Page 1 of 1

Feedback on Coaxial Design Please :)

Posted: Mon Apr 23, 2007 6:39 pm
by AmYisroelChai
Hi everyone got a quick question before I take my first exam,
I am designing a simple co-axial pneumatic mortar for paintballs. I want them to be light and portable and simple, cheap, easy to make. Here’s my design and I appreciate feedback.
Sorry if there is no graphic picture I have no skill with graphics. If someone cares to oblige –tank you but its simple so it may not need one.

22” of 3” PVC – for the chamber
20” of 1 1/2” PVC for Barrel
2 ½” PVC end cap for a Piston
3” End Cap sealing the back end of the Gun.
10 ½ screws to Bolt on the 3” PVC endcap. (Do I need a O-Ring to keep air from escaping?)
3” x 1 ½” PVC Adapter
Blowgun
Bumper (Pool noodle/Half of Tennis Ball/Garden Hose)
L –Shaped coupling threaded into the 3” Endcap
Male quick disconnect with adapter to thread directly into the Blowgun

Here is my question
Will the blow gun be enough to successfully release the air fast enough to allow the piston to port? (Keep in mind I have the Blowgun going trough a L shaped threaded adapter to make it a vertical handle)


Thankx

EDIT:
I realized now I didn’t know what I wanted but now I do –thank you all for helping me clarify.

I want to make to types of co-axial cannons.
Mortar co axial 4” chamber 2” Barrel
Paintball Bazooka to shoot 12-24 paintballs. Using 3” Chamber and 1 ½” Barrel.
Barring any other ideas I have a length of 4” PVC, 3” PVC and 2” PVC etc.

I will definitely make a bunch of 4” x 20” co-axial cannons with 3” end caps and threaded caps for access.

But what can I do with the 3” to make a simple co-axial Paintball-zooka?

Posted: Mon Apr 23, 2007 6:49 pm
by iPaintball
I highly doubt that a lone blow gun will be enough to pilot that piston. Use a valve with a higher flow rate. (1/2" ball valve, small sprinkler, small QEV) The overall design seems fine, but good luck finding cheap 2.5" endcaps...

Posted: Mon Apr 23, 2007 6:54 pm
by hi
yea, you need at least a 1/4'' ball valve, 1/2'' would be even better.

i do see one flaw in the design. you should use a threaded plug instead of just an end cap, that way you dont need to worry about the O rings, it wont save you any space with the end cap, and a threded plug would be so much faster to get off. other than that it looks good.

Posted: Mon Apr 23, 2007 7:05 pm
by AmYisroelChai
Da Pneu Kid wrote:I highly doubt that a lone blow gun will be enough to pilot that piston. Use a valve with a higher flow rate. (1/2" ball valve, small sprinkler, small QEV) The overall design seems fine, but good luck finding cheap 2.5" endcaps...


My brother is a plumber so i can get the 2 1/2" endcap cheaper then Home Depot.
Thank you for the Ball Valve suggestion.

If you have any ideas for a piston that is real easy to make then I am open. Cut down sections of 3” PVC and then make sheet pvc and glue them to the tip?

I will look around but I want to make like 10 -20 of these so I want it to be economical but still safe!

Thanks you

Posted: Mon Apr 23, 2007 7:06 pm
by AmYisroelChai
hi wrote:yea, you need at least a 1/4'' ball valve, 1/2'' would be even better.

i do see one flaw in the design. you should use a threaded plug instead of just an end cap, that way you dont need to worry about the O rings, it wont save you any space with the end cap, and a threded plug would be so much faster to get off. other than that it looks good.

I thought about it and you are correct. It will cost a little more but will save me in time and frustration later on. Thank you.

Posted: Mon Apr 23, 2007 7:26 pm
by iPaintball
No, I mean Home Depot doesn't have any 2.5" fittings, or pipe for that matter. An easier option would be a coax with a 4" chamber and a 3" endcap as a piston. Also, if you use a 2" barrel, the piston will have a 2" exhaust port instead of a 1.5" one, increasing power and eliminating the need for a long barrel and chamber.

Posted: Mon Apr 23, 2007 7:42 pm
by goathunter
If you are planning on using it as a mortar go with the 2" barrel.This is much more versatile when shooting grenades(bouncing betty size),the 1 1/2" barrel won't take grenades.My 1 1/2" barrel only shoots 24 paintballs max.Not what you want when going for a "shower of paint".Also take into effect the recoil,put something on the base so it will stick in the ground and not scoot backwards as it fires.

Posted: Mon Apr 23, 2007 9:06 pm
by AmYisroelChai
goathunter wrote:If you are planning on using it as a mortar go with the 2" barrel.This is much more versatile when shooting grenades(bouncing betty size),the 1 1/2" barrel won't take grenades.My 1 1/2" barrel only shoots 24 paintballs max.Not what you want when going for a "shower of paint".Also take into effect the recoil,put something on the base so it will stick in the ground and not scoot backwards as it fires.
Thank you I was designing a simple Mortar stand that would let me aim in all direction I will make sure to make it steady on the bottom. I plan on setting up Cardboards houses for the Mortars. The Field I go to is not that great. Also what to use for Grenades I have not had a chance to search your profile for your tutorial on Paintball related cartridges etc. Ill check if you don’t hae a link handy. Thank you again.
Da Pneu Kid wrote:No, I mean Home Depot doesn't have any 2.5" fittings, or pipe for that matter. An easier option would be a coax with a 4" chamber and a 3" endcap as a piston. Also, if you use a 2" barrel, the piston will have a 2" exhaust port instead of a 1.5" one, increasing power and eliminating the need for a long barrel and chamber.
Come to think of it you are right. I have not seen 2 ½ PVC endcaps. They wont be cheap if I don’t find them also. Never mind then….

Just an idea. But if I cut out a little from a 3” pipe and then squeeze it into the chamber to make a smaller diameter would a 2” end cap fit in there….I will have to conduct some tests? Maybe a wood piston for economy.

I just want to get started already. Summer is short and I don’t want to spend half of it tinkering.
Thank you both for the feedback.

I added this to my main post:
I realized now I didn’t know what I wanted but now I do –thank you all for helping me clarify.

I want to make to types of co-axial cannons.
Mortar co axial 4” chamber 2” Barrel
Paintball Bazooka to shoot 12-24 paintballs. Using 3” Chamber and 1 ½” Barrel.
Barring any other ideas I have a length of 4” PVC, 3” PVC and 2” PVC etc.

I will definitely make a bunch of 4” x 20” co-axial cannons with 3” end caps and threaded caps for access.

But what can I do with the 3” to make a simple co-axial Paintball-zooka?

Posted: Mon Apr 23, 2007 9:17 pm
by goathunter
Here is the link to my tutorial:http://www.spudfiles.com/forums/paintba ... t7447.html

About the paintball bazooka:built it identical to the mortar(scaled down like you designed) and put a grip on the barrel with a air line and valve to actuate the piston.Go creative.

Posted: Tue Apr 24, 2007 5:57 pm
by AmYisroelChai
goathunter wrote:Here is the link to my tutorial:http://www.spudfiles.com/forums/paintba ... t7447.html

About the paintball bazooka:built it identical to the mortar(scaled down like you designed) and put a grip on the barrel with a air line and valve to actuate the piston.Go creative.

Thank you so much that is an awsome tutorial I posted some questions though.
PS
Is this double posting then? :lol:

Posted: Tue Apr 24, 2007 6:23 pm
by scatdawg
if you have the funds to set up your coaxial with a quick exhaust valve i would highly recommend it. i just changed my coaxial over from a 1/4 ball valve to a qev and the difference is truly amazing. good luck with your cannon.

Posted: Tue Apr 24, 2007 8:17 pm
by AmYisroelChai
I would love a QEV but as I said on a different post I am looking to a bunch of paintball bazookas probably 10-20. I need a safe cost effective easy to make design. I am still in the research stage. Thnks for the feedback