Improved Throwline Cannons (Better than APTA)

S

sinthome

Location
atlanta
Hi y'all, this is a post to gauge interest in a prototype I've been building. It is a pneumatic cannon for launching shotbags. I have a couple made and the performance is outstanding. If anyone is interested in it I could sell you one.

Details: It is made from aluminum pipe for the chamber and barrel with stainless steel valve and fittings. The cannon uses a button trigger with a safety switch and has a built-in pressure gauge. It is safe, lightweight and very effective. For years, I had been using a PVC pipe "spud gun" with a modified sprinkler valve, but over time PVC degrades in the sun and I really wanted something safer and OSHA compliant (all metal). However, the APTA really felt like a downgrade in a lot of ways, particularly the poor performance of the valve (no disrespect but it is basically a couple lengths of pipe with a ball valve or I guess now a butterfly valve.. not very refined). Instead, I designed a new cannon that uses an industrial diaphragm valve for much faster response times.

I will get around to posting some photos of the design soon, but I just wanted to start by checking to see if there's any potential interest in buying one.
 
A diaphragm valve is faster than a butterfly ????
Normally, a diaphragm valve is used for "fine control" not speed.

Is there a mechanical operator on it ?
 
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A butterfly valve or a ball valve are both operated by turning the handle lever 90 degrees. This is a large range of motion and requires the operator to flip the lever as quickly as possible in order to get off a good shot. Diaphragm and piston valves (used everywhere from operating your lawn sprinkler system to large industrial HVAC systems) have a completely different mechanism and will operate with a push button or a trigger. Much easier to use while holding a steady aim! If you want actual numbers on performance, you could visit any of the potato gun websites, some of these guys have been geeking out pretty hard on it.
 
Sounds interesting.

You may want to switch verbage to "Throw Bag Launcher", "Throw Line Installer", or some such. If that verbage comes from the manufacturer as opposed to "gun", "cannon", "taking a shot", etc it could make all the difference for some arborists when being talked to by the police in some locals.
 
A diaphragm valve doesn't react just because you push a button. There is some kind of mechanical actuator. That might be a hand wheel, a spring (which would need to be reset), air pressure (pneumatic actuator), etc

Diaphragm valves are not "inherently" faster; in general, they would be considered slower for "fine" control of flow.

In the chemical industry, butterfly & ball valves can also use actuators with "push button" control which can increase speed. They just add complexity to the system.

Ball valves are used for a very positive pressure seal, and very low flow resistance.
Butterfly valves are used for fast, coarse, low flow resistance.

Got a link ?
 
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I'm not here to talk logistics of how it's made. If I had a throwball launcher with a button rather than a 90° valve to turn while holding aim I would actually use a launcher.

Sent from my SAMSUNG-SM-G891A using Tapatalk
 
All you want is a button ? ? ?

In the last couple years (OH TCC & Jambo), Jacob Sauer (Ohio) has shown up at TCC's w/ a throwball launcher w/ a trigger.
It has a large 12V battery, air compressor, air accumulator tank, a hand truck cart to move it, etc.

It works very well ! It has a trigger. It must weigh 30 - 40 pounds !
 
GregManning said:
All you want is a button ? ? ?

In the last couple years (OH TCC & Jambo), Jacob Sauer (Ohio) has shown up at TCC's w/ a throwball launcher w/ a trigger.
It has a large 12V battery, air compressor, air accumulator tank, a hand truck cart to move it, etc.

It works very well ! It has a trigger. It must weigh 30 - 40 pounds !
Click to expand...
Well Greg ,despite your enthusiastic encouragement, I am interested in seeing this launcher perform.
 
I'm definitely interested ! ! !
I stated that I liked the original post.

I just wanted to know more about it !
If you don't care that a diaphragm valve is NOT inherently faster, as the post stated, that's fine.
It is in fact slower than the other two.
It is dependent on the actuator. (hand, spring, air pressure, electric motor, etc.)

I was just trying to be technically correct.
 
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GregManning said:
All you want is a button ? ? ?

In the last couple years (OH TCC & Jambo), Jacob Sauer (Ohio) has shown up at TCC's w/ a throwball launcher w/ a trigger.
It has a large 12V battery, air compressor, air accumulator tank, a hand truck cart to move it, etc.

It works very well ! It has a trigger. It must weigh 30 - 40 pounds !
Click to expand...
Did you not read the post? It says that it is lightweight in the original post...

Sent from my SAMSUNG-SM-G891A using Tapatalk
 
Yikes! Ok, looks like there is sufficient interest in this design, I will get parts together to make a few more of these and get y'all some photos/video. At this point I have no intentions of making more than a handful of these and compensating myself for r&d plus parts/assembly. It'd be great if an arborist company adopted some of my design features into a launcher at some point, but until then I am just happy to get the perfect TIP, quick and easy and safely.

Here is a link to a basic breakdown of valve types for "spud guns".
http://www.spudgunner.com/spudgun-valves.php

As described, I am using the "Quick Exhaust Valve (QEV)" and they work excellently for this purpose.
 
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I think for the prototypes $350. If I were to make a bunch at once, the cost could go down to under $300, but I don't currently have plans to do that.
 
sinthome said:
Hi y'all, this is a post to gauge interest in a prototype I've been building. It is a pneumatic cannon for launching shotbags. I have a couple made and the performance is outstanding. If anyone is interested in it I could sell you one.

Details: It is made from aluminum pipe for the chamber and barrel with stainless steel valve and fittings. The cannon uses a button trigger with a safety switch and has a built-in pressure gauge. It is safe, lightweight and very effective. For years, I had been using a PVC pipe "spud gun" with a modified sprinkler valve, but over time PVC degrades in the sun and I really wanted something safer and OSHA compliant (all metal). However, the APTA really felt like a downgrade in a lot of ways, particularly the poor performance of the valve (no disrespect but it is basically a couple lengths of pipe with a ball valve or I guess now a butterfly valve.. not very refined). Instead, I designed a new cannon that uses an industrial diaphragm valve for much faster response times.

I will get around to posting some photos of the design soon, but I just wanted to start by checking to see if there's any potential interest in buying one.
Click to expand...
Metal is dangerous in the event of an over pressurization. While PVC degrades and is not very strong, HDPE is very strong and will split instead of shrapnel. High density polyethylene is used for mortar tubes in fireworks shows and is a fairly common building supply. You may want to give it a try? Way safer under pressure.
 
Merle Nelson said:
Sounds interesting.

You may want to switch verbage to "Throw Bag Launcher", "Throw Line Installer", or some such. If that verbage comes from the manufacturer as opposed to "gun", "cannon", "taking a shot", etc it could make all the difference for some arborists when being talked to by the police in some locals.
Click to expand...
yeah shit bag launcher works too!
 
I feel like as long as the shit launcher is made with as thick of metal as the APTA there shouldn't be an issue of too much pressure for tree care. Maybe have a max PSI of 150 or 200 maybe labeled right on it. I mean the air rifles aren't made of HDPE and those things get 1000s of PSI in them. The average pump should be less sturdy than this thing will hopefully be.
Stephen Moore said:
Metal is dangerous in the event of an over pressurization. While PVC degrades and is not very strong, HDPE is very strong and will split instead of shrapnel. High density polyethylene is used for mortar tubes in fireworks shows and is a fairly common building supply. You may want to give it a try? Way safer under pressure.
Click to expand...

Sent from my SAMSUNG-SM-G891A using Tapatalk
 
Yes but air rifles have a heavy steel barrel and far less volume. Don't underestimate air pressure it can blow a split rim tire to bits! If you incorporated a Pressure relief valve, you should be ok from a safety standpoint?
 
Hi folks, I'm excited there seems to be a lot of interest. I plan on making a video next weekend. Not to drag out the suspense, I'm just busy until then!

An HDPE pressure chamber is a good idea, but it would probably have to be custom made. I've not come across HDPE pipe and fittings or a small tank that is rigid enough to work effectively.

The launcher I am using is made entirely from pipe and fittings rated to a safe working pressure (at normal temperatures) of at least 200psi. Burst pressure is much higher than that, obviously, but any launchers for sale will still include a pressure gauge and safety pop valve that opens at 150psi and tampering with it is "at your own risk". Additionally, in the unlikely event the chamber was ever overinflated to failure, there is a rubber gasket in the main pressure valve that would tear long before the metal would burst.

A better safety comparison would be paintballers, who run around with co2 and hpa tanks of an equivalent volume and that are often holding thousands of psi pressure. TBH this terrifies me, but also makes me respect the strength of metal.

Lightweight aluminum pressure tanks, if they can be safely modified and sized properly for the application, make for an ideal launcher chamber and have been used successfully for tshirt launchers, etc. If I tinker around with a different chamber, it'd be using an HPA tank.
 
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