SpudFiles

my idea is to make a repeating piston pistol where the piston between firing and returning to its normal position it reloads the pistol. my problem is I know there are piston valve making how to's but I have trouble understanding them plus i need to know how to make a piston in half inch pipe.
all help welcome.


New South Wales 4 life!

You're asking for a heap of trouble.

1. You want semi-auto. Been done, but not without considerable struggle.
2. You want it in pistol form. You're better off buying an airsoft gun.
3. You want both of the above in the same gun.


Trust me, not something you want to tackle on your own. Buying is the only way here.

another Aussie
good
maybe you could make a normal barrel sealing piston valve, but put a spring behind the piston, and have a pneumatic actuator.
but it seems complicated. get a small solenoid valve and just rig it up to a battery and push the button when you want to fire? they are about 14 bucks.

if I use an electronic trigger I will probably need to add a high voltage capacitor to deliver a strong enough charge to the soleniod in one go pluss I will have to drill a bigger pilot hole in the valve also where do you buy a small solenoid? im guessing bunnings

pilot hole?
noooo dont worry about that, keep it electric.
and yer bunnings
http://www.toro.com.au/product_files/prd_164.jpg
that is the one i have.
you need a 9v battery to use it

no need for a solenoid if u r handy and patient enough with small parts. if it was a rifle then it would be fine. if u want it in pistol for u want to use as little parts as possible. u can pilot with a hammer valve opening it with a revolver type hammer. the piston will open and seal on its own if i make it right. i have a few designs if u want some. i kinda think them up on the spot.

im interested on these designs of yours, feel like sharing the knowledge?
so you mean making the revolver hammer strike the hammer, and opening the valve?

As mentioned, definitely challenging in (mobile) pistol form.

Perhaps a blow forward breech with a regular piston valve, and have the chamber filled from a second chamber through a small hole. By adjusting the size of the hole you could balance how much air was wasted and how fast the chamber would refill.

If you build the semi-auto breech you could start with a valve as simple as a blowgun, and add more complex valves later, so you don't get discouraged trying something too complicated.

If you want it portable and easy to make, it would actually be much easier to have it full auto, take a look at this design.

making a piston in half inch pipe is easy, cut a section of pipe and line the inside with glad wrap, then shove some epoxy in it, this gives you a piston that fits exact. then sand it down a bit so you get equalization through to the pilot space, whack a sealing face on it and there you have it.
or you could just get some dowel.

thanks for all the interest in my concept.

SEAKING9006 - I like a bit of a struggle and I can't
buy an airsoft gun that is why I am buying one and I
have 2 friends helping me.

Cosmic Muffin - thanks for the help with the solenoid
and the piston I have a 1 inch valve at the moment on
my carbine which I havent posted yet but I will use
the half inch on it plus this gun.

i-will - I want to stay with the solenoid because I am
confident with that valve but thank you for the idea I
may use that in a later design.

daccel - that is what I am thinking of doing but instead
of a small hole I am using an air regulator by having a
high pressure chamber which will be roughly 400 psi and
the regulator will bring it down to a comfortable 65-70
psi and i am hoping with this system to get about 4 to 8
shot off without recharging the high pressure.

JSR - I don't want full auto because semi-auto is much
more fun to play with.

In that case, why not combine the tyre inflator with a blow-forward or tee type reloading breech?

I am using a tee reloading breech. I will be firing 2cm long flechettes from this pistol.

You should be able to scale down something like my FANG automatic Nerf gun and depending on what you're shooting it could be a pistol. To reduce the length you'd need to put the air cylinder on top and make it pull instead of push, but aside from what it'd be mostly the same. This would probably be the easiest approach as it uses mostly off-the-shelf parts instead of machining. If you want something smaller you'll have to machine parts.

I've actually thought a great deal about doing this because it would seem very fun, so I suggest it. I was considering 1/2 inch balls as ammunition.

im having 2 main tanks one will be high pressure running along the sides and a low pressure tank after being filled from the high pressure tank is what is being used to actualy fire the round. im firing small darts which i am going to put into foam sabots.