35 bar repeater ( new pics on page 4)

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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Brian the brain
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Tue May 06, 2008 3:13 pm

Hey guys..I just tested one of my modded solenoid valves at 35 bar and guess what..It works fine!
The 16 bar rating applies to the solenoid, I guess, the brass body won;t blow up.

I also modded a blowgun, -that is-- hacked it up and re-tapped it, so it is now super small and able to actuate the valve at 35 bar ( 500 psi).
The blowgun is now no more than a hammer valve inside a small body.

The valve functions semi auto.Fills from chamber side shot after shot.

I've read a topic somewhere where somebody made an impressive gun with a springloaded ballvalve and trigger release.Sorry I can't find it right now.You must've all read it, it;s pretty recent.

This has ( re)inspired me to build something I've always wanted to build.
A selfcontained high pressure repeater with a lock and hammer.
I believe a hammer to knock open the blowgun will save air.Hammer powered not so much by force, but more by momentum.This makes sure only the least needed amount of air escapes the pilot, unlike piloting by hand.Momentum can be preset by the weight of the hammer and the force behind it.

I tested the valve and the hacked up blowgun with a long .50 barrel and a lead muzzleloader ball.Although I had an extremely small reservoir
( twice the volume of he valve itself) the result was already impressive.
This was all the proof I needed to start planning a Girandoni style airgun, although the valve will work in a different ( better!) way.I plan to use the same reloading technique for now.

Be ready for another BTB production!
Last edited by Brian the brain on Mon May 19, 2008 3:58 pm, edited 1 time in total.
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MaxuS the 2nd
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Tue May 06, 2008 3:31 pm

Oooooh, sounds great. Be sure to get atleast a million pictures/videos whilst building and firing. :D
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Hotwired
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Tue May 06, 2008 3:34 pm

Ahhhh it's nothing like a girandoni :P

A Giry has one valve for in and out, you'll be able to give this design a whole new name :)

Hows the reseating time for the valve or is the pilot being vented so little that it's only giving a very quick burst before the force above the diaphragm slams it shut again?
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daberno123
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Tue May 06, 2008 3:35 pm

Brian the brain wrote:A selfcontained high pressure repeater with a lock and hammer.
Sounds interesting, can't wait to see it completed :D
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Brian the brain
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Tue May 06, 2008 3:44 pm

[quote]Hows the reseating time for the valve or is the pilot being vented so little that it's only giving a very quick burst before the force above the diaphragm slams it shut again?
[quote]

By hand yes.
So when activated by hammer valve it should do nicely.
I plan to have a firing reservoir in the stock and an extra under the barrel.

Hammer will be on the right side, venting like a blackpowder rifle would through the spark hole ( forgot the official name for it)
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Tue May 06, 2008 4:05 pm

the "(flash?) pan" for flintlock and matchlock and the nipple for percussion caps

aren't blowguns just made for 90psi or somthing thats kina breaking the rules man, and what about the threads for the solenoid, and check the operating pressure and the max pressure the a direct acting solenoid most likely has a max operating presure
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POLAND_SPUD
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Tue May 06, 2008 4:16 pm

that sounds interesting... what type of bolt are you going to use? a blowforward bolt or a blocker bolt ?
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lockmanslammin
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Tue May 06, 2008 9:18 pm

Oooooh, sounds great. Be sure to get atleast a million pictures/videos whilst building and firing.
Do I sense a bit of sarcasm dripping off of this sentence MaxuS? Hmm

Lock
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Brian the brain
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Tue May 06, 2008 11:31 pm

aren't blowguns just made for 90psi or somthing thats kina breaking the rules man, and what about the threads for the solenoid, and check the operating pressure and the max pressure the a direct acting solenoid most likely has a max operating presure
Thanks for your concern.
This blowgun was rated for 200 psi.It functions just fine at 500.
So does the solenoid.Rated for 16 bar or 250 psi.

I´ve fired it over 50 times now.
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MaxuS the 2nd
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Wed May 07, 2008 1:38 am

lockmanslammin wrote:
Oooooh, sounds great. Be sure to get atleast a million pictures/videos whilst building and firing.
Do I sense a bit of sarcasm dripping off of this sentence MaxuS? Hmm

Lock
Not at all, I just get really interested in something a little more than a simple PVC pneumatic that we've all done, played with and shelved.
I'd like to see millions (many) pictures because it would be interesting to see how it goes together. :D
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daxspudder
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Wed May 07, 2008 2:59 am

it might fire many times at such a high pressure, but its rating is low for a reason, its rating is based on constant strain from water, a substance that doesnt compress like air, but on the other hand eventually it will strain the materials too much and something will rupture, internally isnt so bad, but externally you might not want to be so close to, the rate air expands from 500psi would not be fun to see, and would likely get you nominated for a darwin award.
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MrCrowley
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Wed May 07, 2008 3:24 am

daxspudder wrote:it might fire many times at such a high pressure, but its rating is low for a reason, its rating is based on constant strain from water, a substance that doesnt compress like air, but on the other hand eventually it will strain the materials too much and something will rupture, internally isnt so bad, but externally you might not want to be so close to, the rate air expands from 500psi would not be fun to see, and would likely get you nominated for a darwin award.
Pressurized water is the same as pressurized air, and yes, water does compress, just not much. It compresses differently depending on the temperature.

Pressurized water is still putting 500psi of force on the materials, like air. No difference. Water may even be worse because of the weight.

If it says 'only use with a liquid' that is because if something does go wrong, the liquid absorbs more energy and is heavier then a gas, so it propels the 'shrapnel' far slower and with less force then if it was 500psi of some sort of gas.
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jackssmirkingrevenge
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Wed May 07, 2008 4:21 am

You're taking advantage of my absence to take the lead in autos :D

Sounds great, can't wait to see pics/vids :)
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Brian the brain
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Wed May 07, 2008 6:43 am

Not auto Jack.Repeater.
I'll manually cock the hammer each shot and most likely will make a breechloader that needs to be activated by hand, just for the hell of it.

Using a pneumatic ram powered by the pressure build up in the barrel it would be full auto, but elaborate and not what I intend to build, a sleak 1800's " rifle"
*** song by Cypress Hill going through my head: cock tha hammer, it's time for ac-tiooon, cock da hammer**
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Wed May 07, 2008 10:56 am

Nice! I want to see how it turns out. I've been wanting to build a high pressure repeater for some time, just haven't found a good way. Maybe that hammer valve piloting the piston will work.

Edit: by solenoid valve, do you mean like a QEV or a sprinkler valve? Basically, when you take the solenoid out of it, it's a barrel-sealing diaphragm or piston valve, right?

That'd mean that your repeating action is pretty close to the same thing that Hotwired did with his copperhead: a piston/diaphragm valve, don't pilot it completely, and you can get multiple shots.
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