SpudFiles

Hey guys, I was down at bunnings today (h/ware shop), and i had an idea of
making up a quick, simple ball valve HPA golf ball cannon with a pesticide/weed sprayer
pressure bottle as the air tank. and a air line fitting and guage epoxied in the end of the air tank to fill it..... I have seen guys make smaller calibre type cannons with soft drink bottles etc,
So here are my questions:

What pressure is needed to throw a golf ball at a descent FPS?
How much pressure could you "safely" fill this 2 litre weed sprayer bottle too?
How long should the pvc barrel be roughly?

I think i'll use it to replace my "Oversised Driver" on the golf course, if i
can fit it in my golf bag!
Thanks guys.

I don't think HPA is really the word to use here, that bottle is probably not safe beyond 40-50 psi.

jackssmirkingrevenge wrote:I don't think HPA is really the word to use here, that bottle is probably not safe beyond 40-50 psi.

Wyz makes one on youtube with a soft drink bottle. How much pressure
he uses i don't know, as he doesn't mention it on the video. Be around 150
psi at least wouldn't it? This spray bottle is a lot stronger than a soft drink bottle. Or should
i just make one from threaded pvc pipe and a screw on end cap?

i got a plastic bottle to 250psi then my bottle slid off my rig but those 3lt containers aren't designed for high pressures i suggest a fire extinguisher/paintball tank or a large piece of high pressure PVC pipe

hawktalk wrote:i got a plastic bottle to 250psi then my bottle slid off my rig but those 3lt containers aren't designed for high pressures i suggest a fire extinguisher/paintball tank or a large piece of high pressure PVC pipe

Yes, think i'll get some threaded high pressure pvc pipe instead then.
How much pressure do you need to shoot a golf ball ya reckon?
Obviously a bit more pressure than the girls in thailand with the ping-pong
balls, if ya know what i mean

at least 40 to 50 in my opinion 8)

mattyzip77 wrote:at least 40 to 50 in my opinion 8)

40-50 psi?, it would dribble out the end of the barrel lol, we are talking golf
balls here remember?

hawktalk wrote:i got a plastic bottle to 250psi then my bottle slid off my rig but those 3lt containers aren't designed for high pressures i suggest a fire extinguisher/paintball tank or a large piece of high pressure PVC pipe

How did the plastic bottle slide off your rig after reaching 250psi?
Was it screwed in to your ball valve properly?

jonesy42 wrote:40-50 psi?, it would dribble out the end of the barrel lol, we are talking golf
balls here remember?

And you clearly don't have the first clue of what you're talking about.

First you want to put "HPA" into a bug sprayer. FWIW: "HPA" is loosely defined but I've *NEVER* heard anyone use it to describe air at less than 300 psi. Typically, it's used to describe air at >1000 psi.

Second.... with the right valve, 40-50 psi should be able to send a golf ball off at roughly 250 fps.... That's better than what Tiger Woods does.

Hey hey don't drag me into this, I stopped using soda bottles a long time ago. Soda bottles are ok at >10bar in my opinion.
Btw from the title I was expecting something totally different
You aren't going to get any decent fps with a golf ball from that thing, but your definition of decent maybe different from my

I found high pressure is rapidly negated by poor flow. How long is the path from the bottle to the barrel and what is the diameter? How many bends are in the path? Eliminate all flow restrictions and relatively low pressure below 50 PSI works well.

Soda bottles are ok at >10bar in my opinion.

build a chamber out of pvc pipe alot safer then a soda bottle, if you like your body parts that it

better safe then sorry my friend

D_Hall wrote:

jonesy42 wrote:40-50 psi?, it would dribble out the end of the barrel lol, we are talking golf
balls here remember?

And you clearly don't have the first clue of what you're talking about.

First you want to put "HPA" into a bug sprayer. FWIW: "HPA" is loosely defined but I've *NEVER* heard anyone use it to describe air at less than 300 psi. Typically, it's used to describe air at >1000 psi.

Second.... with the right valve, 40-50 psi should be able to send a golf ball off at roughly 250 fps.... That's better than what Tiger Woods does.

When did i describe "HPA" as being under 300psi?... I used the word HPA in the title
so people know i'm not trying to make a combustion cannon!
Thanks for answering anyway.

double post:

Don't forget that the bottle in the picture has 3 times the wall thickness of a
"soda bottle" and i was never planning to use a "soda bottle" in this project
anyway.... Just using wyz's creation as an example

triple post:

Technician1002 wrote:I found high pressure is rapidly negated by poor flow. How long is the path from the bottle to the barrel and what is the diameter? How many bends are in the path? Eliminate all flow restrictions and relatively low pressure below 50 PSI works well.

What is the diameter? Have you seen a golf ball before?
Bends? Can you see any bends in the photo?
There are no flow restrictions, the bottle screws in to one end
of the valve, and the barrel the other.

mod note (MrC): please don't double (or triple) post. If you are replying to more than one person, do so in a single reply. If you have something further to add, wait for someone else to post again or edit your previous reply.

jonesy42 wrote: When did i describe "HPA" as being under 300psi?... I used the word HPA in the title
so people know i'm not trying to make a combustion cannon!
Thanks for answering anyway.

It was assumed that you would be using pressures under 300PSI as it would be far from intelligent to put more than that in a plastic container like the one you found without first putting it through a rigorous safety test (multiple hydrotests at above the pressure you plan on using it at).

If you want people to think you're not making a combustion, say pneumatic and not HPA. HPA stands for high pressure air and, IIRC, is also a term used widely in paintball and airsoft where it refers to a more specific high pressure fill/storage device.

jonesy42 wrote: Don't forget that the bottle in the picture has 3 times the wall thickness of a "soda bottle" and i was never planning to use a "soda bottle" in this project anyway.... Just using wyz's creation as an example

Is it even the same material as a soda bottle? I know little about the chemical and mechanical properties of materials but I would assume that doubling the thickness does not double the pressure rating for all materials and that changes in container design (shape, length, diameter) would significantly effect the structural properties of said container.

I would do more research in to the type of material used and what kind of pressure people pump weed sprayers to. I doubt the bottle will have been tested at over 100PSI by the manufacturers but it probably can take 150PSI without trouble. I would recommend that you perform some tests beforehand, though.

jonesy42 wrote: What is the diameter? Have you seen a golf ball before?
Bends? Can you see any bends in the photo?
There are no flow restrictions, the bottle screws in to one end
of the valve, and the barrel the other.

Don't be a dick. I'm not sure if Tech saw the attached photo or not but it is possible that he is browsing on a device that doesn't load photos (save bandwidth/increase speed).

I can't tell what size everything is from the photos but it looks as if your valve will be a flow restriction.

As for your original questions:

What pressure is needed to throw a golf ball at a descent FPS?
How much pressure could you "safely" fill this 2 litre weed sprayer bottle too?
How long should the pvc barrel be roughly?

1. How long is a piece of string?

40-50 psi?, it would dribble out the end of the barrel lol, we are talking golf balls here remember?

As others have said, 50PSI will shoot a golf ball.

2. Find out. That's your job, not ours. You haven't given us much info about the bottle and I'm sure that any info on what kind of pressures these things can take is probably on Google. I imagine most people here can only guess, like I did, as to what is a safe pressure. Don't take our word for it; fill it with water and pump it up.

3. GGDT. A very kind person spent a lot of time making that program, it would be a shame if it didn't get used. We also have a GGDT request thread if your computer can't run the program.

If I were you, I would just make a chamber from PVC/ABS. There are times when it is good to improvise and use materials for tasks that they were originally not intended for but I don't think this is one of those times.