G&G GR25 upgrade advice

[Azman1978]

Not an official prowin. Seen the state of some of those and gone for that style but different make. Right. Anyone know if the a&k lower reciever accepts the g&g upper? Thanks. Thinking about getting one to save shaving the innerds out of the g&g for correct fit. 

[Samurai]

I don't think so. Both are companies that make their own stuff their own way.

[Azman1978]

Okay will order a full upper and lower. Saves me chopping and means i can come up with something funky with the gr body. Right so had another play as the gr gearbox and setup was misfeeding. Turns out a priblem with the tappet plate so replaced with a spare i had. No misfeeding and now getting a consistent 369 to 372 fps. Happy with that variance. Must just mean the spring is crap. What spring would people recommend as a true m140 spring. Looking for a consistent 430 to 450 fps. 

[Azman1978]

Afternoon guys. Right. Its working again.  Cinsistant fps of circa 420. However... can someone tell me where the nozzle should sit after firing. Forwards or fully back? At the moment it seems to fit fully back but my head tells me it should be forwards and in the bucking??? If so how do i correct this? Cheers. 

[Sitting Duck]

What juice/volts are you running it on - 7.4v or 11.1v

 

you will get a tiny bit of over spin with SHS HT motor as it is a balanced more than a ultra torque

So it will be a bit quicker than the original motor - even a Blue Powerful or Orange Ifrit 25k

 

you may get a bit of overspin or rather nozzle retraction

the nozzle starts to retract just before the first teeth on piston/sector engage

so the nozzle will start retracting before any real tension from spring helps to stop the drivechain

 

if using 11.1v then you will get more overspin

However - you don't want the nozzle sealing on the bucking lips anyway

if you think about it if the nozzle has sealed tightly against the bucking in storage

well over time in storage those bucking lips might lose high efficiency sealing at higher 425fps

 

Quite normal for nozzle to retracted say 50% - if you run on 11.1v then just fire a few shots on a 7.4v to park it

[Azman1978]

Thanks for that. Running a 7.4 lipo. 3200mah. Can i retard the sector gear a touch to move the tappet nub a bit further away? Or would that not have any effect?  The nozzle is retracted all the way back so there is no movement so a little too much for my liking. 

 

Cheers

 

Aaron

[Sitting Duck]

if you look at pic...

 

 

by the time the sector meshes and begins to slow down from the spring tension as piston is drawn back

The tappet plate is approach full retraction...

I mean this has a delay clip and it is quite a large clip

I like the circular brass type that can be fitted either way and I fit it later

But even without any clip - the tappet is at 50/60% before the piston starts to retract

 

To get the gun to stop asap with less retraction you are probably looking at Active Breaking Mosfet

Or

Ensuring Cut Off Lever is brand new, trigger contacts not too tight-possible flaring of the contacts

So that the COL pops the trolley asap and that trolley is not gripped tightly by contacts so returns asap breaking circuit

(worn COL's and tight contacts can cause delay in breaking circuit & a bit more overspin)

 

TBH - just go with it, think of it as a bit of pre-cocking or chambering assistance if tappet is retracted a bit

fire gun on a low juice 7.4v 15c @ say 7v or something to help "park" the gun better for storage if ya really worried