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Nerf Pistol


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#26 Ginjiroku

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Posted 23 April 2004 - 11:10 PM

I changed your pistol design a little
Posted Image
I took away a little unnecessary bit of tubeing. I also added a mag. It looks really funky but it could work.

http://longboard.dyn...lex/pistol2.GIF
It's a link becuase it is huge. It should be a small file becuase it's just a gif with 2 colors but the actually image size is huge. It's my new pistol design. The trigger looks and works really strangly be it's so there are alot less parts in the frame.

In the last picture I forgot about the air supply. This is a drawing of the outside of the pistol with the air supply added. I'm tking of powering it off of 12grams.
http://longboard.dyn...alex/pistol.GIF

Edited by Ginjiroku, 23 April 2004 - 11:30 PM.

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#27 cxwq

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Posted 23 April 2004 - 11:58 PM

I love that style auto valve. I made and animation of it.

That's not any different from a PC/RF20 valve.

The cycle speed will be determined by air pressure, the force exerted by the spring, the diameter of the piston tube, and the size of the air inlet hole.

The main problem with this design is that unless you have a very large tank relative to the volume of the air bursts, or a high pressure tank with a regulator, the pressure will quickly decrease to the point that it will no longer cycle. I guess you could also employ the Nerf solution and use an elastic tank that maintains high pressure even as volume drops.
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#28 Ginjiroku

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Posted 24 April 2004 - 01:07 PM

I love that style auto valve. I made and animation of it.

That's not any different from a PC/RF20 valve.

The cycle speed will be determined by air pressure, the force exerted by the spring, the diameter of the piston tube, and the size of the air inlet hole.

The main problem with this design is that unless you have a very large tank relative to the volume of the air bursts, or a high pressure tank with a regulator, the pressure will quickly decrease to the point that it will no longer cycle. I guess you could also employ the Nerf solution and use an elastic tank that maintains high pressure even as volume drops.

Along with all those thing the cycle speed will also be determined by the size and strengh of the spring and the distance of the input and output holes.
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#29 Formerly Sane

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Posted 24 April 2004 - 01:18 PM

Now that I think about it, you'd probably be better off with some type of semi-auto valve. This pistol clearly could be automatic, but as I mentioned before, simplicity is often better than complexity. I'll try to draw up plans of my vision of this gun, so I'll hopefully have them up in the next hour or so. (forgot my image hosting site :P )
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#30 Vintage

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Posted 24 April 2004 - 03:06 PM

I love that style auto valve. I made and animation of it.

That's not any different from a PC/RF20 valve.

I disagree, cxwq. I have personally opened up my RF20, and the piston assembly is much more complex. If you read my homemade auto topic, the first picture posted is how the RF20 valve operates.

The type that Ginjiroku showed us is a very simplified version. Yes, the pressure will continue to drop in the tank, and yes, eventually there won't be enough pressure to cycle the piston. Also the ROF will continuously drop as the trigger is held, due to pressure decreasing in air-tank.

But the main advantages outweigh the negatives. For one this valve creates precisely measured, regulated air bursts. No more decreasing pressure shots with a dual/semi zero valve. Also, there is no need to open any second valve, it regulates itself.

The only real, apparent disadvantage is the ROF slowing down as pressure depletes, but every shot (from first to last) will have the same air force behind it.

~Vintage
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#31 Bobert

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Posted 24 April 2004 - 09:55 PM

I designed that valve, and yes it does work perfectley. The rate of fire is adjustable by the spring. It can also be adjusted by making the chamber longer. And the seal is excellent because of the foum rapped around the cylinder.

Edit: The best bart about it is that is took me 15 minutes to make :lol:
Also, it does regulate itself, as Vintage said

Edited by Bobert, 24 April 2004 - 09:59 PM.

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#32 cxwq

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Posted 24 April 2004 - 10:56 PM

I disagree, cxwq. I have personally opened up my RF20, and the piston assembly is much more complex.

Yes yes, so have I.

Air moves into piston chamber through small hole. Air pressure causes piston to travel. Piston travel opens up exit pathway for air. Air leaves, allowing spring-loaded piston to return to original position. They're the same, just made with different parts.
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#33 Vintage

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Posted 25 April 2004 - 12:50 PM

However, in the RF20, air doesn't stop flowing through the barrel until the piston returns to the starting point.

In this simple design, air stops flowing as soon as the piston releases its pressure and starts to move back.

The RF20 system had to be made very complex, so as to guarantee that the piston would make full cycles to rotate the barrel. This simple system will never make a complete cycle due to the piston never retuning to its starting point.

Air moves into piston chamber through small hole. Air pressure causes piston to travel. Piston travel opens up exit pathway for air. Air leaves, allowing spring-loaded piston to return to original position. They're the same, just made with different parts.


True. Boiled down to its basic pattern, every "clip/rotating barrel" nerf automatic needs to do this. So why label every automatic idea as just a copy of the RF20?

Under that argument, any homemade with a basic pump, airtank, trigger mechanism, and barrel is just a copy of the Secret Shot 2. Just using different parts, thats all.

Sorry about any objections I might raise with my argument here, but using logic is one of my favorite passions.

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#34 Zero Talent

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Posted 25 April 2004 - 04:33 PM

Actually, Vintage, the SS2 uses a pressure-driven firing mechanism, sacrificing a little bit of pressure to release a second pressure store. There's a big difference between an SS2 valve and a linear valve, such as on a Supermaxx gun, in the same way there is a difference between Metalstorm and a traditional mechanical pistol.

I wish you the best of luck with your designs, as spring balances are going to take a bit more work than the previous designs you've cited. Just make sure everything is empirically manipulated, as you seem to be doing by controlling pressure input flow rates.

Also, you're operating with a pressure-actuated breech in mind, right? Otherwise those darts aren't going anywhere. I'm pretty sure you know this, though, given your RF20 debate.

The most obvious problem I can see with the design is that the air bursts will be short, requiring a larger hole for larger flow rates out of the valve, or greater pressure behind the spring piston. Greater pressure behind the spring piston means faster flow rates and higher shot frequency (to the point that your darts may be squished by the required spring force), and a larger hole out of the valve may mean larger areas into which the air must diffuse, resulting in lower ranges.
I'm sure you guys will find a reasonable solution though. Good luck!
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#35 Formerly Sane

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Posted 25 April 2004 - 05:15 PM

If you can't see the image see if this link works. Click on "View original image"


Posted Image

Alright, to keep the pressure in the main tank equal for the first few shots, a spring compresses as each shot is fired. This is basically the pvc version of a rubber tank applying constant pressure.

This is how it works: The valve tank is open to the auxiliary tank and filled. As the trigger is pulled 1/4", routes to the air tank and barrel are both closed. Another 1/4" and the air in the valve tank is exposed to the vinyl leading to the barrel and thrusts out the dart. Release trigger, reload via the breech, repeat.

Edited by Formerly Sane, 26 April 2004 - 04:29 PM.

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#36 blink 182

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Posted 25 April 2004 - 06:26 PM

In regards to vintage’s animated design…
Instead of using a spring to move the main chamber why not use a tough spring and then add some sort of bolt to the design. This bolt would move the main chamber and therefore allow the air to move into the barrel. So when the bolt is pulled back the air will have a passage to move (into the barrel)
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#37 THIRST

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Posted 25 April 2004 - 06:35 PM

Formerly Sane,

The problem with your disgn is that you have no way to regulate the amount of air in each shot. Because of that spring, the air will be movig out faster, depleting all of your power. I would also recomending moving the far left blue "plug" farther up a bit, to prevent leakage when your in the middle of pulling the trigger.

Also, it would take insane amounts of pressure to keep that spring back, and there arent many "weak" spring for sale at your local hardware store. The endcaps would pop off before that sprin is held back by the air pressure.

For keeping that pressure, I recomend a small CPS mad out of ballons, encased within PVC to protect it. Although this would create size problems, and essentially create it into a small rifle, and sine the size wouldnt be worth it, you would expand the airtank more, makin gthe gu even bigger, which would destroy the whole purpose of a pistol...so I suggest having a fairly large pistol(no airtank accomodations for the size).

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#38 Vintage

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Posted 25 April 2004 - 06:37 PM

Actually, Vintage, the SS2 uses a pressure-driven firing mechanism, sacrificing a little bit of pressure to release a second pressure store. There's a big difference between an SS2 valve and a linear valve, such as on a Supermaxx gun, in the same way there is a difference between Metalstorm and a traditional mechanical pistol.

I wasn't trying to get into details about how the gun works. I was just explaining how that just because a basic homemade has a tank, pump, trigger, and barrel, it isn't just a copy of another gun.

I guess the analogy could be made better with a homemade and a supermaxx.

Also, you're operating with a pressure-actuated breech in mind, right? Otherwise those darts aren't going anywhere. I'm pretty sure you know this, though, given your RF20 debate.


I actually didn't have a breech in mind for the pistol. I figured that if what Bobert says is true (that the gun has fairly slow ROF if the trigger is held) you would have enough time to pull-and-release the trigger before two air bursts escape.

So, Zero, you would pump the gun, load a dart, squeeze off a shot, load a dart, sqeeze off a shot, etc... until the tank is out of pressure.

By the way, by "pressure actuated breech," you mean a magazine that force-feeds the darts into the chamber with (for example) springs? If so, yes, that's what I have in mind for my other project.
------
Nice job Formerly Sane. It looks very nice. However, I dislike the tube coming out of the rear of the gun. Other than that, if you could possibly find the parts for it, it would be awesome.

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#39 Zero Talent

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Posted 25 April 2004 - 08:33 PM

By the way, by "pressure actuated breech," you mean a magazine that force-feeds the darts into the chamber with (for example) springs? If so, yes, that's what I have in mind for my other project.

Well, actually, that would be a spring clip. A few people have made those, the most currently known of which being Boltsniper (I'm sure you've seen these, if not, search NHQ's homemade section).

I'm talking about an air actuated breech.. A breech that uses air pressure to separate and seal away a new shell or dart for firing. I don't believe Nerf has made such a device, but Paintball guns use these all the time, linking the power tube to the spring-loaded piston that is released by the trigger (see Gin's first design), or some other way (usually linked to another moving part, I have yet to see one that uses the barrel pressure directly). I just think it's fairly important that you isolate the one dart for firing, else you'll throw a whole bunch of power out through the clip or past the dart.
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#40 Diablo

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Posted 25 April 2004 - 08:56 PM

If you can't see the image see if this link works. Click on "View original image"


Posted Image

Alright, to keep the pressure in the main tank equal for the first few shots, a spring compresses as each shot is fired. This is basically the pvc version of a rubber tank applying constant pressure.

This is how it works: The valve tank is open to the auxiliary tank and filled. As the trigger is pulled 1/4" routes to the air tank and barrel are both closed. Another 1/4" and the air in the valve tank is exposed to the vinyl leading to the barrel and thrusts out the dart. Release trigger, reload via the breech, repeat.

Damn, you posted before I could post this:

http://www15.brinkst.../neo2/auto.html

I made that design about a year ago, and it incorporates the same CPS air tank mine does. I think that's exactly what you need.
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#41 Vintage

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Posted 26 April 2004 - 12:32 PM

I'm talking about an air actuated breech.. A breech that uses air pressure to separate and seal away a new shell or dart for firing. I don't believe Nerf has made such a device, but Paintball guns use these all the time, linking the power tube to the spring-loaded piston that is released by the trigger (see Gin's first design), or some other way (usually linked to another moving part, I have yet to see one that uses the barrel pressure directly). I just think it's fairly important that you isolate the one dart for firing, else you'll throw a whole bunch of power out through the clip or past the dart.

Yes, I now understand what you meant. Here is the same model only with your “air actuated” explanation:

Posted Image

Note: This is not to scale, and it would be a little too large for a pistol.

~Vintage
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