SpudFiles

@ psycix it might be easier to use a QEV + solenoid spool valve combo for ease of adjusting ROF and improving performance as well as reducing loss of air (but that would require electronics)..

anyway... as I said earlier getting it to fire real ammo with good performance is the biggest challenge here.. what you did so far was just joining several fittings toghether... implementing a blowforward bolt is going to be a PITA.. I wish you well but I've been there.... and seriously that was a traumatic experience...

you might have better luck with machined parts but.... uhmm you know

POLAND_SPUD wrote:@ psycix it might be easier to use a QEV + solenoid spool valve combo for ease of adjusting ROF and improving performance as well as reducing loss of air (but that would require electronics)..

see what I meant

Guess it would dfinately be parroting to say "Awesome..."

Just wondered, what size QEV is on the big version?
(Maybe I missed it)
I've been avoiding the pop-off pilot because I'm thinking of a large bore myself.

Any Idea what you will build the BFB from?
I suppose a reducer bushing with larger iron/steel pipe (Brass nipple pipe is prob. better) for the bolt housing, and maybe a coupling on the bolt housing.
The mag could be a "T" for round shot.

Not too complicated, but it's cool you have the attention of the "Masters" to consult here.

BTW, cool Dutch accent and vid, you could go to L.A. or even Hollywood probably and get some hot mamas some day!!! 8)

Damn..I should go too then...


Large QEV is 1/2" ....

THUNDERLORD wrote:I've been avoiding the pop-off pilot because I'm thinking of a large bore myself.

I'm sure a 1/4" pop-off valve could pilot a 2 inch piston if you stick to d/4 rules.

THUNDERLORD wrote:Just wondered, what size QEV is on the big version?
(Maybe I missed it)
I've been avoiding the pop-off pilot because I'm thinking of a large bore myself.

Thats this gun.

THUNDERLORD wrote:Any Idea what you will build the BFB from?
I suppose a reducer bushing with larger iron/steel pipe (Brass nipple pipe is prob. better) for the bolt housing, and maybe a coupling on the bolt housing.
The mag could be a "T" for round shot.

Too much trouble. I am going to machine it out of a shiny block of aluminium. With threaded connections and no need for epoxy AT ALL.

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I am going to try to full-auto the larger gun tomorrow. Ohh man that will be loud. I wonder how many shots it will get out of the FE, and just as interesting: how fast...

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Spool valve? No way!

hey mind If I use this design to create an airsoft version?

Davidvaini wrote:hey mind If I use this design to create an airsoft version?

Methinks a qev may be a little overkill for airsoft. But of course this is davidvaini. Now maybe .5g with hpa but that may be a tad over a fields limits.


Actually that would be funny, take that beast to a field and try to get into a game with it. Insist that there chrono is broken and your gun is actually only shooting mach 2. Then maybe volunteer to show how weak it is by putting an airsoft bb through a 2x4.

jonnyboy wrote:

Davidvaini wrote:hey mind If I use this design to create an airsoft version?

Methinks a qev may be a little overkill for airsoft. But of course this is davidvaini. Now maybe .5g with hpa but that may be a tad over a fields limits.


Actually that would be funny, take that beast to a field and try to get into a game with it. Insist that there chrono is broken and your gun is actually only shooting mach 2. Then maybe volunteer to show how weak it is by putting an airsoft bb through a 2x4.

haha eh, Ill just run lower pressures if I have to. Even if its not skirmishable Id still want to make one.

I already did a quick sketch including feeding mech, fuel source and magazines.

Davidvaini wrote:I already did a quick sketch including feeding mech, fuel source and magazines.

I would think if you too your idea here and hooked it up to a QEV-popoff setup you'd get a very powerful launcher, perhaps something that could simulate an emplaced heavy machinegun in airsoft combat, used for long range only.

jackssmirkingrevenge wrote:

Davidvaini wrote:I already did a quick sketch including feeding mech, fuel source and magazines.

I would think if you too your idea here and hooked it up to a QEV-popoff setup you'd get a very powerful launcher, perhaps something that could simulate an emplaced heavy machinegun in airsoft combat, used for long range only.

that was the idea

@jsr&david
damn it!!

I was thinking about the same thing on my way to work

EDIT
What is the pressure rating of hopups ?

I was about to ask if they are ones made from metal... well it seems there are.. if it's that part -> http://www.ceneo.pl/showPicture.aspx?productID=1213989

POLAND_SPUD wrote:What is the pressure rating of hopups?

I reckon you could put at least 300 psi through one without having it blow up, it's only for a brief amount of time and it's not really a sealed system anyway.

Davidvaini wrote:hey mind If I use this design to create an airsoft version?

I'd love it! Go ahead.
By the way, the popoff design was not my idea. Is an old concept. I just was the one giving it a shot.

Today I will hopefully be finish designing the blow forward (ffs stuf is so small!)
And if I'm lucky I can actually machine stuff tomorrow! Then I just need to go by BTB to get stuff threaded. I couldn't find any reasonably priced tap sets yet.

Great work, That is excellent, what a beautiful sound.

Looks like a larger version of this system will have to be my next project Time to start working on a very strong blow forward breech. Has anybody experimented using a piston valve with pop-off before, i'm guessing you would have a much reduced ROF.

subsonic