Fixing your AEG’s Angle of Engagement (AOE) is a crucial step that you should take to ensure the smooth running reliability of your AEG.

Before we get elbow deep into the gears and springs of your gearbox, first you need to understand what AOE is, why we correct your AOE and how you correct it.

What is Angle of Engagement (AOE)?

Angle of Engagement is the angle that the first tooth on the sector gear interacts with the first tooth of your piston. The angle that these two teeth first touch correlates to the surface area that the force is transferred through and the direction that it is applied.

Why correct the Angle of Engagement?

Since the Angle of Engagement determines the directionality of the force applied to the piston. If that force is not applied perpendicular to the motion of the piston, you are putting undue stress on the piston which will cause it to fail.

As correcting the Angle of Engagement helps your AEG run smoother, it also marginally improves firing noise, rate of fire and trigger response.

How to correct your AEG’s Angle of Engagement (AOE)

Here, we’re going to show you how to fix your AEG’s Angle of Engagement using sorbothane.

Sorbothane is a material commonly found in shoe insoles, it efficiently absorbs impact and shock and converts that force into heat energy. These characteristics make it the perfect material for fixing your gun’s Angle of Engagement; not only does it fix AOE but it also quiets your AEG’s operation and reduces the forces transferred into the gearbox shell, resulting in an AEG that lasts longer.

Firstly, open up your gearbox and remove everything. This is a good opportunity to clean up all the parts and check for wear and tear.

Place the cylinder and cylinder head, piston and piston head and the sector gear back into the gearbox. With these parts in place, we can see the interaction of the gear teeth on the piston teeth and decide how you need to change your piston’s alignment.

Here, we are looking for 3 things:

  1. The point at which your teeth engage. We want this position to be as close to 12o’clock as possible. This is when the force of the gears will be translated to the piston in the optimal direction.
  2. The angle at which your teeth engage.The teeth of your gears should contact with the biggest possible surface area.
  3. The gears are interacting correctly. When correcting your AOE, occasionally teeth may rub or contact unintentionally. This is often solved by removing the second piston tooth, or buying one that’s already done.

The most common scenario for a new or stock AEG is that the piston is too far forward. This results in the gear interacting with the piston too early, distributing the motion inefficiently

This is where we use the sorbothane to space the piston further back, to engage properly as outlined above..

Your sorbothane should be the same diameter as your cylinder head, with a hole in the center that allows air to flow through into your barrel. It’s a good idea to have varying thicknesses of sorbothane pad available, to adjust engagement as necessary.

Here, we suggest that you dry fit the sorbothane to your cylinder head and test your AOE now. You should see that your piston and gears come together closer to the 12 o’clock position. Vary the thickness of the sorbothane to align them perfectly.

Next, you need to permanently attach the sorbothane to your piston head. We recommend using a 2 part epoxy for this process. It’s strong enough to hold throughout the life of your AEG, but flexible enough to withstand the shock. Other glues, like cyanoacrylate glue (super glue), become brittle when dry and you risk your sorbothane becoming dislodged during firing.

You cylinder head should be free from grease and oil and we recommend roughing both surfaces with sandpaper to get good adhesion when it comes to gluing the pad. When gluing the pad, ensure that you don’t get any glue on the o-rings, to help keep a good seal.

Assemble your gun again and test fire! Your AEG should have a noticeable difference when firing. It will be much smoother, quieter and will last longer.