SK360 manual - Skookum Robotics
Contents
1. www skookumrobotics com support html to download the latest version of the setup software you will not need to update the firmware 2008 Skookum Robotics Ltd 3 3 Safety An R C Helicopter is not a toy and can cause serious injury to people or damage to property Use of this gyro places a flight control computer the gyro unit between the radio receiver and the servos that drive the swash plate If the gyro unit is mistuned or set up incorrectly loss of control of the helicopter may result See Appendix C for warranty information Please keep bystanders clear of the flight area at all times Be sure to test fly away from spectators especially when flying the helicopter after any change in the gyro s setup or tuning and keep yourself at a safe distance 4 Mounting the Gyro The front side of the gyro is marked on its case The gyro unit can be mounted upside down backwards or sideways but it must be level and have its sides aligned as accurately as possible with the fore aft axis of the helicopter Misalignments of even a few degrees 2mm or 1 16 difference between the front and back edges of the case may cause problems with tuning the gyro The gyro should also be as far as possible from any heat sources and at least 10cm away from Xtremelink receivers The SK360 label must face up or down TOP VIEW Tail Boom Frame Body For vibration resistance mounting tape with good damping must be used such as2. Appendix B Firmware Upgrades cccccssssssesseeeteeeeeeeees 23 Appendix C Warranty and Technical Support 24 2008 Skookum Robotics Ltd 1 Intro The SK360 Digital Flybar is a high performance compact and lightweight pitch and roll stabilizer for model helicopters Its function is to replace the traditional flybar stabilizer bar and its association linkages while saving power increasing flight times and reducing repair costs Features include Control Options e Control over the Bell and Hiller ratio direct vs stabilized control e Control over roll and pitch rates in software e Control feel is adjustable in software on the gyro case or by remote bank switching e Optional remote gain Swashplate Options e Suitable for 120 135 140 and 90 degree eCCPM as well as mCCPM swashplates e Mixing In Gyro for higher precision e Swash Ring anti binding algorithm e Phase Trim adjustable to 90 Servo Options e Works with digital or analog servos e Synchronous with receiver s PWM frames for minimal lag e Groups swash servo PWM pulses for low swash motion error e Swash servo rate equalizing prevents uncommanded pitch during aggressive maneuvers 2 Package Contents Your gyro package should include e K360 Gyro unit Four strips of 3M 4408 mounting tape USB Interface with jumper USB Extension Cable CD with Interface Software Note If your computer can t read mini CDs visit our website at
3. Operating Voltage 3 6 to 8 5 VDC Power Consumption 28 mA Wiring Gauge 22 Input Signals 3 4 Channels PWM 700 2300 us Output Signals 3 4 Channels PWM 700 2300 us Servo Options Analog or Digital Setup USB interface or by Transmitter Sticks Field Gain Setting Bell and Hiller Gain Dials 0 100 Appendix B Firmware Upgrades 1 Obtain the latest firmware update from www skookumrobotics com 2 Unzip the hex file from the compressed archive file using WinZip or a similar program to a convenient directory on your PC 3 Power it down the gyro and connect its USB interface 4 Load the Digital Flybar USB interface software on your PC 5 Set the mode switch away from the gain dials Flight mode hold down the option button gently and then power up the gyro The LED should stay off and Connect on the setup screen will stay red 6 Click the menu item Firmware and then Update Firmware 7 Select the hex file from step 2 and wait for the firmware upgrade to complete 8 When finished the connection indicator on the PC should turn red and the gyro will be in Flight mode 9 Move the mode switch towards the gain dials and cycle the power The new firmware revision number should show up on the top right of the USB interface display 2008 Skookum Robotics Ltd 23 Appendix C Warranty and Technical Support Warranty and Repair Skookum Robotics Ltd warrants this product against any defects in materials or wor
4. The servo travels can be set individually to trim the swash to be level at max zero and min collective pitch 2008 Skookum Robotics Ltd 17 Servo Trims and Reversing Here each servo s center point can be set and each can be reversed if needed This is the same idea as sub trim on your transmitter Be careful that the servo doesn t bind Control Tab Receiver Control Setup Similar to the settings for the servos but here the centers and reversing for the inputs from the radio receiver are set To use this section you must first unlock it on the Options drop down menu Note Features of your radio such as exponential or pitch curves will work normally Use Gain Channel Input With this feature enabled the gyro will use A4 port as a bank select and hiller gain input The concept is similar to the way tail gyros have a rate heading hold mode with the endpoints in each direction setting the gain for each mode Auto Trim at Initialization With this feature enabled the gyro will use the cyclic stick centre it receives at initialization as neutral cyclic If left off the gyro will use the exact values entered in the Control tab Dead Band A dead band can be set for the cyclic elevator and aileron functions so the heli doesn t drift with small errors in stick centering One percent is a good value for most radios note your radio s centering may change with temperature For scale models deadband can give a solid control
5. 6 Try full left aileron control with elevator control centered The blade s pitch should be about 10 degrees 7 Align a blade at 90 degrees to the fuselage pointing over the right side of the helicopter as in the photo below 8 Try full nose up elevator control with aileron control centered Measure the pitch of the blade that points over the right side of the helicopter It should be about 10 degrees 9 Try full left nose down elevator control with aileron control centered The blade s pitch should be about 10 degrees If the cyclic blade pitch range is changed the gyro s stability gains will need to be changed as well For example increasing cyclic pitch range by 10 is the same as increasing the stability gains by 10 2008 Skookum Robotics Ltd 8 7 Connections The gyro normally has 3 inputs and 4 outputs labeled on the top of its case Note that the USB interface does not supply power For the inputs from the radio receiver the connector mapping is Swash Setup Type Input 1 Input 2 Input 3 120 deg eCCPM Elevator Ch Aileron Ch Pitch Ch 135 140 degree eCCPM Elevator Ch Aileron Ch Pitch Ch 1 servo mCCPM Elevator Ch Aileron Ch n a 90 deg eCCPM Elevator Ch Aileron Ch Pitch Ch Left Right means the heli s left and right looking from its tail to its nose The SK360 needs to receive separate aileron elevator and pitch inputs so set the swash type in
6. Heli hesitates in elevator and aileron and continues to move for a bit when the stick is released Bell gain is too low relative to Control Rates Increase Bell gain slightly or decrease Control Rates After an elevator or aileron change the rotor disk springs back after the stick is released Bell gain is too high relative to Control Rates Decrease it slightly or increase Control Rates Responds too sharply to aileron or elevator Bell gain is too high Heli precesses in hover a motion like a child s spinning top as it slows down Gets worse with higher Hiller gains Interaction between the Elevator Aileron and Yaw axes Check that the SK360 gyro and the yaw gyro are both mounted correctly Also check phase angle 2008 Skookum Robotics Ltd Symptom Problem amp Solution Random jitter or jumps in roll and pitch Vibration effects on the gyro Make sure it is mounted on good damping tape and doesn t contact the frame Also check for tail vibration Can t set Hiller high enough without causing oscillation especially with high head speeds Aileron or Elevator don t give fast enough roll and pitch rates Lack of servo speed precision or the frame rate is too slow Rotor head mechanics should use full servo throw for desired cyclic pitch range Increase Control Rate gains You will then likely have to increase the Bell gains slightly Aileron or Elev
7. your radio to 1 servo for all swash setups You also have the option of using the A4 port as a remote gain and bank switching input But do not connect this port to your radio until the SK360 unit is told to use it as an input with its setup software or your radio receiver could be damaged see Section 13 For the outputs to the servos the connector mapping is Swash Setup Type Servo 1 Servo2 Servo3 Servo 4 120 135 140 deg eCCPM Centre Right Left n a 1 servo mCCPM Elev Aile n a n a 90 deg eCCPM Fwd Att Right Left Servo 1 C1 Servo 1 Servo 4 Servo 3 Servo 3 L3 Servo 2 R2 Servo 2 2008 Skookum Robotics Ltd 9 8 Modes Indicators and Power Up The two primary modes are Setup mode and Flight mode chosen by the position of the small switch on the gyro s side Towards the gain dials is Setup mode and away from the dials is Flight Mode Note The gyro will change from Setup to Flight mode right away but won t change from Flight to Setup until you also cycle its power Bell Gain Hiller Gain Option gt CO m N Indicator LED Mode Switch Setup mode lets you use the USB connection and also used for mechanical setup control motions pass straight through with no stabilizing action While in this mode the indicator LED will slowly flash green In Flight mode the LED Indicator will show solid red while it s still initializing and turn solid gre
8. SK360 Fives User Manual and Setup Guide Throw out your 1940 s technology mechanical flybar and replace it with a Digital Flybar Lightening quick 3D and solid hovering in wind with a less complex lighter rotorhead that gives you more power or longer flight times Rev 1 10 SK360 User Manual amp Setup Guide Table of Contents 1 MOn a E e a ae 3 2 Package Contents viiiitinanisissesiiacananstisauaisarvnmssaaxenranaias 3 3 SAIGNY AN E E ETT 4 4 Mounting the GYl Os sesscsctesssasstsdcesscnsssasanasasntassacnsacncdacnts 4 5 Helicopter Airframe Setup ccccccccsssseeeeeeeeeeeeeeeeeeeeees 5 6 How to Check Cyclic Pitch amp Phasing sss 7 7 GONMGCUONS wis seisitisisiisictscsnicnansenitannewinannniniannewinnawennsiiians 9 8 Modes Indicators and Power Up ccccccesssseeeeeees 10 9 Gyro Setup Using the USB Interface 11 10 After Setup Final Check ee seesteeeeeeeeeeeeeeeeeeeees 13 11 Flight with the SK360 Gyf0 cssssseeeeseeeeeeeeeeeeeeees 13 12 Basic TUNING saiwssstsnsertetennnneastsncianniancwnasawiwenntenntanewns 14 13 Remote Bank Switching and Hiller Gain 15 14 USB Interface Software Reference cessssssseee 16 15 Advanced Tuning Options cssseeeseeeeeeeeeeeeeeeees 19 16 Tuning Troubleshooting Guide ccccsssesseeeeee 21 Appendix A Specifications ccsssccccccecsesseeeseeeeeeeeeeeees 23
9. ator give roll and pitch rates that are too fast Decrease Control Rate gains and then decrease the Bell gains slightly Cyclic feels mushy in the centre Reduce dead band Not perfectly locked in hover Try higher dead band Heli drifts slowly in elevator or aileron with cyclic stick centered soon after take off Radio receiver centering drift Many receivers center points drift with temperature up to 3 ticks of trim Use transmitter trims to correct Heli drifts slowly in elevator or aileron with cyclic stick centered after several minutes of flight Gyro temperature changing too quickly or receiver drift Make sure the gyro and receiver aren t mounted near heat sources and let it acclimatize to field temperature Heli jumps in pitch or roll after hard changes between positive and negative collective Check that the heli s centre of gravity CG is directly under the main shaft and tune swash servo throws and tail drag compensation During yaw piros with collective pitch changes or piros during forward flight the heli wanders Damping gains are too low servos are not fast enough swash moves unevenly or tail drag compensation needs tuning see page 19 21 2008 Skookum Robotics Ltd 22 Appendix A Specifications Dimensions 41x31x15mm Weight without cables 16 grams Operating Temperature Range 5c to 45c
10. be required But if the maximum aileron and elevator motion of the heli is not fast enough for you or for other advanced tuning see Sections 15 and 16 Good starting points for the gains can be found in the Default Scale or Basic_3D setup files all of which are included with the USB interface software 2008 Skookum Robotics Ltd 14 13 Remote Bank Switching and Hiller Gain If you have a seven channel radio receiver and your swashplate only uses three servos you can set the fourth servo output to act as a gain input This allows you to switch between two banks of all the settings on the Advanced tab as well as set the Hiller gain input for each bank at your transmitter The concept is similar to the way tail gyros have both rate and heading hold modes with the endpoints in each direction setting the gain for each mode To use this feature first connect to the SK360 using the interface software Then go to the Control tab and enable Use Gain Channel Input then sent the changed setup to the gyro You must complete this step before you connect the A4 port to your receiver or there is a small chance your receiver could be damaged The A4 port is now an input so connect it to the channel you wish to use on your receiver Notice that there are now two versions of the Advanced tab so you can try out two sets of gains at the field or select sport vs 3D tuning This channel also acts as a remote version o
11. can vary by 10 or more 3 If the heli tends to nose up when max collective is applied quickly from a hover subtract one from elevator tail comp If the heli goes right subtract 2008 Skookum Robotics Ltd 19 one from aileron tail comp Add one to the fields if it noses down or goes left Hiller Decay Causes accumulated Hiller response to decay back to neutral to make the gyro more forgiving of insults If you watch a heli with a flybar in hover after a sharp control input you ll see the flybar s disk offset for a moment then drift back to level This provides the same effect A value of 100 here can help smooth out rapid tic tocks piros or other 3D maneuvers especially repeated ones However high values for Hiller Decay will also limit the gyro s ability to hold steady in gusty wind or trim the heli perfectly in hover Disable Gain Dials If enabled the gain dials on the gyro itself will have no effect The gains will be taken straight from those entered in the gains setup tab Hiller Dial Also Scales Damping Gain If enabled then the Hiller gain dial will also adjust the damping gains by the ratio of the Hiller Dial setting vs the elevator Hiller gain in the setup For example if Elevator Hiller gain is 50 on the Advanced tab the Hiller Dial is set to 100 and Damping is set to 20 for elevator on the Advanced tab the resulting damping gain would be 100 50 20 40 This can make it easier to re tune the gy
12. e first percentage is the gain for elevator the second is the gain for aileron they re linked by the ratio of elevator vs aileron for each gain on the Advanced tab of the gyro s setup Swash Tab Swashplate Type Select your swashplate and mechanical mixing type Options are 120 eCCPM 135 140 degree eCCPM 90 degree mechanically mixed separate servos for each of elevator aileron and pitch control and 90 degree 3 2008 Skookum Robotics Ltd 16 or 4 servo eCCPM where servos are directly connected to the swash but 90 degrees apart Mixing The SK360 takes over swashplate mixing so the inputs to the gyro are separate channels for elevator aileron and pitch collective control This gives the full precision of your radio set rather than losing half of its precision with in transmitter mixing It also allows for extra mixing features normally only available on high end radios such as Swash Ring and Servo Equalizing Elevator Cyclic Percent of full swashplate motion at full stick deflection for elevator cyclic This can be a negative number but cannot be zero Aileron Cyclic Percent of full swashplate servo motion at full stick deflection for aileron cyclic Can be a negative number but cannot be zero Collective Pitch Percent of full swashplate servo motion at full stick deflection for collective This can be a negative number Phase Trim Rotates the plane of cyclic action about the mainshaft to allow correction fo
13. en when it s ready to fly The gyro will not finish initializing unless it is completely still It will also not read in new values from the gain dials until it is left still for a few seconds The option button is used for Firmware Updates described in Appendix B WARNING Always check before flight that the LED is solid green If you take off in setup mode the flight will be very exciting short and possibly also expensive The LED flashing red rapidly indicates an error There are four possible causes 1 The cyclic stick wasn t centered at initialization in flight mode 2 The supply voltage fell below 3 6v at some point 3 Itis too hot or too cold 4 The gyro has a systems fault If the first three causes can be ruled out please contact technical support 2008 Skookum Robotics Ltd 10 9 Gyro Setup Using the USB Interface Step 1 Step 2 Step 3 2008 Connecting First install the USB Interface software for your SK360 gyro Unplug the swashplate servos the gyro for now Set your radio s transmitter so Aileron Elevator and Pitch Collective are output each on a separate channel Normal or 1 Servo swashplate mode The initial setup will be easier if you use a straight line pitch curve and no expo or dual rates Later those features can be set in the transmitter as you normally would Connect the gyro to the USB interface and set the mode switch on the gyro toward the gai
14. f the Hiller gain dial Negative side endpoint values of more than 15 on the gain channel will select Bank 1 and positive side endpoint values of more than 15 will select bank two Bank 1 Bank 2 ule endpoint endpoint Gain Channel Also note that now the Bell dial on the case acts as the Bell Gain dial for bank 1 and the dial labeled Hiller acts as the Bell Gain dial for bank 2 To learn how the gain channel Bell dials and Advanced bank tabs work together click Show Actual Gains on one of the Advanced tabs You must toggle the gain channel s switch between banks for a change in the remote Hiller Gain to be registered 2008 Skookum Robotics Ltd 15 14 USB Interface Software Reference To use the SK360 interface software first install the software on your PC and plug in the USB interface Then attach the jumper to the gyro set its mode switch for setup mode and power it up with the motor disabled if you have an electric heli On your PC the Connected indicator should turn green and the gyro s serial number and firmware revision should be displayed Note the servos may be slightly jittery while connected to the USB port due to noise from your computer If the software will not run at all make sure your Windows NET Runtime is up to date Check the Microsoft website for the latest version On the menu bar the File menu allows you to save or load gyro configurations setu
15. feel while in stationary hover Mounting Orientation The motion sensing directions can be flipped or rotated 90 deg to allow the gyro to be mounted in any orientation After mounting always send the setup to the gyro and then move the heli slowly and watch Gyro Rates on the Live Data display to be sure nose down is negative elevator rate and right tilt is positive aileron rate 2008 Skookum Robotics Ltd 18 15 Advanced Tuning Options The helicopter can be tuned in a more detailed way using the settings on the Advanced tab of the USB interface program Maximum Rate The desired roll or pitch rate of the heli at maximum cyclic stick deflection Equivalent to the area of a flybar s paddles If increased Bell gain will also need to be increased slightly Bell Gain Amount of motion of the swashplate in response to cyclic stick deflection Normally set by a gain dial on the gyro s case that dial can be disabled to lock the bell gain to a specific value When the gain dial is used it will set the elevator bell gain but the aileron bell gain will be a fraction of that by the ratio set here Example The Advanced Tab shows Bell gains of 20 elevator and 10 aileron and the gain dial is not disabled Then if the gain dial is set to 50 the elevator bell gain will be 50 and the aileron bell gain will be 25 Hiller Gains Similar to heading hold on a yaw gyro Higher Hiller Gain is equivalent to increasing the weight of a
16. flybar s paddles and adds stability and resistance to wind gusts This feature gives the heli a locked in feel Slop free linkages rigid rotorhead mechanics stronger servos and stiff blades allow higher gains here The Hiller gain dial is used to set the elevator and aileron hiller gains in the same manner as described above for the Bell gain dial Damping Gains Roll and pitch rate motion damping Higher gain is equivalent to having heavier rotor blades or a higher head speed and helps with stability during forward flight and pyros Fast digital servos allow higher gain here The default gains are best for analog servos but can be set to 20 16 for digital servos Appropriate Damping gains are normally about 1 3 as large as the Hiller gains Tail Drag Compensation All helis have uneven drag on their airframes especially the tail For better piros and tick tocks this feature lets you trim out the effects that has during hard collective pitch use To use this feature follow these three steps 1 Make sure your heli s balance point is under the main shaft or slightly nose heavy 2 Check that your swash is level at min zero and max collective pitch while in Setup mode On the servo tab first adjust the swash to be level at zero pitch using the trims then use the servo travels to make sure the swash is level at min and max collective This is needed because servos are not all identical the pots that measure their position
17. h will tilt forward slightly at full positive collective pitch and backward slightly at full negative pitch to compensate for tail drag during fast climbs and descents 11 Flight with the SK360 Gyro In flight mode the swashplate will not respond to the controls directly Its action will be similar to a heading hold tail gyro Also after it has been static for a few seconds it will level the swash during spool up to ensure a stable take off When you land your heli always wait at least 5 seconds after the rotor spools down before spooling up again so the gyro knows the helicopter is spooling up Don t move the cyclic stick until the heli is light on its skids to prevent confusing the gyro when it can t fly If the Auto trim at Initialization feature is on avoid using the transmitter trims for elevator or aileron If you do use trims you ll have to zero them before every flight ALWAYS do these pre flight checks 1 The Indicator LED should be solid green not flashing 2 Positive collective should increase blade pitch 3 Right aileron stick should tilt the swash for a right roll 4 Nose up elevator stick should tilt the swash for nose up 2008 Skookum Robotics Ltd 13 12 Basic Tuning If you have set up your helicopter s mechanics properly and the cyclic throws are correct then tuning should be easy Note always let the gyro be still for a few seconds after adjusting the gain dials so the gyro knows to
18. kmanship for a period of 90 days from the purchase date This warranty is limited to the original purchaser In the event of a malfunction Skookum Robotics will repair or replace the product to meet its standard operating condition This warranty does not apply in cases where the product has been overheated electrically shorted subject to crash damage otherwise abused or had unauthorized repair attempts UNDER NO CIRCUMSTANCES DOES SKOOKUM ROBOTICS ACCEPT LIABILITY FOR INCIDENTAL DAMAGE OR INJURIES RESULTING FROM THE OPERATION OF THE SK360 OR OTHER PRODUCTS Skookum Robotics will provide customers with technical assistance by email free of charge If a gyro is suspect due to a crash we will check it over for only the cost of postage If the unit has malfunctioned and the 90 day warranty period has expired we will attempt repair and discuss the cost of possible repairs with the owner again for only the cost of postage If you wish to return the gyro unit or related product please write WARRANTY RETURN clearly on the shipping box and mail it to the address given below Manufactured in Canada by Skookum Robotics Ltd Email tech skookumrobotics com Website www skookumrobotics com PO Box 46912 Stn D Vancouver BC V6J 5M4 Canada 2008 Skookum Robotics Ltd 24
19. n dials to put it in setup mode Turn on the heli s power and start the setup software Check that the connection indicator in the upper left is green and says Connected Match the Gyro to Your Transmitter In the Offline Setup Values area in the lower half of the window click the Swashplate tab Then select the Swash Type that matches your heli s swashplate and make sure Mixing Location is set to In Gyro Now click the Control tab Center all the trims on your transmitter and be sure the cyclic stick is centered Click the Send Setup button or press the F1 key to set the changes on the gyro You must SEND the setup whenever you want to test changes After a few seconds check Inputs from Receiver again The values for Elevator Aileron and Pitch should be close to zero You can trim the collective pitch centering on the Controls tab Try moving the elevator stick towards you nose up and look at the Pilot Control field under Elevator The number displayed should be close to 100 and show green If it is negative reverse that channel in your radio If it s too low or reaches 100 much before the stick s limit adjust endpoints and sub trims for that channel in your radio Repeat for Aileron Pilot Control but move the stick right green Then repeat for the Pitch input but move the stick up green Check the Gyro s Sense Directions Now look at the Gyro Rates fields in the Live Data area Note the Rate fields
20. only sense movement not angle Pick up the heli and slowly tilt it nose up The Gyro Rate for Elevator should be positive and show green If not click Flip Elevator Axis on the Control tab If the gyro rate for Aileron is high instead click Rotate 90 Degrees on the Control tab Skookum Robotics Ltd 11 Repeat for the Aileron roll axis but slowly tilt the heli to the right The Gyro Rate for Aileron should be positive and show green WARNING All the control input and sense directions in steps 2 and 3 must be correct otherwise your heli will instantly crash if you try to fly it Step 4 Step 5 Swash Mixing Servo Setup Go to the Swashplate setup tab again and set the Swash Mixing values CCPM and Travel just as you would in your transmitter Go to the Servos tab select the frame rate according to servo type and enter the speed of your servos from their specifications Make sure the control sticks are centered and then plug the servos into the gyro Check for good motion and no binding NOTE While in setup mode the gyro will give 100 swash control to the transmitter sticks zero stability gains to allow for mixing servo travel and mechanical setup Check that the swashplate motion is correct Note the correct blade pitch range for elevator or aileron input is about 10 degrees If the servos don t move in the correct directions reverse them on the Servos tab If the Aileron or Elevator m
21. otion is reversed change the sign of their swash mixing value ex to Try to keep swash mixing values below 60 If you need more motion increase the servo travels instead for ex to all to 125 This prevents unwanted interaction at max and min collective Do not try to change cyclic throw using the Control tab Adjust the servos for a level swashplate on the Servo tab Ready for Flight Save your setup to disk then go to Section 10 of this manual Final Setup Note The expo dual rate and pitch curve features of your radio can be used normally as long as they do not exceed 100 travel 2008 Skookum Robotics Ltd 12 10 After Setup Final Check Any time you change the gyro s setup always do these checks 1 Put the gyro into setup mode with the servos connected and the swashplate mechanically set up 2 Try full right aileron Check that the swashplate tilts to the right 3 Try full up elevator nose up Check that the swashplate tilts back 4 Command full up collective pitch Check that the swashplate moves to give maximum blade pitch 5 Try zero collective pitch with throttle hold active Check that the swashplate moves to give zero blade pitch 6 Put the gyro into Flight mode leave it undisturbed and wait for the LED to turn green 7 Pick up the helicopter wait a few seconds and then tilt it nose down and to the right The swashplate should tilt back and left Note In flight mode the swas
22. ove with elevator input but do move with aileron input for 2 bladed rotors This can be set either mechanically or through the USB setup software It is important that the linkages and swash have little slop and the lowest friction possible How stiff the rubber rotor head dampers are will have an effect on tuning the gyro and flight performance Performance will be better with the teeter damping a stiffer than normal but too stiff can cause vibration which is hard on the airframe gyros and servos Tail Because the axis of the tail rotor disk is lined up with the elevator axis of the heli it s important that you minimize tail rotor vibration Also if you have a belt driven tail be sure that your tail boom is electrically grounded to the heli s frame or motor case to prevent static electricity buildup Balance The gyro will perform best with the CG directly under the mainshaft or very slightly nose heavy This is especially important for maneuvers that use fast collective pitch changes combined with yaw such as piros 2008 Skookum Robotics Ltd 6 6 How to Check Cyclic Pitch amp Phasing The goal of mechanical and gyro swashplate setup is to get your normal collective blade pitch range and a cyclic range of about 10 degrees which means a total range of 20 degrees This is important Cyclic pitch is blade s pitch due to aileron or elevator input The rotor blades must also have the correct phasing This mean
23. ps or go back to the default setup The Connect menu allows you to send a setup to the gyro burning it into its memory or fetch a setup from the gyro Any setup sent to the gyro will be labeled with the first 8 letters of its filename Live Data This area displays constantly updated telemetry from the gyro including the control inputs from the receiver and position outputs to the servos Remember that while in setup mode all elevator or aileron stick motions are sent directly to the swashplate as if stability gains were all zero and bell gain is 100 to allow for easy mechanical setup For Inputs and Outputs the units displayed can be percent of full throw from the current setup or PWM pulse width microseconds Note that the collective Pitch display should turn green for positive climb pitch if the gyro is set up correctly Under Gyro Internals the Pilot Elevator and Aileron command percentage is given as a guide for setup It is important that cyclic stick input for nose up and for right roll should give positive values here Nose up stick and right aileron should both show green backgrounds These readings can also be used to test the dead band settings The elevator and aileron Gyro Rates values are in degrees per second and show the currently sensed motion of the gyro The Bell Gain and Hiller Gain dial settings are displayed here for ease of recording values arrived at by field testing For each type of gain th
24. r gyroscopic and aerodynamic effects and the use of 3 or 4 blade rotor heads For example setting phase trim to 90 degrees would make full stick deflection for aileron tilt the swashplate down Note that the phase angle depends on the rotor rpm and load Swash Ring Limits motion of the swashplate to prevent binding when large amounts of both elevator and aileron cyclic are used i e assume the swashplate is round not square Servo Tab Frame Rate The Analog servo mode synchronizes pulses to the servos with your receiver s output for minimum latency Digital uses higher frame rates than analog servos can handle and has little latency Do not use digital frame rates for analog servos Equalize Servo Speeds Accounts for the different radius of motion for the servos in an eCCPM swashplate arrangement For example for a 120 degree swash an aggressive pitch motion will demand higher speed from the centre servo than the left or right servos so it may lag behind causing uncommanded collective input This feature would slow all the servos evenly to the maximum rate of the centre servo Servo Speed Take this from your servo manufacturer s specifications Units are in seconds per 60 degrees of motion This helps the gyro move the swash evenly This field only matters if Equalize Servo Speeds is on Servo Travel Amount of servo motion on either side of centre Servo motion outside of its mechanical limits can cause binding and overheating
25. read the new settings If your heli is nitro powered you ll need to stop the motor Definitions e Bell gain adjusts how much aileron and elevator control will directly tilt the swashplate e Hiller gain adjusts the stability and holding ability of the gyro Follow these steps 1 Asa starting point adjust the dials on the gyro to about 30 for the Bell elevator gain and 50 for Hiller gain 2 Lift the helicopter off into a hover and try some small elevator and aileron motions If it oscillates or does anything violent as you spool up email tech support for help 3 If the helicopter doesn t hold well in pitch or roll or slides to the side turn the Hiller gain up a small amount If the helicopter oscillates while hovering turn the Hiller gain dial down slightly Repeat until you get the best gain 4 Try some forward flight If the helicopter oscillates in roll at high speed turn the Hiller gain down a small amount If it doesn t hold well in pitch turn the Hiller gain up 5 While in a hover pitch the helicopter sharply nose down centre the cyclic stick then do the same nose up If the helicopter is slow to start turn the Bell gain dial up a small amount If the helicopter snaps back a bit and oscillates after it stops turn the Bell gain dial down a small amount Repeat until you get the best balance For sport flyers the Bell gain needs to be only roughly correct For most users no further tuning should
26. ro when mechanical changes are made that will affect the gains such as to cyclic pitch or head speed Show Actual Gains Brings up a table of the actual gains the SK360 will use in flight These gains are based on the settings on the Advanced tab modified by the Bell and Hiller dial s settings This feature can help you understand how the gain dials and base gains work together Default Gains Resets all of the settings on the Advanced tab to those in the Default setup file Does not effect any settings on the other tabs 2008 Skookum Robotics Ltd 20 16 Tuning Troubleshooting Guide Symptom Problem amp Solution Heli tends to drift feel loose in elevator and or aileron Hiller gain is too low Hiller gain isn t high enough even at 100 Increase cyclic blade pitch range using the Swash Mixing setup values or increase servo travel After a sharp elevator or aileron command is released the heli oscillates slowly Hiller gain is too high While in high speed forward flight the heli pitches up or down momentarily Heli tends to oscillate rapidly Test by giving a sharp elevator or aileron command and then release of the stick Elevator damping gain is too low Damping gain is too high While in high speed forward flight the heli sometimes oscillates in aileron Aileron damping gain is too low Warning too high damping gain is hard on servos or Hiller is too high
27. s check their specification and drive them at 6v if they are rated for it Stronger faster servos will let you use higher damping gains see Section 15 which is important for maneuvers such as piro flips Try to have 90 degree angles between servo and blade grip arms and linkage rods for even movement The gyro s USB setup interface will allow fine tuning of servo centers to achieve this Swashplate Rotorhead When setting up the mechanics originally designed for helis with a flybar just removing the flybar but keeping normal servo arm length will likely give too much blade pitch action Either servo travel or servo arm length will then need to be reduced For example on the Align TREX you can adapt the flybar mixing arms as travel reduction arms on the rotorhead to reduce the effect of swashplate slop and reduce servo load This will allow higher gains and better performance Some kind of anti rotation or follower mechanism will be needed to keep the top of the swashplate from rotating relative to the blade grips 2008 Skookum Robotics Ltd 5 If the swashplate is not held so the linkage to the blade grips is at 90 degrees to the blades for 2 bladed rotors the phase angle will need to be set to compensate See the diagram below g Ball Link on Swash Blade Blade 90 For initial flights the phase angle should be adjusted so that when the blades are lined up with the heli s tail boom they do not m
28. s that aileron and elevator control input change each blade s pitch at the correct time For most mechanical setups the phase angle will not need adjusting While checking for good cyclic throws phasing and even swash motion the gyro must be put in setup mode by pushing the mode switch towards the gain dials see Section 8 While in setup mode all stick motions are sent directly to the swashplate as if stability gains were all zero the gyro only does its mixing function The gain dials and gain fields in the PC software will have no effect in this mode To check the cyclic range and phasing 1 Set collective pitch to zero 2 Align a blade along the fuselage pointing over the nose of the helicopter as in the photo below 3 Now try full nose up elevator control with aileron centered Measure the pitch of the blade that points over the nose 4 If the mechanical setup is ideal the blade should not change pitch If it does you will need to adjust the phase angle either mechanically at the swashplate or using the gyro s USB interface If the pitch becomes negative adjust the phasing clockwise if positive then adjust it anti clockwise Note this will give 2008 Skookum Robotics Ltd 7 you normal phasing 90 degree lead multi bladed rotors may fly better with some positive phase trim 5 Try full right aileron control with elevator control centered The blade s pitch should be about 10 degrees
29. the 3M 4408 tape included The gyro s case should not directly contact any hard surfaces of the helicopter s frame and if a safety strap is used across the top of the gyro it should be padded slightly Cables connected to the gyro should have some slack near the gyro s case Before mounting the gyro clean its base and the mounting site with isopropyl alcohol Then use two pieces of the supplied 3M mounting tape on the base of the gyro as shown If you use a pad metal plate pad mounting for a nitro heli be careful that the stack is not too thick as this might result in resonance 2008 Skookum Robotics Ltd 4 5 Helicopter Airframe Setup Good mechanical setup is critical to the gyro performing correctly Please read this section fully The gyro should not be used in addition to a flybar as the results could be unpredictable It is intended for use where the swashplate alone drives blade pitch Blades Flat bottomed rotor blades are not recommended They have a pitch down moment about their axis of rotation that could put heavy loads on the swashplate servos The ideal rotor blades will have a symmetrical airfoil be torsionally stiff but a bit flexible spanwise and balanced both spanwise and chordwise Servos The best performance will be achieved if the swashplate servo s full normal range of movement is used For good 3D performance you will need servos that are fast and if possible digital For analog servo
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