PolarStar Direct Attach Front Cylinder
PolarStar Direct Attach Front Cylinder
PolarStar Direct Attach Front Cylinder
PolarStar Direct Attach Front Cylinder

PolarStar Direct Attach Front Cylinder

$55.00
Engine

Which Polarstar HPA Engine Should You Choose?

All FPS figures are measured with our standard 180mm 6.02 inner barrel and KA Tech's tuned hop-up, bucking, and regulator combination.

Kythera

250–400 FPS · 350 FPS @ ~100 PSI · Semi-auto only

Purely mechanical — no electronics, no full-auto. Just air, BBs, and go, with a realistic trigger pull, break, and reset. Great for training, Milsim, or fields that are hesitant about HPA rifles.

Jack

250–410 FPS · 350 FPS @ ~100 PSI · Up to 50 RPS full-auto

Our entry-level HPA engine. Fast semi-auto with real full-auto capability.

F2

250–440 FPS · 350 FPS @ ~100 PSI · Up to 85 RPS full-auto

The best overall HPA engine on the market — the strongest combination of air efficiency, accuracy, range, consistency, and tune-ability.

Fusion Engine

250–500 FPS · 350 FPS @ ~55 PSI · Up to 75 RPS full-auto

The powerhouse. A clicky tactical trigger board delivers crisp trigger response for players who want the most power out of their rifle.

Our recommendation: First time going HPA? Go with the Fusion Engine. If you're committing real money to get into HPA, go all the way the first time so you're not stuck upgrading piece by piece down the road.
Backed by KA Tech Warranty
HPA Specialists Since 2022
Description

The Alignment Revolution is a Monolithic Assembly

If you've ever spent hours shimming a gearbox shell just to have your nozzle tilt .5mm and ruin your grouping, you know the pain. We got tired of "good enough" alignment. So we made this.

The PolarStar Direct Attachment is a replacement for the original front cylinder on your F2™ or JACK™. It connects directly to The PolarStar Hop Up Thing, allowing the engine to mount directly to the hop-up itself. Because alignment is now built into the Direct Attachment front cylinders, the upper gearbox shell is no longer needed for alignment. Electronics, trigger, and selector systems can still be housed in a modified shell, printed lower, or completely custom chassis.

How It Works

A two-piece system: the Direct Attach Front Cylinder and an internal Adapter. Thread the PolarStar Hop Up directly into this assembly and the HPA engine, hop-up, and inner barrel become one single, rigid, monolithic unit.

  • Zero Nozzle Deflection — Locking everything together eliminates nozzle wiggle or lean during BB loading.
  • Consistency = Groups — If the BB loads the same way every time, hop-up effect stays consistent. Consistent hop means tighter groupings.
  • Perfect Alignment — Physically impossible for the nozzle to be misaligned with the bore.

What Gearbox Does This Fit?

Short answer: it doesn't exactly need one. Whether you're dropping this into a standard shell to fix a lemon, running Monk Customs Oracle shells, or building a scratch-made chassis from a 3D printer — this system is limited only by your imagination.

Note: The Direct Attachment Front Cylinder and Adapter are sold as shown. The F2™ engine, hop-up, and shell shown in product images are not included and sold separately. Ships from Newark, DE.

Parts and accessories ship within 7 business days. Custom HPA rifle builds take up to 45 business days (often less). Need it sooner? Contact us to check current stock.

All sales on parts and accessories are final once shipped. Defective or damaged items are covered under the KA Tech Warranty.