The Spudinator

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.
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MrCrowley
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Sat Nov 15, 2008 7:14 pm

jitup wrote:If I change out the bottle for 3inch pipe that is 8 inches long, what do you guys think the maximum safe pressure is?
What ever the pipe is rated at, read this:
http://www.spudfiles.com/spud_wiki/inde ... _Rated_PVC

For your second question, spring loaded ball valves work fine, they will improve performance. It's a good idea to make one if you can't get a faster valve.
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Ragnarok
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Sat Nov 15, 2008 7:45 pm

Lentamentalisk wrote:well I am not sure that anyone has been killed in a true spudgun accident.
They have. Someone was hit in the chest by a flying cleanout cap and killed, amongst other events, some where the people were shot with them.
There have also been numerous cases of blindings, deafenings, major cuts, broken bones and near misses with finger loss.

I'm incredibly careful about safety, and even then over my time spudding, I've had many injuries and near misses building and using the things. I could bore you with the list, but I'm sure most of you are fed up with hearing my tales of resilience.

EDIT: Speilung.
Does that thing kinda look like a big cat to you?
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jitup
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Sat Nov 15, 2008 8:03 pm

I agree safety is number one. as a certified pro marksman, I know how dangerous any type of fire arm could be, I was obviously supplied with mis information about the bottle and the max psi of 800. When I change it to a pipe (I made sure the stuff I chose at my Home Depot is pressure rated) what is a safe operating psi? aren't glue joints only good for 180 psi? (I read that on the back of my glue can, correct me if I am wrong again) all advice is appreceated, and I tried to do my home work before I built the gun. I just dicovered the site, after my gun was completed. So pleas do not think I am a flaming moron, I was just not completely informed.

ps I thought I was being clever with the valve stem until I found the site and that is what every one else uses as well, great mind must think a like! LOL :wink:
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MrCrowley
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Sat Nov 15, 2008 8:11 pm

jitup wrote:When I change it to a pipe (I made sure the stuff I chose at my Home Depot is pressure rated) what is a safe operating psi? aren't glue joints only good for 180 psi?
Again, depends on what the pipe is rated at. Read this:
http://www.spudfiles.com/spud_wiki/inde ... ng_Pressur e_Rated_PVC


If the pipe is rated at NSF-PW SCH40 and has a diameter of 1.5" or larger, I wouldn't take it above 150psi. If the diameter is 3" or larger I would keep below 125PSI.

If the diameter is smaller then 1.5", it probably can be taken to around 180PSI. Not that I would do it anyway. Too dangerous IMO.

It really depends on the SCH rating, the pressure rating and the diameter of the PVC.
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jitup
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Sat Nov 15, 2008 8:15 pm

it is all i inch at the moment, but I am not sure wheter to use a shoter 3 inch chamber or a longer 2 unch chamber. what do you suggest?
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MrCrowley
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Sat Nov 15, 2008 8:18 pm

2". It'll look better IMO.

Though i'd save your money and build a new cannon, new valve, new chamber.
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jitup
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Sat Nov 15, 2008 8:19 pm

it is all i inch at the moment, but I am not sure wheter to use a shoter 3 inch chamber or a longer 2 unch chamber. what do you suggest?

Thanks for the above link, it was very informative.

I know the 2 inch stuff is rated for 250 psi at 73 and the 1 inch is rated for 450 psi theball valve dose not have a number on it but it is pressure rated.
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starman
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Sat Nov 15, 2008 9:00 pm

jitup wrote:it is all i inch at the moment, but I am not sure wheter to use a shoter 3 inch chamber or a longer 2 unch chamber. what do you suggest?

Thanks for the above link, it was very informative.

I know the 2 inch stuff is rated for 250 psi at 73 and the 1 inch is rated for 450 psi theball valve dose not have a number on it but it is pressure rated.
Most 2" sched 40 is rated at 280 psi. Your big problem is finding something that can pump it that high. You're down to hand held shock pumps or fridge compressors or putting together a regulated CO2 system which is mighty cool but pricey. Most job site type air compressors are going to top out around 150 - 175 psi, if that much.
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jitup
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Sat Nov 15, 2008 9:09 pm

My compressor is 150 ish, but I have 20 oz co2 tank and coil from when I used to play paintball, how hard would it be to rig it to a cannon
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starman
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Sat Nov 15, 2008 10:01 pm

jitup wrote:My compressor is 150 ish, but I have 20 oz co2 tank and coil from when I used to play paintball, how hard would it be to rig it to a cannon
Not hard at all...you just need a CO2 regulator like this one...
Image

If you have that already, you just need to start filling you chamber with it at a safe level and you're ready to shoot.

Paintball regulatorswork as well.
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jitup
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Sat Nov 15, 2008 10:09 pm

Yep, I have one for paint ball, mine is different but it is the same concept, they are not expensive. a cheap one with no features is $20 and a large tank costs $20 or at least thats what I paid for mine
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jitup
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Mon Dec 08, 2008 7:22 pm

I, Know I am not supposed to double post, but look at the last post date!!!

any ways, I hve changed the pop bottle for PVC and it is now an over under type gun.

Also I plan on removing the ball valve (cutting it in half with the band saw then using the dremil to get the res of it off :twisted: ) I was considering building a diaphram valve because to use a piston I would have to start all over again, and I have already built several new guns that are worlds better that this. Any ways, Since it is still a decent gun ( at least it will be) I want a better valve and I do not want to use a sprinkler valve. If any one has a good resource for building a diaghram valve it would much be appreciated! (JSR here is your time to shine :D ) I have been searching for about a week and have come up dry every attempt.

BTW, when it is finished it will also have interchangable barrels
if you live in Ohio join the Ohio Spud Gun and BBMG Association at http://www.ohiosga.webs.com
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starman
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Mon Dec 08, 2008 8:43 pm

Do you have any recent pictures you can show us? Your decision to replace the soda bottle was a high quality one!... at least on concept...:wink:

I know you say you're in the midst of working on it....showing your improvements would be valuable I believe.
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jitup
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Mon Dec 08, 2008 9:25 pm

Ok, I will add a picture. Any resources about a diaphram valve will be helpful :)
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if you live in Ohio join the Ohio Spud Gun and BBMG Association at http://www.ohiosga.webs.com
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