Prime RES III 2m Glider & Electric F3L F5L

Product Code: PRIME-RES3

(6 reviews)

Price: $252.43

Description

We are proud to stock the acclaimed Prime RES III, an advanced evolution of the Prime RES II. Designed for FAI F3L/F5L RES competitions, this high-performance model is available in both F3L glider and electric F5L configurations, with X-tail and V-tail options.

Optimized Design for Superior Flight Performance
The Prime RES III has been engineered for exceptional glide performance, stability, and control, making it ideal for both light thermals and strong winds. Its refined aerodynamic profile and lightweight construction reduce drag and improve efficiency, ensuring smooth and predictable flight behaviour.

Key Upgrades & Features:

Elliptical wing design - Improves lift distribution, reduces drag, and enhances overall efficiency.
Redesigned fuselage - Built-in firewall for motor installation with a lightweight, aerodynamic profile.
Dual independent spoilers - Provide precise glide control for competitive flying.
New carbon tailboom - Longer and lighter, increasing strength and responsiveness.
Adjustable tow hook - Allows quick modifications in the field for optimal launch performance.
Integrated ballast system - Enables in-field weight adjustments to adapt to changing wind conditions (F3L glider version only).

Precision Engineering & Quality Materials
Constructed with laser-cut balsa, aero-grade plywood, and carbon components, the Prime RES III is designed for maximum durability and lightweight efficiency. The fuselage is reinforced in key areas, ensuring strength without unnecessary weight.

The multi-segment elliptical wing enhances glide performance and handling, with dual spoilers that close securely using built-in magnets. A carbon main spar with Kevlar reinforcement ensures structural integrity, while the included CNC-cut styrofoam jig simplifies wing assembly for accurate alignment.

Comprehensive Kit for a Problem-free Build
Includes:

Detailed color plan clearly documents the design.
CNC-cut styrofoam wing jig to ensure precise wing alignment.
Laser-cut ribs and structural components for an effortless fit.
Carbon tailboom, main spar & joiners (carbon & steel) for optimal weight and strength.
Full hardware set including rudder horns, U-nuts, bolts, magnets, and Bowden cables.

Aerodynamic & Competition-Optimized Fuselage
The low-drag fuselage features reinforced key stress points while maintaining a lightweight structure. The adjustable tow hook allows quick in-field adjustments for optimal launch angles and improved climbing efficiency. The magnet-secured canopy hatch provides easy access to the electronics and ballast system, allowing fast modifications during competition. The integrated ballast system (119g max) lets pilots fine-tune the center of gravity without disassembling the model.

High-Efficiency Wing Construction
The multi-segment wing is designed for maximum lift with minimal drag, ensuring excellent stability and smooth flight control. The wing's carbon joiners and alignment pins ensure a secure and precise fit, while the Kevlar-reinforced carbon main spar provides additional strength.

Spoilers & Ballast: On-the-Spot Adjustments (F3L glider version only)
Dual independent spoilers offer precise control and quick response during flight.
Integrated ballast system allows for rapid weight adjustments depending on flying conditions.
Steel ballast modules (90g) + steel joiner (29g) provide added stability when needed.

Please note this is a build-it-yourself kit and not an Almost Ready to Fly (ARF) model. Some assembly experience is recommended. Well-illustrated step-by-step English language manuals can be downloaded by clicking on these links:
Prime RES III Electric X tail Manual
Prime RES III Glider X tail Manual
Prime RES III Glider V tail Manual

Prime RES III Specifications
Wing span	2.0 m	78 in
Wing area	35.0 dm2	543 sq in
Length	129 cm	50.9 in
Flying weight from	450 g	15.9 oz
Wing loading	12.9 g/dm2	4.2 oz/sq ft
Aspect ratio	11.3
Wing airfoil	AG24-26 Mod
Spinner Diameter	30 mm
Centre of Gravity	70-78 mm from wing leading edge
Controls	Rudder, elevator, spoilers

Prime RES III Glider Typical Weights
Bare structure	275 g	9.7 oz
Covering	95 g	3.4 oz
Total structure	370 g	13.1 oz
Receiver	6 g	0.2 oz
Rudder servo	5 g	0.2 oz
Elevator servo	5 g	0.2 oz
Spoiler servos (2)	10 g	0.4 oz
Battery	45 g	1.6 oz
Noseweight	9 g	0.3 oz
Flying weight from	450 g	15.9 oz

Recommended RC
Rudder & elevator servos	Blue Bird BMS-101DMG, Blue Bird BMS-101HV, KST X06, KST A08, KST X08, CHA DS06, CHA LV06, CHA HV06, Emax ES9052 Servo
Spoiler servos (2)	Blue Bird BMS-101DMG, Blue Bird BMS-101HV, KST X06, CHA DS06, CHA LV06, CHA HV06, EMAX ES9051
Receiver	4 or 5 channel receiver to match your transmitter
Battery (F3L version)	HyperFlight 300 mAh 4.8V NiMH, HyperFlight 700 mAh 4.8V NiMH, Bonka HV LiPo 1S 550mAh, Bonka LiPo 2S 300mAh, Bonka LiPo 2S 400mAh, 2S 300-600mAh LiPo

F5L Version Recommended Powertrains
Motor	DYS D2225-19, Vitaprop 8x4, Vitaprop 8x5
Motor	Hacker A10-7L 4.4:1, Vitaprop 12x8, GM 12x8
Motor	HyperFlight 1806 2450, CN 6x4
Motor	ArmSoar 1806 2450, CN 6x4
Motor	T-Motor F60 Pro IV V2.0 1750 RPM/V, CN 9x7, GM 9x6
ESC	Dualsky SUMMIT 30 SLIM 6V, Dualsky SUMMIT 30 SLIM 8V
Battery (3S 300-600mAh LiPo)	Bonka LiPo 3S 300mAh, Radient LiPo 3S 450mAh, Bonka HV LiPo 3S 520mAh

Reviews 6

26/01/2026 14:24

Review by: John Barrow

PRIME RES 3

I’ve been flying my Prime RES 3 for a few months and am very pleased with its performance and the way it indicates lift. The kit is manufactured to high standard and includes EP foam jig blocks for the 6 sections of the wing. This ensures the under cambered ribs have the correct support during construction. Its a very satisfying build with excellent instructions on the net. The recommended motor is the DYS 2225-19 and the fuselage design suits the power cables leading from front of the motor. However the drawings show the prototypes have been fitted with the X-power 2307-14, a cased out runner with its cables off the back of the motor. The DYS motor supplies adequate thrust using a 3S lipo. I needed an 850mAh lipo (75gms) to balance out the model which is a reflection of the relatively light motor. The flying weight of the model came out at 510gms.
The wings diagonal ribs are quite beautifully designed and a thorough study of the Instructions is advisable for this stage of construction. The wing, with is multitude of similar ribs definitely qualifies for the axiom check twice and glue once. The manufacturers intended spoiler servos to be linked to the Rx using loose (flying)connectors . I build mine into the wing and fuselage so the wings are plug and play. The rudder is deigned to be glued to the fuselage. I made mine removable by making longer 2mm carbon pins which slot into the tail-tube and also reinforced the tube to reduce the risk of cracking if there was an impact.
The Prime 3 is a great build and equally good RES flyer.

26/08/2025 10:55

Review by: Doug

Ordered this kit along with various accessories and it arrived within a couple of days. I was very impressed with the quality of the kit, the plans and the build "instructions". All in all a beautifully presented kit.

25/08/2025 07:16

Review by: Trevor

Prime RES III F5L Elecrtric

I ordered this kit on a Sunday. Just after ordering I realised I had ordered the wrong version! I took a chance and called Neil and to my surprise he answered right away and rectified my mistake immediately. I received the correct item a few days later. Great customer service!

24/08/2025 23:15

Review by: Trevor

Prime RES III F5L Elecrtric

24/08/2025 21:31

Review by: Trevor

Prime RES III F5L Elecrtric

15/05/2025 15:07

Review by: Michael Fritz

Prime RES lll F3L kit

I needed a different collet size for my Nan Explorer 3 that I got from Neil last fall. I was having trouble finding one stateside and I wanted to keep my assembly of the E3 moving, so I ordered one from HF. But since it seemed silly to order just a collet, I also ordered the Prime lll kit as Neil had a good price on it. Kit and collet arrived in Colorado on the 5th day after placing my order.

I have built at least 10 different F3L and F5L kits in the past two years, so I've had pretty good exposure to some really excellent products, but this Prime kit is, in my opinion, one of the best I've seen so far. Wood selection, hardware, plans, and laser cutting are just excellent. The model has several unique assembly features that I find very clever. I've only just examined the kit contents, but I am looking forward to building and eventually flying this beautifully crafted model.