13 replies to this topic

[Zyzybalooba]

I am new to this board, and apologize if anything I ask has been asked before, but I have many questions about making a homemade gun based off of my ideas. First a brief history and my scenario:

I started nerfing 2-3 months ago, when I took my friend's Secret Shot 2. I started looking into nerfing and, a month later, proceeded to mod and repaint the SS2, along with his three other guns.

Naturally I wanted more. I recently have come up with a couple of ideas to make some cool homemade guns. I am going for looks, as well as performance. My first idea was to build a powerful gun that looked like a real loser rifle. For this I chose the Steyr Scout. It would give me enough room to give it a pretty big tank with an external pump system.
After making a sketch, with a lot of extra room left over, I proceeded to think of ways to make this better, such as multiple tanks, a semi-automatic firing chamber, and an integrated pump system, while still keeping the original shape of the Steyr Scout. I will get back to the Scout later.

I knew I was going to end up messing everything up, so I decided to make a smaller handgun where I can test out some things, without just jumping into the big gun and killing it. For the handgun, I chose the Desert Eagle. It will provide a lot of space for all of its innards (approximate dimensions):
10.75” in length
6.25” in height
1.25” in width
.495” (.5”) bore
This is where questions arise.
---end history and scenario---

The Desert Eagle:
The air tank will probably be 1” PVC pipe that is around 6” in height. (Question #1) Would this tank be too small? I am going for a pretty good range, but don’t expect it to be that high for a handgun.
The pump would be an external bike/basketball pump that attaches to the bottom of the handle. From the air tank, it will go to one of Zero’s basic valves. It looks like it would work pretty well and the placement is right for a trigger. (Questions #2 and 3) Anyone have any experience with this valve? And what type of tubing should I use to connect the air tank to the valve? I am thinking of using vinyl tubing but have no idea of what width would be best.
For the barrel, I am using a crayola barrel and .5” PVC piping attached with a 3/4” to 1/2” PVC coupler. For simplicity’s sake, I will just load the darts ramrod style.
(Question #4) I will probably be using plexiglass for the casing because it is easy to use and shape with a dremel. If anyone has any suggestions for a better casing, I am open to opinions.

Onto the Scout:
Currently, the most efficient design one would be single big air tank pumped by an external pump. Although it would be nice, I don’t want those extra tanks if I can’t get strong shots with each tank. (Question #5) Is bigger better? I would rather power/range/accuracy than the ability to fire multiple shots but if there is a definite cap on how big the tank should be, I may want to try adding at least a backup/extra shot.
In the first sketch, I used a really long barrel. I realize now that it was nearly 2 feet in length. I have gone down quite a bit to around 18”. (Question #6) Would this still be too long? I think if the air tank was powerful enough, and since I am using Zero darts, it doesn’t seem that it wouldn’t matter much. I want to keep it around the middle somewhat so where the bullets are loaded is in the approximate location of where they are ejected on the real rifle.
I think I am okay for now with nearly everything else. I am using a breech loading system, probably fed from the side so it doesn’t interfere with the scope. I will probably use a thread scope because it will be easy to make and it is just for show anyways. I haven’t decided yet on an integrated pump, it would be possible and I could live with or without it. With it would require the air tank to be in the butt of the rifle, which isn’t a bad idea anyways. This only means long tubing back and forth (at 6-12” in length.) I assume this isn’t really a good thing. (Question #7)Comments?

Remember, I am going for looks as well as performance, I want to keep the gun looking a bit realistic. I have some other ideas that I can’t remember at the moment. I am open to all opinions.

Pictures and sketches:

Steyr Scout: Take 1
So many flaws, but it was a good starting idea. I dropped the Semi-automatic firing valve because I can't see how it would work effectively without depressurizing the air tanks too fast. The dual air tank is not a bad idea, though. I just don't know if they really need to be that huge.


Steyr Scout: Take 2
From those thoughts I dsigned the second scout, which I don't like at all. I am not sure how the 5 tubing to one selector thing would work, or anything else on it for that matter. I know I could figure it out if I tried hard enough. I just don't really like this one because of all the tubing and puny air tanks. It seems exessive and wasteful.


Steyr Scout: Take 3
This one has an integrated pump and one air tank, which is still a good idea in fact. The bottom front of the gun would detach somehow so I can pump the pump. This picture is innacurate as the pump would be moved farther forward to get more out of each pump. The idea seems pretty positive, hold the fact that I might have the same lengthy tubing problems that Take 2 would have had. On the plus side, I could probably design it so the integrated pump hooked onto the air tank externally so I could pump the Deagle from the Scout. Not a bad idea, supposing I could figure it out. Right now, this is my prime working idea.


Desert Eagle: Take 1
This is probably the idea I am going with for now. I am not sure of any of the lengths yet, but the air tank can be anywhere up to 6" of 1" PVC and the barrel can be at least 4". I don't know of the best diameter of vinyl tubing to use either. Otherwise, It seems like a pretty solid plan and so far I can't figure out any problems.

(Thanks to Vintage for explaning how to submit pictures.)

Edited by Zyzybalooba, 16 August 2004 - 08:24 PM.

[Vintage]

For a pistol, you definitely don't want a big airtank. If you look at the Secret Shot 2, you can get a good idea of the maximum your tank should be. A bigger tank will not get you better range. A smaller tank coupled with a good pump is what you need. I would suggest 4 inches of 3/4" PVC for the tank with a pump that can handle high pressure.

The zero valve should be fine as long as you use it correctly. I would like to see a sketch of your design to help you with that.

A crayola barrel is fine, and I would encase it in 4 inches of 1/2" PVC. That leaves about 1 inch at the end of the crayola for air to slip past the dart as it leaves the barrel.

Don't even think about casing until your homemade is complete. You might just decide against it anyways. Your first priority should be making a functional nerf gun.

Anyways, remember to use purple primer and PVC cement when connecting PVC pipes together. Use "Plumber's Goop" for any other connections.

Edit: To upload pictures, go to Imageshack and click browse. Choose your picture, and click 'Host It'. Once you upload your picture, copy the contents of the first white box to your post. It's that easy.

~Vintage

Edited by Vintage, 15 August 2004 - 07:58 PM.

[Techno-Dann]

About the rifle... I'd say that your barrel sounds too small for your air tank. When I was experimenting with my rifle, I found that having the barrel have about the same volume as the air tank works the best. Of course, depending on your operating pressure and dart fit and whatnot, that'd change significantly.

[Alexthebeast]

Hand drawn goodness. I cant wait to see how this goes. Here's a question/advisory. On the sc00t(CS lingo), will you go and buy a stock or heatmold PVC to it? Because the PVC as a stock could double as a huge tank.The only major flaw I see, is, no matter which of the above ways you go, it will be impossible to Fit that all into a stock, unless you feel like gutting solid wood/abs.

[jpshyboi9]

Jyst wondering by looking at the desert eagle and the scout, do you like Counter Strike condition Zero? By the way on that game thats what i almost aways use if i dont use the bullpup. Good weapons set-up.

[Zyzybalooba]

Jyst wondering by looking at the desert eagle and the scout, do you like Counter Strike condition Zero?

No, though it is not a coincidence that I chose the Scout and Deagle combo. I am a Counter-Strike player and was a fan of the Desert Eagle before CS.

[Osiris]

Looks good but a pistol with an air tank is a bad idea man it will be sooo small. You can probably shoot once or twice and its outa air unless you make a good design so that you can fill it up with an air compresser for higher pressure you might be able to get like 5 shots. I dont think that zero valve can support much pressure though. Use 1 inch darts they are better short darts are a lot more accurate than long darts. Long darts also dont travel far distances. Nice plans by the ways. For your air tanks its a good idea to use this nice shreader valve that can be foudn on this website check it out http://www.acehardwa...oductId=1277973 Its built for high pressures and it has a thread so you dont have to glue anything. You just need a compression adapter to go from 1/4" thread to 1/2".

Edited by Osiris, 16 August 2004 - 05:49 PM.

[Zyzybalooba]

Techno-Dann: What would you suggest for a good sized air tank? I was actually afraid the air tank would be too big (on the rifle) and take too long to pump compared to the power output and wasted air.

Alexthebeast: I plan on making my own stock, probably out of plexiglass. I will find some way so that the innards don't move around, such as gluing them down.

Osiris: The idea is that the pistol only has one shot. I am making it mainly so I have working experience before I jump into the rifle. Also, why do you say smaller darts are better? I have tried testing of my own and have found little difference, exept with a slightly longer dart you would have straighter flight, thus better accuracy. I haven't yet found a good chart of someone who has tested dart lengths.


My two questions now, before I start buying stuff are:
What is the reccomended diameter for tubing? And:
On Zero's basic valve, does the space inbetween the two couplers have to be that large? It looks like, to me, it just needs to be big enough so that the tubing can fit in it.

[Techno-Dann]

Well... On my homemade (which is by no means the best, just so you know), my air tank is a 19 inch long section of 3/4 in. PVC. With my bike pump, it takes about eight pumps to hit max pressure. The size of the air tank really depends on the length of your barrel, and your operating pressure. (Or the other way around, if you design the gun around the air tank.) I'd suggest that you make the volume of the barrel be about equal to the volume of the air tank, for a first test. However, I'd suggest you don't glue it in; experiment with different barrel lengths untill you find the one that works for you.

As for the tubing, I'm not aware of anyone who has used it in a homemade. Nerf uses 1/8 in. I.D. tubing in their guns; it works, but it's hard to find fittings for it. 1/4 in. fittings are easy to find, as are 1/2 in. fittings. For the line from the air tank to the trigger, and from the trigger to the barrel, I'd suggest that you use a large tube, simply so there's more air flow. However, I think 1/2 in. would be all that you'd need.

Hope this helps...

[Vintage]

Use 1/4" tubing. Larger tubing would be a hassle to work with, especially if you need the tubing to bend. 1/2" tubing would kink if you tried to bend it on a 90* angle.

For the airtank, I would suggest small, but high-pressure. I just bought an AT2000 Nerf gun, and it shoots 90' flat out of a 5 inch barrel. It's airtank is less than 3 square inches big. My conclusion: Make a small airtank (maybe 6 inches of 3/4" PVC) and combine it with a high pressure pump like this one which can handle up to 90 PSI and costs only $6. I am currently attempting to prove my hypothesis with the homemade I am making right now. If you want, you could wait until I am finished before you build yours.

On Zero's valve, you only need enough space between the o-rings for the tubing to enter the valve.

Smaller darts work better, because they hit less air as they fly. Surface area on the tip of the dart affects drag which affects velocity. Use smaller darts. Some people have suggested the idea of using 3/8" FBR for stefans combined with small brass barrels, but no one has really tried it yet.

Edit: Whoops, I thought you meant dart diameter. You want the diameter to be small, but the length to be long. I would make your darts 2.5" long.

~Vintage

Edited by Vintage, 18 August 2004 - 01:00 PM.

[Zyzybalooba]

I can increase the size of the air tank to 1" PVC. Do you think that is unnecessary? It seems like it could make it more powerful, and it really isn't any extra work or effort.]

Also, when do you plan to test your hypothesis? I want to start working on it tomorrow (supposing I can get the supplies.) My oldest brother is going to college this Saturday and I want to get started before he leaves so I have someone that can help me out.

Edited by Zyzybalooba, 18 August 2004 - 09:14 PM.

[Vintage]

I have all of the parts and just have to cement them together. This is my design. Extremely simple, only to prove or disprove the hypothesis.


When it is done, I will post my findings.

~Vintage

[Zyzybalooba]

Why does Zero suggest using a 3/16" hole for 1/4" OD vinyl tubing? It seems like you would get better air flow with as more open hole, not to mention it would be easier with a bigger hole.

Edit: I should mention, I have a cool drill bit set that gives me every 64th from 1/16 to 1/4. In other words, I have drill bits sized 3/16", 13/64", 7/32", 15/64", and 1/4". It seems that if not 1/4", I could go down one or two sizes and it wouldn't hurt. Comments?

Edited by Zyzybalooba, 20 August 2004 - 03:15 PM.

[Vintage]

The only reason for the smaller diameter hole is for tightness. I don't think it's necessary, because I have had no difficulty sealing 1/4" tubing in a 1/4" hole.

~Vintage