If you plan on having a pirate ship theme setup for your haunted house or front yard like my family and I do then this is the perfect pirate cannon setup for you, it's versatile, you can change it to your own liking which is very nice. You'll shock the faces of your visitors as they pass by and see theses things blowback,lightup, and make loud bangs as they actuate. it's probably the closest you can get to the real thing
In total the materials you will need are:
-at least 5 screen door closers from home depot, you'll find out why in the steps
-about 20' of 4" PVC depeding on how long your cannons are and the distance between each
-if you are to have five cannons you need 2 90 degree 4" PVC joints, and three 4" PVC T joints add more of these with more cannons
-2   4' x 8' sheets of 3/4" plywood
-5 light fixtures as well as 5 red bulbs or whatever color you desire
-electrical wiring to connect all the fixtures together
-a plug in to splice onto the end of the wiring
-duct tape
-1   12' piece of pine
-large plastic drum
-lots of scrap metal for small brackets and the pivoting arms
-screw gun and screws from 1"   to 2 1/2" screws
-jigsaw
-drill with 4" hole saw and a bit large enough to drill holes through metal for screws
-air compressor and air lines
-air fixtures that you can get as you see them in the steps
-1/8" air line, lots
-air regulator

The first thing to do to begin creating the cannons is to gather up 4" PVC pipe, you'll need about 20' of PVC depending on how far you want your cannons spread out, plus three 4" PVC T joints and two 4" 90 degree joints. You can cut and glue the pipes together as shown in the first picture with the 90 degree joints on each end holding the end cannon extensions and the three T joints holding eahc of the three middle cannon extensions. Distances between each of these joints(cannons) can be based on your desire, as well as the length each of the cannons extends out past the main body of the project. Once the main body is built and all the cannons extend then screw a long piece of pine to the bottom of the PVC for support as you can see in the picture

Step 1: Adding the Lights

The materials you will need for this part of the project is 5 Light fixtures, 5 red bulbs, electrical wiring, a drill, a 4" hole saw, and duct tape. start off by drilling a hole into the back of each of the cannons in that back of the joints with the hole saw. then wire all five light fixtures together all on one circuit and splice a grounded 'plug in' to one end of the setup. then duck tape each fixture to the body of the setup with the light facing in. If you choose the same fixtures pictured then you may need to space the junction box of the fixture away from the PVC, we used a 2"x4" to push it away and keep it even.

Step 2: Building the Support

For this part you will need 2 4'by8' sheets of 3/4" plywood, a jigsaw, screw gun, screws, and scrap metal. Start off by cutting the sheets of plywood to look like the picture shown based on how tall you want the cannons off the ground, these will be the stands holding the whole PVC setup up. Then cut scrap metal to size based on how much you want the cannons to pivot, you will need two arms welded together with a pivot crossbar and the bottom holding them together, and add a flat piece of metal welded to the top of the two arms and drill two holes in this flat piece(see pictures for this step). Do this for both stands that you build . Then screw the flat piece onto the PVC, facing the center of the setup. Cut an arched down cut into the back of each stand(see pictures) you built and slide the pivot crossbar you have welded to the arms down into this arched cut, this will allow the whole cannon setup to pivot backwards as it's pushed as if the cannons are 'blowing back'.

Step 3: Setting Up the Air to Move It

for this step you will need 2 of your screen door closers(air cylinders), scrap metal or bought brackets to mount the cylinders to the stands(see pictures), small nuts and bolts possibly comes with you screen door closers, 1/8" air line, drill and tap set,air compressor, air regulator, and air fixtures(see pictures).be sure to look at every picture, there should be a picture for just about every sentence in this step. The first thing you need to do is take the screw out of the back of the screen door closer, this is what holds the pressure so that it will close you screen door but by removing it, it allows you to apply air to push the rod now. you have to take that screw out , drill it out, and then tap the hole you have, this is best if you have a bench vice, put it tighly in the vice, pull the pushrod in the cylinder as hard as you can and put vice grips on it to hold the rod out, this will prevent you from drilling into the rod. Now drill out the hole and tap it to the size of the fixture shown in the picture, part A-22 at home depot, I believe it's in the plumbing section. Once you have it drilled and tapped blow the cylinder out to get as many of the metal scraps out as possible. Now see if the A-22 fixture screws in then take it out. Take the vice grips off and repeat for the second cylinder. Now that you've done that you can hook the 1/8" air line up to the cylinders, the cylinders will mount onto the wodden stands you built so cut an individual length of the air line for each cylinder long enough to meet in the middle between your wooden stands.Hook the line up by using the A-22 fixture and the other parts show in the picture. first put 1/8" air line through the A-22 fixture then put the air line through the white sleeve in the picture, and then push the gold rod thing into the air line. Now do this same thing for another stretch of air line for the other cylinder. To hook up to the cylinders simply push the airline into the hole you tapped and screw the fixture in. Now screw the brackets you bought or made onto the wodden stands wherever plausible and put a nut and bolt through the bracket and back of the cylinder to hold it to the stand. Now put a nut and bolt through the metal arm you welded earlier, do this by drilling a hole through the metal arm and putting a nut and bolt throught the end of the rod and through the hole in the metal. Put air to both just to see if they'll push but thats it, you'll have many fixtures in the next step for the noise being controlled by air and then you can run it all.

Step 4: Making It Go Bang!

for this part you will need a very large plastic barrel or drum, anything you can bang on to make a cannon noise, have enough surface area to bang against though, you also need the rest of the air cylinders you bought whether you have 1,2,3,4,5 etc. Best to have as many of thme as you have cannons, metal brackets to mount the back of the air cylinder to the base. a piece of wood about 4' by 3', scrap from building the stands will probably work, hinges like the ones seen in the pictures, small scraps of wood kind of like a bat and either softballs or mallets enough for each cylinder. Start off by doing what you did to the other two cylinders in the last step, you need this once again for each cylinder with the white sleeve gold rod, and A-22 and 1/8" air line. easier now isn't it? then make or by brackets and screw them down to you wood base. Mount the back of the air cylinders to each of these now. then screw your hinges down to the base and to the pieces of wood, make sure each piece of wood has a different height(see pictures). Once you have these wood pieces mounted sturdy hook the push rod end of each cylinder to each piece of wood using the brackets that should come with your cylinders. Then screw softballs to the top of each piece of wood or mallets to the wood, whatever you like or have access to. My opinion is the mallets make a better noise but I guess it depends on what you're hitting. Now you need to screw the drum down to the base, play with the distance you have away from the hit.The next step will be about hooking up the other two cylinders and these cylinders to where they all tie into one bigger air line and activate simultaneously.

Step 5: Let There Be AIR!!!

For this step you will need the air fixture pictured, an air regulator, and an air compressor, and normal air line 3/8" I believe it is,you will also need the valve off of a washing machine this works really well and is a lot cheaper than a solenoid. connect all the lines as pictured be sure to put the ones running to the cylinders pushing the cannons past the regulator because those will be the ones needing regulation, play with the psi for these be sure its not just throwing the cannons. the other lines run to the drum and those dont need to be regulated, the washing machine valve contols the air flowing in, when the button is pushed the valve opens and lets air to the cylinders the noise goes off and the cannons blow back, the noise will sound like a bunch of cannons going off at different times but quickly, this is why you made the sticks different heights in the previous step, so they dont all hit at the same time. i'll explain the button in the next step.

Step 6: The Button

for this part you will need a sheet of plywood, a spring, wooden dowel rod, the button from a hardware store, I believe it's called a momentary button, electrical tape, screw gun, screws piano hinge. Start off by building the stand as you see it in the picture, size doesnt matter height, width can be anything you want just cut to size and be sure not to put a back on it. after the stand is built drill a hole in the top big enough so the dowel rod you have can fit in it and slide freely, this will be what the people push, view the pictures to see how the insides are constructed, this part will be mainly based on the picture notes you can highlight, this button will open the washing machine valve which, in turn will allow air to the cannons and the drum noise simultaneoously, you could just put the momentary button sticking out of the top of the stand and avoid this whole setup but its much more unssafe because of the wiring being so close to fingertips, this is the safer route to go, next we'll go over pumping smoke, the simplest thing in this project

Step 7: smoke

this is the easiest step, you will need the drill and 4" hole saw, some heat ducting like in the picture, a fog machine, fog juice, and duct tape. drill a hole on each side of the middle cannon into the PVC pipe, its best if it's around the middle cannon so the smoke pipes to all cannons evenly, hook the fog machine up and connect a straight piece of ducting to the tip of the machine for about 1 foot. cut a long piece of ducting that reachesto each hole you cut into the PVC pipe, now cut a hole into that ducting at about the middle and run the straight 1 foot piece into that holeduct tape the 1 foot piece to the other ducting and then duct tape the ducting to the PVC pipe and there you have it ,step done turn the fog machine on and let it spread, once it get going it will start to come out of all cannons, based on wind conditions, be sure to have the straight piece coming off the machine first, if you run the fog machine directly into the piece going to the holes it won't reach each cannon, evenly because it automatically run into a wall and comes back towards the machinethe pictures pretty much explain it all, just leave the machine on the whole time, it looks really good with fog constantly coming out, not only when the button is pushed, next we'll see how to make the lights flash when the cannons blast

Step 8: Light Flash

this is the last step and it's to make the light go simultaneously with the blast, theres two ways of going about this, one way is using a neat little gadget I have that picks up sound decibels and makes light flicker based on the sound decibels it picks up, the louder the noise the brighter the lights, theres a picture of it below, so if you find that online or in a store get it and just place it next to the drum noise you built and plug it into the lights, it works really well because it flashes based on the noise the air cylinders make against the drum, the other way would be to wire the lights directly to the button just as you did with the washing machine valve, that should work well to because the lights will flash right when you press the button, it just might no look as in sync.

Step 9: Conclusion

and thats it, hopefully you stuck with me through it and were successful in completion, have fun blasting away with the cannons setup, feel free to contact me with any questions or comments and i'll get back to you, tommielintner@ymail.com, soon there should be some videos on here of the setup up in action, also be sure to check out my picture slideshow of the ship we built as well as the cannons, it's in the halloween contest too
https://www.instructables.com/id/the-Black-Pearl/