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How to pump up a large cannon in the field?

Post questions and info about pneumatic (compressed gas) powered cannons here. This includes discussion about valves, pipe types, compressors, alternate gas setups, and anything else relevant.
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Unread postAuthor: jmccalip » Tue May 05, 2009 8:18 am

Technician1002 wrote:
jackssmirkingrevenge wrote:
jmccalip wrote:What about regulated HPA? I'm not familiar with this, but isn't it gas only form?


If you're prepared to fork out for a bottle and you have filling facilities nearby, HPA is a good option.


If you do use HPA, don't forget to do the math. Some tanks are 80 cubic feet at atm pressure. Do the math to figure out just how much air you need.

For my field use, I use a high volume hand pump and prefer to shoot the small tank cannon. When we have a big bunch of guys around, they can rotate pumping while building anticipation. Gotta watch the smokers, they tend to be beat at 20-30 PSI while athletes take it on up to 80 PSI.

Some smaller nailer compressors will run on a larger inverter. My Prius has a 1,000 Watt inverter and will run a little compressor or a fridge compressor. Other options are a gas generator or gas compressor.

For the larger launcher I am building, something other than a hand pump will be required, so I am looking into the options.

Don't use a emergency jump kit with battery and compressor. They are OK for topping up a soft tire but worthless for repeated cannon shots.



Great post. Although I wouldn't run that pancake compressor off a 1000 watt inverter. I was reading about generators earlier, and someone said their honda 3800 watt struggled when the compressor was turned on, but then ran it fine afterwords.


I think I'm gonna go to Sams's Club and buy the 2.5CFM tire inflator. If it doesn't work, I'll return it. They have a 40 minute constant duty cycle at 40PSI, and a 15 minute cool down after that. Not bad.
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Unread postAuthor: Technician1002 » Tue May 05, 2009 8:51 am

jmccalip wrote:
Technician1002 wrote:
jackssmirkingrevenge wrote:
jmccalip wrote:What about regulated HPA? I'm not familiar with this, but isn't it gas only form?


If you're prepared to fork out for a bottle and you have filling facilities nearby, HPA is a good option.


If you do use HPA, don't forget to do the math. Some tanks are 80 cubic feet at atm pressure. Do the math to figure out just how much air you need.

For my field use, I use a high volume hand pump and prefer to shoot the small tank cannon. When we have a big bunch of guys around, they can rotate pumping while building anticipation. Gotta watch the smokers, they tend to be beat at 20-30 PSI while athletes take it on up to 80 PSI.

Some smaller nailer compressors will run on a larger inverter. My Prius has a 1,000 Watt inverter and will run a little compressor or a fridge compressor. Other options are a gas generator or gas compressor.

For the larger launcher I am building, something other than a hand pump will be required, so I am looking into the options.

Don't use a emergency jump kit with battery and compressor. They are OK for topping up a soft tire but worthless for repeated cannon shots.



Great post. Although I wouldn't run that pancake compressor off a 1000 watt inverter. I was reading about generators earlier, and someone said their honda 3800 watt struggled when the compressor was turned on, but then ran it fine afterwards.


I think I'm gonna go to Sams's Club and buy the 2.5CFM tire inflator. If it doesn't work, I'll return it. They have a 40 minute constant duty cycle at 40PSI, and a 15 minute cool down after that. Not bad.


Avoid the tire inflators. They are not built for heavy duty use. You can blow out the plastic gears these have after just a couple weekends of shooting. Look to compressors geared to working all day on a roofing job for example. They are built to last.

Start up surge is an important consideration of any compressor.

Some inverters have a 200% surge capacity, some have none. Read the specifications and be sure the inverter, battery, and installation is able to handle the surge. I use my inverter to run a refrigerator, small freezer, the fireplace blower, computer, and a couple CF lamps during winter power outages. The surge capacity is the only reason it starts the fridge and freezer.

Some gas generators have a 25% surge capacity, but almost all do NOT have a 200% surge capacity. The engine stalls. In portable generators, capacity increases cost and weight, so most portable generators have little surge capacity. You will need a large generator to run a moderate size compressor.'

The duty cycle on tire inflators assumes normal tire inflation pressures of 25-44 PSI. Running double that for an air cannon does the same thing to the compressor that it does to you with a bicycle pump. Don't expect a 40 minute duty cycle topping off a 100 PSI cannon.

Do expect a 100 PSI contractors compressor to do OK delivering 100 PSI shot after shot.

Check the power requirements of the pancake compressor. General purpose compressors often have a couple horsepower motor and a several KW inverter will be required. The little nailer compressors are often under 600 Watts and run fine on a 1KW inverter with a 200% surge capacity to start it. I'll be shopping next week and testing the ability of my installation to cycle a smaller 100 PSI nailer pancake. I'll post results when I have it with video.

http://answers.yahoo.com/question/index?qid=20080327233931AAQkVba
Info on why the generator won't start some compressors :(
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Unread postAuthor: POLAND_SPUD » Tue May 05, 2009 9:50 am

for me all these ideas seem way too complicated....

I strongly suggest trying propane first... you don't even need to buy a reg... today I even found an adapter for propane tanks - it was quite cheap so I bought it

you just attach it to the tank and clamp a hose... ohhh but make sure that your gun can handle unregged propane
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Unread postAuthor: jmccalip » Tue May 05, 2009 11:22 am

POLAND_SPUD wrote:for me all these ideas seem way too complicated....

I strongly suggest trying propane first... you don't even need to buy a reg... today I even found an adapter for propane tanks - it was quite cheap so I bought it

you just attach it to the tank and clamp a hose... ohhh but make sure that your gun can handle unregged propane



My gun is a 4" 7ft PVC chamber. I think I've ruled out any compressed gas because of the cooling effect from expansion. If you can figure out a way to warm freezing cold gas(for cheap!), I would be all over this.

In fact, we are already buying a C02 tank later this summer when we make our own root beer. This would be the cheapest route if I could warm the gas.



I can get a 2000/4000 watt inverter off ebay for $50 if I look around. I can also buy a 5CFM pancake compressor(14amp) on CL for under $75, and then buy a 11g air tank from HF for $35.

I could just turn on my car every now and then to keep the battery charged, and I guess we could have a few hours of fun.
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Unread postAuthor: paaiyan » Tue May 05, 2009 11:31 am

Well it'll cost you a pretty penny, but what about a large 4500PSI HPA tank for paintball? Like they said earlier, if you have a shop nearby that can fill it, it'll usually cost you less than $5.
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Unread postAuthor: POLAND_SPUD » Tue May 05, 2009 11:46 am

AFAIK cooling effect is a result of evaporation of liquid propane... but there should be no liquid prapane entering your gun as long as the tank is in upright positon so I assume it's safe

I hope this is right as I never worked with propane tanks... can anyone clarify this??
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Unread postAuthor: paaiyan » Tue May 05, 2009 12:06 pm

Any gas cools with rapid expansion. It's the one thing I hate about my Tippmann A-5. I'm still using CO2 and it hates when I shoot fast. Despite having a remote line and regulator it still freezes up if I shoot too fast.
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Unread postAuthor: POLAND_SPUD » Tue May 05, 2009 12:57 pm

but is it casued because liquid CO2 enters the gun ? or is it just casued by rapid expansion ??

well even a normal pneumatic cools down when firing but I suppose that the biggest problem with gases stored in liquid form, such as CO2 or propane, is casued by evaporation...

IMO if it takes place inside the tank that shouldn't be a big problem for him

also if he is going to use outside I think he won't have problems with pressure drop due to temperature drop.. in fact it might be a good thing since during a hot day the opposite is true... people have problems with excesive pressure buildup due to high temperature... so expansion might even out the pressure rise
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Unread postAuthor: Technician1002 » Tue May 05, 2009 6:33 pm

jmccalip wrote:
POLAND_SPUD wrote:
I can get a 2000/4000 watt inverter off ebay for $50 if I look around. I can also buy a 5CFM pancake compressor(14amp) on CL for under $75, and then buy a 11g air tank from HF for $35.

I could just turn on my car every now and then to keep the battery charged, and I guess we could have a few hours of fun.


If you match those two, you have an excellent chance of having a non start. AC induction motors draw in the neighborhood of 3-8 times the run current. Most 2KW inverters won't provide the current to start that 2 HP compressor. Most 4 KW portable generators won't start it either. Look for a 5 Amp or less compressor to run off a small generator or inverter.

A note on the battery.. Watts is Voltage Times Amps (for DC circuits). To deliver 14 AMPS at 120 volts you will need to provide 140 AMPS to the inverter assuming a perfectly lossless conversion. Most car alternators won't keep up at an idle. You may want to consider a little larger power source or smaller compressor. :D Oh, um did I mention that starting amps is about 3 to 8 times the run current? :shock: If the car isn't running constantly, the inverter is most likely to shut down as the input voltage sags below 11.5 volts. With the car running, it will take just a little longer to shut down. :roll:

This is why so many small emergency compressors take a half hour to top off a tire. They run off the power from the lighter socket which is often fused at 10 or 15 amps.

Been there done that using a sump pump on an inverter.
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Unread postAuthor: jmccalip » Tue May 05, 2009 9:47 pm

Technician1002 wrote:
jmccalip wrote:
POLAND_SPUD wrote:
I can get a 2000/4000 watt inverter off ebay for $50 if I look around. I can also buy a 5CFM pancake compressor(14amp) on CL for under $75, and then buy a 11g air tank from HF for $35.

I could just turn on my car every now and then to keep the battery charged, and I guess we could have a few hours of fun.


If you match those two, you have an excellent chance of having a non start. AC induction motors draw in the neighborhood of 3-8 times the run current. Most 2KW inverters won't provide the current to start that 2 HP compressor. Most 4 KW portable generators won't start it either. Look for a 5 Amp or less compressor to run off a small generator or inverter.

A note on the battery.. Watts is Voltage Times Amps (for DC circuits). To deliver 14 AMPS at 120 volts you will need to provide 140 AMPS to the inverter assuming a perfectly lossless conversion. Most car alternators won't keep up at an idle. You may want to consider a little larger power source or smaller compressor. :D Oh, um did I mention that starting amps is about 3 to 8 times the run current? :shock: If the car isn't running constantly, the inverter is most likely to shut down as the input voltage sags below 11.5 volts. With the car running, it will take just a little longer to shut down. :roll:

This is why so many small emergency compressors take a half hour to top off a tire. They run off the power from the lighter socket which is often fused at 10 or 15 amps.

Been there done that using a sump pump on an inverter.



Lotta info there. But how did you run a pancake compressor off the 1000 watt Prius inverter? Ehh, nevermind.



I found a good deal on a twin tank 4g compressor off craigslist. The guy was only a couple miles down the road, so I thought I'd pick it up. It's 3.4CFM at 40PSI, and it will fill the tank in under 1 minute with left over pressure in the tanks. It's a 50% duty cycle, so not more than 30 minutes run time one hour. As long as I have a power supply, this should work.

I know the HP is weak, but 3.5CFM is good enough for me. I only shoot it at 40-50 PSI most of the time anyway.
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Unread postAuthor: iknowmy3tables » Tue May 05, 2009 10:21 pm

that tsunami compressor you mentioned looks fine from what I see, they should run for a while, hooking up a giant compressor to your car and your car battery or inverter with burn out with that tsunami the fuse might burn out the tsunami or a similar battery hook up compressor seams like the best compressor to run off of your car
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Unread postAuthor: Technician1002 » Tue May 05, 2009 10:47 pm

jmccalip wrote:
Technician1002 wrote:
jmccalip wrote:
POLAND_SPUD wrote:
I can get a 2000/4000 watt inverter off ebay for $50 if I look around. I can also buy a 5CFM pancake compressor(14amp) on CL for under $75, and then buy a 11g air tank from HF for $35.

I could just turn on my car every now and then to keep the battery charged, and I guess we could have a few hours of fun.


If you match those two, you have an excellent chance of having a non start. AC induction motors draw in the neighborhood of 3-8 times the run current. Most 2KW inverters won't provide the current to start that 2 HP compressor. Most 4 KW portable generators won't start it either. Look for a 5 Amp or less compressor to run off a small generator or inverter.

A note on the battery.. Watts is Voltage Times Amps (for DC circuits). To deliver 14 AMPS at 120 volts you will need to provide 140 AMPS to the inverter assuming a perfectly lossless conversion. Most car alternators won't keep up at an idle. You may want to consider a little larger power source or smaller compressor. :D Oh, um did I mention that starting amps is about 3 to 8 times the run current? :shock: If the car isn't running constantly, the inverter is most likely to shut down as the input voltage sags below 11.5 volts. With the car running, it will take just a little longer to shut down. :roll:

This is why so many small emergency compressors take a half hour to top off a tire. They run off the power from the lighter socket which is often fused at 10 or 15 amps.

Been there done that using a sump pump on an inverter.



Lotta info there. But how did you run a pancake compressor off the 1000 watt Prius inverter? Ehh, nevermind.



I found a good deal on a twin tank 4g compressor off craigslist. The guy was only a couple miles down the road, so I thought I'd pick it up. It's 3.4CFM at 40PSI, and it will fill the tank in under 1 minute with left over pressure in the tanks. It's a 50% duty cycle, so not more than 30 minutes run time one hour. As long as I have a power supply, this should work.

I know the HP is weak, but 3.5CFM is good enough for me. I only shoot it at 40-50 PSI most of the time anyway.


I haven't run one off the Prius yet, but testing starts next week. I'm looking at a 0.5 CFM, not a 3.5 CFM compressor. It is rated at 200 run watts. It is for a brad nailer. At 5 times the run current for the start, it is within the 200% surge capacity of my Prius setup.

The Sump pump was a submersible with a 600 Watt rating. I started it dry and threw it in the water. Starting it in water was a no go. It didn't quite pick up speed before the inverter tripped off.

The inverter does start my fridge and freezer just fine.

The compressor I am looking at is 0.1HP and has a 200 watt run spec.
http://www.acehardware.com/sm-campbell-hausfeld-air-compressor-campbell-hausfeld-air-compressor-price-89--pi-2242749.html

I figure a large propane tank can be used to store air while reloading, inspecting damage, looking for projectiles, etc. It should be able to run constantly off the inverter.

that tsunami compressor you mentioned looks fine from what I see, they should run for a while, hooking up a giant compressor to your car and your car battery or inverter with burn out with that tsunami the fuse might burn out the tsunami or a similar battery hook up compressor seams like the best compressor to run off of your car

Most inverters have over current protection and simply shut down. Most have high temperature shutdown. Mine has a thermostaticaly controlled fan.
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Unread postAuthor: jmccalip » Tue May 05, 2009 11:49 pm

My $29 cheapo inverter is "thermostatically" controlled by a tiny cooling fan. :wink:


Now for your setup, wouldn't it be easier to just run a 2.5CFM DC pump like I mentioned? IDK, maybe it will burn out. If you have a Harbor Freight by you, and you want the compressor with the tank, check out these deals:


It's so nice to have this store 2 miles from my house. All the air tools are 1/2 the price of home depot and just as good. Harbor Freight emails me "20% any item" coupons every week almost, so you could get the 2 gallon compressor for $63.







And if you're curious I tested my "1HP" compressor with the Kill-A-Watt and it read 8.4Amps at 900 watts constant. And it is 3.7CFM, my bad. To bad the idiot owner before me didn't empty the tanks everyday...there was brown water when I drained it. Oh well, he said it was a couple of months old and he only used it once for putting up a fence.
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Unread postAuthor: Technician1002 » Wed May 06, 2009 12:53 am

jmccalip wrote:My $29 cheapo inverter is "thermostatically" controlled by a tiny cooling fan. :wink:


Now for your setup, wouldn't it be easier to just run a 2.5CFM DC pump like I mentioned? IDK, maybe it will burn out. If you have a Harbor Freight by you, and you want the compressor with the tank, check out these deals:


It's so nice to have this store 2 miles from my house. All the air tools are 1/2 the price of home depot and just as good. Harbor Freight emails me "20% any item" coupons every week almost, so you could get the 2 gallon compressor for $63.







And if you're curious I tested my "1HP" compressor with the Kill-A-Watt and it read 8.4Amps at 900 watts constant. And it is 3.7CFM, my bad. To bad the idiot owner before me didn't empty the tanks everyday...there was brown water when I drained it. Oh well, he said it was a couple of months old and he only used it once for putting up a fence.


First the DC pump would be easier if you don't already have an inverter setup. Easier is not always better. DC pumps are often brush type motors and high current brush type motors are high maitenance items. A brushless motor is great for reliability.

Great find on the harbor freight 1/3 hp compressors. They should be much higher capacity than the 1/10th hp compressor I was looking at. I'll check them out. Hopefully I can get trial test before purchase or a very liberal return policy.

The problem I would have with the 1 HP compressor at 900 Watts is my inverter won't start it. It is right on the ragged edge of the DC power I have available in the car, so it would be running right on overload in the best of times. It's just a little too big. :( Nice size if you have the power to run it.

Does your power meter record the peak power draw when the compressor starts? That prevents many compressors from starting on a portable generator or inverter. 3 times 900 is 2700 watts. 5 times 900 is 4500 watts. My inverter won't provide it. Many 3600 Watt contractor generators won't start it.
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Last edited by Technician1002 on Wed Oct 07, 2009 12:40 am, edited 1 time in total.
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Unread postAuthor: covey12 » Wed May 06, 2009 1:31 pm

buy an air tank, you put them on your back, and fill them up with air while your at your house, not the scuba ones, they sell them at places like lows normally, or you could always make one, but with a chamber that big you could probably only get a couple of fills,

or you could use the inverter method which i probably would
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