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eCCPM Swashplate Setup 101
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Now that you've built your new CCPM heli, you have to make the servos work together. eCCPM is a mix that is already programmed in your Transmitter, you just have to fine tune it to your specific model and here’s how:
The very first thing you need to do is tell your radio what KIND of eCCPM your helicopter uses. The most common is 120 degree, but 140 degree is becoming popular as well. All modern transmitters have 120 degree, but only a few have 140 degree programmed in. Consult the manual that came with your radio! However it’s usually pretty easy to make program mix so you can use a radio that doesn’t have a 140 degree option. For this quick guide we won’t go into that though. Futaba transmitters use different wording. Refer to the manual for the correct swashplate type for your transmitter. Before you turn on your Transmitter and power up your servos, you need to make sure they are centered. This will be slightly different depending on the model, but ideally you need to put the collective stick in the exact center with all three swashplate servos’ horns removed. Then put the horns on so they are 90 degrees to the linkage. This centers the servo horn on the servo and assures that there will be equal travel on either side of the servo’s center point. If you find that you cannot get the servo horn exactly at center, you have two choices. You can flip the horn 180 degrees, sometimes the splines will line up perfect, this is the preferred method. You can also use a bit of “sub-trim” to center the servo. You really want to avoid using subtrim because it makes leveling the swashplate a little more involved.
Now you need to do is make sure that your servos are all working together. What I mean is the three collective servos need to be plugged into the appropriate channels, i.e. the elevator (which is the servo that controls the center ball on the swash) needs to be plugged in to channel 3, the aileron and pitch servo (the ones that control the sides of the swashplate) need to be plugged into channels 2 and 6 (it doesn't matter which channel just either servo, into either 2 or 6 on the rx).
IF you use a Futaba or Hitec transmitter, the channel assignments are a little different. For Futaba, Elevator is channel 2, Aileron is Channel 1, and Pitch is Channel is 6.
Then, using the servo reverse screen, you need to make sure that the servos are doing the proper function. All the servos need to move up (or down) when the collective stick is moved up or down (it doesn't matter if the collective is reversed, we'll fix that later). If it doesn't, you need to (one at a time) reverse the channels on the servo reverse screen until all the servos move in the same direction when the collective stick is moved.
Now the aileron and elevator functions need to be sorted out. When you move the right stick right and left, the swashplate should tilt to the right and left (it doesn't matter if it moves right when you push the stick left, we'll fix that later). Also, when you move the right stick for and aft, the elevator should tilt forward or back. (again, it doesn't matter if the FUNCTION is reversed)
Now that the SERVOS are all moving in harmony, we need to be sure that the SWASHPLATE is moving correctly for a given command. Pull up the Swash Mix screen. Futaba calls it “Swash AFR” There should be 3 functions and they'll look like this:
Aileron: 60%
Elevator: 60%
Pitch: 60%
So, if the the swashplate tilts left when you move the cyclic (right) stick TO the right, make the value of 60% for Aileron NEGATIVE or -60%, and likewise for the elevator, so if the swash tilts forward when you pull the cyclic stick BACK, make the value of 60% NEGATIVE or -60% to correct it.
Finally, the collective. The swashplate should move up and down with the collective stick, and if you RAISE the collective stick, the blades should show POSITIVE PITCH. And if you LOWER the collective stick, the blades should show NEGATIVE pitch. IF that function is reversed, again, make the value of 60%, NEGATIVE 60% or -60%.
NOW, it is critical that you follow my pitch curve set up guide, and learn how to Level the swashplate. There are several different tools for determining if your swashplate is level. Some have bubble levels on them which work well IF and only IF the helicopter’s main shaft is truly plumb. You will want to use a vertical level on the mainshaft to make sure that this condition is met BEFORE you proceed any further.
Some swashplate leveling tools require the removal of everything above the swashplate. Consult the instruction manual for the swashplate leveling tool you have.
Place the swashplate leveler on the swashplate and check it’s level. The collective stick should be at the center with zero degrees pitch on the blades. At this same time as described in the pitch curve set up guide, the swashplate should then be in the center of its travel, and the mid point of the pitch curve should read 50%. If the swashplate is not level, you can use subtrim to level it, but the preferred method would be adjusting the linkages that connect the swashplate to the servos! If you find that you have to use more than a couple of clicks of subtrim on any channel, you should put it back to zero, and adjust mechanically. After the swashplate is perfectly level at center stick, you need to level it at the extreme pitch range, i.e. full positive pitch and full negative pitch.
Place the Collective stick at full positive stick with the swash leveling tool attached. If the swashplate is not level, you will use the End Point screen or Travel Adjust screen. For instance, if the swashplate tilts slightly to the right at full positive pitch, then you will need to increase the travel for the servo that controls that swashplate ball. Now put the collective stick at full negative, repeat the same procedure with the end points. You do have to be careful that you don’t create any binding at the extremes of the swashplate’s travel.
This is how I set up all my eCCPM heli’s. I also do some flight tuning, to ensure that it flies the way I like. I do climbouts to ensure that the helicopter rises straight up from a hover without wandering in any direction. For instance, if the helicopter drifts off to the left while performing a vertical climbout from a hover, you might try increasing the End Point just slightly on the channel that controls the left side of the swashplate. I also perform the same test inverted.
If you set up your helicopter the right way, and take your time, you will be rewarded with a very nice flying model!
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