RunRyder RC
WATCH
 1 page 508 views POST REPLY
HomeAircraftHelicopterMain Discussion › Trex 450 wobble help
10-12-2013 02:18 PM  4 years agoPost 1
trappg

rrNovice

Concord, NC

My Posts: All  Forum  Topic

I repaired my trex 450 sport (FB) after a mishap and have a side to side wobble I cannot figure out. It will lift up fine but then start into a fast side to side shake (at least it appears to be side to side but it could be an oscilation shake - not sure). Main and feather shafts are straight and all appears to be straight with flybar mechanics. Any thoughts?

PM  EMAIL  GALLERY  Attn:RR  Quote
10-12-2013 02:47 PM  4 years agoPost 2
PilotPin

rrApprentice

Indiana -- USA

My Posts: All  Forum  Topic

Some things to check - head dampeners, blade tightness in the grips, the blade tracking, and breaks in the frame. Plus bent shafts.

PM  EMAIL  GALLERY  Attn:RR  Quote
10-12-2013 02:51 PM  4 years agoPost 3
ICUR1-2

rrElite Veteran

Ottawa, Ontario

My Posts: All  Forum  Topic

head out of balance ?
if every thing is straight and true and the blades are tracking.

spending time, paying attention

PM  EMAIL  GALLERY  Attn:RR  Quote
10-12-2013 03:09 PM  4 years agoPost 4
trappg

rrNovice

Concord, NC

My Posts: All  Forum  Topic

Blades are tracking, shaft is new, will try tightening blades and inspect frame again.

PM  EMAIL  GALLERY  Attn:RR  Quote
10-12-2013 04:12 PM  4 years agoPost 5
icanfly

rrElite Veteran

ontario

My Posts: All  Forum  Topic

you say it's rolling, or shall we say rocking from side to side. How quickly does it rock back and forth?

PM  EMAIL  GALLERY  Attn:RR  Quote
10-12-2013 05:54 PM  4 years agoPost 6
trappg

rrNovice

Concord, NC

My Posts: All  Forum  Topic

The rocking is very fast. As I mentioned, it will lift off smoothly and go into this shake I describe. It never gets to an "out of control" shake but definitely not right.

PM  EMAIL  GALLERY  Attn:RR  Quote
10-12-2013 09:08 PM  4 years agoPost 7
ticedoff8

rrKey Veteran

Morgan Hill, CA. USA

My Posts: All  Forum  Topic

Check all the swash links - servo to swash, swash to head. Check them for overly-tight. Wiggle them around and rotate. They should all be approximately the same tightness - but not too tight.

Check the flybar teeter-totter to see if the bearings are shot. Also check to see (measure it - don't eye-ball it) that flybar is exactly centered and the paddles are exactly the same distance. If the flybar is off center or the paddles are not screwed on the same, it cause weirdness.

Take the links off the blade grips and rotate the main grips - feel for "crunchy-ness", "notchy-ness" and overly-tight. Especially if there is a point where the grip "locks in" to a spot and you have to apply extra effort to keep it moving. Do this while you apply outward pressure (as if the head is spinning).
You might want to go so far as to disassemble the grips from the head block and check that the bearings are stacked up correctly.

Check the swash - again, notchy-ness and overly tight bearing between the crown and the base.

Get some kind of servo tester (the Align RCE-MT8 Multi Tester is perfect) and cycle the servos - see if they are notchy or have a dead spot. While they are on the tester, put some finger pressure on each one's arm and see if you can easily move the arm - and see if one is easier to move than the other 2.

I've had 3 or 4 of the DS410 servos fail on me.
I started with the Trex 450 Pro Combo (flybar) and these DS410 servos would get a vibration / chatter around the center point - but only if they had a slight load. This showed up in flight as a sudden, high frequency vibration in hover or transition from flight to hover (as in landing).
I only had 1 that totally gave up. The heli started flying backwards really fast and I ended up in T-hold to keep from hitting anyone.

PM  EMAIL  GALLERY  Attn:RR  Quote
10-12-2013 11:16 PM  4 years agoPost 8
icanfly

rrElite Veteran

ontario

My Posts: All  Forum  Topic

change your blades

PM  EMAIL  GALLERY  Attn:RR  Quote
10-13-2013 12:02 AM  4 years agoPost 9
trappg

rrNovice

Concord, NC

My Posts: All  Forum  Topic

icanfly wins the prize! A different set of blades solved the problem. Woulda never thought a new set of Align blades would cause that but they will be going back to Amain hobbies. May try them on my other 450 just for kicks.

PM  EMAIL  GALLERY  Attn:RR  Quote
10-13-2013 01:01 AM  4 years agoPost 10
icanfly

rrElite Veteran

ontario

My Posts: All  Forum  Topic

wins the prize!
street cred, that's the ticket.

Sometimes the simplest things are the biggest pita.

happy flying.

PM  EMAIL  GALLERY  Attn:RR  Quote
WATCH
 1 page 508 views POST REPLY
HomeAircraftHelicopterMain Discussion › Trex 450 wobble help
 Print TOPIC  Make Suggestion 

 5  Topic Subscribe

Monday, July 23 - 5:25 am - Copyright © 2000-2018 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online