Decompressing an AEG Spring

[AngelusNex]

Originally Posted by EdisLeado

Okay, so basically what you're saying is that the position of the nozzle as seen through the mag well is moot?

You mentioned previously that the "only reason [you] do the few semi auto shots is to take the stress off the piston teeth." Since the spring itself isn't really the *main* issue here anymore, I guess the question to ask is how do you know for sure when you've taken the stress off the piston teeth after the semi-auto shots to 'release' the spring (other than the obvious; taking out the gearbox, disassembling/looking through a window in the cylinder)?

I have many guns, one for 5 years and all I've ever done is a few semi auto shots to release the energy buildup on the mechbox (spring, piston teeth and gears) I've never experienced ANY issues related to this.

That being said, a new spring is <$10 and pistons are normally <$20 so IF there is an issue it's a really cheap fix.

Opening your gun every game to be sure is guaranteed to cause more problems in the long run (over/under tighten a screw this one time, etc..)

[MaciekA]

I don't have an opinion on whether the spring needs to be relaxed or not, but I do like relaxing it right before I go into the gearbox for maintenance.

Now, assuming you're dead set on relaxing the spring no matter how the above debate shakes out, here are some interesting things:

Some gearboxes have a window on the right half of the gearbox shell where you can see the ARL engaging the bevel gear. They make it easy to relax your spring before gearbox disassembly (makes disassembly so much more pleasant). I've seen this on DBoys, Modify, and elsewhere. Some people dremel a window into the gearbox, I've seen them do it for pinion-bevel viewing. Maybe you can do this to yours.

Another extremely convenient variation on this theme is Modify's anti-reversal latch, which has a flathead screw notch on the top of its shaft, like this:



Once you've seen this you wonder why the heck it hasn't been knocked off by virtually everyone else. Modify should be awarded some kind of medal for this, though I do love having the window on the ARL latch, since it allows me to inspect pinion-bevel engagement too (tempted to go on a lack-of-innovation-in-the-pinion-bevel-alignment-area tangent here... saving for another post). In a perfect gearbox, I'd have both.

Brian Holt from Echo1 actually has a video somewhere where he not only has access to the ARL on the gearbox shell itself, but he actually exploits a small spot near the corner where the pistol grip meets the lower receiver and clears out a bit of material on the receiver, allowing him to relax the spring without even opening the gun. Pretty sweet (though a bit ghetto )

Finally, I've also taken to marking my pistons with a sharpie so that I can look in the cylinder port (which is visible when I open my upper receiver's dust cover -- this of course assumes a port) and tell whether the piston is close to the front of the cylinder or not. This is handy if your gearbox doesn't have a window looking at the spring guide area.

Note that I do not use this because I care whether the spring is relaxed, but rather, because I like to check on where my gearbox settles after firing. Simply visualizing where the gears are at while I'm debugging issues has helped me gain a better understanding of what's going on inside, and Sharpie-marking the piston plastic is risk-free.

EDIT: clarification: in case the original poster didn't pick it up from my rambling above, the reason to get at the anti-reversal latch would be to let the gears fly, and when you do that, they settle in a position where the sector is not engaging the piston.

[Godzila]

I used to release ARL to relive spring tension before opening gearbox. Once bump on sector gear smashed into the rear of tappet plate. Gearboxes aren`t meant to spin backwards. After that I always manually spin gears forward with screwdriver until piston is released.

Uncompressing springs is not needed IMO. Fire few in semi and forget about it. Without AB mosfet there is a big chance that piston is not fully released, but who cares

[ThunderCactus]

FYI firing in semi doesn't necessarily take the stress off the piston, especially if your gun has cycle overlap.
To do it properly it has to be done in FULL AUTO, like I said before, just press the trigger really quickly so the gun only cycles a little at a time, keep doing that until it releases the piston. If done properly, the cycle will end with the piston all the way forward and the sector gear will have it's bare side facing the piston.
Firing in semi isn't a great method since it leaves with the momentum of full speed working, so the sector gear might have enough momentum to push past the cutoff lever position and draw the piston back a little bit.
My 249 with a G&P M120 and without active breaking has the biggest overlap I've ever heard of on an AEG, about 8 rounds. That means when I let go of the trigger, it fires another 8 rounds before the gears run out of momentum.