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You will definitely want to lighten that piston up.
I suggest that you drill holes where you think it is safe to drill holes, and make an airbrake by lubing your cylinder head with PTFE spray if you've got it, or some synthetic oil like Vaseline or WD-40, and then filling the whole thing with hot glue from the threaded end and down.
Then, rough up the base and make it flat.
Put your piston in your cylinder, put super glue on the hot glue and on the piston tip, and screw on the cylinder head and press the piston into the cylinder head.
This will keep it more centered than doing this outside the cylinder.
Then just ram out the hot glue from the cylinder head with a similar diameter rod as the hole, and shorten the hot glue a bit.
There you go, you've got an air brake.

I have seen this done on a Japanese VSR-10, so I figure that if it lasts for him than it should last for you due to the power.
For everyone else, it lasted 400 shots in my sketchy 3.8J VSR-10, so it is very likely that the same would happen for you.
 

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@lukeypoodle
You are correct that decibel scale is logarithmic. Something that is 10 times more powerful is 10 decibels higher. But that is all measured in energy; the term “louder” is imprecise and has various associated meaning that can often be confounded with other terms. Energy measure is an objective term that lives in physics realm. Loudness is a more subjective term that lives in physiology.

@skara
There are definitely more experts here that can chime in on this than I can. I understand things more from an academic physics standpoint and not in the applied. If the sound is inside the cylinder, really there are only two locations from all my reading that it can come from, the piston/cylinder head impact or the spring/spring guide translational movement. Given your desc of your sound so far, I have to imagine it’s the piston/cylinder head. What sort of sorbo did you use? D40 or D70?
 

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No matter the sorbo as the piston very likely reaches the cylinder head after the bb has exited the barrel.
What will work is manage the piston to reach the cylinder head before the bb has exited the barrel, which you could lighten the piston. Get it close to a AEG piston weight and you could apply the cylinder to barrel ratio of an AEG shooting 0,3 and port the cylinder if needed.
 

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Discussion Starter #25 (Edited)
@skara
There are definitely more experts here that can chime in on this than I can. I understand things more from an academic physics standpoint and not in the applied. If the sound is inside the cylinder, really there are only two locations from all my reading that it can come from, the piston/cylinder head impact or the spring/spring guide translational movement. Given your desc of your sound so far, I have to imagine it's the piston/cylinder head. What sort of sorbo did you use? D40 or D70?
No clue what hardness it is, it's this one https://www.softairgames.net/en/var...dumper-for-vsr10-g-spec-laylax-la-584644.html

So anyway, after a tiny bit of research on the Striker Facebook groups, I decided to try and make my own airbrake:


dis the AirsoftPro piston, the rubber pad on top is held in position by a M3 screw.


Removing that screw reveals an M3 thread that goes all the way through the head


The M3 thread is the same one as the screws that hold v2/v3 gearboxes together, so I used a M3x20mm and screwed it in the opposite way (screw head at the rear instead of at the front) and this is the result.

Now obviously this can't work with the screw alone, so I tried to apply a small section of heat shrink to the screw and it fits loosely inside the cylinder head.
So I need to apply multiple layers of shrink tube until I get the result I need.


Also, the M3x20 screw is way too short, so I bought some M3x30mm screws with a flat contact surface on the head.

Have I just "invented" a quick and cheap airbrake for the striker?

All this rambling because, as you guys stated, there's too much air coming out of the cylinder (I think the current ratio is something like 4:1) and the piston hits the cylinder head after the BB leaves the barrel (no resistance at all), so I guess an airbrake would be a viable option in my case.
 
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Discussion Starter #27
Okay.
Brake installed, BUT:
30mm, 0.2J output.
23mm, 0.3J output.
17mm, 0.5J output.
This is on a cut down SP100.

(Mind you, it's the total length of the screw)

Moreover,
ONE layer of heat shrink is fine
TWO layers and the gun just jams (I think it kills the air output so much the bb can't even go past the hop rubber patch)
Have not tried without heat shrink yet.

Any clues?
 

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Discussion Starter #29 (Edited)
You very likely have a leak, have you tried putting your finger over the nozzle to check for seal yet?
just the usual MR-Hop leak, but it's consistent and very slight so it's irrelevant.

Tested without heat shrink.
30mm 0.3/0.4J
23mm 0.4J
17mm 0.97J -.-

I'm doing something wrong somewhere..

I'll be honest, the slap seems to be reduced just by a tiny bit.
 

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Mind you, the piston head need to be air tight. The heat shrink method probably allows air to go to the back of the piston, therefore you're loosing air volume and not really braking the piston.
 

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Discussion Starter #31 (Edited)
Mind you, the piston head need to be air tight. The heat shrink method probably allows air to go to the back of the piston, therefore you're loosing air volume and not really braking the piston.
Fuck me you could be right!!
The original screw tightens the dampening pad against the head's body.
I used a locking nut to achieve the same effect (but could've messed up something tbf). It's hard to see, but it's in there nice and tight.


(pic shows the full length 30mm screw)

I have also aligned the holes on the dampening pad with the ones on the piston head, can't remember how they were before taking the piston apart but I guess they were aligned too.

What I need to understand is the correlation between the airbrake's length, diametre and how it affects the air volume.
What are the measures of the average airbrake? (if you have a Laylax PSS10 airbraked piston, I'd like to know the exact brake measures as this thing is basically the same, but scaled down to fit the striker cylinder)
 

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Only two rules:
Enough tolerance on the brake diameter so it always enters the cylinder head (you can basically measure the diameter difference of your cylinder and piston and apply to the brake, ex: cylinder ID 24mm, piston OD 23mm, therefor the brake OD need to be 1mm smaller than cylinder head exit ID).
Length wise, make it long then tune it down to desired power level. You could also calculate the approx. length by considering for every mm of brake, 80% (exact percentage will depend on the brake diameter and cylinder head exit ID difference) mm of cylinder volume is not used. Say you have 4:1 ratio and want to get down to 2:1, you need a brake that's 80% of half of your cylinder length.
 

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Discussion Starter #33
Did further extensive testing, literally shaving half a mm off the shaft each time, the best I could achieve was 0.65J on a M120 spring (unacceptably hard pull for the output) but the gun is still somewhat loud. the system is airtight (swapped hop rubber for an old TM one I had, perfect air seal).
I've come to the conclusion that an airbrake on a striker is not feasible. Or rather, it's doable, I just don't have the patience to do it

Ordered an Action Army T-11 and the Striker is being sold to a mate (who actually asked me several times to sell him the gun).

I might come back to this project if he wants to, if not.. well, no biggie, I can replicate it on the stock AA plastic piston until I have enough spare money to buy a SCW piston :)
 
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Think about it this way, if your system is airtight (no leakage at barrel-packing, packing-nozzle, cylinder head-cylinder, cylinder-oring-piston head-airbrake) then the only air leak can happen is between bb and barrel bore clearance. If you had reading of 1J before airbrake and .2-.97J with different airbrake setups using the same everything else (piston, cylinder, ect) would tend to say the over volume is not the issue. For example (just using round #s for simplicity sake), say you have a 4:1 ratio and the optimal ratio is 2:1 where the bb exits the barrel right at this moment. That would mean it does not matter what the piston does on the second half of its travel as the bb has already left the barrel. So in your case this is not happening as the airbreak is having a dramatic affect even with a shorter air break which is saying the bb has not left the bore yet. So why is this and where is the air going? This is very curious to me. Relating this to a similar build I have, It could be that your spring just is not powerful enough to create enough pressure to push the bb past the hopup rubber instantly. So that bb is lingering (or moving slowly) against the rubber as some air volume "leaks" around it until enough pressure from piston pushes it past the rubber. I believe this is what 1tonne is referring to when he talks about "pressure spike". It would be curious to try the airbreak with no hop applied and with different weight bbs. So where is the sound coming from? Still anyone's guess without seeing/testing first hand. I still think it is coming from the piston head hitting the cylinder head. From my experience, the quietest piston slap noise I have got was with a swiss cheesed stock plastic piston, 40d sorbo on cylinder head (I do want to try the hammer mod instead sometime), and an airbrake on a 1.15J build. It is noticeably better but still has some "slap". The quietest gun I have built was an L96 with similar setup, swiss cheese plastic piston, 1/4" 40d sorbo, volume balanced for .32 (don't remember length (seemed close to stock size) no airbreak or "can". It was really quiet. Some things are not adding up to me and I believe there is something simple to fix. Maybe the sound really is not that bad. Is it noticeably louder than your ssx23? I know you are just done with it and I understand. I just hope your new gun works better for you. Best of luck man!
 

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I expect that you new T11 should be quieter, but not exactly silent.

I switched to HPA in one of my snipers quite some time ago, and I have already given away one and am planning to sell the other as the sound can't be beat.
There of course is noise, but the majority of it is muzzle noise being electro-mechanical and all.
So, with a really really good suppressor, it should be quieter than any airsoft gun ever, at the same power or more.

Still, it's hard to find where shots are coming from with most guns.
 

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Discussion Starter #36
So, let's resurrect this flaming dumpster in 2021 :D

My mate got the gun, then saw my T-11 and now he wants the striker to be as quiet.

Back to airbrake testing then :D I'll also dick around with solder to see if adding weight does anything :)
 
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