G&G AEG CM18 MOD1 for first AEG.

[Lozart]

 

In that case, this is a good job I looked at it today as it would have otherwise been like that for two weeks instead of 42, hours.

 

Thanks!

 

I take it that means, that one of the things i've learned, through Q&A, that no one told me about AEGs is to check the nozzle is in contact with the barrel before putting it into storage, when firing semi I had difficulty achieving that state.

 

 

If you're firing on semi and it's not returning the nozzle forward reliably then you may have an issue. In auto it's not unusual for a non mosfetted gun to stop mid cycle but on semi it really should complete every time.

[Sacarathe]

If you're firing on semi and it's not returning the nozzle forward reliably then you may have an issue. In auto it's not unusual for a non mosfetted gun to stop mid cycle but on semi it really should complete every time.

 

I just retested, the nozzle is not visible at [trigger] rest on semi, on auto I am able to bring the trigger forward before the nozzle is withdrawn.

 

The issue is over-cycling of the motor? Could this be because of using a low voltage battery?

[Lozart]

 

I just retested, the nozzle is not visible at [trigger] rest on semi, on auto I am able to bring the trigger forward before the nozzle is withdrawn.

 

The issue is over-cycling of the motor? Could this be because of using a low voltage battery?

 

 

To be fair it may just be the way your gearbox is set up. I'm pretty sure mine work in a "out/in/out" manner as opposed to the "in/out/in" yours is. I may of course be labouring under false understanding...I'll have a look tonight at mine.

[Sitting Duck]

I was going by the normal way the gearbox cycles

after a shot is fired and the piston releases on semi

the motor runs on a smidge even when cut off engages and usually starts to just pull nozzle back a little

often sector has just started to get near engaging piston and cam starts to retract tappet - so nozzle is starting to part away from hop

 

I looked at sector's cam for tappet and on a full stock untrimmed tappet plate the nozzle stays fully back as the piston compresses

at about halfway on sector gear the cam starts to release tappet plate so nozzle now starts to shoot forward to load bb & seal against hop

(ready for piston releasing very soon after)

 

The easiest thing is to remove magazine and pop the front gearbox pin

then you may see the cylinder port window in the gearbox

(if not and stock guns being what they are - not so brilliant seals - rotate cylinder until its port is visable)

 

Now what you want to do is inch the gun until the the o-ring on piston passes the rear of cylinder window

which should be aprox 66% to say 75% on the cm18's porting for its 275mm barrel

you will then be able to see through the single hole or port in the cylinder where the bastid piston is

rather than try and "guess" its position by nozzle and gauge if spring is being compressed

which is not as easy as it may sound even if you fully understand how the gearbox itself cycles

 

the front pin on G&G's just pops back but not out - it is just designed to stay in there by a spring retainer on pin

once popped the top receiver will slide fowards from main lower receiver

you may notice it might catch slightly on very top of gearbox case but you can just slightly lift upwards at that point to clear

just do it a little slowly and it just comes away real easy on G&G's

 

look up on google/youtube - not coz it is that tricky or hard but often like my first description it can be difficult to understand anybody

let alone all the crap I type on a regular day to day basis

 

as long as you can see the port/window on the blue cylinder in gearbox it will be a LOT easier to understand and precock the spring

 

or failing that spring compression thingy - you will see where to place a few bits of tape at front of gearbox to reduce the good seal

and in effect lose a tiny bit of seal to bring down fps with a slightly less than perfect seal to bucking/hop

 

hopefully some of this makes sense but soz in advance if you are not fluent in talking duck - even I don't understand most of my crap

 

pop the top receiver and you know for sure where piston/spring is at is the best easiest way

[Lozart]

Of course...by the time you've done all that you could have just changed the spring....

[Sitting Duck]

be nice if it was quick change spring but alas not on most G&G's

(think that is another one of their new ideas to implement on newer models coming out soon)

 

most first time openers spring change/box opening doesn't always go to plan

(mine deffo didn't I will honestly admit - well a few boxes didn't that is for sure)

 

The spring will be fine soonish - just might need a tiny bit of help

either precock or a few bits of tape to push hop away

 

weird thing is though you may get 349.999 at chrono in morning

fire a few hundred shots/bursts or dry fire through it and due to dunno a bit of friction/heat maybe

the cylinder may warm a little and expand a smidge of a smidge - I have found just recently

and after a blast on bb hosing - the fps is bit less at chrono after this spraying

 

I ain't studied this crap very much - believe it or not I ain't that sad

but after a while I guess the cylinder may cool a little and higher fps/seal may return to its higher figure

[Sacarathe]

https://rawairsoft.wordpress.com/v2gearbox/

 

Hard to watch it from the trigger pulls. ^^

 

I'm guessing G&G have deliberately chosen for the spring to be slightly compressed when the nozzle is not visible down the magwell.

[Sitting Duck]

I'm at work atm so I suggest watch if not sure how to separate the two bits of receiver

Doesn't invalidate any warranty coz you ain't opening gearbox or motor, besides if you get a really bad jam or change barrel hop bucking you gotta do this anyway.

 

Look at a video to double check if not sure

 

Separate 2 halves and you will see the piston in port window and understand a lot more what I'm trying to say in my duc-ollox language

 

It is hard to see a black nozzle in a grey hop whilst peering down into magwell even when you understand it a bit. Red SHS nozzle is easier to see at first glance than the stock black nozzle.

So consider separating the receivers

[Sacarathe]

Nozzle is easy to see because there is a silver area with a hole (showing the black upper) so you can see the nozzle movement and position easily. I'm going to leave this alone until I get an opportunity to chronograph the gun.

 

Thanks for all the input, after it's chrono'd I wont need to post anything to check this stuff out.

[Sacarathe]

Sick of this firing 351, bought some springs, going to bring it down to 1Joule.

 

I realised today that I have never chrono'd this gun with the hop off. Would not be surprised if the actual fps is higher than the usual 351 that I get on chronos.

[Sitting Duck]

Thing is you need to chrono it

 

and tbh if she shoots just a smidge over - the best thing is to just correct AoE

as that will bring down fps 10 to 15fps

 

nothing else - just AoE, use a couple of neoprene or rubber tap washers as you are still running her stock

2nd tooth on piston removed already - tiny file to reduce 3rd tooth

2 x neoprene washers with some super glue should do it (clean cylinder head first then glue on to space piston back)

a slightly reduced piston stroke should give you a drop of 10 to 15fps - plus box or rather piston should love you a little for it

 

ak2m4 has some mofo new xcortech ones in at under £70 I think

give him a pm and he could do you a deal

sounds a lot but it is something that people should consider if they own more than just the one gun

if you suspect ya gun is playing up a quick chrono will prove ya fps has dropped badly

or if working on gun will quickly show the fps & rof etc... rather than try to guess stuff

 

If you bought it for say £70 and jack it all in in 12 months, I would reckon you could still get about £50 for it

that £20 loss isn't bad as it saves you waiting to find out at site if gun is ok

or rather it is too hot and can't use it properly or even at all if you can't bring her down a hairline smidge with hop on

 

You could replace the spring and be exactly the same or higher (doubt it but some springs are a bit under rated fps wise) or pi$$ poor sub 300fps

[Sacarathe]

Purchased a CTR stock.

 

Big improvement to the gun when using a plate carrier.

 

http://imgur.com/tkNyix7