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Controlling ROF in a BB SMG without a hammer/bolt (v2)

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Controlling ROF in a BB SMG without a hammer/bolt (v2)

Unread postAuthor: Hurricane Air Arms » Sat Jun 16, 2018 9:06 pm

Hey guys, back again, and before you know it I'm saving for a wedding ring. Honestly I feel like it was only a few months ago I signed up and started checking this site out often.

I'm back to present an idea and possible beacon of hope for my BBMG comrades.

Basically, the simple solution to this age old issue is a pivot-delay with a cam. IMHO.

BB's enter the barrel and push the very weak pivot up and out of the way, as the BB overrides the pivot, the back end (or some other delay pin) will drop down just in front of the next BB and just behind the fired round, far enough and for long enough to seperate the two rounds. Thus initiating delay. Reminding me of the plunger in a VZ .61

The outcome as we all know is better accuracy, power per shot, and a more consistent fire rate. (by how much will depend on various things of course).

This particular gif desgin incoperates a sealed piston magazine that draws the ammo up using the exit flow of air. And so far the tests I've conducted with this system have proven promising. granted the piston doesn't fall back down... which it shouldn't if the magazine is sealed. - Of course, the magazine is sealed because if it isn't air will escape elsewhere rendering the mechanism and air gun close to useless.

Everything in this design was made for simplicity, relaibility and to be fool-proof. The hardest part? making and sealing the pivot. of course.

Thoughts?
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Re: Controlling ROF in a BB SMG without a hammer/bolt (v2)

Unread postAuthor: jackssmirkingrevenge » Sun Jun 17, 2018 4:54 am

Everything in this design was made for simplicity, relaibility and to be fool-proof. The hardest part? making and sealing the pivot. of course.


That's not really a problem, there are easier ways of doing it:

Image

The ultimate airtight manner would be to use a compressed o-ring as a detent:

Image

The issue is a functional one, because the second BB dents to stick in the breech before the first one leaves the barrel. This happened with this prototype for example.

I managed to make it work with airsoft BBs, I would theorize that being lightweight they accelerate out of the barrel quickly before the second BB can stick in the breech.

Here is some discussion (and some previous talk here of possible alternatives, I never really pursued them but my experiments were promising.
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Last edited by jrrdw on Sun Jun 17, 2018 5:53 am, edited 1 time in total.
Reason: Fixes quote tag.
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Re: Controlling ROF in a BB SMG without a hammer/bolt (v2)

Unread postAuthor: jimmy101 » Sun Jun 17, 2018 3:14 pm

The problem with Huricane's design is that the next BB inhibits air flow needed to for the previous bb. I think you want the cam to keep the next bb in magazine, instead of the barrel until, the first bb has cleared the barrel.
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Re: Controlling ROF in a BB SMG without a hammer/bolt (v2)

Unread postAuthor: farcticox1 » Sun Jun 17, 2018 3:58 pm

So put the release mechanism in the ammo tube and not the barrel? It would consume more air maybe :o
Like a toothed wheel :idea:

P1040327.jpg
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Re: Controlling ROF in a BB SMG without a hammer/bolt (v2)

Unread postAuthor: jackssmirkingrevenge » Wed Jun 20, 2018 3:58 am

jimmy101 wrote:The problem with Huricane's design is that the next BB inhibits air flow needed to for the previous bb.


Also in my experience, the magazine tube will also become a "barrel", slamming the stack of projectiles down at every shot, so you want some kind of anti-return latch stopping the flow of projectiles in the opposite direction to the feed.
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hectmarr wrote:You have to make many weapons, because this field is long and short life
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