CSV19 Pneumatic Antenna Launcher Instructions

This air-powered Tennis Ball launcher is designed to launch tennis balls over trees towing fishing line. The fishing line is used to pull up nylon twine and wire antennas, or heavier line and larger antennas. This design is 19 inches long and optimized to fit in a Rubbermaid (tm) plastic tote box so that it may be easily deployed to the field. These launchers are used by Amateur Radio groups doing Emergency Service and other portable work, as well as installing antennas in backyard trees.

Document Notes

Version 1.95  2/19/2006

Building the CSV19 (or CSV17) Compact Antenna Launcher

There are several choices available to the builder wanting to build the CSV19 or a variation of this antenna launcher. Collect the parts, or purchase a kit of parts already prepared.

The builder wishing to do it yourself will find instructions below on doing that.

The CSV17 Launcher differs slightly from the CSV19 model. The overall length is reduced to 17 inches, so the barrel and chamber are shorter. The chamber is also constructed from 3" pipe instead of 4" pipe, so the chamber endcaps are also 3". This reduces the weight and bulk considerably. It does require higher pressures to operate, but the smaller volume pumps up very quickly. The CSV17 is well suited to 12 gram CO2 cartridge usage. The maximum height reached by the CSV17 is just over 150 feet, whereas the CSV19 can reach 200 feet under good conditions.

CSV19 Antenna Launcher Standard Materials List

Finding Parts for the CSV19 Antenna Launcher

CSV19 Antenna Launcher Parts Kits

I can make up part kits for the CSV19 antenna launcher. I keep an inventory of parts on hand, though some machining may remain before a kit can be shipped.

The two bored endcaps are the most difficult parts to make for this launcher. Drilling and tapping the valve is a bit difficult as well, and requires a different size drill and tap than the pressure chamber drilled and tapped holes.

See our new Online Shopping Cart for ordering Kits and accessories.

Parts Kit Contents

Tools, epoxy and Cement Not Included (except as indicated). Reels, Line, Tennis Balls and Ramrods not included (except as indicated). These are parts, not complete units. Assembly required. Subject to availability of my time and components.

Local Parts Sources

CSV19 Antenna Launcher Kit Assembly

The kit builder should read all the instructions about cutting and preparing the parts as some steps may be required - such as deburring, filing off sharp sprue, etc, even though the precision boring and cutting is already complete. They should clean and inspect the parts and follow the instructions for cementing and assembly in the general assembly instructions below.

Recommended Tools and Supplies required for Kit Assembly

CSV19 Antenna Launcher General Assembly Instructions

These instructions are merely a guide of what has worked for us - think through your plan and understand what you are doing. Plan your work, and work your plan... Cemented joints are very good, but hard to change later... Read all instructions before starting. Reread each step through before performing. The cementing is essentially a binary combination process. In each stage as many components are joined in separate subassemblies as possible. In subsequent steps these subassemblies are combined. There are many other ways to do this, but if you decide to change the order be very sure that the new order works.

The quality of your work affects the safety of the finished launcher. Just the other day I read about someone who completely forgot to glue one of their joints in the pressure section of their launcher (a design of their own, not this one). The parts were wedged together very tightly (this can happen while trial fitting - be careful). It held for awhile, then let go with a bang at high pressure. The PVC part that came off turned into a projectile and bounced around their shop and broke the overhead lights, sending a shower of broken glass down on the builder. These joints, done properly, have a significant safety margin. Do them well.

Above all - BE SAFE.

Parts Preparation

Cutting PVC Pipe

I use carbide blades in the radial arm saw to cut PVC pipe. It may also be cut with a hacksaw, bandsaw, or other fine tooth saw. After cutting it is good to deburr and slightly round the sharp edges with a file, sandpaper or deburring tool. A sharp edge on the pipe can reportedly scrape the cement away and cause a potential weak spot in the joint. One fellow reports that he puts his PVC parts into the bathtub with warm water and goes after the outside surfaces with SOS pads or equivalent. This makes the PVC look great and it will take paint well. Light sanding should also be effective, generally on the pipe rather than the fittings. The fittings are usually much better looking, and you can pick through them when buying. Purchasing a cut length doesn't allow the flexibility of inspecting the piece ahead of time. If you plan to paint the fittings sanding off the slick finish will help the paint adhere.

Krylon makes paint specifically for plastic called Krylon Fusion. It is reported to work well on PVC.

The pipe we are using is not necessarily 'pretty' when it is purchased - it may have scratches, rust stains, etc from the storage and transportation. Make sure the material is sound - not cracked or fractured or deeply scarred with scratches. Occasionally I have to throw some away due to these flaws, especially in the larger diameters and near the ends.

It is important to avoid cracking or fracturing the PVC when working with it. Use sharp tools and avoid cutting too fast. Even minor fractures can lead to failure later on. This can be a problem when drilling, tapping, boring, or cutting the PVC. Any fractured PVC should be recut to remove fractured parts or discarded.

CSV19 Antenna Launcher Cut Schedule

Note that if you have a kit all the cutting is already done.

Preparing the End Caps

I use a metal lathe to bore holes in endcaps. These holes must be very close fitting and cleanly cut for a good safe joint. I first bore to 1/2" with a drillbit in the tailstock, then I use a carbide tipped boring bar to take out 0.030 or 0.040 passes up to near the final diameter, then the last 2 passes are adjusted for a tight fit, perhaps 0.003 or less clearance. I make it a snug fit - the parts should optimally go together with some friction.

Preparing the Sprinkler Valve

Solvent Cementing Procedures (EVERYONE READ)

Epoxy Gluing Procedures (EVERYONE READ)

Epoxy Selection

  • Bottom line - get one 14ml double-syringe of flow-mix, and one 25ml double-syringe of 2-ton epoxy. Collect three small mixing cups (1 oz) and one larger cup (2 oz) plus four mixing stirrers. Or get the kit from the order page. (This is all included in the Super Kit).

    Preparation for Epoxy (EVERYONE READ)

    Mixing Epoxy (EVERYONE READ)

    Threaded Joints

    CSV19 Launcher Assembly Photos

    The Valve Top above has been prepared by epoxying closed the three small openings (two are visible in the solenoid socket, the third is under the trigger valve). The Trigger has been epoxied into the brass elbow and that epoxied into the sprinkler valve top in the proper position between the mounting screws.

    The endcap above has been bored to closely fit the short pipe and the pipe solvent cemented into the hole. The supporting ring has been solvent cemented around the pipe inside the endcap, and a puddle of epoxy has been poured around the support ring to lock it in place.

    The three photos above show the drilling and tapping of the pressure chamber for the fill valve and the pressure gauge. It is drilled in the double thick area to provide maximum support for the threads.

    CSV19 Antenna Launcher Parts Assembly (EVERYONE)

    Clearly familiarize yourself with all parts before proceeding. Trial fit them loosely together to insure that they are all accounted for and the fit is snug. Be careful in trial fitting them as they can stick together if inserted too far. Do not insert them with any force - stop when slight resistance is felt. It is normal for them to fit tightly - the cement lubricates the joints during assembly so they can be fully inserted.
    Solvent cement the ramrod handle (1/2" pipe) into the ramrod bushing (1/2 by 1.5 or 2"). Insure that the pipe is fully into the socket. Note that these parts often fit together so tightly without cement that cementing may be optional, but this is a good part to practice on. NOTE that wherever the instructions say "solvent cement" you should use PVC primer and PVC cement. EPOXY will be specified for the few joints it is to be used.
    Locate the 1.25" elbow that has been fitted to the bored hole in the 2.5" endcap. Observe that the elbow has one end that fits better into the barrel endcap than the other due to the raised lettering that interferes with the tight hole in the endcap. Reserve the better fitting end for the barrel endcap - mark it.
    Solvent cement the 1.25" short joiner pipe into the other end of this barrel elbow. Prime the interior socket of the elbow with purple primer, and half the 1.25" short joining pipe. Coat the socket and half the pipe with a coat of PVC cement. Stand the 1.25" pipe with the cemented end up on the work surface. Push the elbow down onto the pipe until it is fully seated. Clean off the excess glue and set aside to dry.
    Solvent cement the 1" to 1.25" bushing into one end of the other 1.25" elbow. One end of the elbow has two mold lines. Cement the bushing into the end that does not have mold lines (as these lines aid in alignment of the elbow during a later step). If the bushing has been shortened it will fit approximately flush, otherwise it will stick out a bit. MAKE SURE that the bushing is installed the right way. If the bushing has been shortened it will fit either way. The correct direction is with the internal stop ring deeper into the elbow. The stop ring should not interfere with the later installation of the 1" pipe inside to a depth of 3/4". NOTE that wherever the instructions say "solvent cement" you should use PVC primer and PVC cement. Prime both the pipe and the socket with purple primer, then coat both surfaces with a thin layer of cement. Set the bushing with the internal stop ring up on a paper towel on the work surface. PUsh the elbow fully down on the bushing. Push against a paper towel on the benchtop to seat the bushing fully in. Wipe up excess cement with paper towels and Q tips.
    Solvent cement the 1" diameter short pipe and ring into the bored hole in the large pressure chamber endcap. NOTE - after 9/15/05 this short pipe is supplied using the stronger schedule 80 material. It is dark grey rather than the usual white PVC. It is installed using the same procedure and cement as before. (Depending on your parts it might be a slightly different length. It should fill the coupler ring, the endcap and have enough left sticking out to fully fill the valve socket. See the cut schedule above for details). This joint holds full pressure for extended periods so it is imortant that it be a good joint. Prepare the endcap, masking it on the inside to protect the inside vertical glueing surfaces to be used later for the pressure chamber pipe. Position the 1" pipe so it extends into the endcap about 1/3 of an inch. There should be 0.75" of the pipe sticking out of the endcap to fit the socket in the sprinkler valve. (This may need to be adjusted depending on your particular sprinkler valve socket depth). Wrap masking tape around the 1" pipe where it extends from the endcap to mark where it should sit and discourage cement leakage there. The joint should be tight enough that the cement will not leak. Test the ring on the pipe inside the endcap. Clear any burrs that interfere with installing the reinforcing ring over the 1" pipe. Remove the ring and set it aside. Remove the pipe from the endcap. Using a Q-tip type cotton swab on a stick applicator to apply purple primer to the inside of the hole bored in the endcap, and to the inside of the reinforcing ring. Apply purple primer to the pipe end that is not masked. Apply cement to the hole in the endcap, and to the pipe. Slide the pipe into the endcap up to the masking tape. Apply cement to the inside of the coupler ring and slide that onto the end of the pipe inside the endcap until it contacts the inside of the endcap. After a minute or two remove the masking tape from the 1" pipe and clean up the excess cement.
    Epoxy the three small holes in the valve top. One is the manual actuation port. The other two small holes are the solenoid input and output ports. The inlet port is a small hole in the bottom corner of the solenoid socket. The outlet port is in the center of the solenoid socket. Clean the areas with alcohol. For proper epoxy adhesion these areas must be clean. Mask the inside/bottom of the cap to prevent epoxy from going beyond the three holes toward the inside of the valve. Blue masking tape is good for this, it does not leave adhesive residue. Carefully dribble epoxy down into the small threaded hole (the manual actuation hole). Apply epoxy into the larger threaded solenoid socket and insure that both small holes in it are plugged by the epoxy. This can be done with one large puddle or two small ones.
    Solvent cement the other 1" dia short pipe to the outlet of the sprinkler valve. This is the pipe that will go into the 1.25:1 bushing. (Depending on your parts it may have a slightly different length. The length should be enough to just fill the sprinkler valve and the bushing). Hold and clamp it tightly - the sockets on the sprinkler valves are tapered and the pipe can creep out if not held in tightly for a few minutes.
    Solvent cement the solid pressure chamber endcap on the end of the pressure chamber pipe. Always use purple primer on solvent cemented PVC joints. Get a good coat of primer on both joint surfaces - inside the socket and outside the pipe. This is a large joint, use plenty of cement. Large joints can leak or stick before fully seated if insufficient cement is used. Get it all the way out to the edge to avoid a leak when the holes are drilled and tapped into the plastic later.
    Take a Glue Drying Break. The durations of these breaks are dependent on the cement that is being waited on, and the stress of the next step. Solvent joints can be handled fairly soon, epoxy really depends on the particular cement. Follow manufacturers recommendations. In general, 8 to 24 hours should be sufficient. An easy way to do this is to stop at the glue breaks for the day and start fresh the next day.
    Make a mask to protect the inside of the pressure chamber endcap from epoxy using four 3 by 5 inch cards. Lay them out in a line, overlapping them by about one inch. They should cover an area about 3.5 inches by 15 inches. Tape them into this arrangement. Alternately, a piece of heavy paper or thin cardboard may be cut to 3" by 15".
    Epoxy support the pressure chamber exit pipe. Support the endcap so that it is level. Wrap the cardboard mask into a ring and position it inside the endcap against the inside cement surface to protect it from epoxy splash. Mix a batch of epoxy thoroughly and pour a puddle of epoxy around the 1" pipe inside the endcap. Approximately 20 mL, or half of a 2 ounce epoxy kit (a kit of two 1 oz tubes of 1:1 epoxy and hardener) should be enough. The epoxy puddle should support the pipe/coupler ring to a depth of approximately 0.2". Allow to set overnight, insuring that it stays in the proper orientation with the pipe, keeping the endcap level. Use a level to insure that it is actually level before leaving it to cure.
    Epoxy the trigger valve to the street elbow. Remove the tip, if any, from the air duster and discard it. Thoroughly clean the female threads on the brass street elbow and the male threads on the air duster (trigger) with alcohol. The strength of this joint depends on getting these areas clean. Mix a small batch of epoxy (a puddle just covering the bottom of a small mixing cup is more than enough). Coat the female threads in the brass elbow and the male threads of the air duster with epoxy. Thread the air duster into the brass elbow. Position the street elbow such that, with the outlet tip of the air dister pointed away from you the brass elbow male threads point to the left. The threads should be tight. The flat side of the brass elbow should be parallel to the flat of the handle.
    Take a Glue Drying Break.
    Epoxy the trigger valve to the street elbow and the street elbow to the sprinkler valve top. Trial fit the parts and insure that the fit and alignment are understood. The solenoid attachment hole that you filled earlier sits toward the rear of the launcher. The solenoid socket is toward you and the valve top oriented so the valve would be to the left. The male streen 90 threads then screw into the valve top center about 3 to 4 turns. The trigger should sit over the small threaded hole (the manual actuator hole) and between two mounting screw holes. Place the two screws into the holes before the glue sets and insure that the screwdriver access past the blowgun handle is ok. On the inside of the valve top the street elbow should even with or just barely enter the valve. The brass should be above the flat level of the interior of the valve where the diaphragm moves by about 1/8".. It should not protrude into the valve and limit the diaphragm motion. Make sure this is properly understood before applying epoxy. Take it apart, clean with alcohol, allow to dry, and epoxy the trigger to the valve top. Mix another small batch of epoxy. Coat both the inside of the threaded hole in the valve top and the outside of the brass elbow threads with epoxy. Make sure the alignment is as desired and set the assembly aside to cure.
    Solvent join the second 90 degree elbow to the other end of the short 1.25" diameter pipe that is already cemented to the other elbow. Insure that it is fully together and flat and the open ends of the elbows are pointed the same direction. This forms the U assembly.
    Solvent cement the pressure chamber pipe with cap into the other endcap (with the outlet pipe). This is another big joint - use plenty of cement.
    Take a Glue Drying Break
    Solvent Cement the U assembly into the 2.5" barrel endcap. Using masking tape, cover the inside of the endcap where the barrel will be glued later to prevent cement from spreading there. Use PVC primer and cement. You can apply the primer with a Q tip to prevent it getting where you don't want it. Then apply PVC cement to both the inside of the bored hole and the outside of the elbow. Position the endcap as far as it will go onto the elbow without forcing it. If forced too far it will not be concentric with the elbow.
    Take a Glue Drying Break
    Prop the elbow and endcap level to make the epoxy flow properly. This is a good joint to use the flow-mix epoxy on, if you have any. I use a whole 14ml kit for this joint. The long nozzle gets it down into the joint easily. Or, mix a batch of epoxy and carefully pour it into the endcap around the elbow. Insure that it remains supported and undisturbed while the epoxy cures, and that the proper angle is maintained.
    Drill and tap the two holes into the pressure chamber 1/8-27 NPT. Locate them along a straight line parallel to the axis of the chamber, close to the barrel. Each hole should be about 1.5" from the 'edge' of the endcap. Drill a 1/8" hole first, then use a 5/16 drill. The tap recommends a larger drill but in plastic I prefer a slightly smaller hole and allow the tap to finish the hole. The most difficult part of the drilling/tapping is getting the hole perpendicular to the surface. Take some care to do so, and keep the tap straight into the hole so the gauge and schrader valve come out straight when installed. Tap without lubrication, but work the tap back and forth as you go forward to cut the PVC. The tap is tapered - the deeper you run it in, the larger the hole and threads. Approximately 1/2 to 2/3 of the tap cutting threads has worked well for me - this makes the threads fairly tight for a good seal.
    Clean out the PVC dust - use plenty of compressed air or rinse repeatedly with water. This dust may interfere with valve sealing if not completely removed.
    Take a Glue Drying Break
    Solvent cement the valve outlet tube into the bushing of the barrel assembly. Align the barrel assembly with the valve quickly before the glue sets. The valve top should be parallel to the elbows, the trigger handle should sit alongside the barrel. You may wish to temporarily install the valve top and trigger assembly to aid in alignment. Refer to the photos. Clamp or hold in position until set.
    Take a Glue Drying Break
    Solvent Cement the pressure chamber assembly to the valve inlet. If it is wet from cleaning out the dust, allow it to dry first. This is a critical joint, be sure to clean, purple prime, solvent cement and clamp it well. This is a tight tapered joint, clamp it tightly to avoid creep. Observe the alignment of the holes for the gauge and schrader valve slightly to the right of the barrel when viewed from behind. Make sure there is enough clearance for the gauge and access to the schrader valve for filling. Refer to the photographs for additional guidance.
    Take a Glue Drying Break
    OPTIONAL - if you have a pressure relief valve (they are included in some kits, and are available as an optional item on the order form), drill and tap a third hole opposite the gauge hole on the 'back' side of the barrel, about 1.5 inches from the edge of the endcap. Trial fit the barrel to help find the position for this hole. Placing the pressure relief valve close to the barrel will allow the launcher to lie on a flat surface without touching the relief valve. Install the pressure relief valve in this hole.
    Install the schrader valve and gauge on the pressure chamber. Locate the pressure gauge toward the rear next to the trigger valve, and the schrader valve toward the front of the Launcher.
    Solvent cement the barrel into the 2.5" endcap.
    Take a 24 Hour Glue Drying Break!!!!!!!!!!!!
    Install the valve top/trigger assembly. Align the top of the sprinkler valve with the body by lining up the hole under the solenoid socket (now epoxy filled) with the hole in the diaphragm gasket and valve seat next to the valve outlet port. When starting each screw, turn it slowly backward until it 'clicks' into the thread previously cut, then turn gently forward and slide into the existing thread cut. The screw should go in easily and not start cutting new threads. Carefully tighten the screws in rotation. Do not over-tighten. Observe the compresssion of the rubber diaphragm gasket at the edge of the valve top as the screws are tightened in rotation. The rubber gasked should just show stress at the edges where the plastic is compressing it when adequate tension is reached. A power screwdriver is NOT recommended for this task - the feel of a manual screwdriver is preferred.
    New CSV19 kits are supplied with a Cable Tie and a barrel to chamber spacer. Tieing the barrel to the chamber increases the strength of the system which can reduce breakage if the launcher is dropped on a hard surface. The supplied spacer is a short length of 3/4" dowel (or 1/2" PVC square rod) with double stick foam tape on the ends. This is the right spacing for most launchers, but some will require a different length spacer. Cut a new spacer from a length of dowel or other suitable material if needed. Remove the cover from the foam tape and insert the spacer between the barrel and chamber. Stick it to the chamber and barrel. Wrap the large cable tie around the barrel and chamber and tighten with the joint on the back side of the launcher. Carefully cut off the excess flush with a utility knife.

    NOTE: The CSV17 has a much larger spacing between the barrel and the chamber due to the smaller chamber diameter. The spacer needs to be much longer, and I have not found a spacer that I am happy with for the CSV17. In the CSV17 I include the cable tie, but do not include a spacer at the present time.


    Pressure Safety Test

    Leak Test

    Launch Test

    Fishing Reel Adapter

    The simple fishing reel attachment is a 2.5" coupler with the fishing reel strapped to it with two stainless steel hose clamps. When attaching a fishing reel, two inches of double sticky foam tape under the reel foot will keep it from slipping, and then squash it down with a hose clamp at each end of the reel foot. The front of the foot should be located at the front edge of the coupler. This coupler is NOT CEMENTED to the barrel - it is a friction fit so it can be removed for transport and while dealing with the line. Do not put it on the barrel too tightly - it can become difficult to remove.

    Another very nice reel is the Saunder's Zip Reel. This large diameter reel can be adapted to a coupler is coaxial around the barrel. It feeds 21 inches of line per turn so it is easy to wind back on and presents a low resistance to the line going out. This is available pre-made by Eric WD6CMU. See our new Online Order Form for details on the availability of reel mounts and reels.

    Have Fun and Be Safe!

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    The Rest of the Story contains information about the support equipment and usage of the Antenna Line Launchers.

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