WaterWar.net

Posted: **Tue Nov 21, 2006 4:55 pm**

I finally found enough time to record a few stats for my launcher. Unfortunately, the battery on my inflator went low after the first shot (I haven't recharged it in ages), so I only have one set of data. I will add more soon on this thread, as soon as my inflator is recharged.

Trial 1:

Firing Angle ~45 degrees (I used a level to do this, so it may be a bit off)
Pressure: 80 psi
Pressurizing time: 2 min 19 sec
Balloons: 1
Wadding: paper towels
Range: ~221.5 feet

This range seems way low for the pressure and amount of air that I used. I think that the friction between the wadded peper towels (I used a lot of them) and the barrel of the launcher is causing this. I am going to buy a few pringles cans this afternoon, and try one of those. Are there any other items I can use for wadding?

Edited By FinalFantasizer on 1164146265

Posted: **Tue Nov 21, 2006 5:04 pm**

Nice stats. I would definetly go for buying the pringles can, it visibly adds range.I don't know of any better things to use for wadding.

Posted: **Tue Nov 21, 2006 5:11 pm**

Just wondering, how tightly does a Pringles can fit inside of a piece of 3 in. PVC?

Posted: **Tue Nov 21, 2006 5:52 pm**

It fits in well. not tightly
, but snugly.

Posted: **Tue Nov 21, 2006 6:07 pm**

Didn't you know? Pringles cans are what Duxburian and the Ridgewood Militia use! Sorry, I just had to point that out--great coincidence, though! I hear they work very well, plus you can probably store balloons inside.

Exactly what is the volume of the PC? Also, remember to open the valve as quickly as possible if you are using a ball valve. And finally, what are the lengths of the barrel and the size of the valve? Maybe too many questions, but the point is that there are a lot of influencing factors. It's still decent performance though--longer range than a water gun!

Posted: **Tue Nov 21, 2006 8:19 pm**

My personal method for assisting in the launching of water-balloons can be seen here. One change I've made recently to it is to cut a 1" hole going straight down the center of the two pieces and to cut a much smaller hole on the bottom piece. Tie a string to the small hole and attach the other end to your launcher.
Using this the balloon is launcher, then released by the shell, allowing for easy re-use.

Posted: **Tue Nov 21, 2006 8:44 pm**

So, I went to measure my wbl and find the vol. and length of the barrel and PC. This happened:

[IMG]http://images4.pictiger.com/thumbs....MG]

So now, it will be probably another week before I can peform any tests.

Anyway, here are the dimentions:
Length of barrel: 24.5 inches
Length of PC: 33.25 inches
Vol of PC: slightly greater than 235.03 in^3

I was wondering if the barrel can be cut short by about 3 inches (so I don't have to buy more PVC pipe to perform the repairs). That should increase the range slightly, but decreate accuracy and max payload.

Edited By FinalFantasizer on 1164160050

Posted: **Tue Nov 21, 2006 10:15 pm**

Aw that sucks. The G2 Douchenator has cracked twice. Great care should be taken when handling and storing in-line launchers. Over-under launchers don't have the problem, but I personally prefer in-line. 2:19 for your inflator is not that bad for doing no manual work. Might be a bit sketchy in a war, but with plenty of support and/or working in conjunction with another launcher, it would be fine. Cutting the barrel 3 inches shorter won't have much of an adverse impact. It's 3 inches! :p

Pringles cans are probably the best wadding you can get. Don't have to do anything other than slide the can down the barrel. The seal is quite good, enough to help get balloons to the 400ft mark at only 60-70 PSI. They also last quite a while, you can get over a year's worth of shots with a single can if you're careful with it. Pringles cans can store about 3-5 balloons, depending on how large the balloons are.

Posted: **Tue Nov 21, 2006 10:29 pm**

Yeah i just shot my douchenator today and i used a piigles can it fits really well.@Duxburian do you put the ballons in the can?

Posted: **Tue Nov 21, 2006 10:35 pm**

Ya, my Simplified Douchenator had that exact same thing happen to it. I think the reason mine broke was because it accidentally dropped it in cold weather.

Making the barrel shorter will actual decrease the range, as you are giving your valve less time to release all the air.
In your stats, you're barrel is shorter than your PC, this means that using a 1" ball-valve, your are using the charged air very inefficiently.
This would be a very good time to increase the length of your barrel. It will make a big difference in your range.

Posted: **Wed Nov 22, 2006 10:44 am**

@ water wolf: Now that you mention it, lenghtening the barrel does make sense, especially for the volume of air that I'm pressurizing. The friction between the pringles can and the barrel shouldn't matter nearly as much as the friction caused by the paper towels.

Posted: **Wed Nov 22, 2006 12:54 pm**

Exactly, its all physics.
My current work-in-progress-WBL is designed to make more efficient use of the air in its PC, since the volume of air will be much lower than most WBLs.

Posted: **Wed Nov 22, 2006 7:23 pm**

I agree with Duxburian in that 3" won't make a difference. However, I am posting to point out the fact that length is better.

I see that WaterWolf got to it first, but I'm kinda sure that isn't why a longer barrel is better. A longer barrel should work even with a modified solenoid sprinkler valve--the opening time is insignificant, and slow opening is going to give you a problem anyway. Which is why the Mythbusters have terrible launchers--the projectile is gone before the butterfly valve is even an eighth of the way open.

The reason a longer barrel is usually better is that it gives more time for the air to expand--no matter how open the valve is. Face it, the air will continue to expand for a while. As long as it is still moving faster than the projectile (which starts slow due to inertia), it will still be transferring force.

That's why it's better to have a smaller PC and a longer barrel. You can get improved performance while spending less time pumping due to a smaller PC. Otherwise, all that precious air will just be lost before being used properly. Of course, at some point the air expansion is too slow, and it won't keep up with the sabot inside the barrel.

Posted: **Thu Nov 23, 2006 9:57 am**

So, with a 33 inch PC, how long do you think the barrel should be?

Posted: **Thu Nov 23, 2006 12:36 pm**

At-least twice that of the PC, and If you've got a 1" ball-valve, then even longer.

Posted: **Thu Nov 23, 2006 1:41 pm**

Face it, making either part longer is going to help. However, I would go for a longer barrel anyway just to maximize the potential energy of the air you've compressed. But size is also important. I would just go for the longest practical barrel.

Posted: **Thu Nov 23, 2006 2:02 pm**

Not sure if this has been done elsewhere, but has anyone tried making the PC out of a larger-diameter PVC pipe such that it can be shorter while still having enough volume to store the compressed air? Then again, perhaps larger-diameter PVC pipe may be either much more expensive or poorer in terms of pressure-rating.

Posted: **Thu Nov 23, 2006 2:47 pm**

Yep, that's the problem--the lower pressure rating, lesser availability, and perhaps greater price. It's a neat idea though, and that's basically what you're getting with an over-under system. Have the PC double back again if you want more capacity...but neat idea.

What's the deal with barrel "suck"? I've heard that in games like paintball and airsoft, if the barrel's volume is greater than that of the "PC," then a partial vacuum can form, pulling the projectile back as it exits the barrel.

Edited By SilentGuy on 1164311323

Posted: **Thu Nov 23, 2006 3:53 pm**

I've got a 1.25 inch ball valve, so a barrel that is twice as long a my PC would make the laucher over 7.5 feet long. That's way too unwieldy in my opinion.

Posted: **Thu Nov 23, 2006 7:52 pm**

I think WaterWolf suggested a longer barrel for large ball valves because they're slow to open. However, as I said, the balloon will probably be out the barrel no matter what. A longer barrel allows more time for expansion of the air that's already let out, so I don't think barrel length can be related to ball valve size.

WaterWar.net

Stats for my Douchenator - Range, reloading time, etc.