger is pulled, but it will not move out of place. This is the hardest part of the project. Use tape or glue as needed.
drill a hole in the top of the handle and run the wires out through the top.
Look at your pvc pipe and see where you want it to be on the handle to look cool and be comfortabe on the back. Now drill a small hole (around 1/8in. dia) into the pipe so you can run the wire through it. Also MAKE NOTE that you are going you force your syring into the back at the end, leave room for it.
this can be tricky. Get out a small piece of pvc pipe and your medicine bottle cap. Use a marker or pencil and trace around the pipe in the center of the medicine bottle cap. Now cut out that hole so you can push the pipe through the cap snugly!
you need to drill a small hole ( around 1/8 in. dia) in the center of the PVC cap, this is for the wires. Also drill another larger hole to SNUGLY fit some 1/4 in. pipe through, this will be for the ventilation from the sryinge.
pull your wires from inside the PVC pipe through the cap hole, and push the cap on the pvc onto the coupling with the medicine bottle cap inbetween the coupling and the cap. See image 3 for help.
glue the medicine bottle lid to the cap coupling, and set your wires up how you want them to create a spark and glue them into place. The idea is that we want an AIRTIGHT combustion chamber. let your glue dry.
To check for airtightness, attach the combustion chamber to the cap and blow through the barrel. If a lot of air goes through it easly, find where it is leaking and GLUE IT UP.
Onto the body spray can. You need to glue the three washers onto the top of the lid. This will correct the spacing between the lever and the lid.
NOw you need to glue a brass tube connector around the nozzle. I actually cut off the back lip of the connector and shoved it into place, then glued it.
For the combustion chamber you will just need to add a hole in the bottom to fit snugly the other brass tube connector. Having these connectors will allow you to detach the combustion chamber if you need to.
STEP 4 firing
my favorite part about this.
just pull the trigger about three times fast.
Dont aim at anyone.
troubleshooting
If it does not work, Try pullng the tube off the connector on the combustion chamber. Then pump the syringe to air out the chamber.
if that doesnt work, open your bottle and blow into it VERY hard, to vent it out, then start again. Make sure to check that your spark is still firing.