Welcome to CrackRoll.com! - please login or click this bar to join our community...

XHeli.com EXI-500CF Heli Kits Lipos Parts 2.4GHz Tools Mfgr.
Create a new account or Log in:     Remember Me    I forgot my password!
 
     

Go Back   Crackroll.com > General R/C Heli Discussion > Beginners

Reply
 
Thread Tools
Old 03-26-2010, 02:39 PM   #1
Fred
Fixed Pitch
 
Join Date: Feb 2010
Location: Dumas Texas
Posts: 30
Default Why does it Wobble ?

OK another New B question
Why do I get a wobble when I first spool up,, my 450 and JS 50 both do it is this natural ?
I have checked and rechecked the balance of everything ? the main blades are snug but not tight . I read where you could hold the heli on it side and a gentle shake should have the blades drop to about a 45 ?
They dont seem to vibrate in the air ?
Thanks
Fred
Fred is offline   Reply With Quote
Old 03-26-2010, 03:44 PM   #2
CSpaced
Administrator
 
CSpaced's Avatar
 
Join Date: Aug 2008
Location: Oak Ridge, NC
Posts: 2,677
Default

Its normal, every heli goes through a certain amount of resonance as it spools up and its usually at much lower head speeds. The important thing is that you've balanced everything, and there is no vibration or wobble when the head is at normal flying speed. Your blade setup is spot on as far as how snug the bolt should be.
CSpaced is offline   Reply With Quote
Old 03-26-2010, 07:29 PM   #3
3D-Seth
Shankin' and Plankin'
 
3D-Seth's Avatar
 
Join Date: May 2009
Location: Champaign, IL
Posts: 162
Default

Quote:
Originally Posted by CSpaced View Post
Its normal, every heli goes through a certain amount of resonance as it spools up and its usually at much lower head speeds. The important thing is that you've balanced everything, and there is no vibration or wobble when the head is at normal flying speed. Your blade setup is spot on as far as how snug the bolt should be.
+1

Seth
3D-Seth is offline   Reply With Quote
Old 03-27-2010, 02:38 PM   #4
Fred
Fixed Pitch
 
Join Date: Feb 2010
Location: Dumas Texas
Posts: 30
Default

Cool ! I sure thought I might have something wrong I watch a lot of Vids on the net and most of the helies I see dont wobble on spool up .
Thank you guy's for the help . I am stuck way out in the No Helie Land and have to rely on The forums and a few phone calls to get answers .
Thanks again
Fred
Fred is offline   Reply With Quote
Old 03-27-2010, 06:10 PM   #5
CSpaced
Administrator
 
CSpaced's Avatar
 
Join Date: Aug 2008
Location: Oak Ridge, NC
Posts: 2,677
Default

Glad to help!
CSpaced is offline   Reply With Quote
Old 04-01-2010, 12:28 AM   #6
exit44rc
Fixed Pitch
 
exit44rc's Avatar
 
Join Date: Jan 2010
Location: Cleveland, Ohio
Posts: 31
Default

They all do that while you're spooling up. What you have to watch is when the head gets to full speed... is it steady? If it is than you're good.
exit44rc is offline   Reply With Quote
Old 04-01-2010, 06:30 PM   #7
Fred
Fixed Pitch
 
Join Date: Feb 2010
Location: Dumas Texas
Posts: 30
Default

Thanks
I gave helicopters a try a few years ago and gave up . I had a Jr venture 50 . and got it set up just enough to hoover . I just didnt have any help back then . But this time around I am having a blast ! I can get help on line and found a few guy's I can call . My closest hands on help is 50 miles from here .
The Finless Bob videos are tremendous help .
Thanks again
Fred
Fred is offline   Reply With Quote
Old 04-01-2010, 08:12 PM   #8
extra1540
Coaxial
 
Join Date: Mar 2010
Posts: 3
Default

I am here with Fred on this heli thing and these explanations are very helpful thanks guys!!!
extra1540 is offline   Reply With Quote
Old 04-07-2010, 10:23 PM   #9
classclown
Just fly it already!!!
 
classclown's Avatar
 
Join Date: Mar 2009
Location: Culpeper, VA
Posts: 108
Default

It wobbles until the rotors are perfectly folded out. Now, if the headspeed is at flying rpm's, and it is wobbling, something is bent, unbalanced, or misaligned.
classclown is offline   Reply With Quote
Old 04-08-2010, 06:27 PM   #10
jones007
Collective Pitch
 
jones007's Avatar
 
Join Date: Apr 2009
Location: Monterey, California, USA
Posts: 129
Default

Also, most of the modern heads will allow the heli to wobble at a low frequency while in flight (usually seen as the tail bobbing up and down slightly) if the headspeed is too slow for the stiffness of the dampers. Generally, the stiffer the dampers, the quicker the response, but the higher the headspeed must be to avoid wobbles. Some helis do it more than others as well. My old 450SE did it a little, my 500 did it quite a bit, and my 600 and 700 have never done it. All of them were smooth if the headspeed was high enough though.

Hope this helps.

--Kevin
jones007 is offline   Reply With Quote
Old 09-09-2010, 04:02 PM   #11
SicMiniT
Collective Pitch
 
Join Date: Sep 2010
Location: Eastern WA
Posts: 21
Default

Always check your setup though. If you make sure that things are as sound as possible you have a much smoother spoolup. You want to avoid too much wobble as it puts extra strain as the wobble is magnified at high RPM. It will be stable but it will still resonate into the bearings/o-rings/maingear etc. I will be getting a digital scale so I can balance my parts perfectly to eliminate vibrations.
SicMiniT is offline   Reply With Quote
Reply

     


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools



All times are GMT -5. The time now is 07:10 AM.

All Crackroll.com content copyright 2008-2014 by RCGroups.com, LLC except where otherwise indicated. The Crackroll.com logo is a trademark of RCGroups.com, LLC.
Please report any misuse of our trademarks or copyright violations using the contact form.
RCGroups Network :: RCGroups :: The E Zone :: Lift Zone :: RC Power :: Flying Giants :: RC Cars

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
All Crackroll.com content copyright 2008