Today's Airsoft Question comes from Sean Carter from Brooklyn, NY.

Sean writes:

"Wassup?  Just wondering what you do to prep your Airsoft AEG piston for installation inside the gearbox?"

Wassup, Sean.  This is a great question for me right now because I just happened to have stripped a piston in one of AEGs a couple weeks ago and I've been meaning to replace it anyway.

Check out my Airsoft answer plus the death & destruction that went on in my AEG gearbox after the jump...

Here's the damaged piston that I stripped in one of my AEGs a few weeks ago during the final game of the ACA Tournament that Team 5.11 Tactical & I competed in...

Stripped VFC HK416 AEG Piston
Pyramyd Airsoft Blog   
The larger, first tooth was pretty much snapped completely off, but just barely hanging on there by a thread.  But that's not all...

Stripped VFC HK416 AEG Piston, PLUS a cracked metal tooth plate thing
Pyramyd Airsoft Blog   

Guess I really did a number on that piston.  She had a good run though.  This was the original piston that I've had in my AEG since I got it about a year and a half ago.  I'm pretty happy about its performance overall. 

So anyway.  What to do now?  I've got a broken and/or stripped piston.  Obviously, it needs to be replaced.  But with what?

Well, I've had a couple different Modify pistons that the fine folks at JAG Precision hooked me up with, so I figured I'd give one of them a try here.
Modify AEG Pistons (Left to Right): Polycarbonate Pistol, Ultra Piston and Quantum Piston
Pyramyd Airsoft Blog
Since the busted AEG piston belongs to one of my Assault/CQB rifles, I didn't really need either of the two super reinforced pistons on the right.  The Ultra Piston has seven metal teeth and the Quantum Piston uses ALL metal teeth.  These are going to be much more useful inside of a higher-powered AEG that uses a heavy spring (130 or higher).

Since I'm looking for a light weight piston to keep my Rate of Fire (ROF) up, I went with the Modify Polycarbonate Piston.

So, once I selected my piston for my Airsoft CQB rifle, I went about prepping it to be installed inside its new gearbox home.  I do this because I've added some foam padding material to my AEG cylinder head, which improves the angle of engagement between the first tooth (the large one on the left, below) and the first tooth of my gearbox's sector gear.

Before I get too detailed on the process, just check out the photo of my modified Modify piston (tricky with the words, I am). 

In case you're not familiar with what a normal piston looks like, there is normally a tooth in that gap you see between the large first tooth on the left and the smaller tooth next to it on the right.  I took a Dremel rotary tool, which is essential to any Airsoft gun smith's tool kit, and removed the original second tooth.  There are other rotary power hand tools from other brands out there, Dremel just makes the most well-known models.  They're like the Xerox of the rotary tool world.   Also, technically, you can do this with hand files as well.  It's just more work and you'll need one small enough to do the precision filing.  

Alright, so I then took a fine hand file to smooth out the surfaces just cuz it bugged me to see those rough surfaces.  However, I'm not sure it's actually necessary to file it smooth, unless it is really bad.

You'll also note in the photo above that the first small tooth after the large one is a bit shorter than the others.  I cut this one down a bit as well.  You probably don't want to go more than halfway on this tooth though.    

I'm sure there are other techniques and all kinds of little tweaks you can do to make a marginal difference, but this is all I've done to the pistons in my many guns, and rarely have an issue.  Like I said, the piston that I stripped was the original piston that came with the gun that I've been using several times a month since I got the thing last year.  So, for me, it works.  For you, it might now.  I don't know.  Try it out and see for yourself.  The good news is, AEG pistons are cheap to replace.

That's all for now.  

*whisper voice*  Airsoft.

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