rrTV-PHOTO   New HD TV
HOME   rrTV-PHOTO   GALLERIES   MY GALLERY   HELP-FAQ
myHOME PM pmRR MEMBERS 417 ONLINE 23 EVENTS SEARCH REGISTER  START HERE
 
1 page494 viewsPOST REPLY
E-flite . Next D . Fast Lad Performance

.
.
Avant Aurora - EFX - FX > Unusual drive train noise
 
 
creightoncarr
Veteran
Location: Missouri City, Texas - USA

I have some unusual drive train noise during flight with my Aurora that I haven't quite been able to track down. You'll notice it most prominently at approximately 4:38 in the following video and it continues for the most part throughout after that. This was not unique this this flight. Usually when the helicopter is cold and hasn't been flown for awhile the noise is not present (or at least is not as noticeable). After it's been running, however, it reveals itself. It's not the tail drive gears - I've checked the mesh and backlash and it's spot on. I think might be a bearing on the pinion. After a flight, if I spin the main gear it'll be smooth most of the way around but there will a spot or two that's not quite right. If you spin it quickly, when it gets to these spots the sound is different, almost like a slight rattle or vibration. If I let the helicopter sit for about fifteen or twenty minutes and after the flight and then spin the main gear again, everything is normal and the rattle/vibration is gone. Any thoughts other than a bad bearing? So far there had not been any adverse effect on flight but the noise is annoying and I would like to try and resolve it.

http://www.vimeo.com/1253566
06-30-2008 12:26 AM
 
 
John Benario
Senior Heliman
Location: Atlanta

Check the runout of the tail rotor main drive gear against the pinion gear. The delrin expands when it gets hot so if there is a slightly tight spot on the ground it will be worse in flight.

John Benario
06-30-2008 02:47 AM
 
 
creightoncarr
Veteran
Location: Missouri City, Texas - USA

The noise is between the main gear and the the motor pinion. When I spin the main gear the tail gears are stationary. I've pulled apart and put the tail drive gears back together several times so far - I really don't think the problem is in that part of the drive train but I'm at the point where I'm ready to yank everything out, change the bearings on the pinion, start shaft and in the clutch bell, and start over again.
06-30-2008 03:04 AM
 
 
JA Allen
Senior Heliman
Location: NYC

It sounds to me just like mine did. It may be the clutch/starter one way slipping and grabbing, chirping noise. It will also make the main gear feel like what your explaining at stand still.

Mine did this also as the one-way and start shaft warm up from grabbing and slipping.

Funny thing is, it will slip during starting, and sometimes lockup just sitting and running. Change that. I sent for a replacement, and ordered the Trex 450 main shaft one way, that some pilots have done. I have installed the 450 one-way, and the problems went away. Will try Avants replacement when it comes in to see if they fixed the part, to let others know if the replacements are fixed.

I am sure thats what it is brother.
07-04-2008 02:22 PM
HOMEPAGE  
 
 
creightoncarr
Veteran
Location: Missouri City, Texas - USA

I haven't had any problems so far with the one-way in the clutch but you never know. I spoke with Augusto yesterday and he suggested that the main gear is expanding just enough as it heats up that it creates a high spot and a slight bind. I've slotted the ratio plate where it mounts to the frame just enough to allow me to move the pinion away from the main gear every so slightly. I should get a chance to try it out tomorrow.
07-04-2008 03:02 PM
 
 
JA Allen
Senior Heliman
Location: NYC

I hear ya. Mine was the one-way, but I also emailed Augusto and he is sending a new one out to me.

I will watch my gear too, but I think its fine now.

Ok, then brother, let us know how it goes. Have a good flying day tomorrow,

J.A.
07-04-2008 03:06 PM
HOMEPAGE  
 
 
1 page494 viewsPOST REPLY
Ace Hobby . Esprit Model . Thunder Power RC

.
.
Avant Aurora - EFX - FX > Unusual drive train noise
  UPDATE SCREEN   PRINT TOPIC Advertisers 

Subscribe to This Topic

Sunday, October 12 - 1:36 pm - Copyright © 2000 - 2008 runryder.com | email | link to rr | runryder needs cookie