Search found 273 matches

Return

by jackssmirkingrevenge
Mon Nov 30, 2020 8:16 pm
Jump to forum
Jump to topic

Re: HA-VI

Ah good, he's still alive! :)

Interesting observations. I always figured that in hybrids, since the mixture is pressurized the homogeneity is achieved without the need for further mixing. Have you tried filling from the reservoir and leaving it for a few minutes to see if it makes a difference?
by SloppyJoeES
Wed Dec 16, 2020 7:00 pm
Jump to forum
Jump to topic

My first working pengun- ammo questions...

I have finally completed a simple coaxial pengun, yet another copy of a copy of JSR's design from so long ago. I'm very happy with it! 20201216_154331_HDR.jpg The build is made up of two 1/8" brass pipe nipples coupled together, with an OD 7mm ID 6mm stainless tube epoxied inside. Inside of that tub...
by PracticallySane
Sun Dec 13, 2020 3:01 pm
Jump to forum
Jump to topic

I got some questions.

So I've put something together, its a hybrid clone of my phenumatic rifle. Right now they share a barrel but it will get its own dedicated when complete. For the time being I have had a few successful test shots at 10x using the chart from the forum. They are hard to repeat. But I have had some succ...
by SloppyJoeES
Fri Dec 18, 2020 7:37 pm
Jump to forum
Jump to topic

Re: My first working pengun- ammo questions...

20201218_163008.jpg
I shot a tin can with a nail using the pen gun @ 1000psi. I was quite happy with the results...

When I shot it, I saw orange sparks fly out, and it smelt like smoke... Is that normal?? Lol.

Entry:
20201218_162936.jpg
Exit:
20201218_162943.jpg
by jackssmirkingrevenge
Tue Dec 22, 2020 5:37 pm
Jump to forum
Jump to topic

Re: JSR's workshop chronicles

Actually gave it a go and pretty happy with the result.

Image
by PracticallySane
Sun Dec 20, 2020 1:25 pm
Jump to forum
Jump to topic

Re: I got some questions.

So you guys were on the money. I was lean for sure. I think higher mixes helps aswell. I have been successful up to 30x with roughly 20psi propane 420psi air. Now it seems to be on par with the phenumatic counterpart. I do intend on mounting it on a stock or something of the sort. Like a bulpup conf...
by SloppyJoeES
Wed Dec 23, 2020 12:13 am
Jump to forum
Jump to topic

Re: My first working pengun- ammo questions...

:D Okay I have all my new components! Unfortunately though, since my piston's seal has already worn out, I cannot shoot the new ammo quite yet. For the new seal, I am using 1/16" Ultra Strength Neoprene from McMaster, which I think will last much longer than the old seal, which was simple Natural Ru...
by PracticallySane
Sat Dec 26, 2020 12:39 pm
Jump to forum
Jump to topic

Re: I'm back!

The "t" fitting that I use is a "street t" so it has one set of male pipe thread. The front of the piston sits inside the male threaded portion of the fitting. The back of the t has a 3/4-1" male to male reducer. The back of the piston sits in the 1" portion of the reducer. With out the reducer the ...
by PracticallySane
Sun Dec 27, 2020 10:27 am
Jump to forum
Jump to topic

Re: I'm back!

Does this make any sense? Art is not a talent I have...
by PracticallySane
Sun Dec 27, 2020 10:42 am
Jump to forum
Jump to topic

Re: I'm back!

Also it is a barrel sealing piston. The "face" sits inside the barrel instead of pressing up against it. The rear oring is a "floating oring" so air passes one way to fill the chamber. It cannot flow in reverse.
by Moonbogg
Wed Dec 30, 2020 3:16 am
Jump to forum
Jump to topic

Re: stainless steel tube burst pressure

If I had the money, I'd make 3 of every cannon I have and test two to failure under different conditions. That way I'd really know the safety factor in a practical way and discover the weak spots and failure mode. Unfortunately, you could buy a nice car for what all that would cost, so it is what it...
by PracticallySane
Wed Dec 30, 2020 8:36 am
Jump to forum
Jump to topic

Re: stainless steel tube burst pressure

I dont know if you can make it out properly but this is a picture I have on hand.

The pipe is stainless, I am not sure what alloy...

Works fine for me. I have been up to 3500 so far. I did not do a hydrostatic test.
by Theonepbs
Tue Dec 29, 2020 11:40 pm
Jump to forum
Jump to topic

3D printing?

7A310B0F-7133-45BD-850D-6A43AFB70666.jpeg Hello all I appear new to the forums, but I’m really not! I have been on here since dial up internet, and the spud tech site forums. Anyhow I stop in now and again to see what’s new here, and what badass things you creators have made! With that being said, ...
by farcticox1
Thu Dec 31, 2020 12:35 pm
Jump to forum
Jump to topic

Re: "In the world of spuds today"

Got a new toolbox for Xmas :o
20201228_143144.jpg
by mrfoo
Thu Dec 31, 2020 12:26 pm
Jump to forum
Jump to topic

Re: I got some questions.

To a certain extent, you'll always be pumping water in, unless you live somewhere with absolutely 0% humidity. You're also adding water vapour through combustion, as you note. After combustion, the pressure in your chamber goes to its maximum, and then reduces as the projectile (if any) is pushed do...