SpudFiles

Gun Freak wrote:But there is another issue... a new bb is being sealed in the detent too quickly after the bb before it shoots, so I'll pull the trigger, there is a slight delay, then a rapid fire of bbs... how can I fix this? I know one solution is lowering the amount of air going in, but is there anything else?

Sadly the classic issue with detent mechanisms in BBMGs. Some sort of reciprocating mechanism would still seem to be the only reliable solution, like the airsoft bullet valve as suggested here:



Another possible option is a large diameter low friction piston which blocks off access to the breech whenever there is any pressure in the BB chamber, conceptually something like this, shown at rest (top) and before firing (bottom):

O.M.G.!!
jsr and air cylinders!! we're doomed

No, it's not what you think! I can explain!

...there is no turning back from a dark path

ohh... before you ask - yes, you can be my apprentice
know the power of the dark side!!

I actually designed a cool semi auto concept today, I'll go MS paint it...

Edit ok here it is... air in through left, pushes airtight piston to the right until it passes over the hole in the bottom, then the air goes down the blue tube to the detent unit. The rod loads a round into the detent unit when it is pushed forward. The piston has a spring on the right so when the bb pops, you let go of the blowgun trigger and the spring returns the piston to the left and a new bb falls in front of the bolt. Thoughts?

POLAND_SPUD wrote:...there is no turning back from a dark path

ohh... before you ask - yes, you can be my apprentice
know the power of the dark side!!

Don't count on building your own dark army just yet, I'm in hybrid mode at the moment

Gun Freak wrote:air in through left, pushes airtight piston to the right until it passes over the hole in the bottom, then the air goes down the blue tube to the detent unit. The rod loads a round into the detent unit when it is pushed forward. The piston has a spring on the right so when the bb pops, you let go of the blowgun trigger and the spring returns the piston to the left and a new bb falls in front of the bolt. Thoughts?

I so agree with you that I came up with essentially the same thing



And damn, no wonder the above air piston idea drawn up in the previous post was familiar:

I so agree with you that I came up with essentially the same thing

And damn, no wonder the above air piston idea drawn up in the previous post was familiar:

lol, you came up??

Acctually I suggested it a year ago or so but then you said something along the lines of

'HERESY!!'

POLAND_SPUD wrote:Actually I suggested it a year ago or so but then you said something along the lines of

'HERESY!!'

lol I looked up "heresy" and "blasphemy" but didn't find any related posts.

It sounds like the sort of thing I would say though, so I'll give you the benefit of the doubt

Yeah, same here... I couldn't find it

damn... searching 'POLAND_SPUD' + 'air cylinders' gives waaaay too many results

ohhh make sure you seal the rod - if air can pass from the chamber to the other side of the piston it won't work

Damn Jack you just beat everyone
I came up with a better design today anyways. Plus mine is was easier to build than the one you posted, although they are similar in how they work. It is essentially the same thing posted before except the air doesn't go through a separate tube to the detent, just around the piston once it passes a certain point in the cylinder. Not worth drawing up, I presume you get the gist of what I'm saying.

Edit, haha, I sketched it anyways Once the piston passes the notches in the pipe, the air can go around the seal and to the breech.

Assuming there's a return spring in there somewhere, looks like it would work

im not ecactly sure how you want that to work but wont it do what my failed blow forward bolt did?

ilovefire wrote:im not exactly sure how you want that to work but wont it do what my failed blow forward bolt did?

It will cycle like mad or not at all with constant flow, but for semi auto with pulse air it should be perfect.

Also, I realised that I had posted yet another blow forward + detent design in your thread!.



Clearly it's been floating around in my head long enough to build it, maybe I'll start on a prototype while the hybrid cartridge stuff cures

An easy way to accomplish this with standard parts is to have a 3-way DCV feeding into an air cylinder acting as the chamber volume. When you actuate the 3-way, it "pilots" your chamber volume into the space behind the detent, eventually popping the BB out. You'd probably have to toy around with input pressure and chamber volume in relation to popping pressure, but that'd be easy with threaded fittings, and once you get it it would probably work flawlessly...probably

Technically speaking a detent is a valve... an air/pressure actuated 2 way valve

since you can emulate a 3 way valve with two 2 way valves you don't need a 3 way DCV