Exxtension, Grüner CNC, Allrounder/Hotliner, Span 2500mm, Laser-cut kit

 The Extension of the Zefixx

WICHTIG - Da aktuell noch kein Verkaufspreis für das Modell vorliegt, ist eine Bestellung derzeit nicht möglich. Das Modell wird erst im Herbst verfügbar sein.

IMPORTANT - Since there is currently no retail price available for this model, it is not possible to place an order at this time. The model will be only available in autumn.

The Exxtension is a performance-oriented hotliner wooden kit from Grüner CNC-Service, aimed at ambitious model aircraft enthusiasts who want to make no compromises in either construction or flight characteristics.

After we introduced the Zefixx in 2025, the first requests for 4 flaps and a larger wingspan quickly came in. Ralf Grüner pursued the demand and achieved exactly that with the EXXTENSION. With a wingspan of 2500 mm and a weight of approx. 2000g, the model is in a class that offers a very balanced combination of thermal performance, speed, and precise handling.

Central to the concept is the three-part wing in rib construction, which is fully planked with 0.4 mm thick plywood. This construction ensures exceptionally high torsional stiffness and dimensional stability of the airfoil. The center section has been reinforced with a pultruded carbon fiber tube spar to better absorb forces.

The fuselage is consistently designed for stability and durability. It consists of selected balsa wood and is stiffened by finger-jointed plywood bulkheads, resulting in a very torsion-resistant and robust structure. Especially in the area of the wing seat, the fuselage has been additionally reinforced with light plywood to permanently absorb the forces occurring there.

The tail units are robust flat plates and functionally integrate into the overall concept. The model is controlled via ailerons, flaps, as well as elevator and rudder.

The kit itself corresponds to the typical quality of Grüner CNC and contains precisely laser-cut wooden parts that ensure high accuracy of fit. This not only simplifies assembly but also improves the dimensional accuracy of the finished model. The kit is complemented by a multi-color construction plan and a detailed, illustrated building instruction in German, which guides the model builder step by step through the assembly. Such detailed instructions are particularly advantageous for more complex wooden models, as they minimize sources of error and support a clean construction result.

The scope of delivery includes all wooden components, CFRP tube spar, and the necessary linkage parts. However, adhesives, covering material, and the complete RC and propulsion technology are not included, allowing for individual configuration. For covering, iron-on film such as ORACOVER is usually recommended, as it creates a smooth surface while additionally stiffening the structure.

Overall, the Exxtension presents itself as a thoughtfully designed wooden kit with high structural quality and a wide range of applications. It combines classic construction methods with modern CNC manufacturing, offering a challenging but very rewarding model for advanced model builders, both during construction and in flight.

Included in the kit:

• Precisely laser-cut wooden parts
• Wing in fully planked rib construction
• Servo frames for the wing
• All necessary linkage parts
• Multi-color construction plan
• Detailed, illustrated building instructions (German)

Not included in delivery:

• Adhesives
• Covering material
• Drive and RC components

ORACOVER iron-on film is recommended for covering the model.

Required accessories:

• Servos for ailerons and flaps: KST DS-135 (30x30x10mm)
• Servos for elevator and rudder: KST CM509 (10-12mm servo)
• Receiver with at least 7 channels
• approx. 2 meters twisted servo cable with 0.14mm² cross-section
• Iron-on film (approx. 3 meters)
• 6-pin connector (wing-fuselage)

Drive variants:

• Motor: Dualsky ECO 2826C-V2, 850kV, 167g #51667
• Center section: (RE-K50.5.0.8)
• Spinner cap: (RE-45)
• Controller: Hobbywing Skywalker Brushless ESC 60A
• Propeller: 12x6.5 (AN723946)
• LiPo battery: 4S/2600mAh-4S/3000mAh