A comprehensive heli guide for beginners

I created this topic to copy and paste some articles someone posted over on RR. I have permission from the individual to post them here so no worries there. So here they go...

aerton (RR)
Location: Longueuil, QC, Canada

I decided to share my experience in a pretty much complete reference from choosing the heli to building, configuring and flying it.
I found that even though there is a lot of info about it, the info is very incomplete particularly when it comes to adjusting the heli.

I plan to post several messages by chapters into this thread. Any additional comments, corrections, work arounds, and know hows are very welcome.

I the flying part isn't yet very well developed since I'm just starting to fly the real thing, so may be somebody has some know hows on it.

The TOC will be like this:
1. CHOOSING HELI
2. Choosing Electronics
3. BLING
4. Building the heli
5. Adjusting your heli
6. Setting up the electronics
7. Simulator training - VERY IMPORTANT.
8. Configuring the radio and ESC
9. Real flying
10. Crashing

1. Choosing a heli
1.1. Always go for 30+ size bird with a reputation for *stability*. Everybody advertises how 3D capable their machine is... Remember you can't yet put your heli into a stable hover without your hands shaking and spine sweating, you don't need 3D setup, you need stability.
1.2. Anything less than 30 size heli is way too unstable. It's a very well known fact.
1.3. Choose heli by watching the videos of it.
1.3.1. Pay attention to slow vertical takeoffs and stable hovers, slow forward flight, instead of crazy 3D moves. Check the drift, if a heli configured by a pro drifts on takeoff, it's not stable enough. Then of course there are degrees of drifts
1.4. Choose an inexpensive stable heli. Remember it's primarily the heli itself you'll crash so it being inexpensive is very important. Check the prices of parts
1.5. I had T-Rex 450 – didn't like it. Not stable enough.
1.6. Bought Swift 16 kit – love it. Just love it. Bought 2 actually, 2nd for replacement parts. Standard size servos, etc.

2. Choosing Electronics
2.1. Shop around for well reputable digital servos. Don't buy non digital, for a heli it's pretty much a waste of money. Not precise enough. Remember 0.1 mm on a swash plate left aileron arm means the heli drifts to the right.
2.2. Select servos with no slope and play.
2.3. Never go for competition grade super fast servos. Way too expensive and not expandable. Remember you can strip a gear on a servo and gear for them costs about as much a lower level servos.
2.4. Don't think that you can invest 1 million and the heli will fly by itself or fly easier. It's the properly designed and properly adjusted heli that flyes great not as much the high-end parts.
2.5. I bought 4 Futaba S3151 off ebay for less than 100. 0.19s/60 degrees
2.6. Since I didn't try other servos, I can't comment on the usefulness for the beginner of buying a faster servo. May be a more precise one
2.7. Buy inexpensive receiver. You can spend 100 on a PCM receiver or 50 on FM one. It flies very well with FM one. I bought Futaba 127DF
2.8. ESC: I bought Castle Creation HV 85. I wanted it to handle 4S setup and 8S later on. Less volts means more amps for the equal power (basic physics: Watts = Amps * Volts)
2.9. BEC: I advise not to use the integrated ESC+BEC combos if possible, because it's a true peace of mind when you can turn on the receiver without powering the ESC. You are absolutely sure the motor can't possibly spool up. I like separate receiver battery with an on switch.
2.10. Gyro: Everybody says GY401+S9254 = $220. Well, I decided to buy Walkera WK-G007 and put S3151. It has AVCS and remote gain, delay and limits. So far I haven't outgrown it but this is most likely what I will change the first. WK-G007=$60+S3151 = $85 and is expandable. I really recommend remote gain feature, because I like to adjust it from the radio. Also AVCS is what I use all the time. I have no idea how to fly without it.
2.11. Motor: Bought quantumdrive "hextronic" hx36-55 off e-bay from world hobby (hobby kong) for $48 with shipiing. Total bargain and is a great motor for 4S-5S setup. 1350kv. I take off at half a throttle. The model weights 2.3kg. Looks like Kontronik FUN 600 clone. Once again don't buy 3D setup motors like Tango 45-10, Neu 1910, unless of course you know what you are doing and that's what you feel. But if you are simply trying yourself in this hobby go for something inexpensive. If this motor burns out – nobody cares it's expandable.

2.12. Choosing Electronics : LIPO
2.12. LIPO: Ridiculous pricing. Build your own save a ton. I bought 4S 4000mah battery for $55 shipped from honk kong : http://www.happitoy.com/. It's 4S 3P really. Looked like one of those on ebay only less expensive than the ebay itself :-). The soldering wasn't perfect and disconnected, so I ripped the cover and resoldered it myself. Works fine. Weights 390g, and is less expensive than NiMh. Second 4S batter is built from truerc 4000 mah lipos. Buy a few, it's less than $15 a cell, buy a 30-40 watts soldering iron and silver soldering (I think any soldering will do) and 14- awg wire along with golden banana blugs.
NEVER SHORTEN LIPO – WAY TOO SCARY! ONLY 1 CONTACT SHOULD BE NAKED, THE SECOND SHOULD ALWAYS BE COVERD WITH INSULATION TAPE. Trust me, freaking scary.


2.13. Here is how you solder it, cause the nickel connectors aren't easy to solder.

2.13.1. Take each cell separately. Find the + and -. Mark +. Take electric insulation tape. Put on every nickel plate, put back the cell
2.13.2. Take first cell. Cut 2 small pieces of wood from those coffe-shop wooden sticks. Glue with CA at the extremities of the cell. This is for ventilation purposes. I think you can avoid it but I prefer doing it anyway.
2.13.3. Take out insulation of the contact you want to solder (-). Bend the insulated (+) contact under the battery because I actually shorted the cell by the iron because it melted the insulation. Nothing bad but still scary.
2.13.4. Take second cell. Take out insulation from (+), bend (-). Put over the top on those glued wooden sticks, with naked (-) from 1st under naked (+) from 2nd. Just to see and then put it away.
2.13.5. Take iron, put on (-), warm it up, while iron is still touching the plate, bring the soldering wire at the point where iron meets the plate, solder starts melting while attaching to the plate. Move iron and solder over the plate to make a bubble of solder over the plate.
2.13.6. Do the same on the (+).
2.13.7. Put the cells one over the other one. Take the pliers, put the iron inbetween those plates to melt both bubble of solder, once melted, press the pliers to connect both plates together.


2.13.8. BANANA CONNECTORS:
2.13.8.1. Make the (+) plate as male, (-) as female.
2.13.8.2. Instead of: "The batteries are always male the ESCs are always female" For several reasons:
2.13.8.2.1. You buy pairs of male female plugs but use only males for batteries
2.13.8.2.2. The most important, you can't confuse the polarity! And believe me I have messed it up almost every other time, resulting in a small fire about 5mm big at the esc. Not very entertaining.

2.13.8.3. SOLDERING banana plugs
2.13.8.3.1. Turn the plug upside-down
2.13.8.3.2. Warm the upper cup with soldering iron
2.13.8.3.3. While warming bring into contact the solder to fill the cup with the solder
2.13.8.3.4. Take out the iron
2.13.8.3.5. Take the wire, warm it up a little bit with the soldering iron
2.13.8.3.6. Touch the solder in the cup with the iron to melt it
2.13.8.3.7. While touching it slide into the melted solder the wire
2.13.8.3.8. Keep the iron for a couple of seconds
2.13.8.3.9. Let go.
2.13.8.3.10. Wait a bit for cooling down (20seconds)
2.13.8.3.11. Try to tear them apart, if you can't, it means it's properly soldered.
2.14. Everybody talks about emoli, well, I don't know much about them. I think if you can put together lipo battery it will be better anyway.

3. BLING
3.1. Don't buy bling in hopes that the heli will fly itself after you invested another grand in it.
3.2. Don't buy bling unless you can fly it and you need it.
3.3. If the heli can't fly without the bling, get rid of it, save your electronics and buy another one. The helis themselves are the cheapest components anyway.
3.4. Don't buy the carbon blades yet. Fly with the standard ones

4. Building the heli
4.1. Building it is straight forward except for a few points
4.1.1. Build your heli twice, you will have to anyway.
I like kits I don't like ARFS, but it's just my choice
4.1.2. For a kit you first build your heli without any thread locks, oil and glue, just to see how it all fits together, then you dismantle it and thread lock it, glue it and oil it.
4.2. Building Rotor head
4.2.1. Every pair of levers, pushrods, and linkages must be of exactly the same size. They say "the distance between the centers is X". Since you can't really measure that distance, measure the diameter of the plastic hole and subtract that from X. This is the distance between the closest points of the holes. Take a caliper, measure it. Make the second lever exactly that big (or as closely as you can).
4.2.2. The plastic hole has to be pushed quite strongly into the metal ball for it to fit. When I can't push it by hand, I use pliers.
4.3. Put main blades at the end when you will be about to fly.
Yet, and this is very important, do not strongly tighten the bolt that holds the blades
4.3.1. First the plastic blade grip can be cracked (happened with my T-rex)
4.3.2. The blades won't self stabilize by centrifugal force, so if you have a small angle in 1 blade the heli will shake
4.3.3. In the event of the crash you risk your whole main rotor instead of just risking the blades.
4.4. Basically the same applies to the tail blades, but I found that on my swift I had to tighten them because the tail stops when motor stops and I had to put back the tail blades between the test flights.
4.5. Flybars
4.5.1. The CA you put in your flybar paddle can always be crushed by turning the paddle with force. So if you noticed they aren't aligned horizontally, don't worry just redo it.
4.5.2. I like in swift that the flabar itself has some nice plain cuts so you know for a fact that the rod itself is aligned fine and now you can align the paddles to the flybar control arms.
4.5.3. Aligning paddles to themselves is kind of hard since the sight is obstructed by the head. So align it to the control arm.
4.5.4. Also just measure the distance between the tip of the paddle wher it meets the rod to the tip of the control arm, make it as equal for both paddles as possible and don't worry if you have some 0.1mm of deviation, it doesn't matter that much. But if you have several millimeters then it matters.

5. Adjusting your heli
5.1. Principles:
5.1.1. Everything must move freely! Always. Do not leave it without attention if something isn't smooth. Untighten the screw and use threadlock and use grease. Solve that stiffness.
5.1.2. But There should be no play. (As good as you can get it)
5.2. Adjusting swashplate
5.2.1. The swashplate IS your heli
5.2.2. It must be adjusted as precise as possible and here is how
5.2.3. Take a caliper, with swashplate at neutral and radio turned on measure the distance between the top of the swashplate little arm and the main frame. Write it somewhere. Measure it from the other arm and compare. Use subtrim to adjust. As precise as possible. You got it, the swashplate must be aligned with the main frame only, provided that it's perpendicular to the main shaft which is always the case, and it should not be neccesarily aligned with horizon, because it has to be relative to the main frame.
5.2.4. Do the same things with full positive pitch and full negative pitch.
5.3. Finally even if you can't adjust it absolutely precisely, it'll still fly much much better.
5.4. Lubricate everything. You heli must be pretty much soaked in the lube. Here are the brands of the lube that I used, and I my comments about them:
5.4.1. Bostik Bearing Lubricant – absolutely amazing for any ball bearing. Just absolutely amazing. Use it on the motor bearing and get more power out of it. Use it on the tail bearing. But useless on standard parts like main shat, ball links, etc. Bearings only.
5.4.2. Lloyds Mooveit penetrating lubricant – very good on ball links. BTW don't as much lubricate the ball and the hole separately, but actually when it's already put together. Makes it much smoother. Also use on main gear\motor gear\tail gear\tail belt. Pretty effective. Pretty good on main shaft\swash plate.
5.4.3. Boeing boeshield T-9 metal protectant and lubricant. I used it on my main gear and related gears, also on the belt. BTW, belt has to be lubricated thoroughly from both sides. Lubricate the tail boom too, because the belt touches it constantly. Increases the efficiency.
5.4.4. May be somebody can tell their brands. These ones I bought from www.leevalley.com It's in Canada, where I am, but they ship to the US.

5.5. How to "work" the ball links on the main rotor:
5.5.1. Just tilt the swash plate to 1 side and manually rotate the head. Since with every totation every lever changes the position, every ball link works and becomes less stiff. Everything must be lubricated.
5.6. Tail play.
5.6.1. If tail blades have a play, you will have to reduce gyro sensitivity or your tail will shake. It's actually better to have the tail more stiff but without the play than the other way around. Always use threadlock there. I found medium blue threadlock to work great.

5. Adjusting your heli - 5.7. GYRO
5.7. GYRO
5.7.1. The most important is the Reverse option here.
5.7.2. First make sure that when you move rudder stick to the right the heli will move to the right.
5.7.2.1. If your main rotor rotates clockwise then your tail rotor should rotate counterclockwise. Make sure it is so
5.7.2.2. Here is the trick if the tail pitch arm (the thing that moves on the tail rotor shaft towards and from the blades) moves to the right the head of the helicopter will turn right, while the tail (obviously) left. So the direction of rotation is actually indicated by movement of this tail pitch arm.
5.7.3. Increase the gyro sensitivity and move the tail long enough to the right (effectively simulating the move of the head to the left), the gyro must compensate by moving the helicopter to the right, meaning that the tail pitch arm should move to the right.
5.7.4. DOUBLE CHECK AND TRIPLE CHECK this, because if gyro is wrongfully configured you'll have a near guaranteed crash on the take off, unless you won't take off. (I actually crashed my T-Rex this way)
5.7.5. Make sure that you have all available range of movement of the tail arm.
5.7.6. Make sure NOTHING touches the gyro, especially the canopy. If during the flight canopy touches the gyro you'll have the momentarily tail shake. I just had it and thought it was a glitch, but then I figured out what it was.
5.7.7. I mounted the gyro on the tail over a piece of foam that I just cut myself and attached with duct tape. No need for carbon gyro plates. Attach the gyro on the double sided thick tape. Well, you can experiment actually.
5.7.8. For the gyro to work at it's best you need a servo with no slope and a tail blades with no play, and smooth moving parts, not as much the fast servo, which I guess is still a plus.

5. Adjusting your heli -5.8. Tracking.
5.8. Tracking.
5.8.1. Now they say some BS like this : Put the heli at eye level hover and watch the blades. If they one is higher than the other one readjust. Well, first of all if you are that good and can put your heli at eye level hover... The nonsense of this is obvious so I'll pass on it.
5.8.2. Here is how you do it on white blades
5.8.2.1. Take red and blue markers.
5.8.2.2. Paint about 4cm of solid red on the tip of 1 blade
5.8.2.3. 5cm from the tip of the other blade paint a blue strip about 4cm wide, and so on a couple of lines like this
5.8.2.4. Start heli, pitch at neutral or slightly negative. Increase slowly the throttle until the blades make a visible filled circle, but as far away from take off throttle as possible (just to be sure).
5.8.2.5. From an angle watch the appearing red and blue circles. It becomes quite visible when all the reds are higher than the blue ones or vice versa.
5.8.2.6. Stop the heli, figure out which one pushrod to adjust and how to adjust it (depending on the heli setup). Adjust it slightly and continue.
5.8.3. Signs of the blades out of tracking: Helicopter shakes on spooling up (starting the rotation) and there is a visible shake even when RPM reach take off level.
5.8.4. HELICOPTER MUST NEVER SHAKE. IT CAN ONLY TREMBLE. It should be as steady as possible. Shake means incorrect tracking.
5.8.5. I never weighted the blades themselves. So I have no idea if it's useful or not.
5.8.6. I love to watch the red and blue circles on spooling up and notice which blade goes higher or lower when it's displaced a bit but a rough start. And also to watch the tracking go back to normal with increased RPM as centrifugal force puts the baldes into the straight line.
5.8.7. Basically your blades should be tighten enought only to withstand only the initial spool up.

ADDED: Also when I see that the tracking is correct but the heli shakes, it means that something isn't right and not tight enough, or became completely loose. Very practical visible test on spooling up

6. Setting up the electronics.
6.1. One word: Interference and RF noise
6.2. Sources from biggest to smallest
6.2.1. Motor
6.2.2. ESC
6.2.3. Servos
6.2.4. Tail belt (static)
6.2.5. Batteries
6.3. Solution
6.3.1. Put the Motor and ESC near each other, and the receiver as far from both and servos as possible. I mounted it on the landing strut of my swift 16. It's pretty far away from the Motor and ESC, and some 6cm (2" ) below servos.
6.3.2. Extend the antenna from the receiver to the lowest point of the fin. But don't put antenna near the tail boom or on it, because of the tail belt generate static RF noise. Lubricate the belt.
6.4. People use deans connectors a lot. I personally don't like them at all, because they are very hard to disconnect. I use golden banana plugs and put insulation tape over them.
6.5. It's practical to put short strips of duct tape over the servo wire connectors to the receiver in order not to pull by wires when disconnecting, but pull by the duct tape strips.
6.6. There are simple practicle little tools that show EMF emission. I use one to make sure that the EMF noise doesn't reach the receiver.

7. Simulator training - VERY IMPORTANT.
Thanks, I did work on it for a couple of days. I really wanted to create a comprehensive guide that has an almost complete experience and know how that I came up with during the last year since my first heli and almost 2 grands spent on this hobby. I had reached a limit of 10 posts per 8 hours so I had to stop yesterday.

7. Simulator training - VERY IMPORTANT.
7.1. I use Reflex XTR and Kyosho model.
7.2. It doesn't matter if your model is there, it's much more important to have the model that is there to be simulated correctly.
7.3. Practice ORIENTATION. Not as much the 3D moves. Practice take offs and landings.
7.4. ORIENTATION is practiced this way:
You move your heli by a cross pattern without rotating the helis tail at every otientation. Heli facing from you, towards you, to the left and to the right. On every orientation Move the heli to your right, back to the center, to your left, to the center, from you, to the center, to you, to the center. Until you learn the orientation and learn to think in the terms of "the right of the heli" "the left of the heli" instead of "my right" and "my left"
Once the orientation is learned flying heli is much easier.

8. Configuring the radio and ESC
8.1. Don't start the ESC right away in the governor mode because you need to test it first and make sure it doesn't overpower or underpower your heli
8.2. Put the throttle separately on a some control arm near the pitch to have a control over it and see how the model reacts on different throttles, what's the take off throttle etc
8.3. Configure Throttle Hold switch at a very easily accessible position because this is your heli savior. If it does anything that you don't understand just hit Throttle Hold and see the heli come back to earth. Rough landings are nothing compared to a heli crash do to the blades hitting something or the ground. The worst thing with rough landings is braking your cheapo struts, that you can actually attach back with a tough duct tape
8.4. The separate throttle slider will require programming the mixing, well it's quite straight forward with 9CHPS that I have, the only trick is to link it with the throttle hold switch. When throttle hold is ON, this throttle-slider to throttle channel mixing is OFF, because otherwise it will add up and you will actually be able to take off with throttle hold ON, which is very bad, since you rely on it for your safety. I was hit by the blade because of this, when I accidentally increased the throttle while on throttle hold, since the mixing wasn't properly configured.
8.5. Make sure your hi\lo throttle and pitch are are manual and not linked to any VR slider, at least not linked to the throttle VR slider and remote gain of gyro VR slider.
8.6. In this setup the throttle curve is a constant 50% all over, since you have a separate throttle slider
8.7. The pitch curve is a standard 3D curve. Middle stick is 0 pitch, lowest position is full negative, highest position is full positive. I didn't buy into the argument that it's easier to start with just a curve when the lowest is a small negative pitch, middle is 50% positive and highest is 100% positive. I decided to use the standard 3D setup right from the beginning. This way I don't have to use the Idle ups. Some people reported here crashing their helis when going to inverted and forgetting to switch idle up to 3D curve.

8. Configuring the radio and ESC : 8.8. DOUBLE RATES AND EXPONENTIALS
8.8.1. Right away configure one switch to Exponential and not Double rate. In fact forget Double rate, use exponential. Negative Exponential curve gives you a refined control at the center during hover while still keeping the maximums available the farther you are to the extremities.
8.8.2. I have 1 switch for Aileron and Elevator exponential control and 1 switch for the rudder. I didn't really use the rudder exponential at all.
8.8.3. The setup really depends on the RPM and your feeling of the position of the control lever. So experiment. I started with -70% exponential, but then found out it's not responsive enough so I increased it, to -45, then -20 and now my setup is -15% exponential when the D switch is towards me. It just has to feel right when you control it.
8.8.4. Configuring the linear rate will simply reduce your maximum and make your model harder to control because sometimes you actually need the maximum and when it's reduced it's a huge drawback for an increased control at the center.

9. Real flying
9.1. Your first purpose is to make sure the heli is adjusted and balanced
9.2. Ideally it should fly without any trims. And 100% end points on every servo. The arms that are actually connected to the swashplate linkage rods should be of the same length. This way you won't need to adjust end points. The only practical use I found for endpoints is when the those arms are of different length, which creates a wider or shorter range of movement, and has to be compensated by end points. So setup it mechanically to be equal instead of using end points. If you do need to use them, increase both the high and low end point at the same time to keep the center at the same point.
9.3. Once the Swashplate is aligned the way I describe it here, the heli flyes pretty much without the trims
9.4. If it tilts one way (usually it tilts forward or backward, since it's much better balanced over the axis of symmetry), move your heavy battery a bit.
If you can't then you'll have to use the trims. I guess with nitros you'll have to use the trims. I actually balanced my swift by moving the battery back a bit instead of using the trim. Mark somehow where exactly you batter should be located so you won't have to redo this.

9. Real flying : 9.5. POINTS TO REMEMBER
9.5.1. The more RPM you have the faster the response.
9.5.1.1. So in throttle hold scenario crashing the model is almost impossible because the RPM drops and the model becomes sluggish.
9.5.1.2. Your double rate configuration really depend on the RPM
9.5.1.3. Basically you switch on the double rate when you have sufficiently big RPM.
9.5.2. When spooling up the tail rotor doesn't have enough RPM to counteract the torque of the main rotor, so slight turn of the heli is normal. Correct it with the rudder input.
9.5.2.1. I tried correcting it with moving the tail servo closer to the main frames, but it's not as good as I thought it would, because if you move it too much the heli actually starts rotating slightly to the other direction, which is much more alarming for me. So may be somebody has a better idea what to do with this
9.5.2.2. The ground has to be plain or the heli will shake and it's not pretty.
9.5.2.3. The vertical fin must protect your tail rotor from hitting the ground. If it doesn't it's useless. Too many times I was happy to witness how the tail fin saved my tail rotor by hitting the ground first.
9.5.3. Also when having a separate control over throttle you can see that when the model is overpowered the slightest movement of the pitch sends the model into the sky. Then trying to correct it sends the model to the ground, so it's pretty impossible to fly it. This is actually the sign of overpowerement. And if you had a governor on then you would have to configure it somehow not to overpower it. So I prefer for now to use a separate throttle lever.