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Unread postPosted: Thu Jan 22, 2009 5:05 pm
Author: POLAND_SPUD
@maggotman

there is one simple problem here... it weights a lot... if you have this moving forth and back 200 times per minute you want be able to hold the gun (yeah it would be cool in a way too)

I see that you use more less the same materials as I do.... so have a look here
http://www.spudfiles.com/forums/i-has-s ... 16872.html

this would offer more less the same rof if converted into fullauto and I feel its better suited to marble sized lunchers

it's one of the simplest design possible and when you have all the parts needed you can build it in less than 2 hours (inluding solderning)

Unread postPosted: Thu Jan 22, 2009 6:05 pm
Author: maggotman
nice marble gun btw
after thing about it i would rather save it for a steam engine or something

Unread postPosted: Fri Jan 23, 2009 12:51 am
Author: jackssmirkingrevenge
maggotman wrote:I'm dreaming of what I could do with this what do you think?
It is a bit heavy but I think it would make nice fully auto marble gun?


With a slapping of epoxy and a good enough spring you could certainly make it so, however the air consumption would be horrendous so you'd better have a massive compressor to go with it ;)

As POLAND_SPUD suggested there would be a bit of recoil forces involved but no more than a normal pistol calibre submachinegun so I don't think that would be an issue, on the contrary it adds to the coolness factor.

Basically, it's a Snapvalve without the resetting problem


Indeed, it's all in the tweaking ;)

Now turn up the pressure ( both sides) and up the ROF about 2x.


Unfortunately my compressor is stuck at 8 bar, unless I get as new one that's not going to happen. I pondered filling say a fire extinguisher to 250 psi from my SCUBA tank but it wouldn't last long, this thing dumps air like there was no tomorrow.

The logical progression for MOAR POWER! would be to up it to 3/4" calibre, hmmm...

Unread postPosted: Fri Jan 23, 2009 5:51 pm
Author: psycix
on the contrary it adds to the coolness factor.

Extreme recoil knocking you over, its awesome! (Rule of cool)

Unfortunately my compressor is stuck at 8 bar

Remember that I was talking about modding the thing? Well I did, and I will post it soon. :D
MOAR pressure!

Unread postPosted: Mon Jan 26, 2009 1:35 am
Author: jackssmirkingrevenge
Status update, I made some repairs to the blow forward unit used here and will give it a go tonight to get a rough idea of performance and we'll see from there, lets hope for a decent damage vid :)

Unread postPosted: Mon Jan 26, 2009 9:50 am
Author: sputnick
YAY! the plot thickens... :twisted:

Can not wait to see it go for real! :D

Unread postPosted: Mon Jan 26, 2009 12:20 pm
Author: jackssmirkingrevenge
You'll have to wait a bit longer I'm afraid. Single shots through the blow-forward valve were suffuicient to but a pellet through the bottom of a soup tin, so that standard's been met, but the improvised magazine I have on at the moment needs a majoy rethink in order to feed reliably, watch this space.

Unread postPosted: Mon Jan 26, 2009 12:23 pm
Author: sputnick
Well what's wrong with the magasine setup you have at the moment? I'm sure people would be willing to give improvement ideas, (even though you do appear to be the most ahead on this subject...)

Unread postPosted: Mon Jan 26, 2009 12:34 pm
Author: jackssmirkingrevenge
sputnick wrote:Well what's wrong with the magasine setup you have at the moment?


For starters, it's made of cardboard and tape :roll:

I just need to make one properly with adjustable width to accomodate different types of projectiles, plus a sprung detent to stop them rolling out when the barrel is pointing downwards.

Unread postPosted: Mon Jan 26, 2009 2:35 pm
Author: sputnick
Why does the mag itself need to have adjustable width, why not just make a larger magasine well, then use different kinds of magasines for different ammo, unless you plan to have different types of ammo in the same mag...

Unread postPosted: Mon Jan 26, 2009 2:54 pm
Author: MrCrowley
plus a sprung detent to stop them rolling out when the barrel is pointing downwards.

Couldn't you drill a small dent inside the barrel right below the mag? On spherical ammo it should keep them in place with the force of the spring acting on it.

Unread postPosted: Mon Jan 26, 2009 3:28 pm
Author: ALIHISGREAT
MrCrowley wrote:
plus a sprung detent to stop them rolling out when the barrel is pointing downwards.

Couldn't you drill a small dent inside the barrel right below the mag? On spherical ammo it should keep them in place with the force of the spring acting on it.


depending on the sharpness of the bolt, there is the potential for the bolt shopping into the ammo and damaging itself.

Unread postPosted: Mon Jan 26, 2009 7:38 pm
Author: jackssmirkingrevenge
I still have to evaluate what the power's like for 0.177 BBs.

For my ball valve strafer <--reading through this thread made me realise that this design has been a long time coming! prototype, technically a valveless design that was at maximum efficiency for a given pressure, I was getting a maximum of around 400 feet per second for steel BBs. If I can get a significant increase over that with this valve then I'll probably finish it in this calibre.

Simple economics really, lead pellets are more expensive and at these velocities, definitely not reusable, and it would simplify magazine construction to no end.

Edit: quite disappointing results for the 0.177 BBs, they were doing around 325-350 feet per second from a 40 inch barrel at 110 psi. Not that bad, but 0.22 pellets seem more worthwhile.

Unread postPosted: Wed Jan 28, 2009 10:05 am
Author: jackssmirkingrevenge
haha RESULT!

[youtube]http://www.youtube.com/watch?v=tZNwfj9Af7Y[/youtube]

This is with a very improvised leaking-all-over-the-place tee magazine using 22 pellets stacked vertically and doing away with the blow-forward bolt. Needs tweaking to ensure relaible fire, ie some sort of spring/weight and maybe an interrupting paddle, but I think this is the best solution. I'll start work on a proper version soon :)

Unread postPosted: Wed Jan 28, 2009 10:08 am
Author: sputnick
*drools* :shock:

nice, very, nice.

make a bigger magasine and give us a whole view of the gun in the next vid, because this is way to cool, I am in slight disbelief.