dex

TBH the blowback system is very simple and doesn't have a great deal of scope to go wrong. G&G internals are far better OOTB - even the shim job in mine was good (there is always room to tweak, but for a factory job it was far better than the G&P). The gearbox shell on the G&G is very good also, with radiusing and reinforcement.
 
It is a shame they couldn't fit a better mosfet though.
 
Just for the record with a Lonex M110 spring and everything else stock the difference the ROF you can expect is 14.5rps with a 9.9 life and 17.5rps with a 11.1 lipo.

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12rps is about average for a stock AEG with an 8.4V NiMh battery. You'll get 15-ish from a 9.6V NiMh. IMO 3 round bursts at 15rps are sufficient for most situations. 20rps is excessive but fun. More than that is asking for trouble from your gearbox and will ultimately cost a fair chunk either in replacing knackered bits or buying upgrade parts that can hack it from the get go.
 
People often say that running a 7.4V LiPo increases ROF over an 8.4V NiMh, but this is not necessarily the case. Put simply more voltage makes the motor spin faster and more current produces more torque. But when people upgrade to LiPo batteries, they also often upgrade the wiring and swap to Deans connectors. Just doing that increases the ROF from NiMh batteries noticeably and, at least in the only build I have tested this, my VP Vapex 8.4V 1600mAh NiMh batteries produce a faster ROF than the Component Shop 7.4V 5000mAh 30C LiPo I bought as an upgrade. However, I then upgraded to SHS 16:1 gears and this was enough to bring the ROF with the LiPo up to about what it was with the NiMh's and the stock 18:1 gears, which I would guess at about 14-5rps but with a significantly faster trigger response for the 1st shot.
 
The reason it works like that is because the chemistry of LiPo's ramps up from outputting 0mA to whatever they can deliver as a maximum much faster than an NiMh, but initially the motor requires a higher spike of current (mA) to get going than it needs once it is moving and LiPo's can deliver much more current as well as doing it faster (for eg I remember reading somewhere that, given low resistance wiring.and a battery that can produce it, a high torque motor can draw an initial spike of 67A, not mA, Amps - that's half again as much as an electric cooker with everything turned on!), so while the NiMh is still struggling to output 10A, a 25C LiPo has already delivered 40A.
 
If you stick an 11.1V LiPo into a stock gun (and it works) you'll get 18-ish rps, which feels fast. It's not too fast to be unable to control burst fire just by how long you hold the trigger however and the same goes for the couple or three rps more you'll get from upgraded wiring, Deans connectors, and a MOSFET. Beyond about 22rps you can't get without combining high speed gears with higher voltage batteries and/or high speed motors. You need to think carefully what you want to do with your AEG though - if you don't mind stripping it down frequently then you may enjoy the really high speeds like 25-30+rps, but even if you follow somebody else's tried and tested plan, it's still to a degree a case of trial and error. To get higher than 30rps you need to short stroke the piston (which only works with short barrels) and also choose the lightest piston and piston head (people drill holes in their pistons to shave a few grammes off), but these are ridiculous speeds...
 
As a simple example a convenient top speed for a running person is about 10m/s over a short distance, so if you fire 20 rounds in a second across an arc which is 10m wide at the distance your target is moving, that gives 1 round every 50cm. Theoretically our running person could slip between them, but in practice neither their nor your movement is completely smooth and even, and you correct your aim if the 1st or 2nd, etc miss - it's just not credible that you could miss unless the target uses surprising evasive tactics, or you're so shit at shooting that you may as well go home.
 
But ridiculous rates of fire can be used to intimidate people, especially in close quarters situations, and you can also suppress people and even make them just give up with a high volume of fire ricocheting around them, even though you can't actually hit them. Is it fair? I dunno. Is it fair that someone could turn up with a 2 grand tuned AEG and no clue whatsoever and still shoot the shit out of you from cover because they've got 10m of range on you and even an idiot can't miss when you need to run 1 second straight towards them just to have a chance to shoot them...?
 
A word on high torque motors: there's a popular theory going around which pairs 13:1 high speed gears with a high torque motor as the way forward for a high ROF. This is because the lower the gear ratio, the harder the motor has to work to pull the spring. But high torque motors spin more slowly than most stock ones. Bear in mind that many guns are designed to use M120 or M130 springs, which are a lot harder to pull than the M100 or M105's that we generally use. Also motors such as the ICS Turbo 3000 can be powerful and fast. IMO it isn't necessary to use a high torque motor in the UK.
 
Another way to increase your ROF is to fit a TBB, because this will increase your FPS, so you can fit a weaker spring to still get under 350 or 368FPS or whatever limit you're aiming for - I've just done it myself - M95 spring to get an AK with a 6.03x455mm barrel under 350FPS with the hop on. I also had to put some poxy shotgun spring (or something, I dunno it came in a job lot and basically it was the shittest spring I had) into a gearbox which has a Matrix double O-ring aluminium piston head and a plastic nozzle with an O-ring - because firing through a stock 6.08x455mm TM barrel was giving me 388-92FPS! I put an 11.1V LiPo on it for the lulz and skirmished it this weekend - this is with stock wiring, including a fuse, however and a TM motor, plus an ICS solid aluminium piston, so the ROF was about 20. It was a laugh and it lasted until about 15mins from the end of the day. I haven't even opened it up yet, but my guess is the pinion gear is chewed...

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Yes ! Had a G&G MOSFET burn out on my guns first use.
(Lucky for me at the end of the days skirmish)
POS replaced the MOSFET straight away with in 10 minutes.
Was running it on a 9.6v nimh battery.
The new one gets hot quick! So not thinking it's going to last long.
If not il probably remove it , seeing I'm not going to run on 11.1v anytime soon.
 
Also the trigger spring broke straight away. This caused the gun to fire continually in safe mode.

I would give gearbox a total clean up. Reshim The gears if they are OK, replace if not. Replace the piston and head. Set aoe with sorbo.

Flung in a heap in my office

I work with electronics and his question makes me wonder if he knows what he's doing and whether he understands how LiPOs are wired. i might be wrong but when its comes to electrics, there are a lot of well meaning amateurs about and for a few quid, its not worth a house fire.

And the cutoff lever.

SHS high torque or Lonex A2. Both are excellent.

This. I bought a G&G top tech as a gun that I wouldn't mess around with that would work well out of the box. My "project" AEG is built from parts worth 2 or 3 times as much as the stock G&G and is a finicky beast. When it works its works its awesome, then I'll go mod something else and screw it all up

Its a moving diagram of a typical (vers 2) AEG gearbox. The only important bits missing is the magazine, which is fed using a long spring in a mid cap or a wound spring in a hi cap and the hop up, which is the part that adds back spin to the BB as it gets shot up the barrel. Its this backspin that gives the BB its range (due to Bernoulli's principle if you want to get really geeky).

Just bought a Helikon soft shell jacket, a 5.11 combat shirt and some Alta knee pads.

it'll help you find out where the resistance is in the circuit, should tell you where/what the problem is!

I bought a couple MAG ones a few weeks back. The cheaper ones are plastic but if you don't mind that they feed brilliantly and are affordable.
I got mine from Airsoft Supply Drop. Unfortunately didn't fit through the letterbox because of the size (so had to pick them up ont weekend) but on the plus side they were very nicely protected. Would recommend.

Posted this pic in another thread. Thought I'd run down the loadout:
 

 
From top to bottom:
 
Helikon cap A-TACS FG
ESS Ice 3 glasses
Miltec Woodland scrim scarf
Helikon combat shirt A-ATACS FG
Warrior RICAS Compact A-TACS FG w/ admin pouch, 5x 5.56 pouches, 2x pistol pouches and 2x utility pouches holding:
- 5x MAG M4 magazines
- 3x TM P226 mags
- Spare BBs
- 2x speed loaders (one for pistol, 1 for rifle)
- Smokes
- Multitool
Magpul MS-3 sling
Oakley Pilot gloves olive
Duty belt w/ pistol holster, dump pouch and pouch holding water bottle
5.11 Taclite Pro trousers in tundra
Lowa Mountain GTX boots
 
Guns:
G&G top tech gen 3 M4 CQBR with Phantom red dot and torch
TM Sig P226R

Check the motor connectors are on properly.
 
Are you handy with tools? it's going to most likely be a connector issue, rather than a 'box issue. Check the wires aren't stripped anywhere and shorting

You don't HAVE to but they work better if you do.

It really doesn't matter. They'll both perform exactly the same, the internals are pretty much identical.

This. I bought a G&G top tech as a gun that I wouldn't mess around with that would work well out of the box. My "project" AEG is built from parts worth 2 or 3 times as much as the stock G&G and is a finicky beast. When it works its works its awesome, then I'll go mod something else and screw it all up

Even Rolls Royces go wrong sometimes. Buying a more expensive brand SHOULD give you a higher chance of getting a better made/designed product but as you have become aware it's not a guarantee. The thing to look at though is the overall throughput versus the failure rate when judging a brand. If G&G for example are having an issue with some of their MOSFET units (I assume that the rest of the gun isn't falling apart as well) then obviously they have a QA problem with that specific part. The value in buying a decent brand is just as much in the after sales and how quickly they move to rectify the fault as it is in the actual product itself.
 
Buying cheap and then spending time, effort and money to get to a point where the higher end products always are isn't always cost effective. It depends on how highly you value your time and whether or not airsoft teching is your thing. Having bought an old TM M4A1 and spent the time and effort (and money) to get it to where it is now pretty much as good as a gun I could have bought straight off the bat with the same total budget has taught me one thing - do it because you WANT to not because you think it'll be a cheaper way of getting a good gun.

Lonex/ASG ultimate-Very precisely made. Although it's Zamak It's a strong alloy. Good tolerances,reinforced in the right places and cast well. Very popular shell for it's reasonable price,good construction and strength. It's probably the most popular one I know of locally. You can find them in a lot of UK shops,often rebranded under ASG ULTIMATE who also rebrand a load of Lonex parts.Airlab have them for a good price.
http://www.air-lab.co.uk/lonex-gearbox-shell-v2.html
 
SHS/PPS/Super Shooter make 'CastNC' shells which are advertised as CNC machined but in Reality are injection molded and finished with CNC just for looks. Made out of 7075 aluminium which is by itself a fair bit stronger than the Zamak used in a lot of shell,although It's probably not heat treated so It is not as strong as an MThaynes or Cradle shell.
Bit pricey though.But good quality and popular.
http://shop.ehobbyasia.com/super-shooter-7075-cnc-aluminum-ver-2-gearbox-shell.html#.U0rB7PldVN0
 
JG shells are also quite strong and very very very cheap.Made of Zamak,but again,a strong alloy. Tolerances might be a bit 'off'(But no where near as bad as some CYMA shells I've seen) and some casting burrs about,there may also be some excess material around where the gears sit. However for the price and the strength you cannot complain.
http://www.wgcshop.com/wgc2008/main/product_detail1.php?search_From=searchItem&item=JG-M-134&search=special&rs=Jing%20Gong%20gearbox&catid=&cat=&view_choice=c
 
In the future to prevent cracking,RADIUS YOUR CYLINDER WINDOW CORNERS. This reduces a great amount of stress of the front part of the V2.
Also,Correct your angle of engagement on the piston with sorbothane pads. Not only will you help reduce shock on the GB shell but you will also prolong the life of your piston. Don;t use metal piston heads too,they offer no real benefits and only add premature wear.

When you google particular airsoft gear, you usually get mostly results with American stores. This is not so useful with postage costs and the Duane and tax. You can google for a particular country, but that takes allot of time. To solve this problem someone on my Dutch forum board created a tool, that let you search within Europe only, or on country selection.
 
http://airsoftfind.com
 
I thought I'd share this tool with you, since I use it allot to to find my gear

- Helikon cap in A-TACS FG
- Woodland scrim net
- 8x MAG M4 mid caps