semi auto & hammer-less pcp, one concept???
watched getcfx vids about his semi auto, I cant stop my head toying to find the idea behind that semi auto airgun. thats definetely new! Ive seen semi auto gun from FX. But I think FX is gas operated and also still using hammer. So this one must be new! as the barrel itself has not been attached to execute gas operated system.
after thinking of some ways how it is done, a glimpse of memory take me back to several local gun Ive owned: the copies of Sharp Innova or Ace (originally Japan made)! those multipump airguns are popular here in Indonesia. Its clones have been produced by some local airgun company under tens of brand names. And those airguns has no hammer!
Before I get to my semi auto idea, let me explain about how hammer-less airgun works ( I think some of you never seen one!) 🙂
Hammerless airgun works by releasing ALL the compressed air contained in the compressing chamber by releasing the pin valve (pardon my english).
Let’s take a look at this:
To the bottom that is the compressing chamber, but still empty. I don’t draw the inlet valve. The grey one is the releasing pin (valve?). pairs of black dots are o-rings. And the dark blue one is spring. (and pardon me for I don’t draw the bolt that holds the pellet).
As the gun is pumped, the compressing chamber will be filled with compressed air. The releasing pin should pressed to move to the right, but the releasing pin can not move because it is stopped by that blue one (I don’t know what I should call that).
As the trigger is pressed, it moves that blue one upward (it has hole) and the releasing pin moves to the right and it releases ALL the compressed air in the chamber.
Chamber emptied, releasing pin moves back to the left due to the spring on it.
Now the idea to this semi auto & hammerless airgun is to build 2 chambers like that, that work alternately. When one is releasing the pressurized air (to push the pellet), the other one (main chamber) shouldn’t releasing air to the first one (lets call it propelling chamber) at the same time (which will cause the releasing pin of the propelling chamber never had the chance to closing). The releasing pin of the main chamber will be opened to deliver air to the propelling chamber only after the compressed air has been totally removed and the releasing pin of the propelling chamber is closed.
State 1: Both chamber have been filled with compressed air. At the same pressure.
State 2: halfway (or whatever) of the trigger, it will lock the RED PIN that will hold the releasing pin of the main chamber.
Trigger is fully pressed, releasing air from the proppelling chamber.
Propelling chamber emptied, releasing pin moves back to the left.
Trigger is halfway released. The blue pin on the right locking the releasing pin.
Trigger fully released. Blue pin on the bottom unlock the red pin.
Red pin move downward automatically due to the force of the releasing pin of the main chamber and opening the way of the air from the main chamber to be delivered to the propelling chamber.
Propelling chamber is full (balanced with the main chamber)
It makes the releasing pin of the main chamber move back to close.
Red pin move back upward, ready to lock the releasing pin of the main chamber.
And of course, if a regulator is added, the propelling chamber is regulated.
That’s all. I just want to share my opinion about how this semi auto airgun works. Unfortunately I am not a mechanical engineer nor a machinist. Further develelopment (with detailed drawing) will be more than appreciated. 😀
Uh and…. Correct me if Im wrong. 😀
PS: and of course designing magazine which works without bolt (and build it without leak) is another thing. 😀
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Is the K-1 from Mrodair http://www.mrodair.com/new_pics_k-1_semi_auto_pcp using the same technology? The k-1 is semi-auto hammerless.
Anyhoo, everyone’s probably moved on from this idea to somewhere far better and more advanced and I should probably be posting this somewhere else but I don’t know where so here it will be!
I had a play with Jwardana’s stuff today because I had a bit of spare time…
I GIFfed the valves he posted originally…don’t know if they will come out:
It’s a sharp Innova valve…
Jwardana’s work GIFfed…
My Play with Jwardana’s Ideas…
I thought that the mag could be indexed and the bolt pin cycled by a bit of gas blowback acting on a teflon piston inside the shroud. It would be a bit like the revolution or monsoon…sort of…but a lot less problematic as far as fouling/cleaning goes.
Some of the issues (among many other drawing faults) that I can see with my dodgy picture are:
1. Bolt, Magazine and ‘firing chamber priming valve’ (I made that name up coz that’s what it does) need to be mechanically linked so that the gun can be manually cocked/cycled/primed.
2. Don’t have a way to off-set the timing of the firing valve and the priming valve or activate it.
3. Bolt is missing some sort of locking mechanism.
4. Magazine indexers might probably need to be operated from cams on bolt mechanism and not from the gas piston push-rods…
5. Can’t think of a way to mount the mag properly…I show it being held in place by ball bearings and springs…would a sprung mag be better?
6. I don’t know if the priming valve actuator are thingy (trap?) will seal properly as I have it. (Maybe if it was formed from rod and had a valve seat seal under the skirt as well as the o-rings…?)
Things that may not be clear from the pictures:
1. I envisioned the priming valve as being an element which could be screwed into the chamber as a unit.
2. The baffle in the shroud is perforated…thus the squiggly lines.
3. The bolt lug spring isn’t supposed to do that…
I know that there is generally an issue with the bolts deforming the pellets if indexing is off on semi-auto actions so, this is the area that I could use the most assistance…that and everything else!
PB mechanisms were mentioned in this thread and I would like to ask if anyone had a mechanism in particular in mind?
The reason I am leaning on this idea is because Sharp Innova valves and firing mechanisms are very easy to come by where i live and re-purposing them for this project would be pretty handy. Minimum of parts, simplicity of function…isn’t that the stuff that air-gunner’s dreams are made of?
I’m going to get a hold of SW soon and start playing around with that so, if I’m barking up a pointless tree and this has all be done elsewhere and better, could someone please let me down gently and point me in the right direction?
Thanks in advance.
see below…
Just curious, but the daisy 2003 model, uses a rotary type mag that ejects one round that is fired by what looks like ram, is easily modified to full auto.
What if you used an aluminum ram to get the pellet in the chamber? I will be posting another series of question about this possible subject as I modded a 2003 into and ar15 airsoft rifle and put a longer rifle barrel on it, and using a bulk air adapter. I need to get home to take some pics of it and finish the “Art” work on it
another one with custom stock.
not a sharp, but its twins: cannon 737. so similar that the parts are exchangeable.
my old local sharps (bought in 95s and 2000s) are so worn out that I gave them to someone.
what is the fee for this scheme poluatomaticheskoy rifle? Approximately?
I mean the accuracy and reliability
Jwardana, that’s a very interesting concept!! 😮 As Buba said that gets our head round, currently working on two airguns. But that hammerless design makes me start thinking on a new one.
Could you please post some good pics of those Sharp rifles you described?
Also, as Buba said, a lots of folks are using PB designs, since their technology is far more advanced than AG technology. And remember that a good PB marker is a lot cheaper than a good regulated AG.
Congrats on this very interesting topic and explanations! Very elucidative!
Best regards,
Filipe
yes I think I should buy a used 1077. take it apart and see its mechanism. but unfortunately here, even a used 1077 will cost around USD150. 😕
Well thats something to get my head round 😀 Jwardana. At the moment Getcfx,s gun looks like it works along the lines of most paintball guns. The fact that hes made a compact rapid shooting gun with an indexing magazine is something else :shock:, but as you say Jwardana whether hes got a probe which seals is another thing. All you have to do is look at the Crosman Nightstalker which works without a probe by blowing through the mag , to see the problems with leaks and not seating the pellet correctly. You end up with a leaky , unaccurate and problem filled gun compared to most other PCP,s. So it will be intresting to see how Getcfx,s gun works fully before you trade in your Edguns 😕 .
Design is adapted from the gc2 by cardew!
Nice gun!
regards,
Marc
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There is a photo of new chinese semi-auto, “huben”:
And some other photos (at the end of the page, #8211): http://forum.guns.ru/forummessage/25/1578551-336.html
Does anybody hold it’s airun at hands? WHAT’S INSIDE!???