Noisy Gearbox

[The Laughing Man]

Hey guys,

First post in the tech section, despite being on this forum for at least 5 years I think.

Basically I decided that I wanted to know what was going on inside my AEGs. So after a bit of exploratory surgery, I can see it's not so complicated.

Lots of mods and upgrades available I suppose, but they're not very cheap, and from what I can see, once you start tinkering with one aspect of the gearbox, it means you may need to upgrade other parts in order for them to keep up. For instance I was immediately tempted to replace my ver 6 gearbox plastic piston head with a metal one, but that might just shear the gears, so nevermind.

But down to it. What would be the best way to quieten a gearbox?

My CA P90 sounds like Sweep, from Sooty and Sweep. You know, like a rubber chicken. Squeaky.

Now is this the motor, or the gears? When I listen closely, this 'whine' noise is probably caused by the gears turning, so perhaps if I simply grease them a little, they'll quieten down? Or should I replace the bushings? Seems tricky..

I can also hear the spring going 'boiiing' after each shot. This cylinder has a window in it so you can see the piston. If I replace the cylinder to a full one, will it stop this noise? It echoes all the way through the damn gun - it makes it feel like a toy. Well, MORE like a toy.

And finally, the shot itself does make quite a loud bang. To remedy this I suppose I need to improve the air seal, which possibly means a better cylinder head. I even read from another post that shaving 1 mm off the tapping plate theoretically allows the cylinder head to move forward slightly more into the hop up, whilst not greatening it's size and therefore jamming a bb.

My friend's TM P90 is quieter than a ninja's fart. It's awesome. How do I get mine to stop squeaking like a distressed puppy?

Cheers.

[JOE90]

Re: Noisy Gearbox

p90s should be quiet, it could be as simple as adjusting the motor height, the small screw.behind the motor may need screwi.g in a few half turns, do a half turn the fire and compare until you get the cleanest and quietest sound when triggered. The gearbox needs that cylinder hole (port) as it matches your barrel length and keeps things in tune with each other, a full cylinder would see the bb leave the barrel before the piston has reached the cylinder head. sorbo pads could be used to correct the angle of engagement of which the sector gears first tooth meets the pickup tooth on the piston, which in turn will increase the life of your piston while the sorbo dampens the thwack on the cylinder head (google airsoft AOE). Reshim the gearbox, that will also quieten down the gears, dont buy a metal piston, get an shs blue for a strong piston, your fps levels dont require more than a.polymer piston. To stop the twang in thee spring, smear some grease over it covering it in a film of the stuff. Either that or replace it as yours could be a bit old, stilll grease the old one, helps takjng away the twang which i too hate.

[Gavin]

Re: Noisy Gearbox

hi mate not being rude but you have it all wrong.... cylinder haed dosent move piston head material not a issue on a stock gun and gears.

i would go with a element silent piston head and cylinder head swith over the bevel and spur gear to bearings but leave the sector metal bushings and a little grease. as for the bongy spring i would perhaps replace or grease but in the end our bbs fly by the power of a spring so unless its stupidly noisy accept it.
ohh adjust motor height would be a biggy.

all the best mate,happy tinkering

[JOE90]

Re: Noisy Gearbox

hi mate not being rude but you have it all wrong.... cylinder haed dosent move piston head material not a issue on a stock gun and gears.

i would go with a element silent piston head and cylinder head swith over the bevel and spur gear to bearings but leave the sector metal bushings and a little grease. as for the bongy spring i would perhaps replace or grease but in the end our bbs fly by the power of a spring so unless its stupidly noisy accept it.
ohh adjust motor height would be a biggy.

all the best mate,happy tinkering

hope that wasnt aimed at me as i clearly dont have it all wrong, i think my post is a whole lot more helpful than yours and better worded/accurate. sorry to sound blunt but what was the issue with my points? All of which were entirely relevent to a good running gearbox. Only thing i forgot was maruis plastic bushings may need changing to bearings or solid bushings.

[JOE90]

Re: Noisy Gearbox

sorry gavin just re read the thread and realised it wasnt aimed at me, use quotes so people know lol.

[laurence]

Re: Noisy Gearbox

For some reason, i heard that CA spring are quite boingy so replacing the spring would solve that i think. In terms or you metal pistonhead theory, first, it gives you no real performance benefit over a plastic one and would not harm your gears at all. It may however damage your cylinderhead if you do indeed have a plastic cylinderhead.
ANYWAY, in terms of the whiny noise, there are quite a few different things that it could bir
-first, AOE, as if this is not perfect, it could add a little motor whine as its putting more strain on the motor, look on youtube for tutorials on "how to"
-second thing, is shimming. This could mean your gears dont mesh perfectly so add some more noise. The main noise creator is in the interaction between the pinion and bevel gear, so try adjusting your motor height to see if you get any noise differences. Also just shim your gearbox the best you can, again, many "how to's" on youtube, or get a tech to do it perfectly if you want it to be excellent.
-Lastly, it could just be that you have a loud motor, it might not be very quiet.
IN terms of getting a "silent piston head" there really isnt that much point as the majorty of the sound comes from the gears and i think that a nice THUNK sound good when you shoot.

Hope this helps, if you want more info, just PM me

[JOE90]

Re: Noisy Gearbox

Again i havent read the thread properly lol, CA springs boing from standard, hence why i hate CA lol, replace the spring and grease the new one for the future.

[danhc]

Re: Noisy Gearbox

i had a ca p90 that did the same thing, for the quietest set up you could do to my knowledge at a reasonable price would be to replace the motor with a tm eg1000, replace the gears for systema helical gears, replace the rubbish bushings, replace the spring for a decent m100 or such like, do the sorbo mod as said above by joe90 to correct aoe and soften the blow of the piston, shim it correctly, possibly add a mosfet with cycle completion and remove the anti reversal latch? also with the p90 body there is alot of space inside so fill that up with sound deadening material, also when you install the hop from the front of the gun, fill the gaps there with sound deadening foam, then buy a decent silencer aswell, then it should be increadibly quiet, hopefully this has helped

[The Laughing Man]

Re: Noisy Gearbox

hi mate not being rude but you have it all wrong.... cylinder haed dosent move piston head material not a issue on a stock gun and gears.

i would go with a element silent piston head and cylinder head swith over the bevel and spur gear to bearings but leave the sector metal bushings and a little grease. as for the bongy spring i would perhaps replace or grease but in the end our bbs fly by the power of a spring so unless its stupidly noisy accept it.
ohh adjust motor height would be a biggy.

all the best mate,happy tinkering

Yeah no worries, no rudeness detected - I expected a certain degree of condescension when I came here.
I'm afraid 'all wrong' isn't a fair assessment though. I know the piston head is the main moveable part, but the cylinder head and nozzle also shift back and forward very slightly along with the tapping plate, unless my eyes are deceiving me when I fire it.
Other advice is great thanks. I'll try adjusting the motor height, perhaps regrease the gears a little, and try a sorbo.

[JOE90]

Re: Noisy Gearbox

cylinder head wont/shouldnt move mate, its fixed in the gearbox with two holding nubs, tappet plate sanding is for a better seal between air nozzle and hop chamber, you shouldnt need to do that. First and foremost try motor height, should be a small allen key.