help with the tail pitch assembly on a trex450

[nashiem]

ok so I set up the bird like the manual says where the tail pitch assembly is in the middle of the tail housing. but when I shut off hh mode the heli wants to turn left. after I adjusted the control horns on the rudder controll rod, the pitch assembly is off center to the left about 1/8 th of an inch. when I fly the bird I get too much turn to the left and not enough turn to the right. what could be the cause that the bird turns so much to one side when I have the pitch assembly in the middle. And can I just leave it center and fly the heli in hh mode or should I be as close to center as possible?

[RCSavager]

I'm not the authority on it but here's what I do. Set your servo to be at a perfect 90 degrees when the slider is in the center of the shaft. Now obviously if the slider is centered then the blades will be about zero pitch. Heading hold will do whatever it takes to hold the tail still during flight. With the gyro in rate mode set the endpoints of the gyro to reach each extreme. If it goes too far one way and not enough in the other during testing then adjust the servo mount accordingly to give the gyro full range of the slider. Then fly in HH and call it a day. Some claim that you should do all this work to tune the tail to fly in rate mode first but then what's the point of having a gyro?

So for me, once the gyro is set to not bind in either of it's directions and you fly in HH then why do anything else? Worked for me, works for tons of users here, and gives the gyro full range to do it's job. Done deal.

[nashiem]

Originally Posted by RCSavager

I'm not the authority on it but here's what I do. Set your servo to be at a perfect 90 degrees when the slider is in the center of the shaft. Now obviously if the slider is centered then the blades will be about zero pitch. Heading hold will do whatever it takes to hold the tail still during flight. With the gyro in rate mode set the endpoints of the gyro to reach each extreme. If it goes too far one way and not enough in the other during testing then adjust the servo mount accordingly to give the gyro full range of the slider. Then fly in HH and call it a day. Some claim that you should do all this work to tune the tail to fly in rate mode first but then what's the point of having a gyro?

So for me, once the gyro is set to not bind in either of it's directions and you fly in HH then why do anything else? Worked for me, works for tons of users here, and gives the gyro full range to do it's job. Done deal.

thanks for the comment the only reason I was trying to get it to fly whithout turning it rate mode was because I saw someone setting there heli up that way, but lets say I did want to have the tail stay still in rate mode, how can I make this adjustment and still keep the tail rotor centered???

[nashiem]

maybe the question I should be asking is (what is the proper way to tune a heli in rate mode)?

[RCSavager]

Try this one, nobody I've found explains things better about our birds than Mr. White (Finless). If this doesn't cover it then I'd think you'd be hard pressed to find out much more of what you need to know.

http://video.helifreak.com/?subpath=...gyro_setup.wmv

[Pinecone]

Which gyro?

With a Futaba 401, it is best to set the tail slider to the center of travel. This is due to the geometry of the Trex 450 tail.

Unless for some reason you WANT to fly in rate mode.

[JMoore12]

Most people advise to setup the tail in rate mode so the servo or the gyro dont have to work as hard. It really doesnt make any sense to me though. I have always setup my tail with zero pitch with the servo at 90 and have always been able to get my tail to hold. However the end points in your radio dont adjust the end point of the servo, they adjust the piro rate with most gyros.

[Pinecone]

THE GYRO AND SERVO DON'T WORK HARDER IF SET UP CENTERED.

Heck, if you had a gyro with dual limit settings, you could set if up with the servo at full travel one direction, and it will work the same.

The gyro is RELATIVE, not absolute. It knows that where the servo is is given this tail behavior versus what your desired tail behavior is, and then makes a correction based on correcting that, but as it makes the correction it is testing to see if it is getting the desired behavoir.

And a servo doesn't care what position it is in, it only uses power to move.