How To Set Up A Model Helicopter.

This is the method I use to set up a new helicopter when a customer brings it to me.

Radio Set Up

Step1: Program the radio. I usually start by programming the radio. I use a set of numbers that I joke about being sent down by the helicopter gods. These numbers work for any helicopter whether it is a 30, four-stroke, or even gas. It doesn’t seem to matter the machine these numbers will work.

These tables shows the numbers for both the pitch and throttle curves in Normal 1/2 stick hover, 1 normal but 3/4 stick hover, V-curve and Hold. The pitch numbers are to provide you with 20 degrees of pitch, -10 to +10.  We run our helicopters in V-curve with –10 to +10, the +12 being at the top of throttle- hold. With these pitch numbers:

0= -10 degrees 35= -2 degrees 45= 0 degrees 70= 5 to 5 ½ degrees 90= 10 degrees of pitch.

If you have a Normal Gyro:

1. Set Revolution mixing for 20% right both up and down. I found that this is a good place to start.
2. We will set the throttle- hold off set later when we have the helicopter turned on.

If you have a  Heading Hold Gyro:

First, let me give you my simplest explanation as to what the HH gyro allows you to do. A regular gyro will hold based on how high the gain is. The gain determines the rate at which the helicopter can pirouette (spin around the main shaft.) A high gain setting hold the tail great but doesn’t allow the tail to move very quickly. A low gain doesn’t hold very well but allows you a high pirouette rate. This is the reason you may have a dual gain gyro. High gain for hover and low gain for 540 stall turns, etc…

Now introduce the "Heading Hold" gyro. The HH gyro works differently than a normal gyro in that you can set the gain and pirouette rate independently of each other. Basically, what this boils down to is now you can run a high gain setting all the time and still set how fast you want the tail. Thus you have the best of both worlds, high gain (great holding tail) and as fast or slow of a pirouette rate as you like. I know this explanation may sound simple but to the majority of us who just want to make them fly, it works.

Now I’ve bought a HH gyro, read the instructions and am completely confused. Put the instructions away and read these three simple steps to setting up your HH gyro.

1. Go to the Travel Adjust in your radio. The Rudder ATV sets your rate of Pirouette. I set the travel at both 70 left and right. This is a good place to start. If you want a faster tail raise the number, slower lower the number.

Now set your gain by going to the travel adjust for what ever switch you plugged you gyro into. (aux2, gear ect…) With a moderately fast tail servo you can start at 80 and 20. The first number is the gain in normal and the second is in heading hold. When you fly the helicopter raise the 80 to get higher gain in normal or lower the 20 number for higher gain in heading hold. 100 is 100% in normal, 0 is 100% in heading hold, 50 is 0%gain.

2. Turn on the helicopter and pull the switch into heading hold mode, the servo arm may drift. You will use the rudder subtrim in the radio to stop this. Add whatever sub trim is needed to stop the servo or at least get it real close to stopping.
3. Fly the helicopter in normal and mechanically set the tail rotor push rod so that the tail doesn’t drift. Once that is done, flip into heading hold and go find a 20mph crosswind to hover in. You’ll be amazed.

You find that your servo drifts in heading hold from time to time, you can change your subtrim, but I just give it a couple of clicks of rudder trim on the radio and fly. This is the drift you will hear people gripe about. It usually never takes more than one or two clicks of trim to fix. Shut up and fly J

Turn off the transmitter and look at your helicopter.

 Helicopter Set Up

Step 1. I check the links to make sure that they are all facing correctly. Most kits like JR and Hirobo will have their name molded onto the outside of the ball links. The name should face out, away from the ball. Miniature Aircraft also has an on side, however there is no easy way of telling the on side from the off. The on side will be slightly larger and easier to push onto the ball than the other side.

Step 2. Check for any binding of linkages. Take the horns off the servos. We will want to center the servos before putting the horns on. Remove ball links and check that everything moves smoothly. #1 problem I find is too much loc-tite around moving parts, arms, etc… If you find something that is stiff, take it apart and check for loc-tite in the bushing or bearing. Once you are satisfied that everything is smooth snap all the links back on.

Turn on the radio and then the helicopter. Let the servos center themselves.

Step 3. Place the servo horns on each servo making sure that they are 90 degrees to the servo and to the part that they control. The rod should be 90 degrees to the arm and the swashplate would be level if it is the elevator or aileron. Make sure all servos are moving the correct direction. The leading edge of the tail blade will point the direction the tale is going to go.

Step 4. Set the tail: so that the arm is 90 degrees to the servo and make the rod to where when you fold the tail blades and face them pointing up. The front blade should be to the left of the back blade about a finger’s width. In other words, from the back of the helicopter with the tail blades pointing up you should be able to put your index finger between the two blades. And the front being to the left.

Step 5. Set the throttle: Check the throttle are on the carb to make sure it is going equal distance left and right of center. Make your linkage the recommended length from your kit. Adjust the rod so that you can get the servo arm and throttle arm to 90 degrees. This is very important!!!! If your geometry is off then your throttle numbers will not make sense. Once your linkage looks the right length, go to high throttle on the radio and high on the carb. Install your push rod. You will then go to low stick and lower your travel numbers until the servo stops binding. When everything is set, you should have full throttle use and arms that are parallel around mid stick.

Step 6. Set the pitch: Put the blades on the helicopter. Use a pitch gauge to find 0 degrees. Set your radio at ¼ stick (45%=0 degrees). Place the servo horn on the servo. Make sure that your push rods have you centered in your pitch throw. X-Cell: aileron servo should be centered in its tilt mechanism, Shuttle: top of pitch arm should be level, etc…

Now adjust your top and bottom pitches using the travel adjust. Go to full collective and set it for 9 degrees, Low stick set the travel so that you have –3 degrees. Go back to ¼ stick and you should still have 0 degrees. Now make the other blade match.

That’s it. You should be very close mechanically.