Introduction
The COMPASS is a 4.78-meter wingspan composite glider designed for electric launches and GPS Triangle Racing, developed by NAN Models—renowned for producing high-quality, competition-grade F3J/F5J RC gliders. GPS Triangle Racing is a popular RC gliding discipline where pilots navigate their gliders through a triangular course using GPS and telemetry for guidance and scoring. The Compass made its first public appearance around 2021 and notably clinched victory at the 2023 US GPS Nationals!
NAN Models incorporated many of the successful design elements from their F5J Explorer Q series into the Compass. Despite its strong performance, this model remains somewhat under the radar compared to others in its category. Let’s dive into an in-depth review of this intriguing glider.
Kit Overview
The wing is composed of four parts with a solid carbon joiner for the outer panels and a strong and big central joiner in the fuselage, and this fuselage is split into two sections, with a self-aligning joint for easy assembly. The tail and fin/rudder are quickly attached using NAN's proprietary locking system, which also simplifies connecting or disconnecting the linkages. The two-part fuselage is particularly practical given the notably long rear boom, making it convenient for transport, especially for those with limited space or smaller vehicles.
The wings feature a hollow-core, double-carbon construction, utilizing lightweight carbon fabric similar to what is found in F3G or F3B gliders. Interestingly, NAN Models has opted not to follow the trend of full Rohacell core molded wings as seen in many F5J models. Only the fin/rudder and tail sections employ a full Rohacell core, offering a balance of reduced weight and increased stiffness.
The wings are equipped with four ailerons and two flaps, with integrated ballast tubes in the center section positioned both in front of and behind the CG. This configuration allows for better balance control and enables the model to reach the maximum wing loading permitted.
The Compass fuselage features fiberglass from the trailing edge of the wing forward, minimizing carbon interference for 2.4 GHz receivers and GPS telemetry systems. This ensures better reception and reliable telemetry even at extended ranges.
The nose section of the fuselage provides ample space for various power setups and battery configurations, accommodating both in-runner and out-runner motors. This versatility allows the pilot to choose between an affordable setup or a more powerful, premium motor combination.
Molding quality is, as usual, with NAN Model top notch, fit and finish is incredible. Components weight:
- Front Fuselage: 463gr
- Rear Fuselage: 246gr
- Tail: 88gr
- Rudder: 62gr
- Central joiner: 129gr
- Center right panel: 572gr
- Center left panel: 565gr
- Outer right panel: 454gr
- Outer left panel: 450gr
- Outer joiners: 28 gr each
Total empty weight before assembly: 3085 gr
Assembly
I began with the motor installation, which required careful attention. I opted for an outrunner motor with a long shaft (Dualsky XM4255EA-12 with the EGL shaft/bearing system, KV=520). To accommodate this, I had to slightly shorten the nose to achieve the correct 42mm diameter section. I then machined two mounting rings from epoxy board—one to secure the motor and another to support the front of the shaft cage. Special thanks to Aaro from Finland for sharing the CNC files for the mounting rings; they were incredibly helpful. The mounting rings were glued in place with the motor, shaft, and spinner assembled to ensure perfect alignment and centering.
Next, I moved on to the fuselage radio equipment. I created a removable mezzanine tray from epoxy board to hold the battery. This design leaves space underneath for the ESC, allowing adequate airflow for cooling. The battery is secured with Velcro. Behind the mezzanine tray, I added a removable long and narrow plate, fixed at the front with a single plastic 3mm screw. This plate holds the receiver (Jeti REX10) and the GPS sensor (SM-Modellbau V3), both secured with Velcro.
The Compass comes equipped with MPX green connectors (6 pins). The fuselage connector is mounted on a printed circuit board, which simplifies soldering by grouping the positive and negative wires and includes screw nuts for secure installation at the wing root.
For the wings, I used green connectors throughout and installed MKS HV6150 servos for the ailerons, despite their thickness exceeding the available height. I could have used MKS HV6120 servos, but those were already installed in the Falco wings (a 60-inch glider I assembled before the Compass). For the inner ailerons, I chose the reliable MKS HV6130, while the recent and powerful MKS HV6160 servos were used for the flaps. All servo frames were designed and 3D printed in-house using PETG carbon filament. Preparing and soldering the wiring harness was a painstaking process due to the six servos and four wing sections involved!
For the fuselage servos (elevator and rudder), I used MKS carbon servo frames with HV6150 servos and printed a custom connector support.
On the scale, the final flying weight is 4,390 grams with the center of gravity set at 120mm. I only needed an additional 10 grams for balance with the battery, which I’ll likely remove after the first flight.
In the air!
For the maiden flight, while still waiting for my 5s battery, I decided to go with a 6s battery and start with a 15x8 GM propeller, based on Jo Grini's test results with the Dualsky motor (Thanks, Jo, for your tests and recommendations!). The plan, however, is to switch to an 18x10 propeller with a 5s battery for future flights.
The maiden flight of the NAN Model Compass took place at Col du Glandon on a calm autumn afternoon with stunning colors. Paragliders weren’t flying much due to weak winds, making it an ideal moment to launch this glider after a final pre-flight check. I had no specific settings other than the CoG recommendation I found online (between 120mm and 125mm from the leading edge). I adjusted the rest to my preferences: full throw on the ailerons, 60% on the inner ailerons, and 30% on the flaps, with 50% differential.
In the air, the Compass is impressive. It can fly very slowly with thermal camber (currently around 8mm down) and is extremely stable in all conditions. Circling is effortless, requiring minimal aileron correction. In cruise mode, the glide ratio is remarkable, allowing you to cover large distances quickly. In speed mode, the plane accelerates smoothly while maintaining excellent glide performance. The roll rate is very responsive, perhaps even too much with my current settings, but it remains highly precise.
Rudder-to-elevator decoupling is excellent, and the tall fin provides outstanding stability, complemented by the outer wing dihedral. The climb rate with the smaller propeller on 6s is decent, though I haven’t fully tested it yet. Unfortunately, the session was cut short due to a motor issue. The motor unexpectedly locked up internally, forcing me to land cautiously before landing downhill. After manually freeing the motor, it began working again, which was puzzling. A closer inspection was clearly needed.
Aesthetically, the Compass breaks a lot of design conventions, but in the air, it exhibits a unique elegance and presence. My only critique is that the canopy should match the fuselage color.
Back in the workshop, I found the issue: one of the screws securing the long shaft was loose and had been grinding against the inner cage/guide, intermittently locking the motor. Fortunately, no significant damage occurred—lucky me!
For the next flight, I switched to a 5s SLS-Quantum battery and used a 16x10 propeller instead of the intended 18x10, after hearing that the combo could potentially overheat the motor. Better safe than sorry! The launch and climb rate were excellent. I handed the transmitter to some friends, and the session turned into a showcase of flybys, climbs, and aerobatic maneuvers, pure fun for all!
Surprisingly, the Compass excels in aerobatics despite its 4.78m wingspan. The roll rate is impressive, making precise four-point rolls a breeze. Vertical maneuvers are equally strong, thanks to the glider’s energy retention and aerodynamic efficiency. The structure flexes slightly under high G-loads, but overall, its performance is outstanding, making the Compass a versatile and enjoyable glider to fly.
Since then, I’ve had several more flying sessions that confirmed the plane’s excellent performance. I also prepared four brass ballast bars from a previous project, allowing me to add up to 1.5 kg of extra weight. With the added ballast, the Compass handles wind better, improves its glide speed and finesse, while still thermalling easily when allowed to circle faster. Landing is particularly smooth thanks to the effective crow brakes. You can slow the plane down while maintaining full control of the descent, and the Compass remains agile in roll thanks to the responsive ailerons.
Time to Conclude!
Characteristics
- Wingspan 4.78 m
- Length 2.205 m
- Wing area: 102.9 dm2
- Elevator area: 10.9 dm2
- Aspect Ratio: 20.3
- Weight: 4390 gr (empty), addition up to 2kg of ballast
- Wing loading (FAI) : 38.6 gr/dm2
- Controls 4-Ail, 2-Flap, Rud, Elev, Throttle
- Wing chords: 267mm / 245 mm / 206 mm / 90mm
My Settings
- CoG: 122 mm from leading edge
- Elevator: 25mm up and down
- Rudder: 45mm left and right
- Ailerons:
- Outer ailerons: 40 mm up and 20mm down
- Inner ailerons: 30 mm up and 15mm down
- Flaps: 17 mm up and 10 mm down
- Butterfly:
- Outer ailerons: 0 mm
- Inner ailerons: 40 mm up
- Flaps: 80 mm down
- Elevator: 9 mm down
- Thermal position:
- Flaps: 7mm down
- Inner ailerons and Outer ailerons aligned with flaps
- Speed position:
- Flaps: 1.5mm up
- Inner ailerons and Outer ailerons aligned with flaps
- Snapflaps
- Flaps: 5mm down full elevator stick
- Inner ailerons and Outer ailerons aligned with flaps
Some additional Videos