View Full Version : flybar and tail linkage setup
Ok, I'm in the home stretch now... just a couple things left to finish off and I'm hoping you guys can help.
First the flybar...
- Should the paddles be screwed all the way on and then adjusted until each is the same distance from the flybar assembly or is there a specific distance that is required there?
- How about alignment... I would assume that the paddles need to be aligned with each other and then aligned with the flybar control assembly itself. Is this correct or is there some other method?
Now the tail pitch linkage...
- How long should that joker be? I guess a better question would be, how much pitch should be on the tail blades when the tail servo is centered? Anyone have a good way of judging this?
Thanks for all the help guys,
syn-
First check that you have your flybar installed with equal lengths extending from the flybar carrier.
I like to set my paddles screwed all the way in, then back off just enough to return the leading edge for correct head rotation. Should be equal distance from the carrier edge. I use paddle guages to align my paddles to each other, after I have finshed my main blade pitch set up.
Since I lock my flybar level during pitch setup, I use the flybar as a reference level for the tops of my paddle guages. I do this while my main blades are at 0 degrees pitch. Everything level and zero degrees.
I did my tail rod like this. Install your completed tail torque tube assembly. Tail servo centered, 90 degrees on the arm to the short rod. Short rod is made to a length that gives a 90 degree at the tail rod bell crank. From the tail bell crank at 90 degrees make a rod that gives you the tail slider centered in its travel on the tail shaft. Everything should be 90 degrees and in the center of it's travel range.
That's what worked for me, hope that helps.
Thanks for the info! Mind if I ask how you are locking the flybar during the pitch setup? Is there a tool to keep it centered up?
-syn
Chuckie
12-20-2006, 09:27 AM
For the tail links I do the same as dugd says but also set the gyro limits to give me almost max and EVEN amount of throw right and left. When all the bell cranks and rods are centered or 90 degrees the tail blades will have the right angle to compensate for torque. As a test fold the tail blades and measure the distance between the blades, you should have 15 to 20mm. This distance is right for a rotor speed of 1600 to 1800rpm.
To set max throws I adjusted my 611 gyro to I think 115% in the settings menu. I had to fine tune the length of the long rod on the boom so full right and left were about even (I find it harder to center the tail slider). I have the link off the ball at the tail box and will adjust both the rod and gyro throw limits to max and even numbers. Move the rudder to one side and position the link over the ball. If you had binding if the ball is installed you need to change the length but also check the other side and make it even. I then reduce the gyro throws a few points to prevent binding at the extremes.
Be careful and don't over screw the SABs as they will crack.
Regards,
Charles
I use a Robart pitch guage, it comes with a long rod that clamps to the boom and then also clamps at the flybar. I use a couple of small levels to level the boom and then match level the flybar to the boom by shimming as needed under the skids as the heli sets on the table.
If you only use a flybar level, you could end up out of wack on some readings depending on your flybar ratio setting.
done and done.... should be good there. Thanks for the tips guys!
-syn
Hey Chuckie,
On the tail blade pitch, is there anyway that you can measure the distance between the brass piece on the slider and the outside edge of the tail gearbox case when you are at neutral? That measurement would make it a whole lot easier to figure out where I need to be. :)
-syn
Chuckie
12-22-2006, 09:40 AM
syn,
Yes but it's not a good idea because if my boom is not in the same position as yours my measurements on your machine might cause your tail link to bind and that would kill your servo. The gyro limits A and B side at 115% are close to binding so its best to physically check yours to be sure. The method I described above is the best method to set your tail linkage. You should recheck it every time you move or replace the boom.
Regards
Charles
Are we talking about the same thing? Here are a couple pics of what I'm talking about, they are of a raptor, but you can get the idea from them. The measurement I'm looking for is noted on the pictures (curtosy of raptortechnique.com) as 4.5mm on a rappy. I would think that distance wouldn't change with the position of the boom. *shrug*
-syn
Chuckie
12-23-2006, 09:52 AM
Yes and sorry for not being clear.
You can set the Synergy bell crank just like the rapter, crank arm is parallel to the output shaft, but mine is not exactly parallel so I didn't want to assume my measurement would work on your machine.
However, its mandatory if you're going to set your gyro limits to check the end point to make sure the ends don't bind. I have seen people burn out tail servos and in these cases most of them never checked the tail servo for binding. I have been asked to look over new machines at the field and the first thing I hear is the tail servo buzzing at full throws. What I'm saying this having the tail bell crank as pictured is not the most important thing to set, its more important to check the end points for binding. The bell crank will center at whatever position is best when set from the end points.
Here's why, in the Synergy and most other helis the bell crank as shown in the rapter will have the tail blades at some angle or pitch but you need to be told what head speed to run. This angle is not correct for all head speeds. The higher the head speed the more angle you'll need. So to set this angel correct you need to fly the heli at one head speed and adjust the tail link so the tail blades have the correct angle to compensate for the torque at that rpm. But change the head speed and now what? With modern gyros we don't need to worry about this angle as most people fly in heading hold. Set the rod length so the tail servo doesn't bind at either side and the gyro will set the blade pitch to the correct angle for what ever head speed your running at the time.
You ask a simple question but the correct answer is not simple. That’s helis for you.
Regards
Charles
And so the light has been shined onto that dark corner. :) Now I get it. I'll be making sure that the heli is setup like you mentioned tonight. I've got a lot of work to do before tomorrow's flight... thats helis for ya too.
-syn