25-Jun-24 - 06:54 PM

Thermal Circle Text - Thermal Circle 57

Written by Hayden Daley - 10 July, 2023.

Welcome to this edition of the Thermal Circle in this edition GPS racing equipment for sailplanes that are triangular racing. All equipment is available from Model Flight if you wish to race you need this equipment and also in this edition the new Pike Prestige 2PK F5J model 1600gm STORM version

Available from:

RC Electronics Raven Airborne GPS Transceiver

 

The RC Electronics Raven is a GPS equipped transceiver for use in GPS Triangle gliders or other large models. It provides global positioning, altitude, vario, speed and Rx battery data to a ground station or via telemetry to your RC system.

 

Features

  • Integrated 18Hz GPS receiver with active antenna
  • Supports GLONASS, GPS, BeiDou and Galileo
  • Integrated Inertial Module with 3 axis accelerometer, 3 axis gyro-meter and 3 axis magnetometer
  • Integrated Environmental Noise Level Detection recognises when the motor, impeller or turbine is started
  • SMA Antenna Connectors allows you to move the RF and GPS antennas for best performance
  • Air Speed Sensor
  • Telemetry Output allows the use of the back channel to your primary RC system to transfer data to the ground via a secondary link
  • USB Connector for data transfer to your PC
  • Integrated IGC logger using 8GB solid state memory
  • Dual high accuracy pressure sensors for improved vario measurements
  • FHSS frequency hopping on 433Mhz so there are no frequency conflicts

Product Information

 

The Raven is one component of the RC Electronics model aircraft telemetry system. The Raven is the onboard unit intended to be used with the Snipe Ground station. The Raven is designed to measure many parameters of an R/C model aircraft and transmit them to the Snipe ground station via the telemetry channel working on 433 MHz frequency. The unit is capable of measuring sink/climb rate (Vario), airspeed, altitude, orientation of the plane (pitch, roll and yaw), noise level, servo pulse on servo
inputs, GPS data with 18Hz refresh rate and supply voltage. For storage it has an internal 8Gb solid state storage which is presented as flash disk drive when the Raven unit is connected to PC via a mini USB connection.

Specs

 

Unit Dimensions

80 mm x 41 mm x 16 mm

Weight

57 grams (without GPS and RF antenna)

Temperature Range1

-10°C ~ +60°C

Input Voltage Range

4.0 – 18.0 volts DC

Input Current

80 milliamps

Measured Voltage

4.0 – 10.0 volts DC

Memory capacity

8 GB

Available from:

RC Electronics Raven 2 Airborne GPS Transceiver

 

Onboard air-data measuring system for R/C aircraft with telemetry.

Features

  • Integrated fast solid state memory for up to 20h of logging
  • Latest pressure sensor for ultra-fast detection of climb/sink
  • Two pressure sensors for altitude and Vario measuring
  • 3 axes accelerometer
  • Enl - Environment noise level detection to detect working electric, impeller or jet motor.
  • FHSS - Frequency Hopping Spread System on 433MHz telemetry channel to eliminate frequency conflicts.
  • 18 Hz GPS working with GNSS, Glonass and prepared for Galileo global positioning satellites.
  • Various telemetry protocols supported over one of the servo inputs (JetiEx, PowerBox System, Hott ...)

Product Information

 

The “Raven 2” is one component of the RC Electronics model aircraft telemetry system. The unit is the “onboard” unit intended to be used with the “Snipe / Finch” “ground station”. The unit is designed to measure many parameters of an R/C model aircraft and transmit them to the ground station via the telemetry link working on 433 MHz frequency. The unit is capable of measuring sink/climb rate (Vario), altitude, acceleration of the plane in all axes, noise level, servo pulse on servo input, GPS data with 18Hz refresh rate and supply voltage. For storage, it has internal fast solid-state storage which will record up to 20h of flying.

 

Specs

Unit Dimensions

63 mm x 22 mm x 13 mm

Weight

16 grams (without GPS antenna)

Temperature Range

-10°C ~ +60°C

Input Voltage Range

4.0 – 12.0 volts DC

Input Current

80 milliamps @ 8V DC

Measured Voltage

4.0 – 12.0 volts DC

Memory capacity

Up to 20h of flying

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RC Electronics Smart Switch

 

The RC Electronics Smart Switch is an advanced switch to connect between Android device, USB power bank and an external device like the RCE Snipe or T3000.

Specs

Unit Dimensions

27 mm x 14 mm x 12 mm + cable 0.5m long

Weight

15 grams
 

RC Electronics Eagle Micro Airborne GPS Unit

 

The RC Electronics Eagle Micro Airborne GPS Unit is an onboard air-data measuring system for RC aircraft.

 

Features

  • Comes with a JR cable 10cm long (female to female)
  • Integrated fast solid-state memory for up to 20h of logging
  • Latest pressure sensor for ultra-fast detection of climb/sink
  • Two pressure sensors for altitude and Vario measuring
  • 3 axes accelerometer
  • Enl - Environment noise level detection to detect working electric, impeller or jet motor.
  • 18 Hz GPS working with GNSS, Glonass and prepared for Galileo global positioning satellites.
  • Various telemetry protocols supported over one of servo inputs (JetiEx, PowerBox System, Hott ...)

Product Information

 

The “Eagle” is one component of RC Electronics model aircraft telemetry system. The unit is designed to measure many parameters of an RC model aircraft and transmit them to the ground via the primary system telemetry backlink. The unit is capable of measuring sink/climb rate (Vario), altitude, acceleration of the plane in all axes, noise level, servo pulse on servo input, GPS data with 18Hz refresh rate and supply voltage. For storage, it has internal fast solid-state storage which will record up to 20hrs of flying.

It has a built-in GPS antenna, one pressure port (Pte – total energy compensated pressure from TEK probe) and a multi-colour LED to show the status of the unit. It also has 3 connectors. The micro USB is used for future updates, settings and flight log downloads. The 4-pin connector is prepared for future use (extended bus). JR 3-pin servo input is used to measure normal PWM servo pulse or to transmit 3rd party telemetry protocol on it (depending on the unit setting). The unit gets power from the USB or JR connector. 

Telemetry output
Connect to back-channel of your primary RC system and transfer all the data from Eagle to the ground via secondary link. Note that the Eagle unit does not have any RF capability. You must use the Telemetry back channel functionality of your radio system. Jeti EX, Powerbox System, Graupner HOTT for example.

 

Specs

Unit Dimensions

47 mm x 22 mm x 16 mm

Weight

17 grams

Temperature Range

-10°C ~ +60°C

Input Voltage Range

4.0 – 12.0 volts DC

Input Current

80 milliamps @ 8V DC

Measured Voltage

4.0 – 12.0 volts DC

Memory capacity

Up to 20h of flying

 

Available from:

RC Electronics Swift Micro Airborne GPS Unit

 

The RC-Electronics Swift is a micro sized onboard device for GPS triangle flying with an 18 Hz GPS module, and an external GPS antenna.

Product Information

 

The RC Electronics Swift is the newest onboard micro GPS device for GPS Sport Class Racing or sport flying where you want to keep track of the model's performance. Micro sized but extremely powerful with its 18 Hz GPS module and external GPS antenna. Fitting between the Sparrow and the Raven in price it is a fully featured GPS device with IGC logging and very accurate altitude and vario monitoring. It can be used with 3rd party telemetry like Jeti EX, P2Bus or Graupner HOTT, or with the external Sparrow RF module (available separately). Using either of these options allows the Swift to communicate with the free Albatross App that works on a number of Android devices. You can also use an optional TEK sensor for even more accurate readings.

 

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RC Electronics Finch RF GPS Ground Receiver 433 Mhz

 

The RC Electronics Finch RF is the ground station for use with the Sparrow GPS unit. The Finch connects to the Albatross App on your suitable Android device.

Features

  • External SD for updates
  • Plug & play
  • FHSS - Frequency Hopping Spread System on 433MHz telemetry channel

Product Information

 

The RC Electronics Finch RF unit is designed as a ground unit for Sparrow / Raven onboard GPS modules. It represents a bridge between the RF link and USB data transfer to an Android tablet or phone running the Albatross App to display the telemetry information.

 

Specs

Unit Dimensions

42 mm x 22 mm x 11 mm

Weight

11 grams

Temperature Range

1 -10°C ~ +60°C

Input Voltage Range

5.0 volts DC USB

Input Current

84 milliamps

Available from:

RC Electronics Finch Serial (Jeti/Core) GPS Ground Receiver

 

The RC Electronics Finch Serial Jeti/Core unit is the ground station for use with the Sparrow/Raven GPS unit. The Finch converts the Jeti (or Core) EX data and then connects to the Albatross App on your suitable Android device.

Product Information

 

The RC Electronics Finch Serial Jeti/Core unit is designed as bridge to convert Jeti EX TELEMETRY DATA to Albatross App protocol. It is converting Jeti data from Sparrow / Raven onboard units and via USB data transfer to an Android tablet or phone running the Albatross App to display the telemetry information.

 

Specs

Unit Dimensions

42 mm x 22 mm x 11 mm

Weight

11 grams

Temperature Range

1 -10°C ~ +60°C

Input Voltage Range

5.0 volts DC USB

Input Current

84 milliamps

Available from:

RC Electronics Raven 2 PRO Airborne GPS Transceiver

 

The RC Electronics Raven 2 PRO is an Onboard air-data measuring system for R/C aircraft with inbuilt 433 Mhz telemetry

.

Features

  • Integrated fast solid state memory for up to 20h of logging
  • Latest pressure sensor for ultra fast detection of climb / sink
  • Indicated airspeed sensor
  • Two pressure sensors for altitude and Vario measuring
  • 3 axes accelerometer
  • Electronic Total energy compensation for Vario as an option.
  • Model polar measurement algorithms.
  • Enl Environment noise level detection to detect working electric, impeller or jet motor.
  • FHSS Frequency Hopping Spread System on 433MHz telemetry channel to eliminate frequency conflicts.
  • 18 Hz GPS working with GNSS, Glonass and prepared for Galileo global positioning satellites.
  • Various telemetry protocol supported over one of servo input (JetiEx, PowerBox System, Hott ...)

Product Information

 

The “Raven 2 PRO” is the premier RC Electronics model aircraft telemetry system component. The unit is the “on-board” unit intended to be used with the “Snipe / Finch” “ground station”.  The unit is designed to measure many parameters of an R/C model aircraft and transmit them to the ground station via the telemetry link working on 433 MHz frequency. The unit can measure sink/climb rate (Vario), airspeed, altitude, plane acceleration in all axes, noise level, servo pulse on servo input, GPS data with 18Hz refresh rate and supply voltage. For storage, it has internal fast solid-state storage which will record up to 20h of flying. 

ENVIRONMENTAL NOISE LEVEL DETECTION INTEGRATED

Automatic detection when the motor is running (electric, gas, impeller or jet).

INTEGRATED 18Hz GPS RECEIVER WITH ACTIVE ANTENNA

Supporting GLONASS, GPS, BeiDou and Galileo.

FAST VARIO RESPONSE

Using the latest sensors on the market, Raven 2 PRO has super fast vario response and a super stable vario signal.

Fine-tuned RF antenna on extended coax cable

External active GPS antenna allows you to install it to a position where reception is the best.

AIR SPEED SENSOR

Measures airspeed using a high-precision sensor. Airspeed is used for accurate polar measuring, which is needed to detect net air mass movement accurately. With airspeed information, wind calculations are faster and more accurate.

Telemetry output

You can connect to the back channel of your primary RC system (e.g. Jeti) and transfer all the data from the Raven 2 PRO to the ground via the secondary link, or you can use the inbuilt 433Mhz telelemtry that can be transmitted to the Snipe or Finch ground station.

Extend connector

For future development

USB connector for PC data transfer

Connecting Raven 2 PRO to PC via a USB cable will offer the user the ability to change settings, download flight data and update the module to the latest version

Integrated IGC logger, using fast solid-state memory

All flights are stored in internal fast solid-state memory in IGC format for later review and upload to online competitions sites (RCmodelspot, …)

Dual high-accuracy pressure sensors

Improved sensitivity for detecting the climb rate of the plane with a true 100Hz measuring rate.

What's in the box?

  • Raven 2 PRO
  • GPS antenna
  • JR cable 30cm long (female to female)

 

Specs

Unit Dimensions

68 mm x 26 mm x 16 mm

Weight

21 grams (without GPS antenna)

Temperature Range

-10°C ~ +60°C

Memory capacity

Up to 20h of flying

Input Voltage Range

4.0 – 12.0 volts

DC Input Current

80 milliamps @ 8V DC Measured Voltage 4.0 – 12.0 volts DC

Available from:

RC Electronics Snipe GPS Ground Receiver with HG Antenna

The RC Electronics Snipe GPS Ground Receiver is the ground unit for use with the Raven or Sparrow airborne units. It produces the vario tones and voice announcements for the pilot or helper and transfers data to an Android tablet or phone running an App like RCE Albatross or SkyNavigator.

Features

  • 433Mhz FHSS receiver
  • Stereo audio output
  • Accepts audio input
  • Accepts 3rd party telemetry input
  • Plug n play operation
  • Powered from the Android tablet or phone, or a power bank, via micro USB connector

Specs

Unit Dimensions

80 mm x 41 mm x 16 mm

Weight

57 grams

Temperature Range1

-10°C ~ +60°C

Input Voltage Range

5.0 volts DC USB

Input Current

84 milliamps

Available from:

Pike Prestige 2PK F5J model 1600gm STORM version

Product Information

 

 

Prestige 2PK STORM version F5J Electric glider - RTF weight 1650g – 1700g, stiffness of the spar – 80%

The Prestige 2PK STORM is a new version for very windy conditions in the F5J category. We were mainly inspired for this change in several windy competitions last season.

It will be much stronger than the Normal version. Its RTF weight will be 1650 - 1700 g. The carbon skin layer is reinforced and the beam is strengthened. The beam reaches 80% of the strength of the F3J version.

Sold and backed up by the Exclusive Samba AU agent since 2002

The basic model is supplied with the complete servo wiring loom, wing, tail and fuselage protective bags, linkages and quick  links for all surfaces.

Colours can be specially ordered according to the scheme and colours shown. Fluoro colours cost extra.

Talk to our sales team.

Optional Extras

  • Fluoro colours + $50
  • Non standard colour scheme + POA
  • Ballast Set for fuselage 3 piece + $79.99
  • Ballast tubes in wing + $25
  • Ballast set for wing 2 piece + $35
  • 8 degree wing joiner (1) + $29.99
  • IDS Set to suit flap/aileron installation (1) + $25
  • IDS servo installation at factory (1) includes frame and labour (no servo incl) + $100
  • Servo installation into fuselage (2) no servo incl + $79.99
  • Model can be ordered with a 30mm nose cone at no extra cost
  • The factory can supply and install servos at competitive prices

First of all thanks to our good friend Philip Kolb for designing an exceptional model in the F5J world. He was not influenced by various fads in the F5J scene and used all his knowledge, experience and the best available software to construct the amazing PIKE PRESTIGE 2PK.
 

To this we added the full rohacell core to the design, the whole model is made in heated aluminium moulds to a very high temperature. This technology creates a light, strong and stable platform that will provide years of flying.

It is worth mentioning a few properties we have found very nice after flying this model for a while.

Circling

In circling the model as expected did not have a need for extreme dihedral joiners since the aerodynamic design and airfoil changes does that work in a better way than increasing dihedral. It was first produced with 6-degree tip joiners and then we added an 8-degree alternative. It has also been flown a lot with 6-degree joiners with good success in low altitude thermalling at EC F3J 2019. There should be no need for extreme joiners though this is again a personal preference.

Circling camber can be extreme (5-8 degrees) while still maintaining speed because of a new tail design that keeps the energy better (less drag). This means high bank angle is possible and yet you can still keep the high lift in a tight thermal.

The large and newly designed rudder makes it possible to yank the model into any thermal you find.

Penetration

As you will find described in the designer Philip Kolb’s writeup the penetration in all camber settings is very good because of the new tail design. Now you can change the camber at any point without losing flying energy as we see with many other airfoils. The model now just speeds up to the desired speed/camber setting and keeps that for a trip over the whole airfield through lift and sink. Night and early morning testing has shown sink values as good as 0,35-0,4m/s in distance mode (1mm up along the whole trailing edge and measured by altimeter). That means search mode for thermals is very efficient and provides a fantastic glide ratio. Flying in full camber in the same conditions gives sink values in the range of 0,25-0,3m/s but less area is covered.

Landing

Landing the Prestige 2PK is easier than ever. No aileron setup is needed (aileron goes to neutral when brakes applied). Only flaps with elevator compensation. Still, the model slows down to a crawl and pushing over is easy as the new elevator keeps the energy well even with full flaps applied. The rudder is also better and bigger and with the new high dihedral middle and aerodynamic airfoil changes, it corresponds well to rudder input and is not as much affected by sidewind as earlier models. Though it should be said that the lightest layup has very light tips and heavier tips (inertia) might be preferred if the landing area has lots of sidewind and/or turbulence.

The nose is removable. It is made longer than needed and can be shortened ( max. 100 mm) according to engine weight and lipo. Install equipment and shorten nose to fit preferred CG. The original nose has a diameter of 32 mm. It is designed to fit cheap and reliable outrunners for lighter versions. We also produce a nose cone with a slimmer diameter of 30 mm to suit smaller, slimmer motors.
The servos and receiver are located in the fuselage under the centre wing panel therefore there is enough space in the front for the motor, controller and lipo. Battery size from very small and up to 2300mah can be used as much care was taken to design a very thin but almost square fuse in the front area.

The complete wire harness is pre-built into the centre panel and the central connector plug is pre-installed. The wire harness for the fuselage is also delivered ready-made.

Servo compartments in the wing are laminated on all sides with carbon fabric, so a very strong box has been created in which the IDS system from servorahmen.de can be mounted. We recommend installing IDS for KST X10 mini, JRDS 181 or 189, Mks 6130 for flaps and MKS 6110HV in the tips. For the fuselage suitable servos sized like MKS 6110 HV work well.

Some words from designer Philip Kolb

Fundamentals of the  design:

Since there is no towing in F5J, the structural challenge is significantly less than in F3J and the design parameters quite obviously are different. There is no need to design a light, stiff and strong spar. This by itself lowers the structural weight of the glider. As well the wings don’t need to be as thick as on an F3J glider out of the same reason – there is no need for a very strong spar to take the occurring high g-loads. In line with this, low flying weights and the resulting low Reynolds numbers call for the use of very thin airfoils.

Nevertheless, an F5J glider due to the rule set can be exposed to flying conditions from absolutely calm air to wind speeds up to 12m/s. For being competitive even in high wind conditions there is a definite need to be able to vary the wing loading of the glider no matter how sophisticated the aerodynamic design of the glider is.

Therefore great care was taken to optimize the design of PRESTIGE-2PK to perform over the whole range of possible flying conditions. Great emphasis was put on the fact that PRESTIGE-2PK actually can handle a lot of ballast very well. To achieve this goal the airfoils of the wing - even as they are very thin – need to be able to provide a high maximum lift coefficient. To achieve this goal a high (but not super high) aspect ratio wing showed the best results, leaving sufficiently wide chords to optimize the airfoils for both, the low speed (low wing loading) case as well as the high speed (high wing loading) case. In the end, the Aspect ratio came out to be 19.2 at 3.9m wingspan. To reduce induced drag with this fixed span the planform was optimized to be as elliptical as reasonably possible. It thereby features a relatively high taper ratio (this measure even helps to lower the weight and inertia in the outboard area of the wing and thereby achieve better manoeuvrability), which in return was counteracted by using a considerable amount of washout twist in the outboard wing panel to achieve docile stall characteristics and a minimal turn radius for thermalling.

Airfoil explanations:

Like with any modern model glider-design the wing features optimized airfoils along its span, taking the local Reynolds numbers into account. For the PRESTIGE-2PK 7 different airfoils were developed and optimized along the span. One criterion was to determine the optimal flap chord. On the one hand, substantial laminar flow which should not be tripped by the hinge line or the gap between wing and flap should be achieved. On the other hand, positive flap deflections should result in minimal curvature change on the upper side of the wing when cambering up the airfoil. The former calls for relatively narrow flap chords and definitely has advantages when flying at higher speeds while the latter shows advantages when putting more emphasis on very low flying speeds.

In the end, 28% flap chord reflected a very wide optimum solution for PRESTIGE-2PK. The wing-planform thereby was developed to maintain the 28% chord depth of the flaps and ailerons all along the span.

To enhance performance, modern airfoils used at low Reynolds numbers (like on almost all F3K, F3J and F5J aircraft) feature a so called “kink”, which means, that the lower side and the upper side of the airfoil are not continuous and smooth at the same time. This allows for a wider envelope of flap angles to be used - especially positive flap angles to camber up the airfoil - because this measure results in a less steep and abrupt pressure recovery on the aft upper side of the airfoil.

Due to the unstable boundary layer conditions at low Reynolds numbers this steep and abrupt pressure recovery on the aft part of the airfoils upper side can cause significantly higher drag as a result of large laminar separation bubbles and thereby a loss of performance especially when circling slow at steep bank angles – which is mandatory in F5J!

For the PRESTIGE-2PK the kink in the airfoils is developed like follows:

The wing airfoils have no continuous smooth surface on the bottom and top at the same time. When the lower surface is clean, the wing is in a configuration optimized for low lift coefficients, thus for fast-flying (i.e. fast cruise when heading towards a thermal through the sink or under motor power when climbing at the same time is not desired). After using 2 degrees of camber flap out of this configuration, the upper side of the airfoils is continuous and smooth.

The tail configuration of the PRESTIGE-2PK is a derivative of the original PRESTIGE. The sizing of the tails and the development of the tail airfoils were undertaken by following aspects of docile handling and reducing drag at the same time. Six non-symmetrical airfoils were developed along the half span of the horizontal tailplane and similar to the wings’ airfoils were optimized according to the local Reynolds numbers at each spanwise position. The airfoils for the horizontal tailplane are in fact slightly different from the ones used on the first PRESTIGE. Now that stabilizer and elevator are built in solid core technology (on the PRESTIGE the stabilizer part was still built in hollow moulded technique), the airfoils on the horizontal tailplane could get thinner considering the very low Reynolds numbers and to save weight on the rear part of the fuselage to keep the inertia as low as possible.

To achieve very precise pitch control a hinged elevator was chosen, but as an F5J-planes’ elevator is pulled up very often, a relatively wide elevator chord was used. This kind of combines the positive aspects of an all-moving horizontal tailplane and a hinged elevator – low drag on the one hand side, precise control on the other. As mentioned, the elevator of an F5J-plane sees major up deflections while pulling tight thermal turns, therefore the airfoils for the horizontal tailplane were specially designed to produce low drag for exactly this configuration. The customer just needs to understand, that for this elevator tailplane very precise high-resolution servos and a slop free linkage are mandatory to reach the actual precision this elevator can deliver.

Different from the horizontal tailplane, the vertical tailplane needs to deliver substantial lift force to counteract and damp sideslip motions. The sizing of the vertical tailplane as well as the sections therefore primarily were chosen to achieve very good yaw damping. Thereby the symmetrical airfoils of the vertical tailplane cannot be extremely thin in order to still provide large maximum lift coefficients. The thickness of the seven vertical tailplane airfoils thereby varies from 7% to 5.3%. They are very similar to the ones used on the first PRESTIGE as there was not much room for further optimization.

All in all, I really do hope that the new PRESTIGE-2PK will perform well for you in F5J and make lots of F5J pilots happy with its performance and handling qualities. It should meet its design purposes to be a worthy successor of the PRESTIGE, as this is still the nicest plane to fly I’ve ever flown.

Thats all from the Thermal Circle, happy,safe and successful soaring Hayden Daley 8/7/2023

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