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Rob15

CNC Machined V2/V3 Airbrake Piston Heads & Laser Cut AOE Shims

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Here are the latest products to be released by Lees Precision Engineering.

After a long wait to get these into production I am very pleased to announce that my V2/V3 CNC machined airbrake AEG piston heads are now in production and available for order.

[center][IMG]http://i17.photobucket.com/albums/b67/Rob_15/LPE%20Products/V2V3AluminiumAirbrakePistonHead.jpg[/IMG][IMG]http://i17.photobucket.com/albums/b67/Rob_15/LPE%20Products/V2V3AcetalAirbrakePistonHead.jpg[/IMG][/center]

LPE Piston heads are an original design being the first AEG piston heads commercially made which are designed to be adjusted for AOE (angle of engagement) easily while remaining securely centred on the piston. The conventional design for the rear of the piston head has been done away with and replaced with an extended locator and a lightweight aluminium bushing in-place of heavier steel thrust bearings, this allows for 0 – 5mm of AOE adjustment using shims between the piston and piston head.

As with all LPE products these are CNC machined in the United Kingdom from high quality billet materials on commercial machines.

[quote][u][b]What is an airbrake piston head?[/b][/u]

Airbrake piston heads are much like standard piston heads but with the addition of a second 'piston' on the front which acts as a suppressor in the gearbox.
[u][b]
How does it work?[/b][/u]

Towards the end of the forward piston stroke the front of the piston head enters the cylinder head and reduces the airflow out of the nozzle, this creates a cushion of air in-front of the piston which slows it down before it impacts the cylinder head resulting in a reduction of sound from the gearbox.
[u][b]
What are the advantages?[/b][/u]

For players who prefer their AEGs to be quiet the biggest advantage is the sound reduction from the gearbox, the area where most of the sound is created. Airbrake piston heads also offer a fit & forget alternative to adding foam padding onto the cylinder head which can wear down over time or even fall off if it is not fixed on securely, an airbrake will give consistent performance and perform the same after thousands of rounds as it will straight after installation when set up correctly.

Another advantage is the reduced stress on gearbox shells from the slower piston impact speeds, particularly useful in V2 gearboxes which are known for cracking around the cylinder windows.
[u][b]
Looks good! Is there anything else I should know?[/b][/u]

As is often the case with AEGs performance of airbrake piston heads will vary from gearbox to gearbox.

The type of cylinder head will have an effect on the braking, flat cylinder heads are recommended to give maximum sound reduction, aero cylinder heads (also known as 'silent' cylinder heads) will also work but the reduction will be lower. Airbrakes also reduce the effective cylinder volume which will in most cases cause a drop in fps, this however will also occur with foam padding so any fps drop is negligible if you are looking to build a quiet gearbox.

While these airbrakes have been designed to work in full and semi auto they may not be suitable for rates of fire above 20rps/1200rpm, in all gearboxes the removal of the second piston tooth and lowering of the third is highly recommended.


These will not fit gearboxes with offset nozzles/cylinder heads.

The following gearboxes and AEGs are known as incompatible with the airbrake piston heads :-

* V6 Gearboxes (P90/Thomson series AEG)
* V7 Gearboxes (M14)
* V5 Gearboxes (UZI)
* Real Sword SVD
* Real Sword Type 97
* ARES/STAR L85
* ARES/STAR FNC
* ARES/STAR M14
* ARES/STAR M249/MK46
* ARES/STAR M60/MK43
* G&G L85
* G&G M14
* KSC Hk33
* Systema PTW series
* Systema Revolution gearboxes[/quote]

In addition to the airbrake piston heads I am now offering Laser Cut AOE (angle of engagement) shims with these piston heads and also in packs for use with other piston heads. Each pack contains two thicknesses of shims which are colour coded as yellow (0.5mm) and red (0.38mm) to allow fine adjustment of the AOE.

Prices are as follows :-
Aluminium or Acetal V2/V3 Airbrake Piston Head & AOE Shims - £20
Aluminium or Acetal V2/V3 Airbrake Piston Head - £16
Laser Cut Piston Head AOE Shims (Pack of 12) - £6
Laser Cut Piston Head AOE Shims (Pack of 50) - £15

Available from [url="http://www.leesprecision.com/product_items.php?cPath=50"]here[/url] with worldwide shipping available.

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The acetal airbrake came in at 5g on the factory scales, the aluminium was about 3g heavier and the AOE shim packs won't even register on the scales we have!

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I havent used this sort of product before, but very interested in trying.

However, I am already using a 5mm sorbo pad to adjust AOE and reduce volume.
How do you expect this to work with that setup ?

Im sure it will work, but will the desired effect be reduced, increased, or..... ?

:)
Cheers

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I'd say it largely depends on the type of cylinder head you are running, if you have an aero cylinder head with 5mm of padding then most of the airbrake itself isn't going to be in action, however if it is a flat cylinder head then there should be some airbraking effect. Also I assume the sorbothane is 5mm in it's fresh uncompressed form and has replaced the original cylinder head pad? From my own use of padding I've found it compresses a lot and doesn't uncompress much in the time it takes your average gearbox to complete a cycle so you could have more of the airbrake in action there and get a double suppressing effect.

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Yeah same here Bane, tried to buy some of the AOE shims, but the site wanted a username and password

Oh, and I just edited this in - Wouldn't these type of piston heads reduce the rate of fire due to slowing the piston?

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I'm also having the username/password issue for some reason, the website developer has been informed and it'll hopefully be sorted soon.

It shouldn't have any/too much effect on rof, the biggest risk with airbrakes is the piston not being fully forward by the time the sector gear has done a full rotation and is trying to pick it up again, this is why a lot of the old home made tighter fitting airbrakes could only be used in semi auto to avoid stripping a piston straight away! These are a looser fit in cylinder heads so there is less resistance on the return stroke and can be used in fullauto.

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Website issues are now sorted out :) I have also added a bulk pack option of red 0.38mm AOE shims which works out 40% cheaper than the standard pack per shim.

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Haha, seriously nice work Rob :)

Ages ago, AmatuerStuntman posted some Philippines based products made by a now defunct company called Optimax, one of their products was an airbrake piston head that I was fortunate enough to be given free by AS...in a spate of absent mindedness I shoved a screwdriver down the cylinder nozzle to test full and fee movement of the piston...damaging the airbrake.

Despite a ~30fps drop in muzzle velocity the dampening effect when used with a silencer, well shimmed box, snappy trigger response etc even with an M160 the actual 'piston slap' noise around and forward of the muzzle was significantly reduced.

And just at a time where my DMR is in bits...

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Ordered a set - piston head and shims on the website on the 25th, arrived this morning (27th) :) Thanks!

I probably won't get round to fitting them for a while - waiting on some other gearbox parts - but I'm impressed with the service and the parts look great :)

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[url="http://www.arniesairsoft.co.uk/forums/index.php?showtopic=194013"]http://www.arniesairsoft.co.uk/forums/index.php?showtopic=194013[/url]

Just reviewed these, and they're pretty durned good! both plastic and metal versions. :)

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Had the good luck to come accross Rob15 himself using one of these piston heads in an MP5 SD3 this weekend. sounded absolutely amazing. spoke to him afterwards and no other soundproofing parts, just the stock silencer and the airbrake piston head, and other off the shelf parts. TM gears, SHS cylinder head, pro-arms piston, systema cylinder, KM nozzle. sounded truly silenced. not quiet, but muffled, tantilising, and super mega hyper cool.

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