BARNARD MICROSYSTEMS LIMITED

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Introduction to helicopter flying: Part 3

http://www.raptor-mad.com/raptor_50_rc_helicopter.htm

• Robbe helicommand
• T-Rex 600 electric helicopter
• The Mikado Logo Bionic 24 helicopter
• Raptor 50 Titan V3 helicopter from Thunder Tiger
• Raptor 60 Pro V2 helicopter from Thunder Tiger
• Raptor 90 3D helicopter from Thunder Tiger

See also helicopter flight training

From http://www.runryder.com/helicopter/t230829p1/

Flight attitude stabilisation and positioning system for model helicopters.

The breakthrough:

Many vain attempts have been made to create a stabilisation system for free-flying helicopters. The control aids familiar in the modelling world are either just additional x-y gyro systems, or simple light sensors which only work if the horizon is very flat, with no obstacles in the line of sight. Until now, regulatory systems offering genuine inherent stability have been enormously complex, due to the unavoidable fact that it is impossible in a helicopter to measure angles of inclination relative to gravity; the second problem is that of obtaining a stable geographic position; these problems could only be overcome if at least a GPS system was installed in the model. If you were piloting a conventional helicopter and left it to its own devices for a few seconds, it would quickly start to drift off in a random direction, at the same time constantly accelerating - in short, it would not survive for long.

The HeliCommand unit stabilises the geographical position of the model helicopter as well as its flight attitude.

This involves a new technique of ground sensing which is much lighter and cheaper than GPS, and also works far more accurately when close to the ground: unwanted movements can be measured much more finely, and automatic compensation applied much more accurately. An additional advantage over GPS is that the system even works where the flying site is closely surrounded by buildings or trees, and even indoors, provided that the lighting and contrast conditions are adequate.

This completely new attitude stabilisation and positioning technology is now available to modellers for the first time. The HeliCommand incorporates several control and measuring systems, and provides a superb level of stabilisation.

Decisive features are a quality of regulation never obtained before, combined with compactness and light weight and a reasonable price.

Applications:

• Ideal as a training aid for the beginner. When set to maximum stabilisation, the system makes it possible to learn the art of helicopter flying without outside help.
• Safety function for advanced and scale model pilots: reduced crash risk (emergency knob).
• Ideal assistance for long-range flying, and when manoeuvring in cramped conditions.

Technical features:

• High-level reliability thanks to two independent instrument systems and sophisticated software.
• New type of sensing process provides reliable geographical positioning, completely independent of the visible horizon.
• Electronic triple-axis gyro provides attitude regulation with an artificial horizon.
• The instruments can be activated individually; the degree of stabilisation is adjustable.

Integral functions:

Tail rotor gyro

The HeliCommand unit features an integral high-quality heading-hold gyro. Of course, a separate gyro can also be used if you prefer.

Auto-trim

Another important feature is automatic trim; a button-press on the transmitter automatically neutralises the three control axes: pitch, roll and tail. For auto-pilot operations the trim is only necessary during the first flight (after installation). However the trim can also be used for manual control. Any reasonably smooth phase of flight lasting a minimum of seven seconds is sufficient for the automatic trim system to define correct trim values. The settings are stored, but they can also be revised and corrected at any time.

Swashplate mixer

The HeliCommand unit incorporates a comprehensive integral swashplate mixer (H2, HR3, H4). This makes it possible to control all current types of helicopter using simple radio control systems (without swashplate mixers). In this case the display module or the PC adaptor and software is required in order to carry out adjustments. The mixer settings are entered using a new form of procedure which is very simple to operate; this saves the user the task of studying the menu system etc.

Pilot channel

The effect of the stabilising / positioning mode can be adjusted proportionally using a spare radio control channel; it can also be switched off completely for 3-D flying.

The in-flight switchable gain system offers three different positions:

• Stage 0 = Off (conventional)
• Stage 1 = Attitude regulation (stabilisation)
• Stage 2 = Position-holding and "ground-speed" regulation

Fail-safe

High-quality fail-safe function with FM receivers. If the radio link fails, the fail-safe responds extremely quickly and almost continuously, setting the roll-axis and pitch-axis functions to neutral, whilst maintaining the collective pitch function at the last value.

How the Heli-Command works

Two independent instrument systems are used in conjunction with sophisticated software to ensure high reliability. The position measurement is based on a ground sensor which works on a similar principle to an optical computer mouse; the difference is that the position-finding continues to work at flight altitudes of around 3 m and more, even when daylight is beginning to fade. The movement sensor detects the ground while the helicopter is flying, and can be considered as a replacement for the eye of an airborne pilot. The sensor is able to detect all relative movement in the horizontal plane by analysing the contrasts exhibited by virtually every type of ground surface; this works just as accurately as a computer mouse on its base surface.

The supplementary attitude stabilisation system contains three electronic gyros and works using an artificial horizon, i.e. it is entirely independently of the visual conditions. This arrangement enables the HeliCommand to stabilise the helicopter´s inclination relative to the horizontal plane, independently of lighting conditions (in contrast to previous types of stabiliser), and also to stabilise the machine´s position above the ground when in regulatory mode. Only in exceptional cases, e.g. in the dark, above stretches of water, or over a totally smooth covering of snow, is the optical sensing device unable to supply a signal; if this should occur, the remaining on- board instruments automatically assume the task of stabilising the helicopter.

If brief, this "bridging" action is not noticeable. If it lasts longer, the helicopter will automatically switch from positioning mode to stabilising mode. The pilot will then detect this, and may have to compensate for any slow drift which occurs by giving a straightforward corrective control command. If particular ambient conditions make it obvious that the optical ground sensor cannot pick up adequate contrast (such as when flying indoors), the pilot would normally switch over to stabilisation mode (attitude regulation).

However, these special features do not need to be taken into account if you limit yourself to normal weather and usual model flying conditions and environments.

Specifications:

• Dimensions: 55x35x12.5 mm
• Mass/weight: 33 g
• Operating voltage: 4.8-6 Volts

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- from http://www.sussex-model-centre.co.uk/shopexd.asp?id=19963

• Length = 1,200 mm
• Height = 388 / 405 mm
• Main rotor diameter = 1350 mm
• Tail rotor = 240 mm
• Motor drive gear = 10 T
• Main drive gear = 170 T
• Autorotation tail drive gear = 180 T
• Tail drive gear = 40 T
• Weight (without main blade) = 1.4 kg
• Fly weight = 3 kg

This model has been eagerly awaited by all electric heli flyers. Aligns new entry offers a 0.50 size helicopter in a purpose designed electric machine. Presented as a kit that requires assembly, further items of equipment such as radio, flight pack (6S LiPo) will be required to complete the helicopter.

The CF Frame Combo Version features:

• Electric power system
• Triple bearing design for main shaft
• Driven tail AutoRotation system
• Tail rotor drive belt system
• High efficiency tail rotor
• Rear tail servo mount
• High strength 10mm main shaft 8mm spindle
• Easy to disassemble

The most powereful T-REX 600 CF version:

• KX016002TAB consisting of T-REX 600 (CF) Kit including RCM-BL75G 75A Brushless ESC (Governor Mode) X1, 600L Brushless motor X1, REC-B3X External BECX1, 6S2P 4,600 mAh 22.2V 16c Li-Po battery

• for a 10 minute flight, estimated power = 22.2 x 4.6 x 6 x 0.85 = 521 watts

Photographs

Above: the massive 5,350 mAh LiPo battery and a fire proof bag in which to store the battery.

The helicopter with the front cover removed.

Above: close up of the variable pitch tail carbon fibre rotor

Cost

Align T-REX 600 CF Kit with  motor + Esc + BEC + 7.4v LiPo + 6S 4,600 mAh Battery

Part Number = SMC-A-KX016002TAB                                                                  £  529.99 as on 30 January 2008

Spare Align High Power 6S1P 22.2v 16c LiPo battery

Part number = SMC-RE-KX860001TA                                                                      £ 157.50 as on 24 March 2008

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- from http://www.helihobby.com/html/logo_helicopter_products.html

and from http://logoheli.com/photos.htm

The LOGO 24 BIONIC helicopter is the result of Mikado's long-time experience in the making and handling of electric model helicopters. The carbon-fiber chassis of the LOGO 24 BIONIC simply cannot be beaten in terms of rigidity and simplicity. The 120º CCPM swashplate control via three lever arms ensures absolute precise and efficient transmission of the control inputs to the rotor head. The stock LOGO 24 BIONIC kit contains hollow main rotor and spindle shafts, thrust bearings and autorotation hub, as well as double ball-raced mixing arms. An extra highlight is the carbon-fiber tail boom for maximum precision in yaw (motion) control. Carbon-fiber stabilizers are standard in this kit and much more.

Mikado Logo Bionic 24 with the Mikado Founder, Ralf Buxnowitz.

Photo from http://logoheli.com/photos.htm

Frame

• Carbon chassis
• Carbon tail boom
• Carbon stabilizers
• New 138 teeth main gear for quieter and more fine-tuned transmission
• All levers ball-raced
• Aluminum swashplate
• Hollow tempered main shaft
• Hollow 8 mm spindle shaft
• 5 mm tail rotor shaft, tempered and abraded
• Driven belt
• 120º CCPM
• Steel control rods
• Thrust bearing set for rotor shaft
• Clamp ring for rotor head
• Explicit assembly manual

Photo from http://logoheli.com/photos.htm

Power, rotors and weight

• Electric helicopter for  24 - 28 battery cells
• main rotor diameter, 2 versions available:

• Item-No. 2280: 1370 mm
• Item-No. 2279: 1500 mm

• Tail rotor diameter approx.  240 mm
• gear ratio 7,6 : 1 - 13,8 : 1
• Weight > 3.8 kg

Cost

From www.revolutionmodels.com                                            £ 417.02 excluding blades as on 31 January 2008

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- from http://www.sussex-model-centre.co.uk/shopexd.asp?id=19732

Above: the new 50 Size Raptor Helicopter kit with an internal combustion engine

Attributes

• Full Length of Fuselage 1,220 mm
• Full Width of Fuselage 1,400 mm
• Height: 400 mm
• Weight: 3 kg
• Maximum payload estimated to be 2.1 kg (max weight estimated to be 5.1 kg)
• Main rotor diameter (600 mm) 1,345 mm
• OPT (620 mm) 1385 mm
• Tail rotor diameter 236 mm
• Engine required 50-53 size helicopter
• Radio required 5 channel helicopter

Number of teeth in Engine Pinion Rear = 10

Number of teeth in Main Spur Gear = 85

from http://www.raptor-mad.com/raptor_50_rc_helicopter.htm

This is the Thunder Tiger Raptor 50 Titan 50-Class RC Helicopter. The Raptor 50 Titan combines all the key features needed for Extreme 3D flight. Whatever the manoeuvre, we are sure you will feel the performance that the Titan provides.

This model was designed and engineered by the World-renowned Mr. Shigetada Taya. It combines elements of his previously successful designs with today's advanced technologies. Combined with all the features of Raptor 50 V2, the new Raptor 50 Titan adds more new features—longer tail boom to fit 620mm blades, push-pull system for collective pitch control and elevator control, rear mounted tail rotor servo plate, harden main shaft and more.

from http://www.raptor-mad.com/raptor_50_rc_helicopter.htm

With all the new features included, the Raptor 50 Titan is the best power-to-weight ratio and accuracy control system of any 50 class helicopter in the market. For 3D pilots, the Raptor 50 Titan will make you enjoy executing crisp maneuvers like – Climbing Tic-Toc, Chaos, Death Spirals and any other radical maneuver that pilots can dream of. Whatever the maneuver we are sure you will feel the performance that the Titan provides. Beginners and advanced 3D pilots will be impressed with this new Raptor, The Raptor 50 Titan.

from http://www.raptor-mad.com/raptor_50_rc_helicopter.htm

See Progress in the MoD Grand Challenge: Part I for photographs of our expereince with the Raptor 50.

Raptor 50 Titan V3 Features

• Metal swashplate
• Hardened main shaft
• Metal rear servo plate
• Pitch push-pull lever system
• Elevator push-pull lever
• Longer tail boom
• Longer tail pushpull rod
• 686XL tail drive belt
• SUS flybar
• SUS linkage rod
• Heavy duty clutch bell
• New style body decal

Available as a Kit only, or, as a kit with PRO 50H engine

The PRO5OH Engine

The new PRO50H engine comes with an updated fuel system to ensure smooth running throughout the RPM range

• Practical RPM = 2,000 to 17,000 rpm
• Output power / RPM = 1.34 kWatts at 16,000 rpm
• Weight  = 405 g

The OS 50 Hyper engine

- from http://www.osengines.com/engines/osmg1951.html

• Displacement: 8.17 cc
• Practical rpm: 2,000 - 20,000
• Power: 1.42 kWatts @ 17,000 rpm
• Weight: 406 g

Spektrum AR7000 2.4 GHz receiver

Futaba GY401 AVCS (Angular Vector Control System) Rate Gyro

- from http://www.futaba-rc.com/servos/servos.html

The Futaba S9254 servo

- from http://www.futaba-rc.com/servos/digitalservos.html

Photographs of the Raptor 50 helicopter

Above: the Raptor 50 with the front cover removed. You can see the small secondary fuel tank located in fron of the larger main fuel tank.

Above: the servo driving the variable pitch tail rotor, shown below.

Above: the various leads to the servos from the 2.4 GHz receiver.

Above: you can see the high performance Zimmermann exhaust, made using laser welding and stainless steel.

Above: the Futaba 401 gyro is visible, and helps to maintain the helicopter attitude.

Above: the Spektrum DX 7 transmitter

Prices in UK £ as on 12 March 2008 for system based on use of an O.S. engine

"Extras"

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from - http://www.sussex-model-centre.co.uk/shopexd.asp?id=387

Stable design - outstanding performance - suitable for novice, competition F3C and outrageous 3D flying - CAD designed with strength, rigidity and precision in mind - Light weight body - available as a kit without engine, and ARTF with 70 size engine fitted.

The Raptor 60 V2 Crash kit contains:

PV0126 Spindle, PV0128 Flap Damper, PV0136 Tail Pitch Slider, PV0146 Flybar Rod, PV00162 Flybar Paddle Set, PV0163 Tail Rotor Blade, PV0164 Tail Fin, PV0165 Main Rotor Blade, PV0168 Tail Control Rod, PV0185 Main Shaft, PV0194 Tail Drive Shaft bearing, PV0199 Tail Boom, PV0249 Tail Rod Guide

Price

Thunder Tiger Raptor 60 PRO V2 ARTF w/PRO 70H engine

Part Number = SMC-A-TT4870A                                                                               £ 495.99 on 28 January 2008

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from http://www.sussex-model-centre.co.uk/shopexd.asp?id=24990

Attributes

• Fuselage length 1410 mm
• Fuselage width 190 mm
• Total height 476 mm
• Main rotor dia 1605 mm
• Tail rotor dia 260 mm
• Gear ratio 8.27 : 1 : 4.65
• Fully equipped weight 4.800 kg
• Maximum payload estimated to be 2.3 kg (maximum weight estimated to be 7.1 kg)

The new Raptor 90 3D was created for the 3D aficionados. The Raptor 90 3D has taken the proven Raptor 90 SE as its foundation, an added only the essential parts for extreme 3D flying.

Thunder Tiger have added the must have options for 3D at a much lower cost. The CNC machined aluminium rotor hub and 30 grams weight paddles with large control surface area and a thick airfoil makes a lightening fast cyclic response and rock solid hover. With two different Bell-Hiller mixing ratios offer the pilots a choice of agile, very agile and extremely agile control responses. The Raptor 90 3D is what you need for all-out 3D flying at a minimal investment.

Features:

• Machined metal main rotor hub
• NEW nonlinear stiffness flap dampers
• Machined metal bearing blocks for main shaft
• Aluminium seesaw
• 3 different Bell-Hiller ratios
• 30g Paddles
• Push Pull system
• Carbon tail fin
• Light weight tail boom braces
• 8.27 : 1 gear ratio

The OS 91 SZ-H Hyper Heli Engine

- from http://www.osengines.com/engines/osmg1984.html

• Displacement: 15 cc
• Practical rpm: 2,000 - 16,000
• Power: 2.46 kWatts @ 15,000 rpm
• Weight without muffler: 605 g

Prices in UK £ as on 12 March 2008 for system based on use of an O.S. engine

"Extras"

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© Barnard Microsystems Limited 2006 - 2008