How can I shoot multiple sized objects out of a 5” barrel?

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.
BCannon
Private
Private
Posts: 14
Joined: Sat Apr 28, 2007 1:39 pm

Thu May 03, 2007 12:37 pm

Anyone have any ideas of how to shoot multiple sized objects out of a cannon with a 5” barrel? The objects I’m shooting range in size from 1” to 5”. I’m just stuffing a rags in the bottom of the barrel for now but there has to be a better solution. Has anyone built a plunger type system? Thanks for the help.
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26203
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 569 times
Been thanked: 345 times

Donating Members

Thu May 03, 2007 12:48 pm

Find a plastic soda bottle as close to 5" diameter as you can and cut it in half. If it doesn't fit exactly wrap it with duct tape until it does.
hectmarr wrote:You have to make many weapons, because this field is long and short life
AmYisroelChai
Specialist
Specialist
Posts: 117
Joined: Thu Mar 29, 2007 10:50 am

Thu May 03, 2007 1:55 pm

Same idea as above.
Find any sort of carton with a diameter bigger then 5".
Then put the round carton into the barrel as far as it will go.
With a sharp blade cut the exposed part of the container.
Whats left is a perfect fitting sabot.

Good luck

PS
Do you have pic of this cannon. I have some 6" pipe I am waiting to mount. Interested to see yours.
:D No smart comments - I just read what I wrote :lol:
User avatar
WOW!!
Corporal 4
Corporal 4
Posts: 891
Joined: Thu Mar 16, 2006 9:47 pm
Location: New jersey

Thu May 03, 2007 3:48 pm

Get some of the expanding foam insulation and make a mold in a section of your barrel with the ammo inside and after it dries cut it in 3 sections and you have your self a sabot
User avatar
paaiyan
First Sergeant
First Sergeant
Posts: 2140
Joined: Wed Dec 27, 2006 10:03 pm
Location: Central Oklahoma
Been thanked: 1 time

Thu May 03, 2007 3:54 pm

Yea, that foam insulation crap works really well. What you can do to improve on that idea though is to cut the stuff like he said and hollow it out enough to hold you object(s). After you do that, cut it vertically twice so there's four quarters. That way, when it exits the barrel, if done right the four pieces of foam should go off to the side after exiting the barrel and leave your object flying high.
"Who ever said the pen was mightier than the sword, obviously, never encountered automatic weapons."
-General Douglass MacArthur

Read my dog's blog - Life of Kilo
BCannon
Private
Private
Posts: 14
Joined: Sat Apr 28, 2007 1:39 pm

Thu May 03, 2007 7:14 pm

I think the expanding foam idea will work great for my situation. Thanks!

Now, does anyone have any suggestions for keeping the foam plug from coming out of the barrel? I only want to shoot objects 20-40 yards so distance isn't a priority. Ideally I would like to reduce the end of the barrel so the plug will not come out. But I guess it needs to be a smooth transition so the objects will not get hung up too.

AmYisroelChai, I haven't built on with a 5" barrel yet. I have a 4" cannon that I'm playing around with to try to find the optimal barrel and chamber ratios. This cannon is nothing special and not pretty... just an air chamber => inline sprinkler valve => barrel.
User avatar
paaiyan
First Sergeant
First Sergeant
Posts: 2140
Joined: Wed Dec 27, 2006 10:03 pm
Location: Central Oklahoma
Been thanked: 1 time

Thu May 03, 2007 7:20 pm

You wouldn't want to prevent the sabot from coming out, that would most definitely interfere with your projectile.
"Who ever said the pen was mightier than the sword, obviously, never encountered automatic weapons."
-General Douglass MacArthur

Read my dog's blog - Life of Kilo
keep_it_real
Specialist 3
Specialist 3
Posts: 320
Joined: Sat Dec 23, 2006 4:41 pm
Location: Bend, Oregon

Thu May 03, 2007 7:49 pm

Get a 5" endcap and drill a big hole (size of projectile). Put some kind of bumper or possibly a gigantic spring around the endcap. I would get some pipe that fits inside the barrel and then spray the foam inside the pipe and drill out another hole (size of projectile) when its dry. This way the foam doesn't break when it hits the bumper.

If you want to reuse the same sabot then why not get a different barrel that actually fits the projectile?
User avatar
dewey-1
Sergeant 3
Sergeant 3
Posts: 1298
Joined: Wed Mar 28, 2007 10:24 am
Location: NE Wisconsin USA

Thu May 03, 2007 8:31 pm

--
Last edited by dewey-1 on Sun Apr 20, 2008 4:02 pm, edited 1 time in total.
User avatar
frankrede
Sergeant Major 2
Sergeant Major 2
Posts: 3220
Joined: Thu Jul 20, 2006 9:47 pm
Has thanked: 1 time
Been thanked: 1 time

Thu May 03, 2007 10:29 pm

BCannon wrote:I think the expanding foam idea will work great for my situation. Thanks!

Now, does anyone have any suggestions for keeping the foam plug from coming out of the barrel? I only want to shoot objects 20-40 yards so distance isn't a priority. Ideally I would like to reduce the end of the barrel so the plug will not come out. But I guess it needs to be a smooth transition so the objects will not get hung up too.

AmYisroelChai, I haven't built on with a 5" barrel yet. I have a 4" cannon that I'm playing around with to try to find the optimal barrel and chamber ratios. This cannon is nothing special and not pretty... just an air chamber => inline sprinkler valve => barrel.
Your setup is crap.
You want to find the optimum barrel? with a sprinkler valve?
haha any barrel 3/4 and under would perform the best.
a barrel bigger than your chamber is crap.
And having such flow restrictions make it even worse.
Current project: Afghanistan deployment
BCannon
Private
Private
Posts: 14
Joined: Sat Apr 28, 2007 1:39 pm

Thu May 03, 2007 11:15 pm

The objects I'm shooting are no more than 10 inches long. With a 4" diameter barrel (18" long), 1" sprinkler valve and 4" chamber (12" long) pressured to 100 psi, the 3" diameter object is launching 25 yards with a rag stuffed in the bottom of the barrel. This is perfect my situation... I just want to find a way to get rid of the rag.
User avatar
dewey-1
Sergeant 3
Sergeant 3
Posts: 1298
Joined: Wed Mar 28, 2007 10:24 am
Location: NE Wisconsin USA

Fri May 04, 2007 4:13 pm

--
Last edited by dewey-1 on Sun Apr 20, 2008 4:04 pm, edited 1 time in total.
BCannon
Private
Private
Posts: 14
Joined: Sat Apr 28, 2007 1:39 pm

Fri May 04, 2007 11:59 pm

dewey-1 wrote:BCannon;
I am willing to help you but please, provide info for asked questions.
1) What barrel diameters, and what schedule pipe for each?
2}What is the weight of each of your projectiles?
3) What is the cannon configuration? Inline or over under?
4) Chamber size should be at least 18 in at 4 diameter.
1) The barrel diameter I plan to use is 5" Sch 40 but I'm using 4" Sch 40 right now.
2) The weight is of my projectiles are as follows:
Projectile 1 - 2"w x 12"l - 5.6 ounces
Projectile 2 - 3"w x 12"l - 14.6 ounces
Projectile 3 - 5"w x 16"l - 3 pounds
3) Cannon configuration is inline.
4) The distance I want my Projectiles to go is 20 to 40 yards. I been experimenting with different barrel chamber rations to try to get the gun as small as possible but still reach my target distance. I tried my gun today with a t-shirt stuffed in the barrel and got a 45 yard launch with Projectile 2 at 100 psi.

I’ll try that program dewey-1. Let me know if you have any suggestions.
User avatar
dewey-1
Sergeant 3
Sergeant 3
Posts: 1298
Joined: Wed Mar 28, 2007 10:24 am
Location: NE Wisconsin USA

Sat May 05, 2007 12:02 pm

--
Post Reply