19 replies to this topic

[Raj Man]

I was just looking at my storm door in my house, and I noticed that the plunger-like thing that makes the door close slowly (using air pressure) looks and functions like the pistons used in RF20's. The fancy term for the piece is a "closer." If you google the words "storm door closer" you will see what I'm talking about. Technically, if you use a pneumatic closer, and unscrew the speed adjustment screw all the way, you have a nerf plunger assembly that has a LOT of power! All you need to do then is put a rubber band or spring on/around the plunger arm and glue a barrel onto it. Tada! You have the basic nerf gun. I have tried it recently using a broken closer that my family has lying around in the garage. However, it was too rusted to be of any real use, and it jammed up most of the time. When I actually try this Idea, I will post again. Thanks!

[Ronster]

Sounds neat!...
I wonder if you can buy spare storm door pistons at Home Depot or Lowes...

[Carbon]

Sounds neat!...
I wonder if you can buy spare storm door pistons at Home Depot or Lowes...

Yeah, you can find replacement door closers at pretty much any hardware store. I've glanced at them, but never thought hard about using one....let us know what you find out, it sounds interesting!

[Raj Man]

[QUOTE] Sounds neat!...
I wonder if you can buy spare storm door pistons at Home Depot or Lowes...

Yeah, thanks! My dad said that most home improvement stores carry them, and you can get them in all sizes and kinds. However, you have to get one that is pneumatic, not oil or hydraulic. That's the only way to actually get AIR to come out of the piston.

Edited by Raj Man, 11 February 2006 - 12:42 PM.

[davidbowie]

How much do they cost?

I would go with a bike pump over one of those, but they might be cheaper.

[Pineapple]

I guess it would depend on how committed you'd be to bring the innovation to the table...

The key word when Nerfsmithing would be 'cost-effective'. Meaning if the door closer costs more than say, a Crossbow or a BBB, would it really make sense for folks to go out and buy one for the purpose of a Nerf blaster? Not to mention the weight of one of those piston/rod assemblies.

I never considered that, despite the fact that I removed 18 of those from some rooms at our facility last year. I'm going to check the storeroom where I left them (at least the bin I threw them into.)

Aah. Mine are hydraulic closers. Oh well.

Good luck, and let's see the progress as you take it on!


-Piney-

[Raj Man]

The closers cost 10 dollars normally, but bigger ones would cost more. Also, you must make sure that the one you get isn't too small, or too big, due to air output and weight.
Some models even have a spring inside them, which makes them more powerful!

[Raj Man]

The first project update:
I have been researching the utilization of closers, and I have found out many things. First of all, they have been used for a wide variety of air pressure projects already, and are especially handy for halloween tricks, spooks, and booby traps. More importantly, i found out that what I am planning on doing WILL work, though it has not been done. Once the main pressure screw is removed, you must drill out a big hole through the threaded hole in which the screw was once held. This is the only way to get even a substantial amount of air flow.

Also, you must use a hose adapter in order to harness this airflow, or even be able to put a barrel on the closer. Once you have a hose adapter, you can even attach vinyl tubing to the closer and transfer air flow from the closer to a separate homemade barrel. You would probably lose air pressure by doing this, but I suppose that some people would prefer their nerf guns that way.

I'm starting my building as soon as I get more of the large sized rubber bands that I have been using (for testing) as well as a new, working door closer from home depot.

Note: The door closers are very heavy, considering that they are metal, so if anyone has any ideas of a similar device that weighs less or is less expensive feel free to post here about it!

[davidbowie]

As I said before, a bike pump! you can buy a plastic pump made by Husky, with a decent displacement, for 9 dollars at Home Depot. Take out the plunger, then cut down the outer tube to whatever length you want, and find a way to attach it to a barrel.

[Raj Man]

How much do they cost?

I would go with a bike pump over one of those, but they might be cheaper.

Yeah, I read your suggestion already, davidbowie, thanks! I was just wondering if anyone ELSE had any OTHER suggestions. As soon as I get that bike pump, a new door closer, and some new big rubber bands, I'll start building and range testing. It all depends on which has better ranges, the door closer or bike pump, whether the range is actually worth it, and when I get the materials. I will post again, with pictures, once testing is complete!

[One Man Clan]

Langley is working on something like this I think. I hope he sees this thread.

[Raj Man]

Project UPDATE:

PICTURES NOW UP AND WORKING SEE THE SECOND PAGE OF THIS THREAD FOR THE CRAPPY PICS!!!

Anyway, I ended up using a Basketball pump and hacksawing the nozzle off the front. I used parts from a dollar store gun to make the marker barrel
fit better. I used an entire stick of hot-glue, and everything is air tight. The air displacement is amazing, and it can shoot stock micros about 20-30'. Once I start using stefans, I should get a little better ranges.

The green on the basketball pump is my own custom paint job. The small bright green tube is the marker barrel. The black thing in between the pump and the barrel is the dollar store gun piece. It works MUCH better than I thought it would, but it has a long way to go before it can be considered "decent." The dart must be fired manually, meaning that you yourself pump out the dart. Because of this, I decide the power. The more force I apply to the pump, the farther the dart goes. Later, I plan to use different ammunition and possibly add rubber bands, so that it is not completely manual. Once I get my hands on some FBR and rubber bands, I'll preform somemore range tests.

Note: Because of some law of air physics I do not understand, the rubber bands make the Basketball pump move fairly slowly, not allowing enough pressure to lauch the dart far at all. This forces me to use an excessive amount of rubber bands just to get the amount of "SNAP" that I need to launch the dart.

Edited by Raj Man, 19 February 2006 - 09:28 AM.

[Carbon]

Yeah, I could imagine that being a problem....pumps are focused on seal, not on speed. What kind of lube was inside the pump when you opened it up? I could imagine it being well lubed, but with something a fair bit thicker than what you'd want to lube a chamber with. Perhaps clean it out and try hitting it with some silicone....just a thought.

[Langley]

for the barrel just use a 1" coupling and a 1"=1/2" reducer coupling inserted into one side. Use a dremel to grind out the inside of the side of the coupling you intend to attach to the closer.

Piney- the 'light duty' closer I bought, which gets single barrel 1500 range and is more than adequate, only cost me about eight bucks at true value. It may even be cheaper at a lowes or home depot.

The closer is already spring loaded, and doesn't need banding or anything. I've got a design in mind for a handle on the casing and a handle on the rod for cocking, but the trigger mechanism I'm thinking about, which utilizes the little metal thing that holds the door open, may need some more work. When I'm not worried about midterms I'll get back to it.

On basketball pumps- My experience is that the o-rings usually get stretched out and come off after the first few shots if you've got a high powered spring or bungee on it, but you may have found a more sturdy basketball pump than I did. Here is a pic of the pump I used, and what I tried to do with it.

[Spider-Waffle]

Did you lube the bike pump?

I couldn't help but notice the HL cd, do you follow any of the speedruns?

[Raj Man]

Here are the working pictures:





Enjoy! All I have to do now is sand off the end of the barrel until it is smooth so that the gun stops shredding up my darts!

[Langley]

I didn't add any lube to the pump, but it already had a thick coating of whatever they lube it with in the factory. The friction wasn't the problem, it was the loose o-ring and the groove that it sat in.

Nice looking so far, raj, but if you have the same problems with the pump that I had, I would recomment getting a light duty door closer from the hardware store. They're almost as cheap as a Basketball pump, and they already have the spring and half the trigger mech.

[Raj Man]

Nice looking so far, raj, but if you have the same problems with the pump that I had, I would recomment getting a light duty door closer from the hardware store. They're almost as cheap as a Basketball pump, and they already have the spring and half the trigger mech.

Yeah, thanks! I'm going to pick up one of those closers as soon as it gets warmer up here in MA. It's been reeeeeally cold recently. My hands turned blue when I went outside! Anyway, the heavy amount of factory lube that was already on the gun is beginning to wear off, so my problem with the rubber bands is fixed because the pumping arm can now move freely. I still need about 5 or 6 bands to get consistent ranges, but I just found a stash of rubber bands at my dad's office. The gun works best without the rubber bands, fired manually. when this is done, I get consistent ranges of 35'. When I use all my strength, I get 40'. I have also recently put a ring of hot glue over the end of the barrel and put tons of electrical tape over all spots from which air could leak, which greatly improves its seal. The only place I have not put e-tape is over the small space in between the metal plunger arm and the back end of the plunger body. Does anyone know what kind of material could be applied there in order to improve air seal?

[davidbowie]

you mean back by where you cock it? I don't think you want a seal there.

[Raj Man]

Here's the current version:



I call it the Hand Cannon of imminent DOOM. Now it has a "grenade" launcher, a sight
(red lego piece), and a whole lot better air seal! Damn, that metal grenade hurts like a bitch when you get hit with it. I should probably cover the grenade with foam.

EDIT: sorry it's so blurry. The grenade is the silver cylinder at the bottom next to the bag o' darts. The silver over the barrel is what allows the grenade to be shot.

Edited by Raj Man, 20 February 2006 - 04:18 PM.