Gearbox Makes a Loud 'Pop' When Firing.

[RonLancs]

Hi all, 

 

Here we have an V2 Orion Gearbox from Specna. 
 

I’m planning to use it as a base to build a DMR. Now, I’ve fitted what I believe to be a M110 (that comes with the Specna as appose to the M90 that is also provided) and it wasn’t the quietest gearbox when I first got it however it’s been shimmed, motor height corrected and it’s been lubed it to where I believe it to be suitable, yet it is now really loud.

 

Below are 2 samples of before and after the insert of the stronger spring. 
 

The video with the one with the metal tray is prior to the heavier spring. 

Thanks in advance

 

Ron 

[Adolf Hamster]

just the pop of the air being blasted out at higher pressure?

 

wee bit whiney (likely just the way the gears are) but sounds ok.

 

you tried it in the gun firing ammo? that'll make a big difference to the report.

[RonLancs]

19 minutes ago, Adolf Hamster said:

just the pop of the air being blasted out at higher pressure?

 

wee bit whiney (likely just the way the gears are) but sounds ok.

 

you tried it in the gun firing ammo? that'll make a big difference to the report.

I’ll have a re-shim. Upon closer inspection tis a bit tight and no not had chance to fire it yet. 

Thanks 

 

Ron 

 

[Skara]

Haven't watched the video.

What barrel length are you running? Because short barrels are noticeably louder due to the system being (most likely) overvolumed.

 

As Adolf said, try loading the gun, bbs muffle the sound a little bit (it's also safer for the gearbox as dry firing for long periods can lead to your shell/piston head to crack)

[RonLancs]

It’s 200mm and in all honesty I haven’t yet assembled it. I’ll take it for a test tomorrow. 

[Skara]

23 minutes ago, RonLancs said:

It’s 200mm and in all honesty I haven’t yet assembled it. I’ll take it for a test tomorrow. 

Yup.

My M4 now has a 130mm inner and is just as quiet as a KORD.

[RonLancs]

30 minutes ago, Skara said:

Yup.

My M4 now has a 130mm inner and is just as quiet as a KORD.

 😂 if it wasn’t for BFBC2 I wouldn’t know what that was. But yea as I said I’m going to DMR it or at least attempt. 
 

Thanks again guys

 

Ron

[Sneaky]

It sounds a like a perfectly working gearbox...