Assignment 2 Technical Document Final

8/2/2019 Assignment 2 Technical Document Final

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Page No.

List of Illustrations ---------------------------------------------------------------------- 2-3

Introduction

Purpose --------------------------------------------------------------------------------------------- 4

Scope ------------------------------------------------------------------------------------------------ 4

Intended Users ------------------------------------------------------------------------------------ 4

Usage ------------------------------------------------------------------------------------------------ 4

Safety Information ---------------------------------------------------------------------------- 4-5

Process Description ----------------------------------------------------------------------- 6

Required Tools List ------------------------------------------------------------------------ 7

Materials List --------------------------------------------------------------------------- 8-11

Before You Begin ------------------------------------------------------------------------- 12

Directions

Assembling the Air Chamber ----------------------------------------------------------- 13-16

Assembling the Barrel ------------------------------------------------------------------------- 17

Assembling the Trigger Valve ----------------------------------------------------------- 18-21

Assembling the Receiver --------------------------------------------------------------------- 22

Final Assembly ----------------------------------------------------------------------------- 23-24Testing and Operation

Air Chamber Pressure Test ------------------------------------------------------------------- 25

Trigger Valve Test ------------------------------------------------------------------------- 25-26

Operation ---------------------------------------------------------------------------- 26

Launching A T-Shirt ----------------------------------------------------------------- 26

Future Options ---------------------------------------------------------------------- 27


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Page No.

Figure 1: Process Flow -------------------------------------------------------------------------- 6

Figure 2: Sch. 40 Example 1 ------------------------------------------------------------------- 8Figure 3: Sch. 40 Example 2 ------------------------------------------------------------------- 8

Figure 4: PVC Primer -------------------------------------------------------------------------- 12

Figure 5: Heavy Duty PVC Cement --------------------------------------------------------- 12

Figure 6: PVC Bonding Directions ---------------------------------------------------------- 12

Figure 7: Air Chamber (Step 2) ------------------------------------------------------------- 13

Figure 8: Air Chamber Bushings (Dry-Fit) ------------------------------------------------ 13

Figure 9: Air Chamber Bushings (Bonded) ----------------------------------------------- 14

Figure 10: Drilling Air Chamber Inlet ------------------------------------------------------ 14Figure 11: Thread Cutting Tool ------------------------------------------------------------- 14

Figure 12: Cutting Air Chamber Threads ------------------------------------------------- 14

Figure13: Applying Teflon Tape to Threads --------------------------------------------- 15

Figure 14: Air Chamber Inlet Nipple ------------------------------------------------------- 15

Figure 15: Pressure Gage and Schrader Valve Configuration ----------------------- 15

Figure 16: Assembled Air Chamber Inlet ------------------------------------------------- 15

Figure 17: Installed Air Chamber Inlet ---------------------------------------------------- 16

Figure 18: Drilling Air Chamber Cap ------------------------------------------------------- 16

Figure 19: Safety Pressure Valve ----------------------------------------------------------- 16

Figure 20: Completed Air Chamber ------------------------------------------------------- 16

Figure 21: Threaded Barrel Connector --------------------------------------------------- 17

Figure 22: Completed Barrel ---------------------------------------------------------------- 17

Figure 23: Unmodified Irrigation Valve --------------------------------------------------- 18

Figure 24: Electronic Actuator Removed ------------------------------------------------- 18

Figure 25: Removing Top Screws ---------------------------------------------------------- 19

Figure 26: Disassembled Irrigation Valve ------------------------------------------------ 19

Figure 27: Taping Valve Hole ---------------------------------------------------------------- 19

Figure 28: J-B WELD --------------------------------------------------------------------------- 19

Figure 29: Sealed Valve Cavity -------------------------------------------------------------- 20

Figure 30: Cutting Valve Body Threads --------------------------------------------------- 20


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List of Illustrations (continued)

Figure 31: Valve Nipple Installed ----------------------------------------------------------- 20

Figure 32: Reassembling Irrigation Valve ------------------------------------------------ 21

Figure 33: Reinstalling Valve Body Screws ----------------------------------------------- 21

Figure 34: Cutting Blow Gun Tube --------------------------------------------------------- 21

Figure 35: Assembled Receiver Adapter ------------------------------------------------- 22

Figure 36: Bonded Receiver Pipe ---------------------------------------------------------- 22

Figure 37: Attached Trigger Handle ------------------------------------------------------- 23

Figure 38: Air Chamber Threads ----------------------------------------------------------- 23

Figure 39: Air Chamber/Trigger Valve Assembly --------------------------------------- 23

Figure 40: Marking Receiver Pipe for Cutting ------------------------------------------- 24

Figure 41: Bonded Receiver Pipe ---------------------------------------------------------- 24

Figure 42: Attaching Zip Ties ---------------------------------------------------------------- 24

Figure 43: Completed Air Cannon --------------------------------------------------------- 25


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PurposeAir cannons are used to launch various projectiles in such a way which surpasses the

throwing range of an ordinary human being. You may have witnessed them in use at

sporting events where individuals on the field launch t-shirts, footballs or other

promotional items to fans in the nosebleed section of a stadium, or on a less powerful scale,

at carnivals where a participant would shoot foam or other soft balls at targets in order to

win a prize. Structural engineers use air cannons to launch two by fours at walls, doors and

windows to evaluate safety while developing tornado resistant building materials, while

still others use air cannons for pure recreational use and entertainment to launch potatoes,

pumpkins or other various produce items distances from 100 yards and up to nearly a mile.

The air cannon you will be building in this project will have a range of 50-200 yards,

depending on the size, shape and weight of the projectile and is also designed withversatility in mind due to the option for interchangeable barrel sizes in the future.

ScopeThis instructional document will direct you through the entire building process from

selecting proper materials to final assembly, testing and operation.

Intended UsersThe individual who will utilizing this instructional document will have a working

knowledge of the tools and their uses required for this project, but not necessarily have

experience when working with plumbing materials. The user will have safety as a top

priority at all times.

UsageThe instructions in this document are intended to be completed in sequence. Failure to

follow the sequence as set forth herein may cause unintended operation and potentially

imminent danger.

Safety Information

It is the users responsibility to research, observe and comply with all local, stateand federal laws and statutes which may govern, regulate of restrict the use or

possession air cannons.

Read and abide by ALL directions and safety precautions within this document.


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Safety Information (continued)

NEVER point the air cannon at any person whether or not the barrel is loaded or theair chamber pressurized. ALWAYS point the air cannon in a safe direction when

using or loading.

ALWAYS treat this unit with the same duty of care as if it were a firearm.

Do not place your hand or fingers on the firing mechanism unless the gun is pointedat the intended target.

ALWAYS launch the air cannon in a safe direction. This means NEVER point or fire atanything that you cannot clearly and identify easily as a target.

Air cannons can be dangerous and even deadly when improperly handled. Neverstore or transport a loaded air cannon. Do not load the air cannon unless you intend

to shoot it immediately.

NEVER attempt to pressurize the air chamber above 100 psi. The pressure safetyvalve it set to open if the pressure rises above 115 psi.

DO NOT attempt to circumvent the pressure safety valve. It is installed for yoursafety and protection.

DO NOT use or pressurize the air cannon if it is become broken, damaged or if youhave dropped it on a hard surface until a full inspection is performed on the

components and joints.

ALWAYS perform an inspection on the air cannon before and after use to check fordamage or leaks.

Always remember to discharge the air chamber pressure when not in use by gentlyopening the safety pop-off valve.

The user of this document assumes ALL liability and risk associated with ANYactions taken pursuant to the information contained herein.

This instructional document is for educational and instructional purposes only. The author of this instructional document is not responsible for the use or misuse of

the plans or any device created from the plans.

----------------------------------- IMPORTANT -----------------------------------

REVIEW ALL OF THE ABOVE SAFETY INFORMATION BEFORE BEGINNING THIS PROJECT

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Read Entire Manual

It is IMPERATIVE that the user read and

understand the entire instructional guide before

starting any processed described herein.

Gather Tools and Materials

Gather all of the tools and materials necessary to

perform each step of every process as instructed

by this guide.

Assemble the Air Chamber

In this process you build the air chamber to the

air cannon, which will be filled with and hold the

pressurized air until released with the trigger

valve.

Assemble the Barrel

The barrel of the air cannon will consist of a 3

diameter barrel, 24 long with a threaded

connector which attached to the receiver.

Assemble the Trigger Valve

Trigger valve is an irrigation sprinkler valve

which will be modified for use in this application.The trigger valve effects a rapid release of air

pressure from the air chamber during operation.

Assemble the Receiver

The receiver is the pipe and adapters which

connect from the outlet of the trigger valve to the

inlet of the barrel.

Final Assembly

The final assembly is possible once all of theindividual components to the air cannon are

assembled.

Testing and Operation

After final assembly the air chamber will be

pressure tested and the trigger valve will be

tested for functionality. A brief on the operation

will also take place. Figure 1: Process Flow

START

Read

Gather Tools & Materials

Air Chamber

Barrel

Trigger Valve

Receiver

Final Assembly

Testing and Operation


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The tools required for this project are common and easy to find in hardware stores if not in

the garages an average hobbyist. The only tool which may be more difficult to find is the

Pipe Thread Tapping Tool, which may need to be sourced from a plumbing or specialty tool

supplier. Be absolutely certain about the type of PVC cement you purchase as further

described in the warning below.

Required Tools

PVC Primer (Purple or Clear)

PVC Cement (Heavy Duty) - SEE WARNING

Power Drill or Drill Press

15/32" Drill Bit

1/4" Pipe Thread Tapping (cutting) Tool

Adjustable (Crescent) Wrench

1 Roll Teflon Thread Seal Tape

Bench Vise or Other Stationary Clamping Device

#2 Phillips Screwdriver

Flat Head Screwdriver

Heavy Duty Box Tape (2-3" Piece)

J-B WELD Epoxy & Sealant

Popsicle Stick (For Mixing J-B WELD)

Hacksaw

Rasp (file)

Measuring Tape

Utility Knife

Permanent Marker4 10-12" Heavy-Duty Zip Ties (Or A Single 3' Tie)

Air Compressor

Safety Goggles or Glasses

DANGER: Do NOT substitute PVC

cement with multi-purpose

plumbing cement, which is labeled

for use on PVC, CPVC and ABSplastic materials. This type of

cement does not create as strong

of a bond as single-purpose PVC

cement. Doing so in this

application may cause joint leaks

or possible bursting or explosion

resulting in severe injury or death.

DANGER: ALWAYS remember to

wear safety glasses, goggles or

other appropriate eye protection

when working with tools and

when building, testing and

operating the air cannon


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The materials list for the air cannon is extensive, but nearly all of the plumbing parts can be

purchased at your local hardware or plumbing store. Gather all of the materials necessary

for each component prior to beginning building each phase of the air cannon.

Danger: ALL PVC used in this project should be Schedule 40 rated PVC, generally

indicated with a Sch. 40 marking on each part, as shown in the figures below.

Schedule 40 PVC is pressure rated (generally up to 200 psi) and able to withstand

the pressure which will be utilized in this application. Failure to use Schedule 40

PVC will cause a risk of bursting or explosion of the air cannon during use which

may result in severe injury or death.

Component Description Picture Source

Air Chamber4" Sch. 40 PVC Pipe - 16" in

LengthThe Home Depot

Air Chamber 4" Sch. 40 PVC Coupling The Home Depot

Air Chamber4" to 3" Sch. 40 PVC Reducer

BushingThe Home Depot

Figure 2: Sch. 40 Example 1 Figure 3: Sch. 40 Example 2


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Air Chamber1" Sch. 40 PVC Pipe - Approx

2" in LengthThe Home Depot

Air Chamber1" Sch. 40 PVC Female to Male

Threaded AdapterThe Home Depot

Air Chamber 1/4" Brass Hex Nipple The Home Depot

Air Chamber 1/4" Brass Pipe Tee The Home Depot

Air Chamber 1/4" Brass Schrader Valve

Locke (plumbing)

Supply

Air Chamber

Pressure Guage - 1/8" Male

Pipe Fitting (Capable of up to

120 psi)

NOSHOK, Inc.

www.noshok.com


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Air Chamber1/4" to 1/8" Brass Reducer


Air Chamber 4" Sch. 40 PVC End Cap The Home Depot

Air Chamber1/4" 115 psi Safety Valve

(Pop-Off Valve)Lowe's

Barrel2" Female to 2" Male


Barrel 2" Pipe - 2.5" in Length The Home Depot

Barrel 3" to 2" Reducer Bushing The Home Depot

Barrel 3" Coupling The Home Depot

Barrel 3" Pipe - 24" in Length The Home Depot


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Trigger ValveIrrigation Sprinkler Valve

1" Female ThreadedThe Home Depot

Trigger Valve 1/4" Brass Hex Nipple The Home Depot

Trigger Valve Air Compressor Blow Gun The Home Depot

Receiver1" Female to Male Threaded

ElbowThe Home Depot

Receiver 1" Pipe - Approx 6" in Length The Home Depot

Receiver 1" Street Elbow The Home Depot

Receiver 2" to 1" Reducer Bushing The Home Depot

Receiver2" Female to 2" Female



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Before you begin assembling the air cannon, you must bear in mind how critical the strength

and integrity of each cemented PVC bond on the unit is to your own personal safety and the

safety of others around you. Review the information below describing Proper PVC Bonding

Technique BEFORE continuing.

Figure 6: PVC Bonding Directions

Step 1: Apply PVC primer to the

hub of the pipe fitting, spreading

with the applicator to coat the

entire surface to be bonded.

Step 2: Apply PVC primer to endof the pipe and let primer dry for

about 1 minute before applying

cement.

Step 3: When primer is dry, apply

clear PVC cement to the hub and

pipe end of the fitting spreading

to coat the entire primed surface.

Step 4: Without delay, push the

pipe into the hub of the fitting

WHILE turning the pipe about

one-quarter turn. This removes

any air bubbles which may have

formed in the cement. Hold for 1minute.

Step 5: Wipe off excess glue with

a cloth or towel.

Figure 5:

Heavy Duty PVC Cement

Figure 4: PVC Primer

Danger: Avoid contact

of PVC chemicals with

skin, eyes or any body

part. Avoid breathing ofvapors and use in well

ventilated area. Follow

all product label

directions, precautions

and warnings during

use.


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Assembling the Air ChamberThe strength and integrity of the air chamber is one of the most important factors to safety

and desired operation of the air cannon. The air chamber is constructed using 4 pipe and

will hold the air pressure until released by the trigger valve. Attached to the chamber will

be a cap on one end with the safety pressure valve, the pressure gage, the air inlet valve

(Schrader valve) and the reducer bushings so that the air chamber may be threaded onto

the trigger valve.

Warning: Make sure you have studied proper PVC bonding techniques as

previously discussed in this guide before proceeding.

1. Gather the listed materials required to

build the air chamber

2. Bond the 4 x 16 long pipe to the 4

coupling using the aforementioned

proper PVC bonding technique.

See Figure 7

3. Prepare a dry-fit of the reducing

bushings and threaded adapter to verify

compatibility prior to bonding.

These items include:

4 to 3 reducer bushing 3 to 2 reducer bushing 2 to 1 reducer bushing 1 pipe2 in length 1 female to 1 male threaded

adapter

See Figure 8

Caution: Be sure to NOT press the pieces so firmly together leaving them difficult to

separate by hand prior to permanent bonding.

Figure 7: Air Chamber (Step 2)

Figure 8: Air Chamber Bushings (Dry-Fit)


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4. Separate the dry-fit components from

the previous step and bond them

permanently with PVC primer and cement

using proper PVC bonding technique.

See Figure 9

5. Drill a 15/32 hole through the coupling

and pipe wall approximately 1 from the

inside edge of the coupling. Deburr and

clean the edges of the hole, if necessary.

See Figure 10

6. Using the 1/4 male pipe thread tapping

tool, carefully begin to hand-thread the

tool into the hole. Try to keep the tool as

perpendicular to the pipe as possible.

See Figure 11

7. Once the tapping tool becomes too

difficult to turn by hand, continue to

thread the tool into the hole using an

adjustable wrench and cut the threads

until approximately 1 of the tapping tool

has been inserted into the hole.

See Figure 12

Figure 9: Air Chamber Bushings (Bonded)

Figure 10: Drilling Air Chamber Inlet

Figure 11: Thread Cutting Tool

Figure 12: Cutting Air Chamber Threads


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8. Wrap one end of the 1/4" brass hex

nipple approximately 3-4 layers of Teflon

thread seal tape.

See Figure 13

9. Thread the nipple into the pipe and

tighten with the wrench until flush with

the surface.

See Figure 14

This brass nipple will connect to a pipe tee which will provide ports for the fill valve

(Schrader valve) and for the air pressure gage.

10. Prepare the 1/4 brass pipe tee, air

pressure gage, 1/4 to 1/8 brass reducer

bushing and brass Schrader valve forconnection by wrapping the threads with

3-4 layers of Teflon thread seal tape

similar to step 8 above.

See Figure 15

11. Connect the components in the

configuration shown in step 10 and

tighten them firmly with a wrench. The

bench vise will be very helpful in this step

by holding the brass tee in place while

tightening the connecting components.

See Figure 16

Figure 13: Applying Teflon Tape to Threads

Figure 14: Air Chamber Inlet Nipple

Figure 15: Pressure Gage and Schrader

Valve Configuration

Figure 16: Assembled Air Chamber Inlet


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12. Prepare the brass nipple on the air

chamber for connection with thread seal

tape and connect the assembled tee to the

chamber. Tighten firmly and position the

tee as shown in Figure 17.

13. Drill a 15/32 hole in the center of the 4

end cap.

See Figure 18

14. Using the same technique in steps 6-7, cut

pipe threads into the hole then remove alldebris created from the drilling and

thread cutting process.

15. Prepare the 1/4" brass safety pop-off

valve for connection by applying Teflon

thread seal tape, thread into the 4 end

cap and tighten firmly with a wrench.See Figure 19

You will now prepare the 4 end cap for connection to the air chamber. In performing steps

5-7, debris such as PVC shavings and curls has fallen into and collected in the air chamber.

Now is the time to clean all debris from inside the air chamber before sealing it with the

end cap because you will not have access to this area after step.

16. Bond the 4 end cap to the air chamber

using proper PVC bonding technique.

Figure 20 shows the completed air

chamber. Set aside until the air cannon

final assembly.

Figure 17: Installed Air Chamber Inlet

Figure 18: Drilling Air Chamber Cap

Figure 19: Safety Pressure Valve

Figure 20: Completed Air Chamber


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Assembling the BarrelThe barrel of the air cannon will hold the projectile prior to launching. Just like the air

chamber, the barrel must be capable of withstanding a significant amount of air pressure.

The difference between the barrel and the air chamber, however is that the barrel will be

subject to instantaneous pressure spikes when the air is released from the chamber,

therefore the integrity of the barrel connections is crucial to the safety of the individualusing the air cannon. The air chamber is constructed of 3 pipe which will be reduced to 2

pipe and connected to a 2 male threaded adapter which will attach to the air cannon via

the barrel receiver.

1. Prepare a dry-fit of the barrel coupling,

reducer bushings and threaded adapter to

verify compatibility prior to bonding.

These items include:

3 coupling 3 to 2 reducer bushing 2 pipe2.5 in length 2 female to 2 male threaded

adapter


the previous step and bond them togetherusing proper PVC bonding technique. The

assembled barrel connector is shown in

Figure 21.

3. Bond the 3 x 24 barrel to the barrel

connector coupling using proper PVC

cementing technique. Figure 22 shows the

completed barrel. Set the barrel aside

until the air cannon final assembly.

Figure 21: Threaded Barrel Connector

Figure 22: Completed Barrel


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Assembling the Trigger ValveThe trigger valve is a unique component in this model of air cannon due to the fact that it is

not a typical PVC or brass pipe fitting. The trigger valve is actually an electronically

actuated sprinkler valve used residential and commercial lawn irrigation systems which

will be modified for use in this application. The purpose for using this type of valve as a

trigger in the air cannon, as opposed to using a standard brass or PVC ball valve, is thatvalve can open and release the pressure from the air chamber much more rapidly, near

instantaneous, which can have a dramatic effect on the power and speed in which the

projectile is launched from the barrel.

The modification of the valve as described in the steps below removes the electronic

actuation motor and essentially turns it into a manually operated combo valve, whereby

opening the outer valve via the trigger handle effects the opening of the main pressure

release valve, thereby releasing the pressure from the air chamber and allowing rapid flow

into the receiver and barrel of the air cannon.

Caution: Pay attention to this process carefully because performing the steps

incorrectly may render the valve permanently inoperable.

1. The trigger comes from the box with the

electronic actuator motor attached. The

actuator is the black cylinder with two

wire leads attached.

See Figure 23

2. Remove the electronic actuator by

unscrewing it from the valve body.

Discard, if desired.

See Figure 24

Figure 23: Unmodified Irrigation Valve

Figure 24: Electronic Actuator Removed


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3. Using a screwdriver, remove 8 screws

from the circumference of the valve body

and set aside. These screws will be used

again when reassembling the valve.

See Figure 25

4. Separate the top half from the bottom half

of the valve body. You may need to use a

flat head screwdriver along the seam to

pry apart the pieces. Be careful not to cut

the rubber seal just inside the outer edge

of the seam. Set the base and spring aside.See Figure 26

5. Apply a small piece of heavy duty box

tape covering the small square-shaped

hole along the inside edge of the valve

body. This will prevent leakage of the

sealant into the inner valve.

See Figure 27

6. Prepare a mixture of equal parts

J-B WELD (steel + hardener) sealant to be

applied to the cavity where the electronic

actuator was located. Mix the twocomponents together thoroughly with a

popsicle stick on a thick piece of paper or

cardboard. You will need approximately

15cc, or a half-dollar size amount of

prepared sealant.

Figure 25: Removing Top Screws

Figure 26: Disassembled Irrigation Valve

Figure 27: Taping Valve Hole

Figure 28: J-B Weld


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Danger: Avoid contact of J-B WELD with skin, eyes or any other body part. Use in a

well ventilated area to avoid breathing of vapors. Follow all directions, safety

precautions and warnings included on the product packaging.

7. Transfer the prepared J-B WELD sealant

mixture with the popsicle stick to the

threaded cavity on top of the valve body

covering the air ports inside completely.

Transfer the entire mixture to the cavity.

Place the valve body on a flat, even

surface to cure and this process will allow

the J-B WELD to settle into a smooth, even

seal inside the hole as shown in Figure 29.

Caution: You must allow the sealant to cure 10-12 hours before proceeding.

8. Now that the sealant is fully cured,

remove the heavy duty tape which was

applied previously in step 5. Drill another

15/32 hole in the center of the valve

body and cut 1/4" pipe threads with the

thread cutting tool. Be sure to center thehole as closely as possible within the

circle.

See Figure 30

9. Prepare the other 1/4" brass nipple with

Teflon thread seal tape and thread into

the hole in the valve body as shown in

Figure 31. Tighten thoroughly with awrench. The trigger handle will attach to

this brass nipple which will allow the

valve to be opened manually.

Figure 29: Sealed Valve Cavity

Figure 30: Cutting Valve Body Threads

Figure 31: Valve Nipple Installed


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The modifications to the sprinkler valve are now complete and it is time to reassemble the

unit and prepare the trigger valve for assembly.

10. Re-attach the top of the valve body to the

base of the valve body while carefully

centering and aligning the internal spring

and the screw holes along the outerdiameter.

See Figure 32

11. Reinstall the screws which seal and hold

the valve together and thread the screws

in by hand until they are about halfway

inserted as shown in Figure 33.Tightenthe screws with a Phillips screwdriver

and set the unit aside until final assembly.

Caution: The valve body is made of softer plastic material. When tightening the

valve body screws with the screwdriver, be as careful as possible not to over-torquethe screws causing them to strip the threads of the valve body. This will cause the

valve to leak under pressure and result in undesired operation of the air cannon.

The air compressor blow gun which will connect to the irrigation valve consists of a plastic

body, plastic trigger, brass threaded receiver and a metal tube approximately 4-5 long. The

metal tube will not be need in this project and will need to be cut from the blow gun. The

blow gun will be attached to the modified irrigation valve during final assembly.

12. Using the bench vise to hold the blow gun

firmly, use a hack saw to cut the metal

tube off as close to the blow gun handle as

possible. Set aside until the air cannon

final assembly.

See Figure 34

Figure 32: Reassembling Irrigation Valve

Figure 33: Reinstalling Valve Body Screws

Figure 34: Cutting Blow Gun Tube


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Assembling the ReceiverThe receiver of the air cannon consists of the pipe and adapters which connect the trigger

valve to the barrel. The receiving end which attaches to the barrel has a 2 threaded female

adapter which would allow multiple sizes and types of barrels should you wish to build

them.

1. Prepare a dry-fit of the receiving

adapter components to verify

compatibility prior to bonding. These

items include:

2 female pipe to 2 femalethreaded adapter

2 to 1 reducer bushing 1 street elbow


the previous step and bond them together

using proper PVC bonding technique. The

assembled receiving adapter is shown in

Figure 35.

The second part of the receiver is the 1 male threaded elbow and the 1 PVC connecting

pipe. The second part will not be bonded to the receiving adapter above until the final

assembly process.

3. Bond the 1 x 6 PVC pipe to the 1 male

threaded elbow as shown in Figure 36. Be

sure to remember proper PVC bonding

technique.

Figure 35: Assembled Receiver Adapter

Figure 36: Bonded Receiver Pipe


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Final AssemblyNow that all of the individual components of the air cannon are assembled and all adhesive

is fully cured, it is time to assemble the components into one unit. You may want to refer to

the picture of the fully assembled air cannon on the cover page for reference.

Caution: The trigger valve is directional and air flows only one way through the 1

female threaded ends of the trigger valve, or the inlet and outlet. The body of the

valve will have arrows ( ) indicating the flow direction of the valve.

Steps 1, 2 and 4 below involve connecting components to the trigger valve and

ensuring these connections are made on the appropriate side of the valve is critical.

1. Wrap the 1/4" brass nipple on the trigger

valve with 3-4 layers of Teflon thread seal

tape and attach the air compressor blow

gun. Turn the handle until almost

completely tight and then point the

trigger lever towards the inletend of the

valve body.

See Figure 37

2. Wrap the threads on the 1 male threaded

adapter located on the end of the air

chamber with 3-4 layers of Teflon thread

seal tape and attach to the trigger valve

on the inletside. Turn until the valve is

firmly attached and continue turning until

air pressure gage is at the 10 oclock

position and the valve handle is in the 6

oclock position.

See Figures 38 and 39

Figure 37: Attached Trigger Handle

Figure 38: Air Chamber Threads

Figure 39: Air Chamber/Trigger Valve

Assembly


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3. Insert the 2 male threaded barrel connector into the 2 female threaded receiving

adapter and turn until hand tight. Do not over-tighten and do not apply Teflon

thread seal tape when connecting these components.

4. Wrap the 1 threads on the male threaded elbow from the lower half of the receiver

with 3-4 layers of Teflon thread seal tape and insert into the outletend of the

trigger valve. Continue turning until the connection is tight and the 1 pipe is in the12 oclock position in comparison to the pressure gage and trigger handle.

5. Lay the barrel and other components side

by side where the barrel touches the air

chamber and make a cutting line with a

marker on the 1 receiver pipe to allow

enough material to be bonded into the

receiving adapter.

See Figure 40

6. Remove the 1 receiver pipe from the trigger valve and make a cut with a hacksaw

at the cutting line. The bench vise may come in handy one more time to hold the

pipe steady while making the cut. File the cutting debris left on the edge of the pipe

with the rasp. Re-attach the receiver to the trigger valve in preparation for the next

step.

7. Using proper PVC bonding technique,bond the receiving pipe to the receiving

adapter with the barrel attached as

shown in Figure 41. This is a one-time

shot at aligning the barrel and air

chamber correctly. As soon as you press

the pieces together with the cement

applied rotate the barrel to come into

alignment with the air chamber.

8. In order to hold the air chamber and

barrel securely, attach a series of zip ties

around the air chamber and barrel along

the inside edge of the air chamber end cap

as shown in Figure 42.

Figure 40: Marking Receiver Pipe for

Cutting

Figure 41: Bonded Receiver Pipe

Figure 42: Attaching Zip Ties


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Air Chamber Pressure TestThe pressure test of the air chamber is the first in a series of steps which will test the

functionality of the air cannon. Make sure you wear safety goggles!

1. Begin this test by pressurizing the air chamber with an air compressor to 20 psi andwait 3-5 minutes. Observe the pressure gage and note if the chamber holds thepressure for the entire period. Slightpressure drops (0-5 psi) are normal the first

few times the chamber is pressurized. Release the pressure by manually opening the

pressure safety valve.

2. Repeat the process in Step 1 at 40 psi, 80 psi and finally at the maximum 100 psi.3. If pressure leaks are found, determine the source of the leak and take the

appropriate steps necessary to remedy the leak. This may be as simply as applying

more Teflon thread seal tape to leaking joints.

Trigger Valve Test

1. Pressurize the air chamber to 40 psi and, while pointing the air cannon in a safedirection, release the pressure using the trigger valve.

NOTE: Squeeze the trigger valve quickly and completely. (Squeezing the

trigger valve slowly does not work well)

Figure 43: Completed Air Cannon


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2. Repeat the process in Step 1 at 60 psi, 80 psi, and 100 psi. Be prepared because the

air cannon will become increasingly LOUD as the pressures increases.

Operation

----------------------------------- IMPORTANT -----------------------------------

REVIEW ALL SAFETY INFORMATION ON PAGES 5-6 OF THIS DOCUMENT PRIOR TO USE

PERFORM ALL OPERATIONAL TESTS DESCRIBED ABOVE PRIOR TO USE

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During the testing process, you should now be familiar with the general functionality and

mechanism of the air cannon and you are ready to start launching projectiles, but first you

must understand how to load the barrel.

In order for the air pressure released from the air chamber to have the greatest effect on

desired projectile, the projectile must seal as tightly as possible in the barrel. If there is any

airspace between the walls of the barrel and the projectile, the majority of the air pressure

will simply bypass the projectile and will not propel the projectile with any substantial

force. Choose a projectile that can be slightly compressed when loaded into the barrel to

achieve the most effective seal. For smaller projectiles, change to a smaller barrel, which

will be discussed below.

For the purposes of this document, the air cannon will be used for launching t-shirts as

discussed in the introduction.

Launching A T-Shirt1. Fold the t-shirt lengthwise 2-3 times and then tightly roll the shirt into cylindrical

shape, ensuring the rolled shirt will be slightly larger than the internal diameter of

the barrel.

2. Wrap the shirt with 2-3 strips of heavy duty box tape to maintain shape.

3. Insert the shirt into the barrel while slightly compressing the shirt to create a good

seal.

4. Push the shirt down to the base of the barrel.

5. Pressurize the air chamber. 50 psi is the initial recommended air pressure until you

become more comfortable with the air cannon.

6. CAREFULLY pick up the air cannon WITHOUT placing you hand on the trigger

handle.

7. Aim at the intended target and firmly squeeze the trigger handle to launch.


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Future Options

The air cannon built in this instructional document was engineered with the capability to

have interchangeable barrels in order to launch a variety of sizes and types of different

projectiles. A 2 diameter barrel is the optimum size for launching potatoesand a 2.5 size

is the optimum size for launching slightly larger projectiles such as tennis balls. Smaller

diameter barrels such as 1 to 1.5 also have their uses and size of the barrel is determined

by the size of the desired projectile.

By building this air cannon you have now gained enough knowledge and experience to

select appropriate materials and build different barrel sizes. Whatever size (diameter)

barrel you choose, simply install a bushing to increase the size to 2 and attach a 2 male

threaded adapter. Then you can simply detach the 3 barrel, attach the new barrel and

operate as normal.

Have fun and ALWAYS remember to practice safe launching.

Documents

Assignment 2 Technical Document Final