SpudFiles

It'll be interesting to see what you get out of the schrader..Keep in mind that more pressure will increase the cracking pressure, but increase the amount of blowback and power you get..so some experimenting should find you a "sweet spot".

Good luck

Well here it is, farting away

[youtube][/youtube]

This is attached to my track pump using on the air in the pump as the "chamber", going from 160 psi to 0 psi...

[youtube][/youtube]

... while this is at 110 psi hooked up to my compressor.

Methinks a heavier bolt is in order to bring that rate of fire down.

Baha! That sounds so pathetic...

You might want to mod the schrader a bit, after the energy used to recock the bolt there wont be much left for propelling the projectile.

Good job on getting it to cycle so fast..lets see if it shoots!

Attach some wings and you will have a hummingbird .

Or you replace the bolt with a needle and tattoo yourself.
:headbang:

Otherwise great work.

now I know why you always talk about flatulence and stuff

I can't wait to see it shooting though

Good job on getting it to cycle so fast..lets see if it shoots!

No question of shooting anything for now.

Note that this is all done at relatively low pressure, at higher pressures power should go up and rate of fire should go down. The high cycling rate is definitely not a good thing, but with more pressure the hammer should be thrown back more and therefore it will shoot slower.

Currently making an adapter to hook it up to a 12 gram, let's see how that goes

I made somthing long ago that used a shrader and had that same effect the bolt was 1/2'' in diameter. I forgot to mention this in my previous post, My bad. I would run it at 160 psi and off of a I think 325ml tank I got about 30 seconds of buuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuur Are you going to use this like btb's machinegun? Glad to see it works, sorry I have no pictures.

Have you given any thought to increasing the hammer mass? It'll increase dwell time (improves power) and reduce the cyclic rate.

But, you knew that already, didn't you?

Erm, Gippeto:

jackssmirkingrevenge wrote:Methinks a heavier bolt is in order to bring that rate of fire down.

By the way, by cycling fast I meant good job on getting it working quickly, not the actual speed that it cycled at.. Keep in mind you should expect fast cycles as your basically replacing the crank on a co2 motor with a spring and exhausting it early..

It'll be interesting to see what you can get this into.

I mentioned a heavier bolt in the video post ;p already did it by the way, added several grams of lead and it made a significant difference. I'm hoping though that higher pressure will make the real difference in reducing cycling rate. I can already tell from testing at 160 psi that as the "chamber" pressure goes down, the rate of fire increases.

In the meantime, I've been experimenting with single shots using 3mm BBs at 400 psi in the pen gun v2, very impressive, will go clean through a soup tin easily.

Here's the adapter I made for the hammer valve (using the back end of the original pen gun), tomorrow I'll hook it up first to a 400 psi air chamber and if that goes well, I'll try a 12 gram using a CO₂ tyre filler.

My bad.

Note to self;

Always.. :banghead: read.. :banghead: the.. :banghead: whole.. :banghead: thread. :banghead:

The farting machine works! Cool, this thing r0xx0rz mai b0xx0rz n mai s0xx0rz!
Do you think there is any "air power" left besides having it cycle?

Keep adding more and more weight, and make a vid of that too
In the end, daka-daka-daka is more useful then braaaaap!

Be careful with the 12 gram and the 400 psi. It would be crap to blow the thing up. Do you figure that it will hold it? Or will you simply assume it?

I'm not using it to launch tennis balls.

You.. aren't...?

Be careful with the 12 gram and the 400 psi. It would be crap to blow the thing up. Do you figure that it will hold it? Or will you simply assume it?

If you're hoping for a repeat of the epic marker gun fail I fear you'll be disappointed this is exactly the same construction technique and materials as my pen guns so no worries - other than the bolt head slamming into the valve repeatedly and destroying it, but I've added an airsoft BB as a bolt head to give a gentler impact.

Do you think there is any "air power" left besides having it cycle?

There's quite a breeze coming out of the exit port at 100 psi, I'm guessing it will be good enough at 400 psi+ I'm also considering a floating o-ring on the bolt as you can feel the air blow past it and it seems a shame to have it wasted.

You.. aren't...?

Balls no bigger than 3mm, I'm not compensating for anything

The one thing I really see you having a problem with is getting it to stop (and then start back up when you want it to)
You may have to make some sort of shear that connects to your little needle extension thingy.

Lentamentalisk wrote:The one thing I really see you having a problem with is getting it to stop (and then start back up when you want it to)
You may have to make some sort of shear that connects to your little needle extension thingy.

I had outlined a rough mechanism here, if I get it to function well at high pressure I'll first add a barrel to evaluate power, then add a reloading mechanism for the ammunition and eventually a sear/bolt handle and trigger.