Interesting AEG piston head design

[Zarrin]

Just spotted this on an AE store... never used or even seen this design:

https://www.aliexpress.com/item/33013397872.html?spm=a2g0o.productlist.0.0.144a2ed0WFsRXw&algo_pvid=498973c2-0ba6-4be5-9ce1-b0bb2d4eb115&algo_expid=498973c2-0ba6-4be5-9ce1-b0bb2d4eb115-8&btsid=0b0a0ae215824847451447153e2254&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_

 

Very curious about the potential such a design might have, my first instinct would be to say there would be a higher chance of catastrophic failure due to alignment being way more sensitive than with a traditional setup.

But if it does work perfectly, what kind of performance boost or difference would it make. Possibly higher compression at the nozzle end onto the BB resulting in slightly higher fps from a more concentrated blast of air and maybe better shot to shot consistency.

 

What do the fellow techs out there think?

 

The set is fairly well priced so I may pick one up and test it out vs a more standard setup.

 

[ImTriggerHappy]

Nothing about that design makes sense.

 

Sticking that pin on the piston head will do nothing as all you want is the head to push air down the cylinder nozzle and sticking anything in the way especially a pin with an o-ring to create a pointless seal will add nothing and could potentially could cause issues.

 

Can't see the reasoning at all.

[heroshark]

similar to an air break type spring sniper piston head.

 

[Sitting Duck]

Looks like airsoft piston porn to me

 

as been said similar to bolt braked piston head

but way too long - way way too long imho

 

it would plug & brake the piston with say a couple of teeth, even 3 or more teeth to go

working on piston face is say 23mm the dick sticking out is say 13~15mm long

(is it a bit longer in black colour ???)

 

seriously, working on say 12mm or 4 x 3mm pitch teeth

the brake or slowing of piston begins quite early and screws up your stroke/air volume

 

so you would need to factor in loss of air/compression/stroke crap

so ported cylinder needs to be further back for starters....

 

plus good luck using that shit in higher speed build pushing it close to limits

where piston slows so early and thus may not return fully on crazy speed builds

 

all in all, I can not see why anybody would really need that unless firing a 500fps DMR

with little to no impact planning up front

(not going to mention the word:  s o r b o t h a n e or other stuff like that)

 

nahhhhh the whole thing is a weird bit of airsoft porn of little to no use at all in UK guns imho

better off just using a Haribo in the spring

[Zarrin]

Unless i'm overthinking this i'm not sure how this can actually complete a shot cycle...  "behold my stuff"... sorry no, aright I did this in paint ... just bear with me 🙄

 

So, surely the moment the small O-ring hits the cyclinder tube, it creates a seal between the piston head O-ring and itself.

 

That being the case... that air is totally trapped, i.e the piston head is never gonna be able to even reach the front of the cylinder head and would likley cause a malfunction and jam the gearbox after one shot as the piston teeth would still be locked up with the sector gear.

 

right!? 😕 

[Sitting Duck]

1 minute ago, mzjango said:

 

 

Do not post explicit images as we have younger players on here !!!!

 

but yeah you are correct though the air trapped will disperse eventually as one of the o-rings will allow it to escape

but probably not in time for fast cycling in a snappy aeg

 

in a bolt dmr it will be fine, no risk of PME

in a DMR aeg - probably ok unless you can spam ultra quick

in reality an aeg dmr it is maybe of some consideration as not on full auto

 

but on a full auto gun - nah asking for trouble

unless piston porn floats your boat

[Zarrin]

4 minutes ago, Sitting Duck said:

 

Do not post explicit images as we have younger players on here !!!!

 

but yeah you are correct though the air trapped will disperse eventually as one of the o-rings will allow it to escape

but probably not in time for fast cycling in a snappy aeg

 

 

Ha ha yeah my bad 😅

 

But yes, i suppose it wouldn't fully lock it up but just really slow the last part of the cycle down.

 

As you say, may be aright for a DMR setup.

 

But actually that could reduce the FPS surely - that slow down effect at the end of the shot cycle. 

 

hmmm

[Sitting Duck]

20 minutes ago, mzjango said:

 

Ha ha yeah my bad 😅

 

But yes, i suppose it wouldn't fully lock it up but just really slow the last part of the cycle down.

 

As you say, may be aright for a DMR setup.

 

But actually that could reduce the FPS surely - that slow down effect at the end of the shot cycle. 

 

hmmm

 

it "may" not alter the fps a massive amount as such as piston would travel at nigh on same speed

up to the "plug" point so speed of piston travel would be about the same....

 

BUT the amount of volume of air pushing the BB out of barrel would be reduced a bit

a rough reckoning would be 10~12mm lost in stroke volume off top of my head

so it would be like using a type C cylinder when when want a type B cylinder

(hate those cylinder letters but in this case - fuck it)

 

so the actual volume of air expelling the BB would be reduced coz 12mm is trapped/plugged

ergo you would need to compensate for loss of air volume by using a larger volume cylinder

(with port say 12~15mm further back)

 

On a DMR, full volume higher spring to expel the trapped air past the o-rings, yeah it might work

the whole bollox is just to brake or brace for impact and reduce the slap of piston against cylinder head

 

An aeg DMR might have a silent piston head to not give away your position so much

but you still have a fucking sewing machine running the drive chain to keep quiet

 

nah - bolt sniper is probably where it might end up being used, but not so much on aeg's imho

adding one of these wankers would under volume and increase risk of PME in aeg's

so nah - I ain't buying it

 

heck find a piston head and shove a longer M3 bolt though it and create your own piston dick

[Zarrin]

1 minute ago, Sitting Duck said:

 

 

BUT the amount of volume of air pushing the BB out of barrel would be reduced a bit

a rough reckoning would be 10~12mm lost in stroke volume off top of my head

so it would be like using a type C cylinder when when want a type B cylinder

 

so the actual volume of air expelling the BB would be reduced coz 12mm is trapped/plugged

ergo you would need to compensate for loss of air volume by using a larger volume cylinder

 

 

Mmm yeah that would make sense 👍

 

Though part of me still thinks if the air seal is perfect, it could theoretically just hang there so that the sector gear tries to then pick the piston up on the next shot half way down the teeth causing a lock up or tooth damage.

[Sitting Duck]

2 minutes ago, mzjango said:

 

Mmm yeah that would make sense 👍

 

Though part of me still thinks if the air seal is perfect, it could theoretically just hang there so that the sector gear tries to then pick the piston up on the next shot half way down the teeth causing a lock up or tooth damage.

 

It would expel eventually unless your piston's o-ring is insanely good

in rare cases does the seal remain 101% airtight 101% all the time

as you test for compression the compressed air inside usually subsides

(eventually), unless the seal is absolutely f**king fantastic - rare but can get near this if your'e lucky

and after a minute of compressing the piston you are left with a punctured finger from the cylinder head spout

 

and even so the o-ring on the dick may not be a perfect seal

so the trapped air will somehow disperse with some of the spring tension behind the piston at near rest

but the issue is if the piston slowed to this point will return in time before sector attempts to engage pick up tooth

but might engage with second/third tooth instead and potential havoc may risk taking place

 

it will return - but just not in time on faster cycling setups - even on semi

as the piston gets picked up even on semi on slower stock guns @ 10rps semi

 

the brake is simply way way too long - reckon just a small 3 or 4mm brake is all that would be needed

 

just buy a mushroom piston head perhaps though the couple I tried didn't seem to have a great seal

so never bothered to fit them into any of mine but others swear buy them to soften the impact/sound

which is effectively what this dick (piston) head is trying to achieve

 

 

but to each their own, but think that porno piston is not a good idea for an aeg imho

[Zarrin]

7 minutes ago, Sitting Duck said:

just buy a mushroom piston head perhaps though the couple I tried didn't seem to have a great seal

so never bothered to fit them into any of mine but others swear buy them to soften the impact/sound

which is effectively what this dick (piston) head is trying to achieve

 

Yes, it is actually labeled as 'silent' in the title, so I suppose that air cushion is actually exactly what they were going for.. instead of slapping rubber/plastic on rubber/plastic they are going for zero initial impact contact, which actually is kind of clever, but certainly you may want to swap out your cylinder for one with a lower port. I used a silent piston/cylinder head setup when my MP5 was in SD configuration, I seem to remember it being reasonably effective. I would go with the mushroom over this.. *cough* more innovative design just out of fear for reliability and jam ups!

[Spoon987]

Im going to quickly duck in and out here. But another factor to think about is the piston will hit that cushion of air and then bounce back a little, maybe enough for the rest of the air to escape out of the CH. This is a common thing with spring powered air rifles and the reason why it’s recommended to use the Artillery hold whilst shooting them. 

[Zarrin]

2 hours ago, Spoon987 said:

Im going to quickly duck in and out here. But another factor to think about is the piston will hit that cushion of air and then bounce back a little, maybe enough for the rest of the air to escape out of the CH. This is a common thing with spring powered air rifles and the reason why it’s recommended to use the Artillery hold whilst shooting them. 

Oh interesting point, perhaps that is a factor... though I would imagine that the spring pressure would counter any backwards motion.

[Spoon987]

3 hours ago, mzjango said:

spring pressure would counter any backwards motion.

Yeah possibly but it doesn’t in air rifles and they use much stronger springs. 

[Adolf Hamster]

I can see the theory of this, but tbh silent aeg builds arent something that i've put much store in.

 

Hpa silence on the other hand.....

[Rogerborg]

12 hours ago, mzjango said:

<pornpic.png>

 

+1.  It's going to prevent air from going down the nozzle.  So why compress it in the first place?  Why not short stroke?

 

Anyone who fits that is going to do so because they know exactly what they're doing, or nothing at all about what they're doing.

[Zarrin]

5 hours ago, Spoon987 said:

Yeah possibly but it doesn’t in air rifles and they use much stronger springs. 

mmm fair point, i wonder if the design could actually rely on this to happen consistently on each shot.

[ImTriggerHappy]

14 hours ago, heroshark said:

similar to an air break type spring sniper piston head.

 

Spring sniper rifle is a very different to animal to an aeg so while some people reckon it is great for a spring rifle on an aeg it won't work as well.

 

Air breaking an aeg piston especially on a high rof build will most likely lead to pre-engament issues. Most aegs vary a little bit on rof from day to day so to balance timing would be a pain. People get issues with timed ab mosfets and this will be worse.

 

Also an aeg on full auto varies on fps to semi so single shot might work but full auto will lead to results going everywhere.

 

As for silent piston heads it is snake oil as gearbox whine is most peoples problem.

 

 

 

 

[Zarrin]

23 minutes ago, ImTriggerHappy said:

Spring sniper rifle is a very different to animal to an aeg so while some people reckon it is great for a spring rifle on an aeg it won't work as well.

 

Air breaking an aeg piston especially on a high rof build will most likely lead to pre-engament issues. Most aegs vary a little bit on rof from day to day so to balance timing would be a pain. People get issues with timed ab mosfets and this will be worse.

 

Also an aeg on full auto varies on fps to semi so single shot might work but full auto will lead to results going everywhere.

 

As for silent piston heads it is snake oil as gearbox whine is most peoples problem.

 

 

 

 

 

Yeah as @Sitting Duck was saying, it would definitely be more geared towards a DMR build if anything atall! The issue/question I still have is regarding just how fast the air cushion at the front dissipates - a delay here potentially runs it into trouble - as you say, pre engagement at the very least!

[Samurai]

Looks cool to me, I've ordered one, thanks for the link. I'm very much into silent builds.

Changing the small o ring will adjust the impact speed of the last few mms.

The mushroom type is useless.

[Samurai]

It has arrived. It looks super well made. Let me find a gearbox to put it into.

[Rogerborg]

Any chance of a before-and-after video?

[Zarrin]

2 hours ago, Samurai said:

It has arrived. It looks super well made. Let me find a gearbox to put it into.

 

Awesome dude, looking forward to your findings! 😁

[Samurai]

First try: it indeed fully seals between the two O rings, even just by pushing it in by hand. There is an air cushion of about 6-7mm. This would break the piston or the gear on the second shot.

I removed the small O ring and there is a noticeable resistance when pushing it in by hand and covering the nozzle, but that didn't make much difference to the impact sound. The gearbox cycles fine like that though.

I'll check with smaller O rings that won't seal perfectly.

[Zarrin]

7 minutes ago, Samurai said:

First try: it indeed fully seals between the two O rings, even just by pushing it in by hand. There is an air cushion of about 6-7mm. This would break the piston or the gear on the second shot.

 

hmm, this is what I thought might happen! I must be scientist alpha foxtrot 😎 

 

One question though ... ehm...  did you use lube? 🤭