3 air chambers??? Is there a better way??? (UPDATED new pic)

Show us your pneumatic spud gun! Discuss pneumatic (compressed gas) powered potato guns and related accessories. Valve types, actuation, pipe, materials, fittings, compressors, safety, gas choices, and more.
ImHUGEnJAPAN
Private 4
Private 4
Posts: 77
Joined: Thu Apr 03, 2008 12:08 pm

Thu Apr 10, 2008 9:02 am

This is what I came up with. I added a 60" air chamber for more power. I hope this helps. For now I have to wait until the glue dries.


<a href="http://s273.photobucket.com/albums/jj23 ... 81800a.jpg" target="_blank"><img src="http://i273.photobucket.com/albums/jj23 ... 81800a.jpg" border="0" alt="Photobucket"></a>

I want more power out of my air cannon. I can very easily expand the air chamber. Would 3 2" x 12" air chambers be effective? I'm concerned the flow might get restricted using a 3 chamber design. I'm trying to keep the gun compact.

New air chamber design, will the flow be restricted too much???
<a href="http://s273.photobucket.com/albums/jj23 ... 080932.jpg" target="_blank"><img src="http://i273.photobucket.com/albums/jj23 ... 080932.jpg" border="0" alt="Photobucket"></a>

With my current cannon design the air chamber is not big enough to prodce the power I need to shoot a paint grenade or grape shot.
<a href="http://s273.photobucket.com/albums/jj23 ... 2002-1.jpg" target="_blank"><img src="http://i273.photobucket.com/albums/jj23 ... 2002-1.jpg" border="0" alt="Photobucket"></a>
Last edited by ImHUGEnJAPAN on Thu Apr 10, 2008 6:19 pm, edited 2 times in total.
User avatar
biggsauce
Specialist 3
Specialist 3
Posts: 338
Joined: Thu Jun 07, 2007 9:42 pm

Thu Apr 10, 2008 9:07 am

It wont increase your power much, sorry to say. But if you feel like bilding 3 chambers, use 3 valves. Now THAT will definitely give you a power increase
User avatar
Jared Haehnel
Corporal 2
Corporal 2
Posts: 611
Joined: Tue Feb 19, 2008 4:15 pm
Location: White River Jct, Vermont

Thu Apr 10, 2008 9:08 am

It would have an adverse affect on flow but I would think that you would seen and definite increase in power...what does GGDT say about it? Enter it as a (single chamber with a equal volume of the combine three chambers)

You may do better by increasing barrel length...
My current projects....

Currently buying part for...
http://www.spudfiles.com/forums/my-new- ... rt,15.html
Still on the drawing board...
C02 tank hybrid
Screen doors for submarines...
grumpy
Specialist 3
Specialist 3
Posts: 331
Joined: Wed Sep 26, 2007 7:48 am
Location: tampa,fla.

Thu Apr 10, 2008 9:29 am

what pressure have you tried firing it at? the heavier the projectile the higher the pressure you will need to use.
User avatar
Lentamentalisk
Sergeant 3
Sergeant 3
Posts: 1202
Joined: Tue Aug 07, 2007 5:27 pm
Location: Berkeley C.A.

Thu Apr 10, 2008 9:47 am

the reason for the crap capabilities now is that your valve has little flow in comparison to your barrel. Your barrel has 4x the flow of your valve. If you stuck another modded sprinkler valve then you should see a large increase in performance
Do not look back, and grieve over the past, for it is gone;
Do not be troubled about the future, for it has not yet come;
Live life in the present, and make it so beautiful that it will be worth remembering.
brother361
Specialist
Specialist
Posts: 129
Joined: Wed Sep 19, 2007 12:19 pm
Location: maryland

Thu Apr 10, 2008 9:52 am

the three chamber design would be good but you would need a way to support them or they might just snap off at the cross
User avatar
jrrdw
Moderator
Moderator
United States of America
Posts: 6571
Joined: Wed Nov 16, 2005 5:11 pm
Location: Maryland
Has thanked: 39 times
Been thanked: 22 times
Contact:

Donating Members

Thu Apr 10, 2008 10:50 am

If you double the chamber size instead of trying to be fancy, it should increse you power nicely, orrrrrrrr -- Build a piston valve if you want real power from a pneumatic.
ImHUGEnJAPAN
Private 4
Private 4
Posts: 77
Joined: Thu Apr 03, 2008 12:08 pm

Thu Apr 10, 2008 11:20 am

I have fired it at 90psi. I removed the saftey tip on my blowgun and also removed the spring from inside the cp-100 valve. Those 2 simple things helped a LOT. It's still not powerful enough. I think a smaller bore size barrel will help. I have been doing some more research and seems that your projectile needs to form a good seal aroung the inside diameter of your barrel. I just tried shooting loose paintballs and the only thing I accomplished was making a LOT of noise. I would have more luck throwing a handfull of paint at someone....lol.

I think if I add another valve I can accomplish my goal.
User avatar
starman
Sergeant Major
Sergeant Major
United States of America
Posts: 3027
Joined: Wed Dec 12, 2007 12:45 am
Location: Simpsonville, SC

Donating Members

Thu Apr 10, 2008 11:36 am

Lentamentalisk wrote:the reason for the crap capabilities now is that your valve has little flow in comparison to your barrel. Your barrel has 4x the flow of your valve. If you stuck another modded sprinkler valve then you should see a large increase in performance
Lentamentalisk has it right here, your restricted flow is the issue. 2 more tanks feeding the same restriction is not going to appreciably increase your performance. Go with 1 more tank and another sprinker and mix them on the barrel side of the sprinklers. At the mix, go up to 2" connectors all the way to barrel. This will double the flow you have now.

If you go with another tank, you can also help yourself with a longer barrel.
ImHUGEnJAPAN
Private 4
Private 4
Posts: 77
Joined: Thu Apr 03, 2008 12:08 pm

Thu Apr 10, 2008 12:20 pm

What if I reduced the bore size of the barrel? lets say to 1"
User avatar
judgment_arms
Sergeant 3
Sergeant 3
Posts: 1272
Joined: Tue Oct 17, 2006 8:49 pm
Location: Not so beautiful North Carolina, but at least it’s the U.S.A.!

Thu Apr 10, 2008 12:57 pm

With your current set up you should be running at regulation velocity; actually, depending on were you go, you may be shooting hot, it should do about 240 with a NERF which is 10fps faster than regulation 230fps.

How heavy is your projectile?

Your best bet for better power is a longer barrel and longer chamber; with an 18 inch chamber and 26 inch barrel you should be getting 170 yards of distance from a 5oz round.


**all figure’s from GGDT**
Call me "Judge", it's easier to type.

Spud gun safety rules
User avatar
starman
Sergeant Major
Sergeant Major
United States of America
Posts: 3027
Joined: Wed Dec 12, 2007 12:45 am
Location: Simpsonville, SC

Donating Members

Thu Apr 10, 2008 1:10 pm

ImHUGEnJAPAN wrote:What if I reduced the bore size of the barrel? lets say to 1"
Then a 1" sprinkler is closer to ideal (for a sprinkler) for a 1" barrel. If you go with a 2' barrel length and keep the tank the same, you'll have roughly 2:1 c:b ratio. A 4' barrel roughly 1:1. Depending on projectile weight, both good performers.

In your config, you still have a dead space issue on your back elbows. With your short barrel, that is contributing to your low performance as well. Move the sprinkler right behind the barrel.
ImHUGEnJAPAN
Private 4
Private 4
Posts: 77
Joined: Thu Apr 03, 2008 12:08 pm

Thu Apr 10, 2008 1:19 pm

I got the same results from "ggdt". Actual performance differs greatly, I think the flow is being restricted too much. I think I will just expand the air chamber and see what happens. I will probably not see a big increase in power but I plan to extpand the air chamber to 50" using a "T" connector and 2 elbows. I will extend the two extra air chambers backwards towards the valve. see picture below.

Do you want your projectile to match the bore size of your barrel? Does a tight fit (but not too tight fit) help. ggdt implies that it does.

<a href="http://s273.photobucket.com/albums/jj23 ... 081413.jpg" target="_blank"><img src="http://i273.photobucket.com/albums/jj23 ... 081413.jpg" border="0" alt="Photobucket"></a>
User avatar
judgment_arms
Sergeant 3
Sergeant 3
Posts: 1272
Joined: Tue Oct 17, 2006 8:49 pm
Location: Not so beautiful North Carolina, but at least it’s the U.S.A.!

Thu Apr 10, 2008 1:21 pm

What ever you do a longer barrel always helps. :wink:
Call me "Judge", it's easier to type.

Spud gun safety rules
ImHUGEnJAPAN
Private 4
Private 4
Posts: 77
Joined: Thu Apr 03, 2008 12:08 pm

Thu Apr 10, 2008 1:40 pm

judgment_arms wrote:What ever you do a longer barrel always helps. :wink:
Thanks, I'm trying to keep the gun as compact as possible, it's slowly growing in size....lol. I might have to scrap the whole PB idea and just make a fun cannon to play with.
Post Reply