23 replies to this topic

[Hubb]

Hello. I am Hubb. I've never actually "Nerf'd" but I play paintball regularly. I found this site when I purchased some Nerf guns for me and my son and looked to increase their performance. He got the Maverick and I got the Recon. After modding the Recon (using mods on this site), it averages 85' flat. I'm satisfied with that. I've yet to mod the Maverick (I don't know if I want to, since I am his primary target). This site has very excellent information, especially concerning homemades, which led me to believe you guys know what you're talking about.

Currently, I am designing a homemade. It is a magazine fed, pump action (modeled after Boltsniper's FAR). It will run off of regulated CO2. I have everything worked out except one thing. You see, I would like for the valve to be a semi-auto type of valve, which will allow for fast follow-up shots and be efficient with the CO2.

My question is, is there a way I can construct a semi-auto type of valve that will do this? I saw Dr Nerf's valve and that is pretty much exactly how I want my valve to work, however, his valve just seems to big and bulky for what I am trying to do.

More detail: The homemade will be designed to shoot 5 paintballs simultaneously at around 250fps. It could probably shoot those big Stefans as well. Currently, I have a piston valve (courtesy of Spudfiles). Having a bit of experience with that, I would have to release the trigger fairly quickly to give the desired effects and preserve CO2. I prefer to conduct follow-up after the shot (any of you with shooting experience will know what I'm talking about).

Any help would be appreciated.

Edited by Hubb, 17 March 2008 - 11:01 PM.

[Quilan Fett]

I'd try a Zero valve.

[Hubb]

Okay, so I have thought, and drew this up. This is actually a combination of several different valves, combined to attempt to accomplish my goal.



At rest, the main chamber and barrel are sealed off. When the chamber pressurizes to, say, 100psi, so does the secondary chamber, by sliding the chamber piston forward. Once the pressures are even in both chambers, the chamber valve will reset via the spring. The barrel piston is connected to a pull rod. When the rod is pulled, the barrel piston opens the barrel. Because the barrel piston is sleeved over the chamber piston, the barrel piston will keep the chamber piston from opening, that is, until the force overcomes finger strength, which will actually reset the trigger. This, in turn, will cause the secondary chamber to refill.

Any thoughts?

[Quilan Fett]

I don't have much experience with ressurised gasses, but here are my thoughts.

1. I don't see the trigger rod moving. This setup could run into problems when the rod is connected and both washers are moved at the same time.

2. I am not sure, but I think it will be nearly impossible to open that with the big rubber washers @ 100psi. It sounds to me like it would take 100 pounds or so of force. Am I wrong?

3. I think it will be more effective it the hole to the barrel is at the end, not partway in. This is the way most compressed air NERF guns are buit, and it lessens the need for the spring.

Edited by Qui'lan Fett, 18 March 2008 - 12:57 AM.

[Hubb]

I don't have much experience with ressurised gasses, but here are my thoughts.

1. I don't see the trigger rod moving. This setup could run into problems when the rod is connected and both washers are moved at the same time. The trigger rod is only connected to the barrel piston. It is able to slide through the chamber piston. The chamber piston will be moved only by the air going from the main to secondary chamber.

2. I am not sure, but I think it will be nearly impossible to open that with the big rubber washers @ 100psi. It sounds to me like it would take 100 pounds or so of force. Am I wrong? I do not think you are wrong, and that is my biggest concern about this valve. Maybe I can do some math and see what I can do.

3. I think it will be more effective it the hole to the barrel is at the end, not partway in. This is the way most compressed air NERF guns are buit, and it lessens the need for the spring. I was thinking along the lines of a barrel sealing piston valve, but I see what you're saying. The spring is there only to assist in re-seating the pistons.

[Quilan Fett]

3. I think it will be more effective it the hole to the barrel is at the end, not partway in. This is the way most compressed air NERF guns are buit, and it lessens the need for the spring. I was thinking along the lines of a barrel sealing piston valve, but I see what you're saying. The spring is there only to assist in re-seating the pistons.

This way, the air would assist in sealing the opening.

[VACC]

I will alert our resident mad scientist to your presence.

[imaseoulman]

Wait a minute...am I the only completely thrown off by:

After modding the Recon (using mods on this site), it averages 85' flat. I'm satisfied with that.

???

Either I've missed some mod write-ups for the recon (I'd be impressed with 60') or you have some amazing modding skills. What mods did you do to get those ranges? Thanks.

[CaptainSlug]

What you're proposing is a dump valve with a check valve added to it. I will just say that it is not likely to work as predicted.
Also the valve you make IS GOING TO HAVE TO BE LARGE. You will need a rather sizable opening to provide the flow rate needed to fire your dart.

Before I go any further suggesting designs I would like to know what kind of tools you have access to, and what firing pressure you're working with.

The configuration you're proposing won't really be semi-automatic anyways since you have to cycle the breech manually.

Edited by CaptainSlug, 18 March 2008 - 10:56 AM.

[Pineapple]

Hey there Hubb... I'm Piney, and I too am a former paintballer (age and a lack of facilities on my island keep me from PBing regularly), and also a parent of two, of whom just about all my Nerf focus is for.

You want to home-make a blaster that shoots FIVE paintballs at once? As Cap'n Sluggy said, that's gonna take a lot of energy to move. Most of the technology in Nerf requires moving weighted foam projectiles that weigh half or less than that of a paintball, much less five. So even with the pneumatic homemades, which for the most part are variants from the spud gun world (I too am a Spudfiles fan), we've dialed things WAY back to make things reasonable (we do intend to shoot each other with them), so I don't know how much the Nerf world can lend to your project.

You'd best borrow much of the tech stuff from Spudfiles, which has some pretty decent multi-shot designs that are based on the energy to move a potato shot, which would equal very sufficient power to shotgun five paintballs.


I guess what I wonder is how you are going to contain five paintballs for each pump-action shot. As a stock-class PBer, pumping is just part of my game, but both my Phantom VSC-45 and my Carter-modified Tunnel Rat have detent rings, and the Brass Eagle Stingray I have has a detent ball to keep things from rolling out. The only other thing I imagine you intend is some pre-loaded PVC cartridges that are loaded into a box magazine.

Nonetheless, it's a daunting project, and I wish you well on it! While you're here, you may as well enjoy the Nerfy goodness (you'd be surprised how good a work out you can get from one hour of Nerfing with your kids) and the qualities and quirks that actually make Nerf a very fun shooting hobby right there alongside paintballing and airsoft (of which I don't do). Glad you're here.



-Piney-

[Doom]

A smaller, simpler version of Dr. Nerf's valve would probably work for you.

I don't know if you've seen this, but Dr. Nerf made a guide for his gun as a water balloon launcher and it could help if you want to make it: http://www.sscentral...de/testwbl.html

The problem as you said though is that the valve is really large for Nerf. It's so large that it works decently as a water balloon launcher. It's definitely still too large for 5 paintballs as well.

I'm his brother and I wanted to make a smaller, simpler version of it. I didn't (and won't) finish it, but I have some obnoxiously large photos from the construction phase here: http://www.sscentral.../images/update/ . The gun is obviously far from complete because not all the pipe is cut and nothing is even put together tight.

My version of that valve used cut rubber sheeting as seal material. The seal in the valve itself worked quite well. However, what prevented me from finishing the gun was that the seal on the back of the rod wasn't working as planned. I probably should have ordered the right sized O-ring, but I didn't and then went to college. I don't plan to continue this gun, but I did learn a few things from it so it wasn't a wasted project.

Some things to note about the photos I uploaded:

The grey plastic is PVC sheeting. I cut it into two circles to align the rod as it moves through the chamber. In the photos I did not drill the vent holes through them yet.

The chamber itself was changed later to be smaller. I used the short PVC couplers.

Another gun you might want to check out is the GB Semi. It uses a valve similar to everything I mentioned.

[Cheese-Boy]

hmmm... not the same 'Hubb' that i was thinking... *is sad*

[analogkid]

After modding the Recon (using mods on this site), it averages 85' flat.

Excuse me, how did everyone miss this? Usually range flames are people's favorite thing around here. 85' with a recon is extremely difficult, maybe inpossible, to achieve. But before I call your bluff, tell me what you did and the conditions you tested under. Not trying to be an ass, I just have put a lot of time into modding the Recon, and nothing that I've done has even approached this. In fact, I don't think anyone has. Oh, and welcome to the 'Haven.

EDIT: imaseoulman caught this too

Edited by analogkid, 18 March 2008 - 05:11 PM.

[Hubb]

Let me see here.

imaseoulman: The only mod I did to my recon that was not on this site was adding a brass barrel. It held the loaded Streamlines just enough to keep them from falling out. The plastic thing (I think would be called a barrel) comes out. Other than that, everything else is (a variant) of mods from this site. Now, the Recon may have been angled a litte (more than 0 but less than 30), but it averaged that with the 6 shots.

CaptainSlug: That's exactly it. I just couldn't think of what to call it. As far as tools go, I got plenty of drill bits, a hacksaw, a bench grinder, a vice, and a pocket knife. I do understand that it will not be a true semi-auto, but what I was hoping to accomplish was this; I don't want the main chamber to dump all at once. BTW: That +bow of yours is quite a sight.

Pineapple: I understand that to move 5 paintballs, I am going to need some force. It's been thought out (actually, I've been thinking about it for about four months now). Basically, I am hoping that you guys can show me things in here, and I could modify them to work for me. I plan on using the shell design with a ball detent for each shell. I do know that this is not too practical, but it would be so cool. If I do get to play with it, I would not think of using it in a real game. Just something to shoot around the yard. A guy has his hobbies. BTW: Me and my wife occasionally play inside the house. Nerf seems to be easier on the walls than paintballs

Doom: Thank you. I will study this and see what I can do. If you allow, I will probably base my valve off of these.

Cheese Boy: Check the PM.

Again, thanks guys. I'm trying to think "outside the box" here and you guys are really allowing me to do so.

Edited by Hubb, 18 March 2008 - 05:11 PM.

[CaptainSlug]

You should just consider using a modified solenoid sprinkler valve. It will provide the kind of flow rate you need. Then have a secondary push-button valve for refilling your firing tank.
You don't really have the tools needed to make a valve that can withstand high pressures, and making such a valve work is very difficult.

Edited by CaptainSlug, 19 March 2008 - 02:18 PM.

[keef]

If he used a solenoid the ROF would be really slow. You could make two tanks. One to fill while the other shoots, gets refilled.

[Doom]

He could use two solenoids like this if he wanted the same effect as the Dr. Nerf valve: http://nerfhaven.com...?showtopic=6486

It's basically the same thing, but with two solenoids instead of two sealing faces.

Of course, one solenoid might not be necessary because it just refills the second air chamber and it doesn't need the (relatively) high flow and fast opening time of a solenoid. A different cheaper and smaller valve should work there.

Edited by Doom, 19 March 2008 - 09:28 PM.

[Hubb]

CaptainSlug: Although I am limited with my tools, I have made several custom parts. It only takes a bit of imagination. I imagine I would not be able to construct one of your +bows, but I can do more than most. Besides, if I run into a situation where I need a tool I don't have, I'll go buy one.

Doom: That would work, however, it is just a little too bulky on what I would like to do. Maybe I can make a varient of it. I'll think about.

Now, over the past couple of days, I've been browsing these forums and have come up with another possible solution to my problem:



Basically, it is a normal piston valve. To exhaust the pilot area, the check valve must open. It does so by the hammer / sear / trigger setup. Hopefully, the hammer will strike the check valve (firing pin?) and close it almost immediately.

Initially, I thought of having the pilot volume, as well as the compression from the hammer, reset the hammer, but I don't know how feasible that would be, especially with low pressures. This can be solved with a cocking handle.

[camo]

you might be able to use the rapid fire barrel here. (it's the last picture) It seems to be kinda inefficient, but with a CO2 tank that won't matter as much.

[Gyrvalcon]

Hey Hubb, just thought I might be able to contribute. I was working on a variation of Dr. Nerf's/Doom's valve myself, although it's "on hold" at the moment. Here's the scheme.

Action Concept


Making it Easier to Manufacture


The original thread is here.

It's pretty low on parts, (threaded rod, O-rings, PVC)and you shouldn't need many tools to build. Whether it would actually work is another question entirely.

[Quilan Fett]

Awesame design, you just neeed a smaller peice of brass that fits inside of your normal barrel that remains stationary to ensure the dart is fully into the main barrel before the valve is actuated.

[Shadow 92]

If you're going to make a semi auto valve, why not just make a semi auto valve too? It wouldn't be too hard. All you would need is a regular piston, a valve that both fills air and cuts it off, and a semi auto valve.

Here's a diagram that shows a valve that will both allow air in to fill the chamber and pilot it. Its the part labeled 3 port valve. (I didn't make the diagram, someone else on Spudfiles did to help me with a semi-auto design.)


Heres a link to working semi-auto bolt.

Combine those two things with a barrel sealing piston and you have yourself a semi auto blaster.

Or you could try and improve on this



^Link^

[Gyrvalcon]

Personally, I'd try and find a design with few seals and moving parts that can be made with simpler tools. Especially for your first homemade.

[Hubb]

Gyrvalcon: That looks promising. If I were to use something like that, I would connect a trigger to a rod, which would open the valve, leaving the barrel stationary. It should work quite well with lower pressures but I would worry about the pull on a higher pressure system (say around 100psi).

Shadow: That looks complicated (which would be the work of the fellow who helped you). I like the idea of using a smaller piston valve to pilot the larger valve, which would probably solve the problem of a higher pressure system from Gyrvalcon. Also, I do believe that I don't quite understand the 3D drawing there. Please explain.