Building a gun...

Homemade water gun threads that are notable.
mikeyi
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Joined: Sat Apr 05, 2008 9:00 pm

Building a gun...

Post by mikeyi » Sat Apr 05, 2008 9:29 pm

Hi guys,

Let me start off by saying what an absolutely awesome website. I've been looking for a site like this for a few days now, just stumbled across this, and and completely blown away. Vey nice.

I'm a newbie to the DIY, so I'll go take my time and go slow with each step. I need to build a gun for a boat parade this summer at the beach, in which many people have super soakers and throw water balloons. I'm very interested in Roland Tower's Ultimate Water Gun, but he didn't list the cost and potential range. I was wondering if anyone has built this, and if so (or not), could guesstimate the approximate cost and how far they think it might shoot, and what they think of the gun.

Thanks so much guys!! I'll take pics once I set it up.


http://www.sscentral.org/homemade/

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Drenchenator
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Re: Building a gun...

Post by Drenchenator » Sat Apr 05, 2008 10:04 pm

Welcome to SSC! Thanks for the compliments! We just finished a major update to the site in January and are glad you like the site.

I don't know of anyone that has built RolandTower's gun. It's a fairly standard air pressure backpack gun though. I'd estimate the range to be no more than about 55 feet. I also can't see the gun costing more than 100 USD, likely around 50 to 70 USD.

The gun definitely looks the part--large air pressure reservoir, purple PVC primer stains--but it has several key weaknesses. To fill it with water, you'd have to unscrew a cap. Though this may seem innocent in the design phase, the cap could leak air when pressurized and overall it's just a plain pain to deal with. For this reason, Ben used a plain old 1" ball valve for his SuperCAP backpack gun for easy filling.

Pressurizing the gun creates another problem. Just putting a schrader valve in a hole drilled into the pipe is not only a pain but also messy; it could leak just the same under pressure. The best solution dedicates a check valve and then a filling apparatus attached with a female threaded fitting for the job (either air tools or a schrader valve, whichever works better for the builder). An example is available here.

Other than that, RolandTower's gun performs well and is a excellent example of a standard air pressure backpack gun. The homemades page has links to several other similar backpack designs if you would like. I'd just recommend those updates to it if you plan to go along with it.

There are also several similar designs on the forums if you want to look.

On a side note, RolandTower's gun needs a pressurized air source. Compressors or hand pumps come to mind, but some guns don't need either. If you're just looking for an easy, step by step guide for a gun like this, Ben's APH guide is another option. The gun boasts the same capabilities as RolandTower's--only with a hand pump. The guide is the most detailed out there for a water gun.
The Drenchenator, also known as Lt. Col. Drench.

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SSCBen
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Re: Building a gun...

Post by SSCBen » Sat Apr 05, 2008 10:47 pm

Welcome to SSC! Glad you like our website. The general response has been great.

I should make a list of relatively basic designs people want guides for. I wouldn't have a problem knocking them out this summer and I know people would appreciate it. I'll work on that offline.

If you don't want to wait until then, I would suggest a few things. First, read a bunch of our website and forum. There's a goldmine of information in the forum especially. When we updated our website, we were really just bringing it to the level of the forum. You can get some ideas from here and you'll become more familiar with DIY water guns.

You also might want to just jump into building. One day I decided I wanted to make a water gun, drew up a design, and went to the hardware store to buy some parts. Quickly I realized that my design wouldn't work, so I changed it up after messing around with the parts a bit and got the basic APH design. You can learn a lot just by having the parts in front of you. ;)
Last edited by SSCBen on Sun Apr 06, 2008 3:16 am, edited 1 time in total.

ben@sscentral.org / Please read this before emailing or PMing me

Do not ask me water gun questions by email or PM. Please post the question at the forum. Private questions and suggestions are welcome by PM and email. Also, I do not sell or buy water guns online.

mikeyi
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Joined: Sat Apr 05, 2008 9:00 pm

Re: Building a gun...

Post by mikeyi » Sun Apr 06, 2008 1:31 pm

Wow, thanks guys, I really appreciate it. I think I might go with Roland's design with Ben's add-ons. I might be a bit over my head, but what the heck, why not! I can't even begin to explain how extremely excited I am about beginning this project!!

I do have a question regarding Ben's check valve filling apparatus. Again, I'm new so bear with the dumb questions which may follow...

In the following link, http://images.sscentral.org/supercannon/22.jpg , is the ball valve present in this picture as a pressure release/drain for the tank?

Main question...Was any modification needed to thread the piping into this cap, or was everything threaded and attached with copious amounts of tape?

Did I mention how excited I am about this?

The boat parade (War as I call it) occurs on July 4th. I can guarantee you that I'll have many pics to post from the war as well as during the construction.

Thanks again guys, I appreciate all the expertise.

-Mike

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SSCBen
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Re: Building a gun...

Post by SSCBen » Sun Apr 06, 2008 3:10 pm

The ball valve is a pressure release, which is a good idea for safety reasons. This lets you drain the tank without shooting water out. On that water gun it's necessary for more than safety because the gun uses a piston to separate the air and water.

The pipe wasn't threaded into the cap. PVC fittings are not designed for that but people still do it. Drilling holes in fittings so they don't leak with tapped threads is hard for newbies and even people like me. I used a reducer to a bushing with threads in it. Everything was threaded together with the right amount (not copious) of tape. Don't use more than two or three turns of tape (or whatever the tape recommends). More will help create a "wedge force" and break the fitting if screwed in too tight.

Check this page out if you have any more questions about that assembly: http://www.sscentral.org/homemade/supercannon2.html

I built a PVC version of it first that wasn't durable enough. This January I replaced it with a metal version that's much more durable, but heavy. I would suggest a PVC version for your gun because your gun should not face the same problems. The part broke off during storage likely because the gun was so long.

Good luck with the project too. ;)
Last edited by SSCBen on Tue Apr 08, 2008 5:31 pm, edited 1 time in total.

ben@sscentral.org / Please read this before emailing or PMing me

Do not ask me water gun questions by email or PM. Please post the question at the forum. Private questions and suggestions are welcome by PM and email. Also, I do not sell or buy water guns online.

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Drenchenator
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Re: Building a gun...

Post by Drenchenator » Sun Apr 06, 2008 5:34 pm

Main question...Was any modification needed to thread the piping into this cap, or was everything threaded and attached with copious amounts of tape?


Threading stuff into a cap or pipe creates far to many problems; use a bushing--it's what it's designed for. In fact, because Ben used one in his SuperCannon II, when the original PVC filling device broke off (little brother messed with it), Ben only had to make a new one and screw it into place. A PVC version should be fine for your project given that you don't want too much extra weight.

Good luck on the project!
The Drenchenator, also known as Lt. Col. Drench.

mikeyi
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Joined: Sat Apr 05, 2008 9:00 pm

Re: Building a gun...

Post by mikeyi » Tue Apr 08, 2008 1:58 pm

ok, two more questions, again, bear with me....

Ben, is the bushing you used in the picture PVC or metal? It's hard to tell because of the primer.

So, you can screw a metal pipe into a PVC bushing? I imagined you could as long as the threads were the same, but always thought metal had to go to metal and pvc to pvc to assure a good connection. can you tell I'm new to the plumbing world...

If you think the PVC bushing is strong enough, I'll go that route.


Thanks again guys. I'm off to Home Depot this evening....

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Silence
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Re: Building a gun...

Post by Silence » Tue Apr 08, 2008 3:35 pm

Bushings as used in pipe fittings are not the same as bushings used as axles. Pipe bushings are compact reducers; the smaller pipe fits inside, and the bushing fits inside a larger-sized fitting (which could be a coupler, tee, etc.). The overlap saves a good bit of space. In the APH, a PVC bushing is used to convert from 1/2" to 3/4" pipe. No threads, just a socket on the small side and a plug on the other. (A plug just means the fitting is the same size as actual pipe and can fit in other fittings.)

Sorry for the long explanation. Basically, go to the plumbing section and get a 1/2" to 3/4" PVC bushing. One end goes over 1/2" tube and the other goes in a 3/4" fitting. :cool:

mikeyi
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Joined: Sat Apr 05, 2008 9:00 pm

Re: Building a gun...

Post by mikeyi » Tue Apr 08, 2008 4:39 pm

My apologies, I was asking about the assembly in the attached picture of the supercannon

http://images.sscentral.org/supercannon/22.jpg

Thanks,
Mike

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Silence
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Re: Building a gun...

Post by Silence » Tue Apr 08, 2008 4:46 pm

Sorry!

That bushing looks like it's made out of PVC, which is probably a safe decision. Although only PVC is solvent welded together, the metal and PVC are connected using compatible threads with Teflon tape. :cool:

mikeyi
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Re: Building a gun...

Post by mikeyi » Tue Apr 08, 2008 4:58 pm

SilentGuy, Ben, and Drench, thank you so much for your assistance. I'm off to the store in 4 hours! I'll keep you posted. You'll be hearing from me....

Thanks,

Mike

mikeyi
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Joined: Sat Apr 05, 2008 9:00 pm

Re: Building a gun...

Post by mikeyi » Mon Apr 14, 2008 7:09 pm

Ok guys, I'm back with a few questions...

I'm building RolandTower's Ultimate water gun with enhancements from Ben's Supercannon2 and supercap backpack gun.

I'm using 4 tees total with 4 inch PVC tubing and a couple of street elbows...
1 Tee for water intake with 1 in ball valve
1 Tee which dwindles down to 1/2 inch pipe Tee for pressure gauge on one side and Schrader valve on the other
1 Tee for air muffler attached to the end of a ball valve
1 Tee for water leaving tank into hose/gun.

Schrader valve to fill via air compressor- Do I need a check valve here?

Air muffler on ball valve for a muffled air release- Do I need a check valve here as well? Will I need check valves anywhere else? I was thinking I would just need 1 check valve behind the schrader valve, but I'm new to plumbing and want to make sure.

From Supercannon2...
"The back end of the gun is the part that fills the gun with air. The back end features a check valve with an air coupler to attach to an air compressor. The check valve lets air in one way, but not out the other way, which is what you want in a design like this. The ball valve is necessary to vent compressed air from the back of the water gun."

Thanks,

Mike

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SSCBen
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Re: Building a gun...

Post by SSCBen » Mon Apr 14, 2008 7:51 pm

Schrader valves work as check valves, so any additional check valve would just be wasted money. The air muffler also does not require a check valve. If you're using a schrader valve, you shouldn't need any check valves at all.

ben@sscentral.org / Please read this before emailing or PMing me

Do not ask me water gun questions by email or PM. Please post the question at the forum. Private questions and suggestions are welcome by PM and email. Also, I do not sell or buy water guns online.

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Drenchenator
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Re: Building a gun...

Post by Drenchenator » Mon Apr 14, 2008 9:04 pm

Sounds good so far! A schrader valve's technically a tiny check valve, so you don't need another one.

Ben and I use air tools with our air compressor--which is just a hose connection with no valves. To keep the air in the gun, you need a check valve.

Seems like you have everything covered. Good luck with the build! Keep us posted.
The Drenchenator, also known as Lt. Col. Drench.

mikeyi
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Joined: Sat Apr 05, 2008 9:00 pm

Re: Building a gun...

Post by mikeyi » Mon Apr 14, 2008 10:20 pm

Thanks guys. I appreciate it!

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