Setting up a Helicopter

Notes

This was written and updated as I went through the learning curve using whatever references I could find, and is still a good basic introduction to all the detailed aspects of setting up, both mechanical and electronic.

However, experience and practical testing shows that this is not the best way. A summary improved and simplifiied method is shown in the section "Pitch & Throttle Experiments".

Introduction

One of my problems is that I cannot find a concise account of how to set up a Helicopter documented anywhere. However, you could always pay the local Model Shop to do it for you (to the tune of  £100-150) ...........................

This is most unhelpful if, like me, you have purchased a second-hand Helicopter.

Until I can find one, here is my current knowledge limited technique. Note that this will be updated as my knowledge improves. I used a Manual Heli. Transmitter (Skysport 6H) at first to gain some knowledge of what was required.

I soon realised the limitations of this Tx (no fine pitch/throttle hover trims or sub-trims) but it gave me a good insight into the areas required. ( or how not to do it as one wag said ! )

The first part of this section is intended for beginners and covers setting up for the hover. By implication, this covers all Helicopters. The second part is setting up for Aerobatics and 3D, and will follow later as my knowledge improves. Note that some Helicopters do not have enough pitch range for 3D - these should at best be regarded as Trainers, or mildly Aerobatic Helis.

Note that there are mainly two Mechanical setups quoted by Manufacturers ;

a) Beginner (normally referred to as "Normal") where mid-stick = 5-6 degrees.

b) 3D where mid-stick = 0 degrees.       (see "Experiments in Pitch & Throttle curves")

PART 1 - Setting up for the Hover.

Helicopter Controls

Note that the Helicopter controls work this way ;

a) Elevator is controlled by the flybar paddles.

b) Ailerons are controlled by the pitch differences between the left and right main blades - one goes down and the other up just as per Fixed Wing aircraft.

c) Pitch is controlled by the Cyclic movements where upwards movement of both main blades usually increases pitch - linked to throttle. More throttle  = an increase in pitch.

d) Rudder is controlled by the tail rotor and (if in use) Gyro.

e) Note that with a "normal" swashplate the Elevator and Ailerons are mechanically mixed at 90 degrees. This can be seen best by moving the head 90degrees and moving either Elevator or Aileron - note that at one point the Ailerons move and at a further 90 degree point, the Elevator (flybar) moves.

Control Response

Note that to ensure predictable and constant control response in all 3 axis, the main blade speed should be at a constant speed (rpm), regardless of whether flying circuits, aerobatics, or hovering. To increase the response, the head speed has to be raised. This is ultra important for stability and is usually covered in the build manual, but you have to look for it.

Examples : Shuttle Z (OS.32)       - hovers at approx. 1300 rpm, but up to 1600rpm is available (tested).

                    Shuttle Plus (OS.32) - hovers at 1450 rpm approx. ,  but up to 1800-1900 is available (tested).

                                                       - flys better at 1500-1600 rpm

                   Raptor 30 (OS.32)     - hovers at 1600 rpm approx. , but up to 1900rpm is available (tested).

A)  Mechanical Setup

All helicopter kits, regardless of age have a build Manual, and this is what you need to obtain. I got mine on the Internet, downloaded 66 pages and printed it. This gives you all the linkage lengths and servo arm size and which holes to use.

It also gives you the servo directions and suggested positional settings for the servo arms. Pay special attention to the relationship between the cyclic pitch and the throttle servo arms, as these have to be synchronised. Note that, depending on the age of the Computer Tx, a mixer may have to be set up to mix the throttle & pitch servo channels. Check that the Ailerons, Elevator, Pitch, and Rudder move the correct way when the radio is operational. Note that the Gyro should be disconnected for this test. 

(Note that there are two Mechanical setups used ; the Beginners with less pitch and Hovering set to mid-stick, and the Experienced with full pitch and mid-stick set to 0 degrees).

The mechanical side must be done before the computer Tx programming. Note that the mechanical setup is not precise enough due to the splines on the servo, which is why these are modified by the Tx to adjust the servo centre points. Note that a manual Tx will work, but is more difficult to setup and precision is limited.

On some Helis. (Raptor for example), the mechanical setup can be done using the pitch indications on the frame.

On others, a pitch gauge will have to be used. (Shuttle)

Stage 1 - Head Rotation

Some Helis rotate anti-clockwise, although the majority tend to be clockwise. Check this as setting the tail direction compensation is dependent on this. This may have to be set in the Tx. Note that the main blades leading edge(LE) has to be towards the direction of movement (it's easy to mount the blades upside down !) Main blade mountings  should just have enough resistance to stop the blades moving to the vertical position when the Heli. is held vertically.

Stage 2 - The CG

1) Check that the CG (nose to tail) of the Helicopter is on the main drive shaft by holding the rotor head in the fingers. If the Heli. does not sit horizontal add weight to the nose or battery area untill it does. A larger capacity battery is an obvious solution. The Heli. should be horizontal or slightly nose down. Tail heavy is not acceptable.

Stage 3 - Control Linkages

1) Check that all control rods are the correct length (measure them and check against the Manufacturers manual).

2) Check they are connected to the correct ball joints.

3) Check the main rods are vertically aligned for maximum movement.

4) Disconnect the Gyro initially.

5) Turn on the Tx, then the Rx. Wait 10secs for the Gyro to initialise.

6) From the rear, check the sense of all servos ;

ie) Right aileron moves rhs of swashplate down. Down elevator moves swashplate down at the front. Opening throttle moves the carburettor arm the correct way. Opening the throttle should also move the cyclic pitch but depending on the Tx, this may have to be programmed using a mixer. Left rudder and the rear part of the tail blade goes left.

7) Check that the swashplate is horizontal in both planes with Tx and Rx on. If not, you have to adjust the elevator and/or ailerons until it is. First move the servo arms until it is as close as possible. If it still cannot be achieved, then the rods will have to be adjusted.

8) Make sure the Flybars are of equal length (measure them against the Manual recommendation)

9) Make sure that all screws into plastic are CA'd for security.

10) Cap head bolts or allen headed bolts or lock nuts should be thread-locked for security. If this is not done, they will come loose. Check after every flying session. Any vibration will loosen all connections, so blade balancing is a must.

***  There is an issue when the throttle and pitch relationship is not defined in the Helicopter manual. The pitch must be enough to Hover at mid-stick and the Throttle must be set to (1/2 power) approx. mid-stick, or just fractionally above. This is a starting point only as each heli/engine power band/blades/fuels are different. The goal is to get a Hover at mid-stick and fine throttle/pitch adjustments to neutral. A complementary aim is to get servo arms at their mid-points at the same starting point. If this is correct, then only minor fine adjustments will be necessary.

Stage 4 - Checking the Main Blades pitch angle

The pitch angle is usually specified in the Build Manual and is set with a pitch gauge. Pitch gauges can be simple cardboard/paper type to sophisticated Commercial items. A range from +15 to -5 degrees is fairly normal, with 5-6degrees (the Shuttle is 5.5degrees) for Hovering. Note that the Flybar must be held horizontal to the boom while this is set. I used a cardboard template for mine. Note that if this is not done correctly, the Heli. will have too much pitch, will have too low a head speed, and be very hard to fly as well as potentially vibrating (over time), itself to pieces.

An example from the Hirobo Shuttle manual (in degrees) is below :-

Stage 5 - Setting up the Rudder

The Rudder should be set up without the Gyro in circuit first. Mechanically, the servo arm should be mid-way when TX/Rx are on and both Tx trim and stick are centered. Make sure the rudder can move equally in both directions the same amount. Moving the stick left should move the TE of the rudder blade left. The servo linkage should be set up so that 7-8degrees of right pitch are set at the mid-point of movement. This is to counteract the Helis tendency to turn left on take-off, assuming a clockwise main blade(s) rotation. Once this is set, move on to Stage-6.

Stage 6 - Setting up the Gyro

Mechanically, the Gyro has to be ;

a) Connected between the Rx and the tail servo.

b) The correct way up (sense). (refer to the Computer Tx section) Note that if this is incorrect, the Heli. will pirouette viciously, so double-check.

c) Mounted as close to the main drive (CG) as possible on thick foam sticky pads to avoid vibration.

If the Gyro is of the Piezo type, then Revolution / Acceleration mixing will probably have to be used. If the Gyro is a heading-hold type, then no Revo./Acceleration mixing is necessary.

6.1 General

Historically, the mechanical sensor was used, then the electronic piezo, then the electronic transistor HH. The Piezo gyro tends to be cheaper than the HH gyros. The HH device is intended for very fast speed servos and is much quicker to react than the piezo. However, they both perform exactly the same task. Because of the slow (relatively) speed of the piezo type, revolution and acceleration mixing are usually used on the Tx. These are usually "free" on the Tx. These comments are based on my known examples ; CSM HLG200 and GWS PG01. neither of these have any visual indication of power on. The more expensive electronic types have a power LED to indicate power is present.

The Gyros job is to oppose the tail swinging, keeping the Heli. on a constant heading, and reducing the amount of work done by the Pilot. Instead of 4 axis to control, the Pilot only has 3 if a Gyro is holding the Tail. The HH Gyro will quite often include Exponential to lessen the effect of the rudder stick movements.

6.2  Heading Hold Gyro setup

To check that the Gyro is operating correctly in the right sense, power on both Tx and Rx. Allow 10 secs. for the Gyro to move the tail blades. Move the nose of the Heli right as a jerk and note the opposing action of the Gyro - it should move the rudder blade TE left. If this does not happen, and the Tx/Rx/servo direction was correct without the Gyro in circuit, then the Gyro is in the wrong sense and will have to be re-programmed (reversed) or set upside down, depending on the correction method and the Gyro type.

6.2  Piezo Gyro setup

This type usually has one or two potentiometers  - a) Neutral servo b) Gain. Neutral is for setting the mid-point of the servo. It also has a servo reverse switch. Follow the above procedure for testing, remembering that at the mid-point servo arm position, the tail should have 7-8 degrees of right tail blade thrust.

6.3  Revolution Mixing

Revolution mixing compensates for the main blades torque effect, by introducing an opposite pitch (%) at the tail blades. The neutral point is the hover. Unfortunately, you have to be able to fly the Heli. to set this up, so you need your expert again.

6.4  Acceleration Mixing

This compensates for the difference between hover compensation and power on/off compensation. Usually, if a Heli. is set up as per the above table, or for constant head speed, it is not necessary.

6.5  Gyro Gain

Gain is usually set to around 50-60% for beginners, so this is a good place to start, if setting on the ground. Alternatively, if you can hover already, set to 80% and if the tail starts to "wag" while flying in a straight line, reduce the gain until it stops. The problem with excessive gain, or single gain settings is that when aerobatic manouvres are attempted, the Gyro attempts to prevent quick movements of the tail. This is where a switchable gain setting is useful, once you progress to that stage.

Stage 7 - Balancing the main blades

What you are trying to achieve here is twofold ;

1) Both blades need to have the same weight.

2) The position of the CG of each blade must be in exactly the same place on each blade.

This reduces the overall vibration level of the Helicopter and avoids things coming prematurely loose, so is very important.

Method

There are two areas of balance needed and need to be done in this order ;

a) Static balance (blade CG)

b) Dynamic balance (blade weight and combined blades CG)

Additionally, tape needs to be added to both blades for later tracking setup. It is better to do this before balancing takes place. *** In flight testing showed it is difficult to tell which blade is the higher unless tape is only added to one blade. The tape can be removed later if concerned about balance.

7.1) Tracking Tape

Strip off any existing tape and the glue remnants. Cut two equal size (weight) pieces of tape to add to each blade tip. These should be different colours to aid the Tracking adjustment which comes later. (see *** above)

7.2) Static Balance (Blade CG)

Place the blades (with the plastic shells if they exist) with the root end off the table, over the edge of a table. When they "teeter", mark the edge of the table point on each blade with a pencil or marker. I found this is much more accurate and easier to do with a steel ruler edge mounted in a vice.

If one mark is further towards the root than the other, add coloured tape to the end of this blade until the two blades balance points match lengths - the CG should now be at the same point (measured from the hub) on both blades. Re-mark the new balance point on the adjusted blade. This will change the weight of the blade adjusted. If it is difficult to obtain a balance with one blade, or the amount of tape used is excessive, use two pieces of tape at different points on each blade until their CG points are equal.

7.3) Dynamic Balance ( Blade Weight and combined blades CG)

Bolt the two blades together and suspend them using either string or wire to the bolt, or use the original bolt and nut suspended across the jaws of a vice. Make sure the nut is not sitting on the flat, but on the corner, so you get a true reading.

If one blade hangs lower than the other, place coloured tape on the higher level (lighter) blade at the already found CG point marked on the blade until both blades leading edges are horizontal.

Stage 8 - Balancing the Rear Blades

Although this is not usually necessary, it is still worth doing. It is obviously easier to do while building the tail assembly in the first place. The tail tends to be steadier and gives the tail gyro/servo less to do. Hold the assembly horizontal and check that both blades are also horizontal. if not add weight (tape) to the heavier blade until they are horizontal. Mine were perfectly balanced once I removed the sticky tape decorations.

Stage 9 - Balancing the Rotor Head

1) Disconnect the connecting rods from the head.

2) Check that the Flybar rods are of equal length (usually described in the manual) If not adjust until equal.

3) Check that the Flybar stays level when rotated. If not, add tape to the lighter paddle until it does. 

B)  Computer Tx Setup

Most Computer radios have throttle and pitch curves preset which is very useful for a first flight. The defaults are usually a straight line. Basically it means that you can ignore them temporarily, We are interested in the digital trims and sub-trims. These should be set to zero prior to the first flight. Pitch and Throttle knobs should be centered.

Initial Checks

a) Turn on Tx and then Rx.

b) Check Tx. Swashplate Type - usually normal = 120degrees

c) Check that the Tx. is in "normal" mode if various modes are switchable.

d) Sub-trims are all set to zero.

e) All Tx to Rx channels align with Tx controls.

f) All servos are moving in the correct direction.

Detailed Setup

a) Swashplate movement is correct and level in both pitch (elevator) and roll (aileron) planes. If not, then use sub-trims to achieve this. (Note that sub-trims are primarily used to centre servos, not used as substitutes for fine trims, or to correct for incorrect mechanical setup)  If the Heli. needs a lot of sub-trim on a servo, then the mechanical setup will need adjustment. Check that when the Flybar is horizontal, and the Tx throttle is at the mid-point, with pitch and throttle pots at the mid-point, that the main blade pitches are at the designated Hover pitch point for that Heli. If not, adjust the pitch rods or aileron rods accordingly. Check accuracy with a pitch gauge.

c) Setting up the tail is easier without the Gyro, so take that out of circuit. You need to set the servo mid-point to the mid-point of the tail movement bar, so there is equal movement in both directions. This is done with the Tail servo sub trim. At the same time, the mid-point bar should show around 7degrees right pitch on the rear blades. This gives a good start point for the hover, so the later fine trim needed should be minimal. Re-connect the Gyro.

d) Throttle Curve should be a straight line initially.

e)  Pitch curve should be a straight line initially.

You are now ready for a ground check.

3) Ground Check

1) Make sure the Beginners safety harness (undercarriage) ("the balls, the balls" - apologies to Quasimodo) is strapped to the Helicopter. Do this prior to all test flights. A test flight is where changes have been made but not tested yet.

2) Double-check all servos are in the correct sense (again)

3) Hold the head and blade roots while starting the engine as if the throttle is too high, the clutch will engage and attempt to move the rotor blades. Start the engine and adjust the tickover so that the clutch is almost disengaged and the tickover is reliable. New engines are preset at the Factory, so the slow jet should be correct. Leave the main jet alone also. You may have to adjust the throttle trim/rod to get a proper reliable tick-over without engaging the clutch.

To do it properly, setting up the slow jet, and main jet on the engine requires head-loaders and a rev counter. Full throttle head-loaders should be approximately 1600rpm on a .32 size engine.

4) Find a test site which is flat and preferably sheltered from wind. This is important as you need to see which way the Heli. is moving easily. Grass causes balls to stick giving completely the wrong indications and is not consistent.

5) The rule here is gently and slowly. Place the Heli. well in front of you (15 feet at least) and get the Heli "light" on the balls (ie) apply just enough power so the spring goes out of the undercarriage) - it will tend to move either left/right or forward/backward or the tail will move left/right or a combination of all three. Check all Heli. movements are in the correct directions.

Start with the Rudder - adjust the Tx trim the opposite way - if the nose goes left, then the trim needs to go right. Adjust trim until tail stays put.

Apply the same procedure to the Ailerons until the Heli. does not move right or left.

Apply the same procedure to the Elevator.

You are now at the stage where experienced help is required, You need an experienced pilot to finally trim the machine in the air. The fine trims should be used for this.

Test Flight

Once this is done, the subtrims can be moved in the same directions as the digital trims (x%) and the fine trims centered. (there is a school of thought that states only fine trims should be used here, but I consider that starting every flight with all trims at zero is more important) Again you will need your experienced help to re-trim the Heli. except that the changes should be minor. The aim is to get the Heli. to Hover without moving in any particular favoured direction in no wind conditions. (it's impossible to get it to stay there permanently, but that is the nature of Helicopters) 

Your experienced help will advise you of any problems needing attention.  Once you have got to this stage you are nearly ready for your first flight, preferably on a buddy-box.

Main Blades - Tracking

The main blade tracking should be checked at this time by taking off and hovering so the blades are at eye level and under load (blades flex upwards under load). Check that both blades are tracking at the same height. The different tip colours you added to the blades while balancing are used to see which blade is low and which one high. (Note that one colour temporarily on one blade was used in practise)

Adjust by either ;

a) lengthen the pitch rod or equivalent when elevating the lower blade. (increase pitch)

or

b) shorten the pitch rod or equivalent when lowering the upper blade. (reduce pitch)

This may/does affect the head speed (rpm), so this should be checked at the Hover value again, and the throttle (linkage or curve values) adjusted acordingly. If the head speed is high (judged by sound) raise pitch and if low decrease pitch on the relevant opposite blade.

YOUR first flight

1) Simulator

The Simulator is a must prior to trying to fly a model so as to gain orientation and get used to the controls and the Helis response. Failure to do this will almost certainly cause a crash on the first flight with the model.

2) Buddy Box

Although this is not so easy to set up and needs two of the same model TX's, it is still the easiest/safest  way to learn without breaking anything. The problem is it's expensive.

3) Non-Buddy Box / Training

Although this is not the ideal way to learn, if you have no access to a Club Member or help, then you can teach yourself, but it's not easy and the secret is as little control as possible. A Beginner should use Exponential if available of around 30% on Aileron/Elevator/Tail Rotor.

3.1) Bunny Hops

Short take-offs and landings with the Training U/C on - height just above the ground. Control from directly behind the Heli. into wind. Increase height gradually to around three feet and Hover.

Training manouvers are well covered in most Helicopter reference Manuals, so this is where you go next once you can Hover.

Switch Modes

These modes are usually controlled by switch combinations depending on the Tx's capability.

Idle Up

This mode sets a minimum setting below which the throttle will not close, even though the throttle stick continues to be pulled back during aerobatics.

Hold, or Throttle Hold

This is used for practising Autorotations. Throttle hold disconnects the throttle channel from the collective pitch channel and leaves the throttle stick controlling only the collective. The throttle is set to provide a reliable idle.

Flight Mode 1

This is also referred to as "circuits" or forward flying. It requires more head speed than hovering, but less throttle due to transitional lift effects.

Addendum

Two setting up aspects were bugging me ;

a) a lack of pitch gauge.

Having borrowed a pitch gauge, I found my Heli. was way out on the pitch settings (around +10 instead of +5.5 at the Hover point). Trying to set this up caused me to revise my ideas a little. I think it is a must now. This was causing a large loss of head speed (rpm), I estimate it was around 1000rpm instead of 1300rpm and making it much harder to fly.

Moral :- invest in a decent accurate pitch gauge !

b) how do you measure revs. at  the Hover point ?

Reference books suggest 1400 -1500rpm. Having tested full throttle on Head Loaders at 1600rpm maximum on my rev. counter, I have my  doubts about these figures. I consider 1300 more likely in my case. In fact a later discovery in the Hirobo Shuttle Build Manual suggests 1300rpm as the Hover speed !

Maybe I could fly the Heli. over a rev. counter and find out ? - as long as the rev. counter retains it's highest figure, I should get some idea. This was tried and did not work due to the rev counters inability to retain the highest setting.  Mine came out at approx. 1300rpm. Headloaders are definately safer, so this is my preferred method. If the headloaders and the blades are close in weight, figures obtained should be close. The head speed has to be fast enough to stabilise the Heli. while allowing the Gyro to operate correctly. Helicopters tend to be either unstable or "nod" when the head speed is too low. Confirm with an experienced flier.

Summary Procedure

Procedure used was ;

1) Mechanical as close to neutral as possible.

2) Pitch gauge at 5.5degrees at mid-point throttle with Hover trims centered and Flybar horizontal with boom on both main blades and perpendicular to the main shaft. ( A pitch gauge is a necessity here) To check the Hover rpm(1300 in my case), a rev. counter is necessary also.

3) Elevator and Aileron Sub-Trims adjusted at this point so Swashplate is level in both planes. (Needs Computer Tx for Sub-Trims)

4) Tail servo arm at mid-point (use Sub-Trim) and rear arm at mid-point at 5-8degrees right thrust. The right thrust is different for every Heli. and may have to be adjusted slightly, but is a good starting point.

5) Fine trim by flying - trim with fine trims only and Hover pitch/throttle potentiometers set to mid-point.

6) Re-adjust sub trims and reset fine trims to 0.

This was tested on the field and worked very well. All fine trims were within + - 2%.

Someone commented a while ago that Flying a Helicopter was 90% setup and 10% Pilot - after this exercise, I tend to agree with them !

Gyro / Tail Servo relationship

Experience with slower servos (Futaba148 - 0.22s/60degrees at 4.8volt) and a faster Gyro (HLG200) shows a slight constant movement (wag) on the tail, especially in a wind. Gain changes have not affected this. CSM advise 0.12s or less servo speed for this Gyro and a Hitec Digital 6965HB is advised, so this may be the cause. 

PART-2  - Setting up for Aerobatics

1) The Heli. has to have enough mechanical pitch range.

2) You must have a computer Tx with at least 4 flight switch settings and programable pitch and throttle curves for each setting. Four switch settings are used ; Normal (for hovering) ; Idle up 1 (for aerobatics) ; Idle up 2 (for 3D) ; Idle up 3 (for Autorotation).

Aerobatics (idle up -1)

This includes fast forward flight, rolls, and loops/bunts.  The existing "Normal" switch (hovering) settings are left alone - all changes are programmed to the second switch position - normally "idle up 1". This allows a switch back to hovering at any time.

Head speed : needs to be raised up from the hovering speed by at least 1000rpm. (1600 + 1000 =1700 in my case)

Mechanical settings : 

Throttle : set to bottom stick at aerobatic head speed.   (1700rpm in my case)

Pitch : Max = same as Normal.

           Mid = same as Normal (may have to reduce mid-stick pitch if Heli climbs too much in forward flight)

           Low = -5

PART-3  - Setting up for 3D

3D (idle up -2)

This includes mostly inverted flying and manouvers and uses "idle up 2" switch position. Setting up this way bears no relation to the two previously mentioned setups and may not be achievable on some Helis if they were not designed for 3D.

Mechanics are set to 0degrees pitch at mid-stick and as much pitch as available in either direction.

Head Speed : 1000 more than Aerobatic speed.

Mechanical settings : Mixing arms ; Blade mixing arms ; swashplate ; cyclic bellcranks - all horizontal when blade pitch is at 0 degrees.

Pitch Range setting : (20) +10 to -10 degrees

Low stick is  (max -10 degrees) normally approx. - 4.5 for inverted.

Mid-stick is zero degrees. (inverted Hover is approx.  - 4.5 to - 5.5 degrees)

High stick is (max +10 degrees) normally approx. +5-6 for hover.

Throttle setting : "V" Curve (full throttle at -10 and +10 pitch half throttle at mid-point)

With these settings therefore : Heli. hovers at 3/4 throtlle ; inverted at 1/4 throttle.

PART- 4 - Autorotation

Autorotation Setup (throttle hold or Idle Up 3)

Pitch = 15 high stick ; 5.5mid stick ; -5 low stick

Throttle = idle (no clutch engagement)

Throttle hold switch is a seperate "flight condition" switch and disengages the throttle while maimtaining the idle engine speed.

Helicopter Flight Mode Comparison Chart  (rpm and pitch range)

      Suggested starting points for Mechanical / Pitch & Throttle Setups for Hover/Flying/Aerobatics.

Fine tune by flying.

Note that some Transmitters have only 4 positions - Normal, ST1(Idle-1),ST2(Idle-2), and ST3(Idle-3 orThrottle Hold), whereas others have 5.

In the first case Flying and Aerobatics should be combined on Idle-1 and 3D on Idle-2. Note that 3D will probably require +/- 10 degrees pitch and a servo upgrade.

Suggested starting points for Mechanical / 3D & Autorotations.

Fine tune by flying.

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