Little help for a semi noob

[enginerd]

Ok to start out i am not an idiot i am a mechanical engineer and know more about some of these things than you guys do i just choose not to put the hours into trying to solve a problem when i could ask for help of someone who has more practical experience. I am constructing a golf ball cannon i know there is a pipe size, i forget what it is that will nearly perfectly fit a golf ball but i am wondering, can it be purchased at home depot or menards? Also what size and brand of sprinkler valves are used? I was looking into industrial valves but didn't feel like putting up 150+ bucks on my first cannon for just the valve. And the most important question is does menards or homedepot keep the valves in stock year round, and if not, will a large ball valve work? Thank you.

[mopherman]

i just choose not to put the hours into trying to solve a problem when i could ask for help

OOOOOOHHHHHHHH boy... don't do that. people here hate that.
Anyway, the golf ball pipe is 1.5 sdr21 or a well sleeved 2" barrel will work. most places carry 3/4 sprinkler valves. You can get them for a decent price online in sizes up to 3".

[potatoflinger]

A large ball valve will work, but it won't give you that great of performance. You may have sprinkler valves at the stores near you, but you can check their website to make sure before you go spending a lot of time looking around their store. (And it probably wont do any good to ask their employees, since very few of them even know what a sprinkler valve is.) The most commonly used sprinkler valves are Orbit Watermasters and various RainBird valves. Almost any type of sprinkler valve will work, but you might want to try to find one that doesn't have a guide rod, because a guide rod will make it a little harder to mod the valve. I really don't know about the golf ball barrel, but I'm kind of interested myself...

[MaxuS the 2nd]

I'd like to see how you would spend $150 on a valve? I've never seen an American valve over $80. It would be worth your time to search yourself rather than waiting for replies.

[rcman50166]

I know for a fact that 1.5 in barrels are the closest size pvc that will fit. (The golfball is just a little larger than the bore.) I have seen pvc barrels used for golfballs, which has always confused me because of the fact that I've stated above. Pehaps 1.75in PVC exists? That seems like the only answer to my confusion. However if it does exist, they don't sell it at Home Depot. They also don't sell tennis ball sized PVC. (2.5in) That's why I have one cannon with a 1.5in bore (to actually shoot potatoes, 2in. is typically too big) and a cannon with a 3in bore, for most plastic bottles. The reason that I've gone off on a random hijacking-topic-seeming tangent is to recommend other ammunition. Oh and .75in PVC is best size PVC for paintballs.

[Hubb]

rcman: I do not believe that the PVC pipe is made in 1.75". Also, the best pvc pipe size for a paintball is 1/2" SDR (with .69"ID).

[daberno123]

The size for golfballs is SDR21 1.5" pipe. It probably won't be sold at your local hardware store but can be purchased online sleeved in 2" schedule 80 or unsleeved

If your lucky your local hardware store will carry sprinkler valves but they're are also sold online here

BTW almost everything you need is on BCArms

Welcome to the forum and good luck on your first gun

[DYI]

There is no such thing as 1.75" pipe in North America. You can likely find 1.75" tube, but not pipe.

SDR 21 is indeed the size for golfballs - it is a near perfect fit that can really only be bettered by a custom sized tube. With a bit of work*, you can create a golfball sized barrel by cutting a 2" pipe down the side, and removing the proper amount of material so that it can be sleaved inside another 2" pipe. However, even done well, this creates a seam.

BCARMS is the place for your spudding needs, they sell the commonly needed materials that are hard to find otherwise.

* several hours of shear hell

[jimmy101]

Ok to start out i am not an idiot i am a mechanical engineer and know more about some of these things than you guys do i just choose not to put the hours into trying to solve a problem when i could ask for help of someone who has more practical experience.

Well, you clearly weren't an English major!

I am constructing a golf ball cannon i know there is a pipe size, i forget what it is that will nearly perfectly fit a golf ball but i am wondering, can it be purchased at home depot or menards?

You see there is this new fangled thing called the "internet". A key tool for the proper use of the internet are things call "search engines". Google is a good search engine. In addition to "search enginges" most discusion web sites have a "search function". Usually this "search function" is initiated by clicking on a rectangular "button" that has the word "SEARCH" on it.

Pretty amazing what non mechE's can do isnt' it!

[D_Hall]

Ok to start out i am not an idiot i am a mechanical engineer and know more about some of these things than you guys do i just choose not to put the hours into trying to solve a problem

Am I the only one who thinks idea presented in the first part of this statement is mutually exclusive to the idea presented in the second?



editagain: I originally had a statement to the effect of, "A good Mech Eng would know a ball valve won't cut it." I decided it was a bit harsh and edited it out. Alas, enginerd had already read it and decided to respond to it so I'm putting this note in here to explain where his comment came from so people aren't confused.

[rcman50166]

It seems that people on this site have very short tempers. Sarcasm, cold shoulder, or just plain insults. Not calling anyone out but does anyone else think the community can be a bit "nippy" at times? His first statement was implying that he didn't want to be baby fed info; that he is a perfectly capable person that has a perfectly usable brain. The fact that he didn't use google or the internet is because he's smart. I'm not sure if you guys have noticed but this is a primary source on the internet for homemade launchers. I'd post here rather that do research because it is the most time efficient method and probably garners the best results too. Take it as a compliment not an insult. He was only requesting a detailed, mature answer, not placing himself above the rest of us.

[enginerd]

Here is where you would find expensive valves, they are industrial valves not sprinkler and say they are good to 150 psi, but could probably take many of thousands of psi before it would yield.

And well this is my first pneumatic gun, i have a combustion one that'll put a golf ball out to about 700 yards but from a few calculations this will go much, much further. The combustion gun just doesn't have any valves.

To Jimmy: Correct i am not an english major, i do not care if i have bad grammar. And this "internet" led me to this site called spudfiles.com.

To D_Hall- A ball valve with a strong rotary solenoid would work better then any other valve out there because it would be a straight shot from tank to barrel with no losses from corners or reductions.

[D_Hall]

To D_Hall- A ball valve with a strong rotary solenoid would work better then any other valve out there because it would be a straight shot from tank to barrel with no losses from corners or reductions.

Experience says otherwise. You just can't open a ball valve fast enough with any reasonable system.

And here's your clue for the day: You're not the only Mechanical Engineer on this site.

[DYI]

Spudblaster15 hooked up a high explosive driven ram to a ball valve, which likely achieved opening times similar to that of a barrel sealing piston valve. I don't think he found very much of the ram afterward though...

A burst disk valve would trump a ball valve in any case for a given size of porting, simply because there is never any restriction, and therefore less turbulence and less shockwave formation. If you could build an HE driven ram that didn't get ripped to shreds every time on actuation, it could probably beat a barrel sealing piston valve, simply due to the straight-through flow. Obviously, an HE driven ram opening a ball valve doesn't count as a reasonable system in most cases.

[D_Hall]

Spudblaster15 hooked up a high explosive driven ram to a ball valve, which likely achieved opening times similar to that of a barrel sealing piston valve. I don't think he found very much of the ram afterward though...

Thus why I said "reasonable system." I don't think a system that complicated that is single use counts as "reasonable."

Obviously, an HE driven ram opening a ball valve doesn't count as a reasonable system in most cases.

D'oh! And here I was arguing with a guy who agrees with me.