450 SE Tail Servo Binding Question
11-02-2007 | 10:38 AM
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From: Tulsa, OK
450 SE Tail Servo Binding Question
I recently rebuilt my 450 after a crash (tail servo case got owned so I had to replace that which = taking apart the servo) and my first test flight showed the tail pulling to the right. I never took it off but when you get it light on the skids you can see it's going to piro if you let it get off the ground. The gryo is reacting correctly from all my ground tests.
The only thing I really did was adjust the endpoints on the rudder to reduce mechanical binding on one side of the servo travel. Do I need to make the endpoints the same on both sides or can you just adjust one side? It's like the gyro is confused becase the endpoint to the left is 150 and the endpoint on the right is like 95, so it's trying to find the middle which is not going to happen.
Any help would be awesome, thanks guys and gals.
The only thing I really did was adjust the endpoints on the rudder to reduce mechanical binding on one side of the servo travel. Do I need to make the endpoints the same on both sides or can you just adjust one side? It's like the gyro is confused becase the endpoint to the left is 150 and the endpoint on the right is like 95, so it's trying to find the middle which is not going to happen.
Any help would be awesome, thanks guys and gals.
11-02-2007 | 11:23 AM
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From: montreal, QC, CANADA
RE: 450 SE Tail Servo Binding Question
I am a newbie, don't believe me much, but I have crashed so many times replacing tail boom and having to move the servo. What I do to set it up fast is to play with the servo mounting in the tail boom, I don't move anything from the Tx, I leave SUBTRIM 0, Endpoints 100,100, and I initialize the servo to see where the center position of the servo is, I put the ball linkage to the hole that is in the certer position and I move the servo mounting forward, backwards until the tail pitch is in the middle of the tail shaft, then I screw the servo mounting and if there is some bindind, there will be on both sides (because the pitch is in the middle), if so, I just reduce the LIMITS of the GYRO (GY401) in the gyro and that is it, It has always worked for me.
11-02-2007 | 12:49 PM
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RE: 450 SE Tail Servo Binding Question
So Limits on the Gyro will effect how much travel the servo arm has? Basically when I go full left rudder I get full deflection and everything is OK. When I go full right rudder the tail servo makes that grinding sound because it's tryin to pull the further than the tail slider will mechanically allow. I'm nearly positive it's because I'm using a different servo arm now since nothing else has really changed.
I've got the servo on the boom right, everything is centered I'm just trying to remove that binding and grinding sound.
I've got the servo on the boom right, everything is centered I'm just trying to remove that binding and grinding sound.
11-02-2007 | 01:10 PM
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From: Town Creek,
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RE: 450 SE Tail Servo Binding Question
tmry:: .... So Limits on the Gyro will effect how much travel the servo arm has?
If you are getting (mechanical limit) binding (hitting the stops) in one direction compared to the other then your slider is probably not centered in it's travel range when the servo is centered.
Ideally you want the mechanical limits to be the same in both directions.
Once you have the slider centered when the servo is centered ... then setting the limit should affect both sides of the slider travel equally (as opposed to hitting the stops in only one direction).
11-02-2007 | 01:15 PM
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From: montreal, QC, CANADA
RE: 450 SE Tail Servo Binding Question
If you leave your end points 100,100 and SUBTRIM 0, the movement of the servo should be equal for both sides. What you have to do is to center the pitch in the tail shaft VERY CAREFULLY because it can be tricky to know what the center of the pitch is (that happens to me first) and Yes, what I understand is that if you increase the LIMIT in the gyro, the servo will move more (both sides) if you decrease it, servo will move less (both sides). That is why you have to center the pitch in the tail shaft, that way, you don.t mess with End Points. I do what I read in a forum: "try to do all what you can mechanically". I never mess with the Tx in order to set up my rudder, I just move the servo mount forward of backward along the tail boom (having the rudder servo centered, better to use a round arm with many little holes, easier to center the ball link) until the tail pitch is centered, after that. Move right and left and increase, decrease the LIMIT in the gyro if you need or have too much. Being the tail pitch centered, if there is binding it will probably be in both sides, then you decrease, otherwise, increase if you see that there is a big gap between the pitch and the end of the tail shaft (both sides). Usually there must be a little gap at the end of both sides to avoid binding. As I told you, I might be wrong, but this has worked perfectly for me. After my first crash, I was all confused about end points and subtrims in the rudder. I read about setting it up mechanically and it's what I do, works perfect, I hope you have good luck.
11-02-2007 | 01:34 PM
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From: Town Creek,
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RE: 450 SE Tail Servo Binding Question
ORIGINAL: matador_24
If you leave your end points 100,100 and SUBTRIM 0, the movement of the servo should be equal for both sides. What you have to do is to center the pitch in the tail shaft VERY CAREFULLY because it can be tricky to know what the center of the pitch is (that happens to me first) and Yes, what I understand is that if you increase the LIMIT in the gyro, the servo will move more (both sides) if you decrease it, servo will move less (both sides). That is why you have to center the pitch in the tail shaft, that way, you don.t mess with End Points. I do what I read in a forum: "try to do all what you can mechanically". I never mess with the Tx in order to set up my rudder, I just move the servo mount forward of backward along the tail boom (having the rudder servo centered, better to use a round arm with many little holes, easier to center the ball link) until the tail pitch is centered, after that. Move right and left and increase, decrease the LIMIT in the gyro if you need or have too much. Being the tail pitch centered, if there is binding it will probably be in both sides, then you decrease, otherwise, increase if you see that there is a big gap between the pitch and the end of the tail shaft (both sides). Usually there must be a little gap at the end of both sides to avoid binding. As I told you, I might be wrong, but this has worked perfectly for me. After my first crash, I was all confused about end points and subtrims in the rudder. I read about setting it up mechanically and it's what I do, works perfect, I hope you have good luck.
If you leave your end points 100,100 and SUBTRIM 0, the movement of the servo should be equal for both sides. What you have to do is to center the pitch in the tail shaft VERY CAREFULLY because it can be tricky to know what the center of the pitch is (that happens to me first) and Yes, what I understand is that if you increase the LIMIT in the gyro, the servo will move more (both sides) if you decrease it, servo will move less (both sides). That is why you have to center the pitch in the tail shaft, that way, you don.t mess with End Points. I do what I read in a forum: "try to do all what you can mechanically". I never mess with the Tx in order to set up my rudder, I just move the servo mount forward of backward along the tail boom (having the rudder servo centered, better to use a round arm with many little holes, easier to center the ball link) until the tail pitch is centered, after that. Move right and left and increase, decrease the LIMIT in the gyro if you need or have too much. Being the tail pitch centered, if there is binding it will probably be in both sides, then you decrease, otherwise, increase if you see that there is a big gap between the pitch and the end of the tail shaft (both sides). Usually there must be a little gap at the end of both sides to avoid binding. As I told you, I might be wrong, but this has worked perfectly for me. After my first crash, I was all confused about end points and subtrims in the rudder. I read about setting it up mechanically and it's what I do, works perfect, I hope you have good luck.
You can also adjust the length of the t/r control rod to achieve the same thing (within limits) that moving the servo mount does (just in case you have a t/r servo mounted up forward in the frame. Changing the length of the t/r control rod while the servo is centered will move the slider's position relative to the servo position. If you are binding on one side, adjust the t/r rod so that you move the slider away from the binding side slightly. Eventually, you'll have the slider centered in it's travel range when the servo is centered.
Also ... Your TX rudder channel end points do NOT set the travel limits of the t/r servo. One must remember, that (in HH), the stick position does NOT tell the servo where to go ... it tells the gyro how fast to YAW. So adjusting your end points in the TX will adjust your max YAW rate. It will not set how far the servo will move ... that's determined by the gyro and that's why there is a Gyro limit.
So if you want a slower YAW rate at full stick deflection reduce your end points ... want a faster YAW rate, increase the end points. This is the reasoning most say to set the end points to 100 and leave it alone (unless you absolutely must change it).
11-02-2007 | 01:50 PM
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From: Tulsa, OK
RE: 450 SE Tail Servo Binding Question
Makes sense, I'm not sure why it's only binding in one direction and I've checked the center but will re-check it. I'll put my endpoints back (you all say 100 but on my DX6 it seems 150 on each side was the default) and play with the limit to see if that will clear up the binding if I still have it.
