Spring vibration/echo

[THE FNG]

Hi guys,

Just swapped an m100 spring into my VFC SCAR that came with it as part of a sale. At the end of every cycle, there is a vibration/echoing noise coming from the mechbox.

I've read about it being that the spring is too short.

My question is:

how much damage can the spring do to my gearbox and Is it a big problem if I leave it in?

I'm just trying to find out if I am going to have to spend another tenner on a spring

Thanks in advance,

Andy

 

[Monty]

Yeah, the spring might be a bit short. My King arms M4 did the same thing, swapped the spring for a stronger one and it was fine.

 

[Ian_Gere]

My CM.048 AK-74 has a Guarder SP100 spring downgrade and does that. So far it's been fine. I'm not planning to do anything about it, so we'll see if it turns out to be a problem.

 

[Samurai]

If the spring is so short that the piston can actually move freely or can bounce back a bit after it hits the cylinder head then that's bad. The sector gear could hit the piston in a wrong position.

 

[Ian_Gere]

Yeah, but I think the spring would have to be clipped to be that short. I think the sound may be a result of the spring vibrating from side to side. Some spring guides are quite thin; I know that the standard CYMA plastic ones are. This may allow more sideways movement than a fatter spring guide.

 

[Rock-climby-Dave]

as stated, no damaged caused.

Unless it's too short and is allowing the piston to rebound.

If it's the right length, grease up the spring guide and it usually fixes the problem