Kythera SA™ Conversion Kit, Semi-Auto, V3, AK

For this reason, we named the valve mechanism, which is the core of the new line of mechanical HPA PolarStar systems, Kythera. Although it contains very few parts and easily installs and maintains, the system features a very intelligent design and doesn't resemble anything else on the market. The system was designed from the ground up as a mechanical system and utilizes realistic trigger mechanism, which can be used for single-shot, semi-automatic, and fully automatic systems.

The first of these systems is Kythera SA (Semi-Automatic), only a semi-automatic variant.

Realistic Trigger:

This system differs in trigger construction from other mechanical systems. The trigger mechanism is designed to replicate the function, weight, and feel of a real single-action firearm trigger. It acts realistically. Hardened grooves of alloy steel capture and release the stainless steel poppet valve in the same way that grooves in a real firearm capture and release the hammer or striker. As a result, the Kythera trigger is exactly what you would expect from firing a real single-action firearm. The trigger mechanism of the Kythera SA is also adjustable, allowing the user to fine-tune the weight and travel. Additionally, the internal trigger valve is balanced, and the only force acting during the shot is the main spring. This means that the function and feel of the trigger are independent of input pressure and velocity.

Complete Firing Cycle:

The Kythera SA firearm construction completes the firing cycle upon pressing the trigger. This gives you the proven performance of a closed-bolt Fusion Engine and F2 in a completely mechanical, waterproof system with a realistic trigger. It does not require releasing the trigger before the nozzle charges another round and replenishes the firing volume. This happens automatically and consistently with each shot, with an adjustable nozzle delay and return speed.

Since the system resets and reloads immediately after each shot, it is ready for the next shot even before releasing the trigger. This means the system can cycle very quickly for faster subsequent shots and lower chance of double feeding.

Extremely Efficient and Consistent:

The Kythera valve design operates without the need for air to control the opening or closing of the valve. Without a pilot valve, 100% of the air going into the system is fired through the nozzle, allowing it to operate very efficiently. In addition to being extremely efficient, the system is also extremely consistent. The valve is released at the same point every shot with the same force applied, regardless of trigger input.

Universal Charging Cable

The steel cable visible on the rear side of the system is connected to the winding mechanism of the internal poppet valve. While the system automatically snaps the poppet valve shut when the system is pressurized, because Kythera uses a balanced valve, in certain situations, the valve may stall and needs to be manually snapped shut. This usually only happens if the system is completely out of air, causing the pressure to drop below the operating range of the system. The cable is designed to either be routed through the rifle grip for easy access or even potentially attached to the charging handle in some way.

Easy Installation:

The Kythera SA system installs into standard mechboxes as a single unit and typically requires no modifications to the mechbox. No need to install any separate parts, and the parts that need to be removed from the mechbox, are the trigger, spring guide, selector, and safety components.

Wide Range of Velocity Adjustments:

Kythera has a wide range of operating pressures from 60psi to 180psi, allowing for fine adjustment of the system's velocity and adaptation to various requirements and applications. In this pressure range, we observed muzzle velocity of 270 - 500 fps with 0.20 g using a 6.05x380 mm barrel. This allows for the use of a single Kythera in any role from CQB to sniper, primarily by adjusting the input pressure from the air supply.

VIDEO demonstration: Installing the system into the mechabox:

Video demonstration: shooting