SlingAirGun with a spoon trigger

[boyntonstu]

[suburban spudgunner]

Sooo...the spoon releases a "plunger" which, powered by the bungee (?) pushes a cushion of air through the barrel in order to shoot the projectile?

It definitely looks interesting. I'd like to see a video of it in action.

[THUNDERLORD]

Looks clever.
I was wondering what the fork the ammo will be?
Course then I was thinking it could shoot a fork(s). 8)

[maverik94]

cool idea, what kind of performance do you get?

[UKSGC]

Its great, what a novel idea. I was somehow expecting you to build something much bigger or somehow more complex.
I am now fairly sure you are as mad as a brush sir.
I wonder, do you keep it in the cutlery drawer?

[jackssmirkingrevenge]

Love the "blast shield", very panzerschreck

Damage pics and more details are always appreciated

Sooo...the spoon releases a "plunger" which, powered by the bungee (?) pushes a cushion of air through the barrel in order to shoot the projectile?

It appears that the bungee acts directly on the projectile

I was wondering what the fork the ammo will be?
Course then I was thinking it could shoot a fork(s)

Class

[inonickname]

Admittedly I wasn't the keenest during the buildup threads, but even in this simple form I like it.

Few questions:

Do you o-ring the piston, and how? Floating?
What pull strength did you decide on?
WHEN DO WE GET DAMAGE PICZ?!?!?

To be honest, if I happened upon some suitable rubber I'd do this. Any bets on jelly rubber?

[CpTn_lAw]

looks like it was inspired by some kinda airow gun...nonetheless, very cool for a first and i'm looking forward to reading more about this one erhaps damage pics as soon as you get some?

[inonickname]

looks like it was inspired by some kinda airow gun=

Noooooo way?

[boyntonstu]

Admittedly I wasn't the keenest during the buildup threads, but even in this simple form I like it.

Few questions:

Do you o-ring the piston, and how? Floating?
What pull strength did you decide on?
WHEN DO WE GET DAMAGE PICZ?!?!?

To be honest, if I happened upon some suitable rubber I'd do this. Any bets on jelly rubber?

I use the Silver Thera Band tubing.

http://www.thera-band.com/store/product ... oductID=27


Damage?

Look at the damage of just a simple Ther-band slingshot can do:



Joerg uses Thera-Band but his rubber is not as strong as the Silver tubing that I am using.

When I get all 10 bands going, it will be something.

Drawing back a single rubber is SO MUCH easier than trying to draw and cock a pouch/wishbone (spear gun) setup with 2 rubbers.

I just grab the bulge before th constrictor knot, pull it back, and slip the loop onto the plastic covered horizontal bolt.

BTW A swing away safety under the spoon handle is a distinct possibility.


Also, a trigger with a string or cable to pull the spoon down, could be mounted almost anywhere below the stick.

The Airowgun uses a grooved plastic piston, fairly loose fitting.

I am experimenting with a copy of the Airowgun piston and also "O" rings.

BoyntonStu

[JoergS]

Stu, that will be a mighty weapon.

I still suggest to use a larger diameter tube, like a 2" instead of 1". Further, a pretty long barrel with a small caliber would be good. I suggest using a 9mm barrel and lead balls.

This way, the speed of the ball could be much higher than the speed of the pouch/piston.

The speed of the pouch is limited by the maximum speed of the retracting rubber. I have tested this extensively, more than 300 feet per second is not possible. 260 fps is more realistic.

But ten strings of silver tubing will create a ton of force. The silver tube is so strong that is can't be used for a slingshot, noone could draw it out to the limit. So using compressed air and a small caliber barrer/bullet would achieve very high speed.

10 strands of silver tube for a 1" tube is overkill, I think. There would still be a lot of unused energy at the end of the stroke, potentially damaging your dowel and breaking the piston.

Remember once the dowel reaches 300 fps, even 30 more strands could not increase the bullet speed. More air is the answer. Hence, a bigger diameter.

Jörg

[Mitchza89]

Oh man I love it. I used to do a similar thing 'back in the day' before I get into spudding. It was like a crossbow mixed with a slingshot. I used to shoot U shaped nails at a damn good speed. I gave it up after It backfired and shot the U shaped nail edge first into my forehead....the damn thing actually shood out..

[boyntonstu]

Stu, that will be a mighty weapon.

I still suggest to use a larger diameter tube, like a 2" instead of 1". Further, a pretty long barrel with a small caliber would be good. I suggest using a 9mm barrel and lead balls.

This way, the speed of the ball could be much higher than the speed of the pouch/piston.

The speed of the pouch is limited by the maximum speed of the retracting rubber. I have tested this extensively, more than 300 feet per second is not possible. 260 fps is more realistic.

But ten strings of silver tubing will create a ton of force. The silver tube is so strong that is can't be used for a slingshot, noone could draw it out to the limit. So using compressed air and a small caliber barrer/bullet would achieve very high speed.

10 strands of silver tube for a 1" tube is overkill, I think. There would still be a lot of unused energy at the end of the stroke, potentially damaging your dowel and breaking the piston.

Remember once the dowel reaches 300 fps, even 30 more strands could not increase the bullet speed. More air is the answer. Hence, a bigger diameter.

Jörg

Joerg,


"The silver tube is so strong that is can't be used for a slingshot, no one could draw it out to the limit."

I can draw a single silver tube to full draw using my 70 year old no gym arms. lol

The beauty of having a trigger is that you don't have to hold the rubber force for more than a few seconds.

My airgun barrel changing idea:

A method for changing the barrel diameter relative to the air compression chamber.

I do not intend to use the 3/4" tubing as the barrel.

The barrel will be slid into the 3/4" tubing with a tight "O" ring piston seal through which the smaller diameter barrel goes.

I am working through the muzzle attachment method.

Any suggestions?

I will be able to adjust the position of the barrel breech where the maximum pressure is achieved just ahead of the piston stroke stopping point.

The barrel could be as small as .177.

One of my goals is to break the SOS using rubber.

BoyntonStu

BTW WalMart sells a 50 pound fish scale for $4.95.

It will yield very useful data.

[JoergS]

Well, a slingshot uses two strands of tube, and also keep in mind the limit is 550%, not the 300% you go for.

I can draw out my non braced slingshots with black tubes to 550%, but the silver type, no way.

A non-braced slingshot puts a lot of strain on your wrist, which is usually the weakest part and effectively limits the power of the slingshot. Braced slingshots CAN take the silver tubes (so I am told).

Barrel attachment, I recommend a threaded barrel that is fixed with a nut is probably the easiest way for now.

Jörg

[boyntonstu]

Well, a slingshot uses two strands of tube, and also keep in mind the limit is 550%, not the 300% you go for.

I can draw out my non braced slingshots with black tubes to 550%, but the silver type, no way.

A non-braced slingshot puts a lot of strain on your wrist, which is usually the weakest part and effectively limits the power of the slingshot. Braced slingshots CAN take the silver tubes (so I am told).

Barrel attachment, I recommend a threaded barrel that is fixed with a nut is probably the easiest way for now.

Jörg

I find the % draw a little confusing.

For example: Thera-Band indicates that a gold band has a 11+ pound draw at 100% elongation.

10" to 20" is 100% correct.

10" to 30" is 300% elongation according to the factory. Strange!

What do you mean by 55% draw for a single 10" length?

A fish scale will eliminate all doubts and will not measure the length lost to knots, etc.

A screwed on barrel is fine for a finished product.

I intend to use a piston sealed barrel in order to experiment with at least 3 parameters, diameter, length, and position.

BoyntonStu

P.S. I would get a kick if you referenced my (banned) photos on slingshots.com.