RunRyder RC
WATCH
 4 pages [ <<    <    ( 1 )     2      3     NEXT    >> ] 3351 views POST REPLY
12-26-2010 04:04 PM  9 years ago
Topic Vote0Post 1
Supercoolheli

rrKey Veteran

Dallas, TX

MyPosts All Forum Topic
Sub-trim on tail servo
I have a Rave ENV that i have been flying for a little while now (just breaking in basically-nothing fancy). I have noticed a consistant drift to the left, and i have verified that this is not because of my tail gain or linkages. I have discovered that, with the posision of the servo itself in the frames, that it is not possible to get the arm perfectly at 90 degreees on the gear. I know that this is important, and i think i've heard somewhere before that it is safe to use sub-trim to fix this problem. Obviously i'm not using any regular transmitter trim but sub-trim is different. I'm just veryifying that this is ok before i try it out. Thanks
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
12-26-2010 04:05 PM  9 years ago
michael88997

rrElite Veteran

Lewisville,Tx

MyPosts All Forum Topic
it is ok as long as you reset your gyro so it reads it as zero position
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
12-26-2010 04:06 PM  9 years ago
Supercoolheli

rrKey Veteran

Dallas, TX

MyPosts All Forum Topic
I'm using the Total-G as my helicopter is flybarless. How do i do this? I'm not quite sure what you mean by resetting the gyro?
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
12-26-2010 04:07 PM  9 years ago
helismash

rrKey Veteran

Gloversville, NY - Fulton

MyPosts All Forum Topic
I have done the same thing here with no problem. I just needed that little bit of sub trim to get to 90.Hey, Who put the ground there!
T-Rex 500/T-Rex 600N FBL/T-Rex 600E PRO/T-Rex 700N/T-Rex 700FBL
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
12-26-2010 04:07 PM  9 years ago
michael88997

rrElite Veteran

Lewisville,Tx

MyPosts All Forum Topic
ive never used the total g but on most gyros you can set the subtrim to where its 90 degrees, then go back and redo the endpoints and center point
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
12-26-2010 04:08 PM  9 years ago
Supercoolheli

rrKey Veteran

Dallas, TX

MyPosts All Forum Topic
oh ok i think i get it now. So i just adjust the sub trim until the servo arm is at 90, AND THEN go back and reset the limits of the arm...gotcha
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
12-26-2010 04:56 PM  9 years ago
BarracudaHockey

rrMaster

Jacksonville FL

MyPosts All Forum Topic
Resetting the gyro means turning it on and off but yes if you use sub trim to change the center then you may need to adjust the end points.

It all depends on the gyro, Futabas memorize center at boot up, JR's assume a center and need sub trim to prevent drift so there's no stock answer.
Andy
AMA 77227
http://www.jaxrc.com
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
12-26-2010 05:05 PM  9 years ago
Supercoolheli

rrKey Veteran

Dallas, TX

MyPosts All Forum Topic
haha yea...I'm running JR servo and it goes to center but it must be because of the off-centered placement in the frames. here's a picture. Not that good quality but might give you an idea haha.

The tail servo is actually on the other side of the frames but it's at the same angle as the one shown.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
12-26-2010 06:25 PM  9 years ago
Swoop

rrElite Veteran

Newark, DE USA

MyPosts All Forum Topic
I have noticed a consistant drift to the left, and i have verified that this is not because of my tail gain or linkages
If its drifting you prob have a vibration or something is changing the rudder input after initialization. Servo horn angle, linkages, etc have nothing to do with a constant drift if you are in heading hold mode (unless for some reason you are not getting enough physical pitch in your tail).

I don't know the specifics of the solid G, so I could be missing something as well.
Chris
X50, B320, Radix, Spartan
Titan,Kasama,MP5,Radix,JR770
Trex450SE,MavrikkG5,Phoenix35
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
12-26-2010 07:07 PM  9 years ago
Supercoolheli

rrKey Veteran

Dallas, TX

MyPosts All Forum Topic
Well i'm going to try the sub-trim and see if that does anything for me.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
12-27-2010 02:25 AM  9 years ago
Ironhide

rrVeteran

dexter mi us

MyPosts All Forum Topic
Subtrim nothing ! Set up subtrim in your mechanical setup . Shorthen your long tail push rod or lenghten it . No subtrim !

And always setup your gyros in rate mode in a hover . You will always get the most out of it .
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
12-27-2010 06:12 AM  9 years ago
alvinrc

rrKey Veteran

Mobile, AL, USA

MyPosts All Forum Topic
You could use a wheel and drill hole exactly at 90 degrees.
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
12-27-2010 01:21 PM  9 years ago
KingJoeMack

rrVeteran

New Baltimore, Mi USA

MyPosts All Forum Topic
You could use a wheel and drill hole exactly at 90 degrees.
And always setup your gyros in rate mode in a hover . You will always get the most out of it .
The electronic components will always work best if properly mechanically set up.
Gyro or flybarless.
I think especially with flybarless, 0 subtrim is more inportant than ever.
Fly with scheduled ground contact !
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
12-27-2010 01:31 PM  9 years ago
Supercoolheli

rrKey Veteran

Dallas, TX

MyPosts All Forum Topic
i have a flybarless helicopter, not sure if i mentioned that already. I wouldn't see any problem with a few clicks of sub-trim; regular transmitter trim is the big no-no i thought. i've tried adjusting the tail pusrod links, but it's always off and the servo arm is never at 90 when the tail output shaft is in the center of the output shaft. I have to move the trasmitter stick in the LEFT direction to center the servo, but have to move it in the RIGHT direction to center the output shaft. This was telling me that i have to adjust something other than links, correct? If the only downside to subtrim is losing a little bit of servo throw, i wouldn't mind in the slightest
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
12-27-2010 01:46 PM  9 years ago
KingJoeMack

rrVeteran

New Baltimore, Mi USA

MyPosts All Forum Topic
The setup principles in flybarless, is NO subtrim.
The flybarless controler does this.
Take a round servo wheel, Turn on transmitter and heli, put round wheel on tail servo, mark 90 degrees, down.
Establish how far out you want the ball on the horn, drill hole and mount.
Continue mechanical setup. Everything at 90 and centered.
If you put in subtrim, controller will be fighting itself, sending servo what it thinks is correct center position, and then correcting it when it does not hold center.
I can hover hands off for 10 seconds in a heavy wind.
Because the flybarless controler is doing what it is intended to do.
Fly with scheduled ground contact !
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
12-27-2010 01:50 PM  9 years ago
Supercoolheli

rrKey Veteran

Dallas, TX

MyPosts All Forum Topic
ok that makes sense to me, but some things to mind:

1. How do i know the center position of the servo travel if the power is not turned on?

2. I have a round servo wheel (stock JR wheel) that gives me the EXACT length out on the horn i need (17.5mm)
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
12-27-2010 02:01 PM  9 years ago
Hellsiege

rrVeteran

Colorado Springs, CO

MyPosts All Forum Topic
1. How do i know the center position of the servo travel if the power is not turned on?
If no trims are introduced via the transmitter and you add power the servo should auto center. I get the servo in, add power, turn off, then put horn on so I know I'm at 90. Something else to keep in mind I noticed on my 700 cyclic is they are angeled like your rudder is. In the manual it shows arms at 90 to the servo not 90 to where the servo connects because of the angel.
SHARE  PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
12-27-2010 02:03 PM  9 years ago
KingJoeMack

rrVeteran

New Baltimore, Mi USA

MyPosts All Forum Topic
Turn Heli on (wheel not attached) and let servo center, then install wheel and establish 90 degree and hole position.
Don't be shy about drilling a hole to get what you want.
It's the little things that make the difference.
Make sure in your flybarless controller you have no inputs to tail (default) and start form there.
Fly with scheduled ground contact !
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
12-27-2010 02:08 PM  9 years ago
Supercoolheli

rrKey Veteran

Dallas, TX

MyPosts All Forum Topic
oh haha, i thought you were suggesting that i know 90 without turning on power and auto-centering .

Yea, i did that, using the horn that has the correct hole spacing (the one that it says to use in the helicopter manual), but it's either cocked to the left, or the right. I can't get it lined up because of the position of the gear of the servo when centered. Now if i'm supposed to do it like Hellsiege says then that might make sense, because the arm would probably line up 90 degrees with the SERVO CASE and not vertical to the frames themselves. Is this really the way to do it? Cause i'm sure that would work and might actually explain why i'd be getting a drift lol.
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
12-27-2010 02:14 PM  9 years ago
KingJoeMack

rrVeteran

New Baltimore, Mi USA

MyPosts All Forum Topic
90 degrees off the servo case.
A wheel will do the same function as a arrm.
Heck, after you get it where it is supose to be, who says you can not trim off 3/4 of the wheel.
Start with basic setup 101, and go from there.
Without proper mechanical setup, you will never get the controler to function properly.
Fly with scheduled ground contact !
SHARE  PM  EMAIL  GALLERY  Attn:RR  Quote
WATCH
 4 pages [ <<    <    ( 1 )     2      3     NEXT    >> ] 3351 views POST REPLY
 Print TOPIC  Make Suggestion 

 10  Topic Subscribe

Sunday, February 23 - 10:14 am - Copyright © 2000-2020 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online