Deathray Marble Machine Gun

[Brian the brain]

Here is a preview to my current project.
I finally obtained a QEV and was eagre (sp??) to try out the QEV-safety pop-off principle to achieve full auto in a marble gun.

Boy does that work!!
I currently use a small chamber, because I still have to get a CO2 refill and now pump up the bottle with my trackpump to test the principle.Therefore I need to reduce gas consumption to the minimum for now.As it is, I can only fill the bottle to give me 5 full auto shots at the required 11 bar.I like the fact it doesn't give weak shots as the tank empties.It just stops.Very clean..BANG-BANG-BANG-BANG-BANG.Then silence..I love it!!

I have been tinkering with the pop-off to achieve higher pressures than it's set 11 bar, so far I can only get it to go up to 13 bar.I'll work on it some more coming week.I want 16 bar minimum, rather 20 if possible.


The bolt is a "regular" blow forward bolt with some additions.
I'll explain that with some pictures.
The bolt ensures a no more than one marble can ( ever) be loaded at a time and it prevents the marble from rolling out.It works 100%.
When the bolt is moved forward the marble is released.

I didn't want to use a paddle and I also dislike the idea of "blocking" marbles with an O-ring or a smere of silicone or whatnot.
All of those use friction and friction means wear and redoing.

[SpudUke5]

Sounds interesting, destructive, and creative (messy minds tend to be creative )

Well, at least you have a general workshop. I just use my garage and i dont have too many tools. But i have all that is needed to make a cannon. Well i am curious to see a video.

EDIT: Wow BBMGs with semi auto and full auto are really popular on the website recently. (random Smily)

[mopherman]

wow, looks great. I'm afraid I dont get how the marbles can slip past the bolt though... what did you put on the pressure washer handle? bondo?
BTW, Is that the Ye olde' pirate pistol under the overkill in the last pic?

[Brian the brain]

THe top hole in the blow forward bolt provides just enough space for the marble to...well..be.. as the bolt travels forward.Without that entry hole in the top the marble would be unable to pass the blocker.
THe pirate pistol has been sent to Davy Jones locker I'm afraid...
What you see is nothing more than a random piece of left over pipe and fittings..

Oh and yes, I believe that is what you guys call bondo.
Body filler if you will.

Yeah, I'm glad to see some things happening again.Idea's like these can spawn other idea's in other people and the ball starts to roll as we Dutch say.
I learned tonight that an old random idea of mine has resulted in the birth of piston hybrids...Although I can't really take credit for it because I never even tried it myself.

Anyway.I'm glad with what I have achieved so far.I'll tinker with it some more and clean up the look..I just love that clean sound..
I invite anyone that has a QEV and a pop-off to try this.It's really cool
( oh and the qev-pop-off thing was NOT my idea!!)

[rna_duelers]

I love the break open barrel,and the black goes well with it.Any chance of some damage pictures/videos?

[jackssmirkingrevenge]

glad you're getting better results than I am, looking forward to seeing this in action

[Brian the brain]

When I get around to it.I'm always more interested in getting it to work, building, designing etc than I am in the actual shooting it part...

[POLAND_SPUD]

I am impressed... can't wait to see some dammage pics/videos....
or at least more schematics & blueprints

[jackssmirkingrevenge]

When I get around to it.I'm always more interested in getting it to work, building, designing etc than I am in the actual shooting it part...

Clearly you don't work with epoxy

I do enjoy building, but the proof of the pudding is in the eating, so it's great to see your efforts come to life.

Very ingenious bolt design by the way, I like

[Brian the brain]

Proof of the spudding is in the beating indeed.
I'll beat some stuff up with it when I think it's ready for it.

I can only record soundless vids..and I forgot how to post them..( only tried that once..)

I would like to know how to make those animations some guys use...
that way I could make a nice bolt animation wich would be easier to understand..

[MrCrowley]

I would like to know how to make those animations some guys use...
that way I could make a nice bolt animation wich would be easier to understand..

I use Macromedia Flash MX, you probably can download a trial and *cough* crack it *cough*

[SpudUke5]

Actually instead of *cough*cracking*cough, sneeze, fart, burp*( ), you can download a version of it with a crack and just follow the instructions.

PM me is help needed

[Fnord]

I can only record soundless vids..and I forgot how to post them..( only tried that once..)

Well, most people just make a youtube account and upload videos there.

I can't wait to see a video of this thing. Once it's painted you should add a detachable laser sight (it would just be wrong not to add one on such a gun:).

w00t.

[Brian the brain]

The two laser sights I have now are from airsoft guns...not very sturdy or accurate.

[Brian the brain]

Still working on it.I managed to mod a safety pop-off.I tapped the hole that is normally kept shut by the piston thingy, and screwed in a 1/8 fitting.
THe goal was to make a smaller surface area for the pressure to work on.( I reduced the hole size so to say).
THis makes higher pressures possible.I'm aiming for 16-23 bar..somewhere along those lines..


I reconfigured the gun to be more bullpup like, so without chopping the barrel, the gun is now much shorter.I used brackets to hold the barrel to the blowgun.glue kept coming loose wich in hindsight is a god thing because I would not have been able to change it.
..and I found out that socks make excellent cheap-o bottle covers.
I redid the chamber and found a better way of connecting it.It is now tucked away nicely.
THe temporary marble hopper will be replaced by a proper sports-drink bottle.I painted some parts before I changed all of this so it still looks unfinished