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by Xenophile
Wed Dec 30, 2020 1:44 pm
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Re: Ammo feeding for a QEV/popoff cannon

Thanks again, although I believe I've found a different solution. Crude magazine.jpg This is a crude magazine I've cobbled together with some brass pipe, compression springs, epoxy and heat shrink tubing. The capacity is about 50 .177 bbs. There's a large "L" shaped groove I cut to allow the followe...
by hectmarr
Wed Dec 30, 2020 2:05 pm
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Re: I got some questions.

You may be able to direct the air - mixture inlet towards the spark plug contacts. A little air with some speed might do the trick. My combustion chambers are no more than 10 cm3, and I have the gas inlet stuck to the spark plug contacts. Matter of testing.
by farcticox1
Thu Dec 31, 2020 7:05 am
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Re: about accuracy

It's 2020, would you expect anything different, wait until next year at least.
by Theonepbs
Tue Dec 29, 2020 11:40 pm
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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 jackssmirkingrevenge
Thu Dec 31, 2020 11:53 am
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Re: about accuracy

Here's to ending 2020 on good terms and hoping that 2021 will not get too much worse before it gets better, cheers!
by mrfoo
Thu Dec 31, 2020 12:26 pm
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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...
by hectmarr
Thu Dec 31, 2020 1:33 pm
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Re: I got some questions.

Butane when burned releases a residue of water and carbon dioxide, which is what you say, referring to the "internal factor 1". The second internal factor is the pressure drop with respect to atmospheric pressure, which condenses moisture, as Mrfoo says. There is at the same time, the normal humidit...
by jackssmirkingrevenge
Mon Mar 23, 2020 9:38 pm
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Re: Shock absorber spring rifle?

This outbreak really is bringing people back online :D a lot of force needed to compress it though It would probably look like a ratchet mechanism on an ancient ballista. Doubtless an interesting project but on this scale pneumatics are so much more practical in terms of using off-the-shelf materials.
by farcticox1
Thu Dec 31, 2020 5:41 pm
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Re: Ammo feeding for a QEV/popoff cannon

So it's firing one BB every shot ? I made a semi-auto airsoft with a bolt which blocks the ammo feed tube which works great, now that it's sorted :o
piston.jpg
by hectmarr
Fri Jan 01, 2021 9:32 am
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Re: about accuracy

The magnus effect, joins in airsoft to oppose the normal parabola made by the plastic ball. We are using a "defect" to compensate for another "defect" to the contrary. If the effecyo magnus cannot be used in contrast, the ball will definitely go off target. I shoot 1/4 "steel bb's with a smooth bore...
by Moonbogg
Wed Mar 11, 2020 11:02 am
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Re: JSR's workshop chronicles

JSR, could it be an option to apply an abrasive polishing paste between the rough parts and work them back and forth, allowing them to polish themselves in a natural way? Just a thought. I'm sick with jealousy by the way. SICK! Not coronavirus sick, but still quit green with machine envy :mrgreen:
by hectmarr
Fri Jan 01, 2021 12:27 pm
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Re: about accuracy

It is logical what it says. A 1/4 "steel pellet weighs almost exactly 1 gram. The mass of the ammunition should influence its rotational speed as it exits the barrel intentionally or unintentionally. The heavier, the more resistance to rotating at high speed. Unfortunately, I only have steel bb's th...
by hectmarr
Fri Jan 01, 2021 8:59 pm
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Re: I'm back!

válvula de sello con oring.png
This is the drawing of what I built.
by hectmarr
Sun Jan 03, 2021 2:55 pm
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Re: I'm back!

A photograph of how it was. I am building a mechanism so that it closes automatically. The small piston with two o'rings and the hole in the center is for decompressing. It is fiberglass because it only supports 6 or 7X pressure. The hard part is the one that seals the chamber. I leave here in this ...
by hectmarr
Mon Jan 04, 2021 7:57 pm
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Re: Hybrid repeat system

:) Seriously speaking, thank you. There is really no weapon that makes holes at the moment, but I am going to put all this together and another weapon will be born to play a bit. I already had this design of dispenser, but the present work was to adapt it to any piston valve with pilot, in this case...