DIY TREE AIR CANNON FOR ARBORISTS
What is a Tree Air Cannon?
A tree air cannon is a device similar to a potato launcher. However, an air cannon uses pressured air, rather than explosive gas, to launch the projectile. I call my version a 'TREE' Air Cannon because it is specifically a tool for professional arborists to get into trees, safely. This is not a potato gun toy! Like many professional tools, this tool needs to be treated with caution and respect. In the wrong hands, someone can cause injury to themselves or others. I was reluctant to release this information publicly, for concern that it would be used inappropriately. But I do believe it increases the overall safety for Arborists to precisely place their throw lines into trees. So here it is. Don't be a dummy and ruin it for the rest of us by treating it like a toy.
A brief introduction of myself: My name is Edwin and I'm an avid DIYer. My professional background is as a General Contractor, Arborist, and Bungee Jumping Guide. I went to College for mechanical engineering but didn't finish my degree. When the possibility of a DIY solution comes into my sphere, I can get fixated on it- to an unreasonable level. This tree cannon was one of those times.
Why did I get fixated on building this TREE AIR CANNON?
My region is surrounded by tall conifer trees, (like over 200 feet tall). Many of these trees don't even have limbs till 100 feet up. The main tool for getting a throw bag and line over these limbs has been the Big Shot. The Big Shot is essentially an 8-foot slingshot. This tool bothered me for multiple reasons.
Problems with the first Air Cannon
My brother, Luke, is also an arborist (He's actually a much better arborist than me. He's been a professional climber for over 12 years. He's now the one who gets called out to climb and remove trees that other tree companies are unable to do). Luke built the prototype air cannon between us. His version consisted mostly of galvanized steel piping. Even though it had several flaws, it still outperformed the Big Shot. The success of his first design is what inspired me to create my version. My Air Cannon design improved on the three main flaws of first prototype.
Cons of the first air cannon prototype:
1. Weight: being made out of steel made it cumbersome to lug around 2. Trigger: the trigger mechanism was a lever that needed to be slapped down to fire. This action could sometimes interfere with the accuracy of the shot 3. Monitoring Air Pressure: Knowing the exact air pressure in the cannon is useful for gauging the height of the shot you are taking. I've realized that sometimes I may only need about 60psi if I'm aiming for a specific limb only 50 feet high. That way I can get the weight to just go over that limb and not send it smashing up into the rest of the tree.​
Pros of the new air cannon:
1. Weight: The new cannon is built using Sch 40 PVC rather than steel. 2in Sch 40 PVC is still rated to a capacity of 200psi, which leaves about 50psi of margin for the max pressure that would ever be possibly needed. PVC is much lighter than steel, so this solved the weight problem of the first cannon. 2. Trigger: The new cannon revolves around using an electronic trigger to launch the weight. This means I can keep my aim steady through the entire firing sequence. 3. Monitoring Air Pressure: I built mine with an Air Pressure Gauge attached to the pressure body. This allows for real-time pressure monitoring (and an easy option to release pressure to a specific psi if necessary)
Without further ado, let's get to the reason we're all here:
How I built my best Tree Air Cannon: 10 steps
Parts: Below is a list of parts I used to create this Air Cannon. I found that I could purchase all the required parts from Amazon. However, if I purchased the PVC and fittings from Ace, Lowes, or Home Depot, I realized I could save about $85 on the total cost. The list below will be hyperlinked to the specific parts via Amazon. (All prices are rounded up to the nearest whole dollar)
All parts are hyperlinked to Amazon for convenience
Honestly, this isn't bad when considering the Big Shot slingshot costs over $200 when purchased from Amazon.
A few other tools and parts are required to complete this project that I didn't include in the parts list above because I already own them. I have provided a list with hyperlinks to them below.
Other Required Tools & Parts | Product Photo | Amazon |
|---|---|---|
Plumbers Tape | 4 | |
PVC Glue | 13 | |
Wire Connectors | 9 | |
Groove Joint Pliers | 20 | |
Wire Stripper & Crimper | 14 | |
Pipe Saw | 20 | |
Drill Bits | 20 | |
Powered Drill | 100 |
STEP 1: Using a pipe saw, I cut all the PVC pipe to the appropriate length.​
Cut the 2" PVC pipe to 28" Cut the 1.5" PVC pipe to 27" Cut the 3/4" PVC pipe to 6"
STEP 2: Layout all of the pieces on the floor or a table in their corresponding positions.​
Starting from the upper left and going to the right: 1.5" pipe, 1.5" union, 1.5" reducer, 3/4" nipple, solenoid valve, 3/4" elbow Then come down with the 3/4" pipe and begin placing pieces to the left 3/4" elbow, 2" reducer, 1/2" to 1/8" NPT, pressure gauge, valve stem, 2in pipe, battery, and trigger assembly
STEP 3: Drill the hole for the high-pressure valve stem
Drill 1/2" hole in the 2" threaded cap (This is a different location than the current photo shows. I modified this after my brother and I realized the high-pressure stem can fail sometimes. So I wanted to make it easily replaceable) I was surprised by how large of a hole was required for the valve stem. I was tempted to make this smaller, to be closer to the diameter of the stem. However, after examining the rubber gasket I realized the hole needed to be about 1/2" to get the proper seal A drill press was really useful for getting a precise hole. If using a hand drill I recommend starting with a smaller pilot hole and being aware the bit could slip off the PVC and drill into something you don't want it to (like your other hand) Use a razorblade or sandpaper to clean up any burrs around the hole after drilling
STEP 4: Attach the valve stem and the 1/2" to 1/8" NPT to the 2" Tee
Unscrew the nut from the valve stem and remove the upper rubber grommet. Place the valve stem and lower rubber grommet through the 1/2" drill hole but from inside the Tee so the stem is pointing out of the Tee Place the upper rubber grommet and the hand tighten the nut. Use pliers/wrenches to get the nut tighter Use plumbers tape on the 1/2" to 1/8" NPT and screw it to the Tee (Finish tightening with pliers)
STEP 5: Prime and glue up all the slip joints
Glue the 1.5" pipe to the 1.5" coupling and then glue that to the 1.5" reducer Glue the 3/4" elbows to either end of the 3/4" pipe (Make sure both elbows face the same direction exactly) Glue the 2" pipe to the 2" Tee and glue the Tee onto the Reducer Glue the 2" Socket to 2" Thread on the end of the 2" Pipe
STEP 6: Screw all 3/4" joints together and Pressure Gauge
Use plumber tape on all threaded connections I started with the Solenoid Valve since it was the more awkward of pieces to connect. There is an arrow on the Solenoid Valve, make sure it is pointed down the barrel. Make sure the Pressure Gauge can still be screwed on but with its' orientation close to the solenoid
STEP 7: Wire the Solenoid Valve, Trigger Assembly and Battery together
I used the disconnect crimps for connecting my wires together because I like to be able to easily replace parts in the future if necessary. However, solder, shrink wrap, or wire nuts would work as well. Disconnect the main power wire from the battery. Cut the main power wire about 6in from where it connects to the battery Strip back the insulation to reveal two wires Connect the negative wire from the power wire to the negative wire on the Solenoid Valve Cut the wire on the trigger assembly leaving about 6in of tail. Split the two wires apart about 4in down and strip the ends so they are exposed Connect the positive wire from the battery to one of the trigger wires (doesn't matter which) Connect the other trigger wire to the positive of the Solenoid Valve When the battery is plugged in and turned on, there should be an audible "click" from the solenoid valve when the trigger is pressed
STEP 8: Drill or melt holes for the trigger assembly and secondary handle
This part can be a little tricky. I had to be careful that I did not drill or burn into any of the components inside the trigger assembly. Drilling 1/4" holes and using zip ties is probably the easiest method, however, it doesn't look as clean and is more difficult to adjust after installed The best method is to use a soldering gun or heat a thin piece of metal to melt 1/2" long slits on the upper and lower parts of the assembly. Make sure the slits are wide enough for the band clamps to fit through The same method can be used for the remaining 3/4" pipe that is used as the support handle. The pipe will need to be cut to size first (the tighter the fit the better). I notched my pipe ends so they fit more snuggly against the 2" and 1.5" pipe
STEP 9: Spray Paint (Optional)
Remove or cover with painter's tape all components that should not receive paint Spray with consistent spacing and direction until everything is painted. Let the paint dry, flip it over, and repeat on the other side. Do multiple coats if necessary.
STEP 10: Use band clamps and zip ties to attach the battery, trigger assembly, and support handle to the 2" pipe
I use zip ties to attach the battery to the 2" pipe, placing it right next to where the 2" Tee begins I also like to use a little super glue right beneath the battery to assist it in not slipping, but I'm not sure it's necessary Thread the band clamps through the trigger assembly and the support handle and attach them to the 2" and 1.5" pipes respectively The band clamps allow for easy adjustment and modification for various arm lengths.
done.
Tips and Tricks for Operation: -->Use the on/off button on the battery like a gun safety. If the lights are green, then the battery is on and the cannon is "hot" -be careful If the pressure chamber is over-pressurized, and a weak connection or fracture occurs, the tool could potentially explode, injuring you or others with PVC shrapnel. For safety, use the cannon with low pressures first (Starting at about 40PSI). Then work your way up from there in increments of 10 to 20PSI. DO NOT TRAVEL OR STORE THE CANNON WHILE PRESSURIZED. There is some kickback from the cannon under high pressure. I like to keep the charging cord attached to the cannon so I don't lose it For me to hit a 100ft high shot I typically need about 120PSI
Here's some Tree Air Cannon Accessories to consider
Air Cannon Accessories | Image | Amazon |
|---|---|---|
Battery Air Pump | 35 | |
Manual High Pressure Pump | 29 | |
12oz throw weight | 23 | |
Large Storage Backpack | 41 | |
Throw Line Cube | 41 | |
Throw Line | 25 |