QEV+popoff experiment - update: NOW WITH AMMO!

[psycix]

At first I wanted to make a BFWB, but when struggling with the design, jack simply fed stuff through a T... so then I thought "what the heck" and tried it.
I may skip the BFWB for BB's and build one for marbles...

[jackssmirkingrevenge]

haha, finally! Shame about the poor feeding though, I'm sure you could stock with a simple tee and improve reliability.

[SubsonicSpud]

That is impressive

what pressure is the pop off triggering?

I was mucking around with a hopper feed as well but it was too much of a pain to work with, I think a hopper is really only effective with a blow forward bolt. Try it with a tube mag, you will get much better loading.

By the way, you are crazy shooting inside the house lol, must be high on energy drinks or something

SubsonicSpud

[psycix]

what pressure is the pop off triggering?

Just at ~8,1 bar.

A tube mag doesnt hold enough BB's.

By the way, you are crazy shooting inside the house lol, must be high on energy drinks or something

Haha, I don't drink that much energydrinks. I (and my brother) just saved em up for months. Gotta start refilling the empty can supply now...
Shooting inside the house? Well, with this size of ammo and power I figured it is not that much of a problem. There are worse things.
Ever dry-fired a full size combustion in your bedroom? Or smacked an AA battery against the wall, propelled by 30 bar flowing through an 1/2" QEV? Oops.

[Brian the brain]

Naughty boy!

It's just getting better and better.I'm sure you'll find a way to prevent jamming...

Impressive video, again..!

[POLAND_SPUD]

There are worse things

marbles are much worse... they have a tendency to bounce when hitting a hard target... trust me my shooting range is placed parallel to a greenhouse (the one seen in my vids)...

what about switching to marbles ??

[SubsonicSpud]

A tube mag doesnt hold enough BB's.

You can have a 30round mag less than a foot long, you can also keep track of the number of rounds you have fired too. I am just in the process of making a quick change design for my mag tubes so they just clip into the top of the Tee, and unclip by pressing down a latch. 8)

SubsonicSpud

[jackssmirkingrevenge]

marbles are much worse... they have a tendency to bounce when hitting a hard target...

Not if you fire them fast enough

You can have a 30round mag less than a foot long, you can also keep track of the number of rounds you have fired too. I am just in the process of making a quick change design for my mag tubes so they just clip into the top of the Tee, and unclip by pressing down a latch.

This is what I had in mind, 30-50 rounds mags. Unless you're playing with beta-c mags this is a very typical smg/assault rifle loading.

[psycix]

30 is not enough.
Heck, I can get 700 shots out of the tnak!
If I wanted a tube mag for 700 shots it needs to be 4,20m long...

Oh and I fixed the jam, it feeds just too good now, way too good. It double or triplefeeds every shot... quadruples or even more are not uncommon.
Damn thing.

I'm going to machine a marble BFWB within two weeks!

[jackssmirkingrevenge]

Well, the tnak makes it more suited to a fixed machinegun type launcher, say you had a 1 metre long barrel on it, and a tube magazine parallel to the barrel, that's over 200 BBs - then again doing the same for marbles would give you much less shots.

Have a look at clide's GB semi for inspiration as far as larger blowforward bolts are concerned

[SPG]

You could always coil your tube mag into a spiral to take advantage of your tnak's capacity. I should think you could get enough ammo in a spiral coil mounted on top of your gun, and you could always put the coil inside a tube to give a more hopper-like look. The plastic tube used for brake line linkages on articulated lorries would be pretty good, if it had the right ID.

[psycix]

marbles are much worse... they have a tendency to bounce when hitting a hard target...

Not if you fire them fast enough

True, its safer to shoot at hard targets.
When I shot marbles at particle board with probably 210 m/s or more, they went a few cm in, and bounced back!
One hit me on my cheek and deflected. Didnt hurt that much but I surely felt it and scared me a little.
However, when I shoot the marbles at a steel plate, they simply obliterate and the remaining dust falls down to the ground.


-----Fiddling report!-----

Oh and I fixed the jam, it feeds just too good now, way too good. It double or triplefeeds every shot... quadruples or even more are not uncommon.
Damn thing.

Well I've been fiddling with the feed and here are more details about it. I made a leak in the back of the mag and I changed the inside of the T, made more room for them so no more jamming there. (see attachment)
To have a leak in the top, I replaced the cap for a quick connect with a QD in it. This gives a restricted hole where air can leak out a bit. With that air, the bb's are shaken up and feed better.

Well as I said, this made it feed so damn good that it double feeds almost every shot.
When I used the other popoff (which is a little bit more powerful) this was solved. This small amount of pressure extra seemed to be the thing to push the second BB back up the mag instead of feeding it.
Lots of damage pics from that here!

BTW
I have a vid of killing the pictured cans with a lot of doublefeed. Want me to upload?

[jackssmirkingrevenge]

I have a vid of killing the pictured cans with a lot of doublefeed. Want me to upload?

Is there even any need to ask?

[psycix]

Its not that great. And I will have to do a lot of cutting since its over 10 minutes of video material with 90% of it being nothing (fixing the jams, cursing)
Ill record some more stuff and then include it in one video.

[SPG]

You can include some of the cursing though, that always makes me laugh.