Push-Pull Elevator Setup
last updated 4-29-2006

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Step 1: Initial radio setup Set the elevator trim on the radio to center and the elevator sub-trim set to zero.
Step 2: Servo direction Check the direction the servo moves. When you move the elevator stick forward the servo needs to rotate clockwise. This is opposite of on non-push-pull setup.
Step 3: Align servo arm Now completely ignore the position of the intermediate arm (the one to the left of my hand in the picture). Hold a rod from the center of the screw on the intermediate arm to the center of the screw on the elevator servo. Place the servo arm on the servo spline so that the holes are 90 degrees to the arm. If you find that due to the teeth on the spline the arm will not position exactly 90 degrees then try flipping the arm 180 degrees. Find the closet position then use the Sub-Trim (aka CNT) function in the radio and use that to get the arm exactly at the right angle.
Step 4: Install the balls on the servo arm Now that you have found the angle the servo arm needs to be at you can install the balls. Place them about 11mm from center.
Step 5: Set the angle of the intermediate lever Adjust the length of the 'back rod' so that with the back elevator straight up/down the 'intermediate lever' is at an angle that is perpendicular to the servo. Get it as close as you can. We will fine tune this in the next step.
Step 6: Set the length of one front rod. NOTE: Make sure the elevator lever is straight up/down (swashplate level).
Take one rod and adjust it to exactly match the bottom balls. This would be the bottom ball on the intermediate lever to the bottom ball on the servo arm. Now move that rod up to the top set of balls and see if it matches. If so then go to Step 7. If not then you need to adjust the 'back rod'. When you adjust the 'back rod' you need to make sure the swashplate remains level at all times. As you adjust the back rod you want to find a length that will make the top set of balls the same distance apart as the bottom set of balls. Note you will have to readjust the front rod each time you adjust the back rod and do not forget to always make sure the swashplate remains level.
Step 7: Set the length of the 2nd front rod. Now that you have one of the front rods set so that it perfectly fits the bottom set of balls and the top set you need to snap that rod on the bottom set. Now adjust the second 'front rod' so that it matches the distance between the top set of balls. Snap this link in place and go to the next step.
Step 8: Set the servo end points In the radio set the elevator end points (aka travel adjust, EPA, ATV) to 100/100. Now move the elevator stick forward. Watch the elevator servo as you turn off the receiver on the helicopter. If you see the servo move when power is cut then the servo was in a bind and you need to decrease the elevator end point. If the servo did not move then see if you can move it any further. If so then you can increase the servo end point. Do the same for setting the end point for elevator back.
PS: Another way to tell if the servo is in a bind is to twist one of the front links. Feel how easy it is to move while the servo is in center then move the stick all the way forward and feel if it requires more force to twist the link. If it does then the servo is in a bind and you need to decrease the end point. If you find you have to decrease the end points less then 90% then move both balls on the servo arm in one hole. Note if you do this you will need to go back to Step 6.