Step 7: Firing Circuit

The solenoid valve says it requires 24 volts to open, if I remember correctly. Three 9v batteries in series will definitely open the valve. Connect them i series with a switch as shown in the image below.

Some people like to have a rocker switch as a safety, and then use a pushbutton switch for firing. What you do is up to you.
<p>This is not spam, but a warning. PVC will fail suddenly after a while. This was band member that hurt badly by a T-Shirt launcher explosion.</p><p><a href="https://fundrazr.com/campaigns/1Zs3c" rel="nofollow">https://fundrazr.com/campaigns/1Zs3c</a><br>..</p>
<p>They do not have compatible threads. Buy a pressure gauge with a 1/4 inch thread and use a bushing reducer. It will also be easier to read. Yours is for garden hoses, not pipes.</p>
I do find the pneumatic vale<br> <a href="http://www.air-matics.com/Pneumatic_valve/" rel="nofollow">http://www.air-matics.com/Pneumatic_valve/</a>
What would happen if instead of a PVC pipe for a air tank, you used a copper pipe? I suppose the increased strength of the tank would lower the risk of rupturing and allow you to put more pressure into it.
I suppose you could use higher pressure and have less chance of a rupture. Also pieces of copper embedded in your body will show up on the x-ray so the doctors can pull out all the pieces, if the worst comes to worst. Honestly I think the pressure limitation comes from the valve primarily, so if you switched to a ball valve or other value instead of the electric diaphragm value, you could use higher pressures with the same PVC. Perhaps the best option would be an all-metal design with a piston valve (info here http://www.spudfiles.com/spud_wiki/index.php?title=Piston_valve) ?
url for your website doesn't work
Thanks for the heads-up, I just fixed it!
Have you ever considered building a &quot;P&quot; trap tipe loop to contain the water before it is fired? <br>
Huh, that's a good idea, I might have to try that sometime. Sort of like a mini reservoir for the water. I wonder if you could use something larger too...good idea!
hello bro. This is one idea i did for kinda safe projectiles, didnt document it anywhere but the idea is simple. I mashed newspaper and inserted into PVC pipes, then compress to squeeze the water out. make them real dry and then remove from mould and dry under the sun or other means for drying. Its ready now but i prefer to coat them with a clear cellophane tape for more durability. Can be substituted with foam things, but the density of paper makes the hardness and inertia feel just right. i dont know why, but it feels just right. And its cheap
how can i make littel one of it anyone no ? <br>
mine is like yours but HUGE <br />
mine has an oxigen tank lol :)
never knew guns can kurt you.
Is the ideal gas law Pv=nRt?
You are correct!
I could not help but notice the snow, just another word of caution, cold temperatures drastically slows down the curing time and the PVC Cement should never be applied or used below 32 degrees, always read the labels for working temperatures. I'm some what surprised that some of the last joints haven't failed.
Wrapping the PVC with a couple of layers of 3M Filament tape (the stuff used for packaging) will reduce the danger of shrapnel
What if your solenoid runs on AC?
It should still work, just fine, I can imagine how it could anyway. Hook it to a 9v battery and see what it does. (It can't hurt it)
Dang it! The solenoid blew up! JK! Yeah it works, it makes that clicky noise.
Good, you actually got me there. Yea, do you have a sprinkler system that uses these which plugs into your outdoor AC, if so then that control box actually adapts the power to lower voltage DC. That may lead to the belief that it is an AC valve, or I don't know what I'm talking about.
some kinds of pvc are not for pressure but others are designed for pressure<br>
Coolest sound ever! lol cant wait to build one...or 2...ah hell go for 3 how big are paint balls... :D
paintballs come in different sizes but the best to easily fit is the .50&quot; paintballs <br>
3/4 inch pvc barrel<br />
hmm... wonder how a 3 barrel separate trigger system would go....?
dose the size of the air chamber matter
YOu used a dwv reduser, this means its not pressure rated a can explode&nbsp;
Thank you for your comment. This is a very real and serious concern, and has been mentioned at least once in my writeup above. I have never had problems with my DWV reducer, but in future designs I will only use pressure-rated fittings as I&nbsp;mentioned in step 2. Thanks for your concern.<br />
&nbsp;ok sorry I just noticed it in the intro, also you may not want to shoot it in the snow because pvc becomes brittle, for more info you can check www.spudfiles.com<br /> <br />
I was wondering if you should make a picture of a End-Around Pneumatic Cannon except with a 3<em> barrl</em><br/>
Part of the design restrictions that come with using the U-shaped valve is that the barrel can't be too large, otherwise it would collide with the pressure chamber. The 1.5" barrel is probably the largest diameter that would work alright with this valve.
what size wood a tennisball need.
Spudtech sells 2.5&quot; Schedule 40 PVC that fits tennis balls. I have never purchased any pipe this size, but I've heard of people getting good results.<br/><br/><a rel="nofollow" href="http://www.spudtech.com/detail.asp?id=38">http://www.spudtech.com/detail.asp?id=38</a><br/>
try this<a href="http://www.spudgun.com/product.htm" rel="nofollow">www.spudgun.com/product.htm</a>
i'd use shooter marbles as ammo. lots of them. you ever seen what happens when a marble hits a wall at 300 FPS? it explodes. loudly.
You should use some disposable cameras for your firing circuit i bet you could get a pretty good power increase if you try it tell me how it goes
why do you even use nine volts? it has so much less power than operating the valves when pneumatically modded. you should look up on spudfiles.com how to mod a sprinkler valve, it uses a blow gun as a filot so you have an actual trigger on the gun
4th Doctor, Thanks for the comment. I don't think that the current firing circuit of 3 - 9v batteries and a switch impacts the power of the cannon. I could certainly get a more powerful cannon by modifying the sprinkler valve, but I haven't done that yet.
the 330volt pulse capacitor in disposable cameras should open the valve faster which should increase the power of the cannon, maybe a small pointless increase maybe a pretty decent increase or maybe something entirely unexpected too
Certainly, a quicker-opening valve would increase the amount and rate of airflow through the barrel, but I don't think the limitation is from the electronics or the solenoid, but rather the diaphram action of the sprinkler valve. In addition, the huge voltage spike would probably damage the solenoid coil, as they are really only designed for up to 30v operation. A quick google search can help you find videos and instructions about moding a sprinkler valve:<br/><br/><a rel="nofollow" href="http://www.google.com/search?q=mod+a+sprinkler+valve">http://www.google.com/search?q=mod+a+sprinkler+valve</a><br/>
ive used solenoids alike to the solenoids in sprinkeler valves the capaciters give a pulse that they put up with fine and give a quick strong pull which should open the valve faster it could be a pretty pitful or a pretty impressive increase it should help itleast somewhat and its simpler then modifying valve all you need is a disposable camera if anyone trys this post results
urs looks cool :D check out <a rel="nofollow" href="https://www.instructables.com/id/potato_cannon_with_interchangeable_barrels/">mine</a> plz<br/>
Out of curiosity (this lack of curiosity may kill the cat. :P), anyways, I am not sure whether you should or must drill the hole for the tire valve stem where the pipe and end cap meet or it does not matter? Thanks for the reply(-ies) in advance.
I've never had a problem with putting the tire value stem in the middle of the the end cap, but some people suggest drilling the hole where the end cap overlaps with the pipe.
I would not use it in snow cold weather weakens pipe
The valve you used makes the coolest noise! You should try modding it to be manual for more power, if you don't know what i'm talking about, search "mod a sprinkler valve" on youtube. I don't know if it would work on your type of valve though.
actually, with 27volts it has more power than manually, also you press a button and it fires!
oops, UberNoober already told you to do that but oh well

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