Anatomy of replicas

1. 01

   Store energy

   A spring (definition) compressed by an engine or by hand, liquefied gas, or air under pressure.

2. 02

   Push air

   This energy casts a volume of air behind the ball, through the nozzle (definition).

3. 03

   Guide and spin ball

   The hop-up (definition) gives the ball a rearward rotation that carries it, then the cannon guides it to the exit.

The Gearbox is the heart of an AEG (definition). Its format depends on the model: version 2 for the M4 and MP5 (definition) family, version 3 for the AK and G36, version 6 for the P90 (definition), version 7 for the M14.

1. 01

   Arms

   The engine drives the bevel gear (definition), then the spur gear (definition), then the sector gear (definition), whose teeth pull the plunger back by compressing the spring.

2. 02

   Loading

   Meanwhile, the flat tablet (definition) pulls back the nozzle: a ball descends from the charger in front of it.

3. 03

   Release

   The sector gear drops the plunger. The spring throws it forward, the nozzle moves forward and pushes the ball into the hop-up.

4. 04

   Shooting

   The compressed air in the cylinder (definition) crosses the cylinder head (definition) and the nozzle, and pushes the ball into the barrel.

• Ratio

  Gears

  The ratio of speed to torque: around 18:1 initially, 13:1 for a high rate, more than 25:1 for a powerful spring.

• Compression

  Piston and piston head

  The piston (definition) carries the teeth driven by the sector gear. Its head and joint must be perfectly sealed.

• Air volume

  Cylinder

  Its volume must correspond to the volume of the cannon: cylinder full for a long cannon, cylinder pierced for a short cannon.

• Power

  Spring

  Designated by an M index: an M100 gives about 100 m/s with a ball of 0.20 g, in an original replica. It is only a landmark, only the chronograph is authentic.

• Engine

  A neodymium magnet motor has more torque and heats less than a ferrite magnet motor. Its height adjusts to properly gear the bevel gear.

• Relaxation contacts

  On an original Gearbox, the motor current passes through the release contacts, which wear out by sparks.

• MOSFET

  A transistor moves the current in place of the contacts. It protects the release and, if programmable, adds shooting modes and battery protection.

• Battery

  Tension and capacity condition rhythm and autonomy. A LiPo (definition) 11.1 V spins faster than a 7.4 V, but requires more mechanics.

The hop-up brakes the top of the ball as it passes, which makes it turn backwards. In flight, this rotation diverts the air down behind the ball: by reaction, it receives a upward thrust that compensates for gravity. It's the Magnus effect (definition).

• Bucking

  The rubber seal that touches the ball. Its hardness is chosen according to the power: 50 to 60 degrees for a standard replica, 70 to 75 degrees for a powerful replica.

• Nub

  The piece that presses the fucker. Its shape and hardness regulate the surface of contact (definition) with the ball.

• Flat hop and R-hop

  A longer and more regular contact surface for a more stable rotation. More precise, but more delicate to install.

The charger contains the liquid gas. By evaporating, the gas absorbs heat: the charger cools with each shot, the pressure drops, and the power with it. This is why a long gust or cold day weakens a gas replica.

• Shipper valve

  She releases a dose of gas when she's hit. His joint is the first suspect in case of a leak.

• Knocker hammer and valve

  The hammer hits the valve every cycle. A tired hammer releases less gas.

• Mobile ass

  Sent back by part of the gas, it creates the back and rearms the hammer.

• Nozzle

  She pushes the ball into the hop-up and channels the gas. On many replicas, an adjustment (NPAS (definition)) adjusts the amount of gas sent to the head.

1. 01

   Bottle

   Air compressed at 200 or 300 bar (about 3000 or 4500 psi), aluminium or composite. It requalifies periodically, like any pressure equipment.

2. 02

   Regulator

   It lowers the pressure at a few bars, often 5 to 8 bar (70 to 120 psi) depending on the engine and ball: this is the main power setting.

3. 03

   HPA engine

   An electronic card-driven solenoid valve opens the air passage. The opening time (dwell) and rate are programmed.

• When arming, compress the spring behind the plunger, held by the trigger (sear (definition))
• By pulling, the sear releases the piston: all the energy of the spring starts at once
• Spring guide (definition) prevents spring from twisting and regularizes shooting
• A spring left armed gets tired: the replica is stored unarmed
• The original parts of the sear and piston are often the weak point of a reinforced spring