RunRyder RC
WATCH
 1 page 3062 views POST REPLY
HomeAircraftHelicopterHelicopter Main Discussion › Help with Trex 450 rudder control
11-02-2013 11:20 PM  5 years agoPost 1
Ozziief16a

rrNovice

Lillian, AL, United States

My Posts: All  Forum  Topic

Hello all,

I am the proud but frustrated owner of an Align T-Rex 450. I am also new to the sport of
rc heli flying, approximately 5 months. As Newbies are prone to do, I had a very hard tail first
landing that resulted in me replacing the tail boom and support struts, landing skids, etc. I have not
been able to fly my 450 since the crash due to a tail rotor control actuation problem.

I will try to explain my problem: When I increase the throttle to near 50% and the heli gets light on
it's skids the heli will start to yaw (piro) in one direction or the other (which is normal)Let's say
to the left. When I move the rudder stick slightly to the right to oppose the yaw the heli goes into
a rapid right piro. Then when I make a rudder input to the left to oppose the right piro that I induced
the heli goes into a piro to the left. These piros are so rapid that the heli is unflyable.

I brought the heli inside to investigate the problem. I found that the tail rotor was moving in the correct
commanded direction when rudder inputs were made, but it then "froze" in that position instead of returning
to the neutral position commanded by the heading lock system when I moved the rudder stick back to the rudder
centered position. I found that, using the rudder stick, I could move the tail rotors from their centered
positions progressively out to their end points and they would stay in their last commanded position instead
of returning to center after I centered the rudder stick. By the way the tail rotor control linkages all moved
smoothly through out their full range of travel. There is no binding or resistance at all.

I suspected that the problem might be in the Heading Lock mode of the gyro or perhaps the gyro itself. I unplugged
the motor power wires then powered up the heli. I rotated the heli's nose left and right by hand to varify that the
Heading Lock was working, heading lock pitched the tail rotor blades in the correct direction in response to
me yawing the heli left and right. I also installed a new rudder servo to eliminate it as a possible source
for the problem. I borrowed and installed a friends spare gyro to see if my original gyro was the culprit. The
test results were the same with the newly installed gyro, the heading lock feature worked correctly by moving the
tail rotor blades to counter the left and right yaw that I induced by rotating the heli's nose with my hand.

This is a real head scratcher for me, I'd appreciate any help that my fellow heli drivers can give me on this.

Regards,

Larry Osborne

PM  EMAIL  Attn:RR  Quote
11-03-2013 12:55 AM  5 years agoPost 2
RCHSF

rrKey Veteran

NC

My Posts: All  Forum  Topic

What transmitter are you using? And what gyro setting in radio? Under gyro sense, or are you using say gear ch end points? Give us a full run down of all on board electronics, name, and so forth. Gyro, tail servo, rx, or fbl, servos, etc.

PM  EMAIL  Attn:RR  Quote
11-03-2013 01:01 AM  5 years agoPost 3
dkshema

rrMaster

Cedar Rapids, IA

My Posts: All  Forum  Topic

A Trex 450, when properly assembled, requires that the tail rotor servo PULL the tail pushrod FORWARD, toward the nose of the heli, when given RIGHT rudder command from the transmitter.

If you give RIGHT rudder stick, and the servo pushes the rod toward the tail, you MUST reverse the rudder channel in your transmitter.

-----

Next, if you pick up your heli and turn its nose to the LEFT, the tail rotor servo once again MUST PULL the pushrod FORWARD, toward the nose of the heli.

If, when you turn the nose to the LEFT, the servo PUSHES the rod toward the REAR, then you MUST reverse the GYRO using the controls built into the Gyro (typically labeled "NOR" and "REV" ).

-----

BOTH the TRANSMITTER and the GYRO have to be set up for the correct direction or you will experience exactly what you are seeing.

-----

As for the heading hold gyro function. With the helicopter sitting still, moving the rudder stick either left OR right will cause the servo to move in the commanded direction. When you let go of the stick there is no reason for the gyro to move the servo back to neutral. Generally, the servo will stay close to where you last commanded it to go. With NO MOVEMENT of the airframe, the gyro sees no reason to change heading, or do anything additional with the servo.

Were you to change the gyro into Normal or Rate mode operation, you will find that the servo faithfully follows the rudder stick AND returns to neutral when you let go of the stick.

What you have observed is CORRECT behavior of a gyro operating in Heading Hold mode, with no helicopter motion.

-----

Also, as to what radio you are using, and what gyro you are using, the question is asked to insure that you are controlling the gyro gain with the correct channel, or at least the channel that is supposed to be controlling gain when you go to adjust it.

-----

If your 450 has a belt-driven tail rotor system, and if it worked correctly prior to your crash, you most likely assembled the tail stuff with the WRONG quarter-turn twist in the drive belt.

Or you installed the tail rotor servo differently than its original orientation.

-----

If belt driven, looking at the right side of the heli, nose to your right, tail to your left, the tail rotor should turn Counter Clockwise when you turn the main rotors. If it turns the other direction, you have the drive belt twisted the wrong way.

Tail rotor blades should have the control link ball on TOP of the blade on the right side of the tail rotor shaft (leading edge), and that rotor blade should be sweeping UP.

The tail rotor blade on the left of the tail rotor shaft is sweeping DOWN, its leading edge is down, and the control link ball is on the bottom.

If any of the above is wrong, fix it, the go way back to the top and make sure BOTH the gyro AND the transmitter are commanding the correct directions.

-----
Dave

* Making the World Better -- One Helicopter at a time! *

Team Heliproz

PM  EMAIL  GALLERY  Attn:RR  Quote
11-03-2013 01:44 AM  5 years agoPost 4
RCHSF

rrKey Veteran

NC

My Posts: All  Forum  Topic

dkshema^^^One of best, heli problem solver. The marine of helicopter world.

PM  EMAIL  Attn:RR  Quote
11-04-2013 11:07 PM  5 years agoPost 5
Ozziief16a

rrNovice

Lillian, AL, United States

My Posts: All  Forum  Topic

Help with Trex 450 rudder control
I'd like to thank Dave and the other members who've posted responses to my Trex 450 rudder control problem post. There are
some really great trouble shooting tipss in your posts and I can't wait to try them out.

My motor stopped working about the same time I started trouble shooting my rudder control problem. After I turn on my tx and connect the ship's battery, the beeping sequence starts but it's not the same series of beeps that I normally get. It starts with the usual "warble" sound followed by a series of beeps - not
the 3 sets of double beeps followed by one set of 3 beeps. I've ordered a new motor and ESC, hopefully they'll be here by Wednesday
and I'll be able to try some of your suggestions.

thanks again,

Larry

PM  EMAIL  Attn:RR  Quote
11-05-2013 03:16 AM  5 years agoPost 6
Trickycopter

rrApprentice

Tulsa, Oklahoma

My Posts: All  Forum  Topic

Did you try recalibrating your esc did you move the end points for your throttle might take a look and save some dollars

Synergy E7 AMA member Team Old Farts citizen 401 www.trickycopterrc.blogspot.com

PM  EMAIL  GALLERY  Attn:RR  Quote
11-05-2013 04:29 AM  5 years agoPost 7
dkshema

rrMaster

Cedar Rapids, IA

My Posts: All  Forum  Topic

What ESC do you have, what transmitter do you have?

Does your ESC look like this:

Set your throttle full low, and your trim full low. Apply power, let's see what happens.

If you have the ESC shown above, and you have the throttle stick high enough when you turn things on, the ESC will go into throttle/ESC calibration and setup mode.

Just go through the throttle/ESC programming steps one more time. You really didn't need to buy another motor and ESC.

-----
Dave

* Making the World Better -- One Helicopter at a time! *

Team Heliproz

PM  EMAIL  GALLERY  Attn:RR  Quote
11-05-2013 10:46 AM  5 years agoPost 8
Richardmid1

rrProfessor

Leeds, England

My Posts: All  Forum  Topic

Could you have possibly reversed the throttle channel when you went in and reversed the rudder channel?

If the ESC sees high throttel instead of low it will enter programming mode, again, you probably didn't need to buy a new motor and ESC!

60% of the time, it works every time!

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
11-06-2013 01:49 AM  5 years agoPost 9
Ozziief16a

rrNovice

Lillian, AL, United States

My Posts: All  Forum  Topic

Help with Trex 450 rudder control
Dave, I just rechecked that all of the switch positions on my tx
[/B](the tx is an Align T6 [made by Futaba], it came standard with the 450)[/B]were in the desired positions, including that the throttle stick was a idle. I powered up the heli after powering up the tx and I still get no response from the motor (I move the throttle stick from idle all the way up to full power and the motor doesn't rev up at all). As we used to say in the fighter pilot business; I'm outta airspeed and ideas! Yes I am running the ESC that you showed in your post, it too came standard with the heli.

PM  EMAIL  Attn:RR  Quote
11-06-2013 02:27 AM  5 years agoPost 10
dkshema

rrMaster

Cedar Rapids, IA

My Posts: All  Forum  Topic

Check throttle normal/reverse setting, and make sure you have good, solid solder connections.

-----
Dave

* Making the World Better -- One Helicopter at a time! *

Team Heliproz

PM  EMAIL  GALLERY  Attn:RR  Quote
11-07-2013 11:35 PM  5 years agoPost 11
Ozziief16a

rrNovice

Lillian, AL, United States

My Posts: All  Forum  Topic

Help with Trex 450 rudder control
Dave, you and the other members who wrote in suggestions to fix my "inop" motor are the best, Your diagnosis was right on the money!

Apparently while trying to trouble shoot my rudder control problem I changed settings in my tx that caused my motor to appear not to respond to throttle input. That's to say that when I advanced the throttle stick out of idle all the way up to full stick throttle
the motor did not respond (it remained off). However, when I powered up the tx and heli with the throttle stick at max throttle the motor came on and increased power proportionately up as I moved the throttle stick towards idle. In other words the stick throttle function was reversed.

I have a PDF copy of the 450s manual and the T6 tx manual. I went through the tx manual and found the factory setting charts for the 450. I changed all the settings on my tx back to the factory settings and the motor now responds correctly. The silver lining in all this is that I now have an ESC and new motor in my crash kit.

Now that I've regained normal motor function control I'm anxious to get back to solving the rudder control problem that originally prompted this post.

Thanks again Everyone

PM  EMAIL  Attn:RR  Quote
11-08-2013 04:51 PM  5 years agoPost 12
Ozziief16a

rrNovice

Lillian, AL, United States

My Posts: All  Forum  Topic

Help with Trex 450 rudder control
I took the 450 outside to check to see if the rudder control problem that I've been having was solved when I set all of
my tx settings back to the factory settings... The problem is
there.

I've taken a video of the problem... I thought that I could attach
the video clip to this post; apparently I was mistaken, sorry.

Regards

PM  EMAIL  Attn:RR  Quote
11-08-2013 11:54 PM  5 years agoPost 13
dkshema

rrMaster

Cedar Rapids, IA

My Posts: All  Forum  Topic

Now that you seem to have things up and running again, I highlighted some very important, key points in my earlier long reply. They are highlighted in blue. Now would be a good time to go back and read that post.

Is your video on YouTube? If so, send the link, it's easy to embed it in a post.

Also, back to very basic, original questions which haven't yet been answered.

1. Which version of the Trex 450 do you have?
2. Is the tail driven by a belt, or by a torque tube?
3. Has it ever flown successfully?

-----
Dave

* Making the World Better -- One Helicopter at a time! *

Team Heliproz

PM  EMAIL  GALLERY  Attn:RR  Quote
11-09-2013 12:40 AM  5 years agoPost 14
aliosha323

rrApprentice

Los Angeles, California

My Posts: All  Forum  Topic

Keep in mind, that with the align transmitter (and all futaba transmitters) the throttle channel MUST be reversed. Make sure to check for that. It's typically channel 3. Hope that helps!

PM  EMAIL  GALLERY  Attn:RR  Quote
11-09-2013 03:43 AM  5 years agoPost 15
Ozziief16a

rrNovice

Lillian, AL, United States

My Posts: All  Forum  Topic

Help with Trex 450 rudder control
Greetings all,

I'm happy to report that my rudder control problem has been solved.
As Dave and other forum members correctly deduced the problem was that the gyro was reversed. I changed the setting on the GP790 from NOR to REV and the problem went away. My 450 flies just fine again. Thank you again Dave, et al for sharing your heli experience and knowledge.

Regards,

Larry

PM  EMAIL  Attn:RR  Quote
11-09-2013 04:05 AM  5 years agoPost 16
dkshema

rrMaster

Cedar Rapids, IA

My Posts: All  Forum  Topic

Glad to be of service. Happy flying.

-----
Dave

* Making the World Better -- One Helicopter at a time! *

Team Heliproz

PM  EMAIL  GALLERY  Attn:RR  Quote
WATCH
 1 page 3062 views POST REPLY
HomeAircraftHelicopterHelicopter Main Discussion › Help with Trex 450 rudder control
 Print TOPIC  Make Suggestion 

 2  Topic Subscribe

Friday, December 14 - 5:12 am - Copyright © 2000-2018 RunRyder   EMAILEnable Cookies

The RC discussion world needs to consolidate. RR is now one choice for that. Its software is cutting edge. It hosts on-topic advertising. Help RR increase traffic buy making suggestions, posting in RR's new areas (sites) and by spreading the word.

The RunRyder Difference

• Category system to allow Rep/Vendor postings.
• Classifieds with sold (hidden) category.
• Classifieds with separate view new.
• Answer PMs offsite via email reply.
• Member gallery photos with advanced scripting.
• Gallery photo viewer integrated into postings.
• Highly refined search with advanced back end.
• Hosts its own high end fast response servers.
• Hosts thousands of HD event coverage videos.
• Rewrote entire code base with latest technology.
• No off-topic (annoying) click bait advertising.
Login Here
 New Subscriptions 
 Buddies Online