Where do I start?

[vng21092]

Hi everybody, I'm new to Spudfiles so I'm not yet familiar on how to search for threads. Has anyone here ever attempted to make a spring powered bb gun? How does one get started? Ive seen the internals of a spring powered airsoft pistol and I can assume you just scale it up, but I have no idea where to start...

[fenrir]

Well, to search, you click on the search button on the top. I don't think any of us built a spring gun, what do you want to get out of it? For a beginners project, you can look around this forum for ideas.

[Ragnarok]

I don't think any of us built a spring gun

I tried it, crushed the side of one of my fingers open, then didn't try it again.

Fortunately, the only lasting cost is some ugly scarring and occasional twinges - I didn't injure anything that cost me noticeable mobility in the finger and most of the bits glued back into place - but it's still an illustrator that compressed springs can pack one hell of a punch and the trigger mechanism (or, indeed, anything that has to take the force of the compressed spring) should not be half-arsed.
It later led me to choose the Air Arms TX200 over the otherwise similar Weihrauch HW 97 when buying a spring air rifle - the TX200 is designed with an additional catch to avoid the chance of the mainspring smashing the user's fingers in the loading port. (Some people find having to release it an annoying extra step in loading, but they've probably never smashed their fingers up).

Anyway, I digress. The point is that to get any real go out of them, spring mechanisms need pretty sturdy (and careful) construction - and even that ultimately won't provide particularly rip-roaring performance.
That's not to say that they don't have potential advantages, but you should be aware of the challenges before you embark.

Best of luck, either way.

[tigerblues28]

I suggest you start with a good trigger mechanism and a strong sear. Hopefully you have good dremel tool skills or a mill. I'd use some sheet steel, springs, and a double sear so if one fails you're safe.

I'd also make sure you have a safety button like found on legitimate firearms. Safety is key.

Next I would fit this trigger to a, I don't know if it's called a chamber, but where the piston, spring, and pressure will be.

I'd use something strong like a brass or steel nipple to hold the short burst of high pressure that's generated for just a quick instance. It would have to be bigger like 3/4" x 12".

Look on a store like mcmaster-Carr for a good spring. I'd have to experiment with them to understand what works best.

A piston made from derlin with an o-ring or two would work. Just make sure that the trigger has something strong to hold onto like a few steel washers or something. You could get this custom made.


Cocking the heavy spring back will be a pain. I leave system like in a brake barrel airgun would probably be best.

On the front end, use a nozzle of some sort like a 1/4 barbed hose nozzle threaded to the end of the 3/4" "chamber would work well.

Yeah, I guess I really whipped out my spoon an fed ya like a child.
Spring guns aren't anything to mess around with so stay safe and double think everything before doing something crazy.

I think a pneumatic build would be better, or maybe a hybrid if you know what you're doing with everything. But I don't know if you're up for it being new to the forum. Can't stress enough safety!!


Nick

[jackssmirkingrevenge]

Pasted a bunch of thoughts on the subject from previous posts:

As often stated on this forum, couldn't agree more. If it's power you want, unless you're John Whiscombe, don't bother. On the amateur level most spudders operate, it is countless times easier to build a powerful pneumatic or combustion than it is a spring piston airgun, what you'll end up with will doubtless be less powerful than a cheap airsoft pistol.

This is the closest I ever came ten years ago, never made a springer since.

I've always said it on this forum and will say it again, springers are great because they're self contained but unless you have a machine shop to make one, don't even consider it. Also, if your aim (see what I did there ) is accuracy, then the vibration associated with a spring piston rifle is a distinct disadvantage - a springer is much more difficult to shoot accurately than a pneumatic.

Also, power is an issue. A launcher capable of hitting a target at 50 metres has to be quite powerful, and if it was a springer it would need substantial construction, certainly not something you're going to achieve with rubber bands.

A simple QEV pneumatic is much easier to build and will be much more powerful, even if you're limited to 8 bar.

It's not the best of ideas, if you look at commercial spring rifles one of the most powerful is the Webley Patriot which doesn't exceed 30 ft/lbs, and is about as powerful as you can get before it's impossible to cock.

Pneumatic rifles on the other hand go up to several hundred ft/lbs and are much easier to shoot accurately, unless you have a machine shop and are making it out of mechanical interest, it's best to steer clear of home-made springers.

[vng21092]

but arent most pellet rifles spring powered? why are those so powerful?

[Ragnarok]

Firstly because they're precision engineered and built like bomb shelters - a good spring rifle is heavy.

Secondly, because they're not "so powerful". Even the most powerful spring rifles struggle to exceed 40 joules (and become exceptionally hard to reload) - a benchmark easily beaten by pneumatics of similar size and weight.

Springers do have their advantages, but they're hard to safely and properly make without specialist tools. Unless you're up for a challenge, have the right tools, know what you're doing and aren't looking for much punch, they're something to buy, not build.

[vng21092]

oh, ok, i see, on another note, how do i make something that i can use to aim with? iron sight, scope, etc? so far i used a 1/4 bolt that sticks out 1/4 inch on the tip of my barrel and i use a 1/4 nut on the back of my rifle. the top of the bolt in front through the center of the nut on the back is parallel to the barrel, so i always have to aim above a target, is there a better way?

[jackssmirkingrevenge]

Have a look here

Adjustable, see.



Or just buy a cheap-oh reflex sight from eBay

http://www.ebay.ca/itm/Tactical-1X22X33 ... 19e48e861a