Register | Log in
 
Electric-RC-Helicopter.com's Homepage
AlbumAlbum  | FAQ | Search | Memberlist
 

Tracing Vibrations on your helicopter


Custom Search
Post new topic   Reply to topic
Electric Rc Helicopter Forum Index -> Tip and Tricks
View previous topic :: View next topic  
Author Message
Burgess
Extreme 3D
Extreme 3D


Joined: 27 Mar 2012
Posts: 1098
Location: Wales

PostPosted: Sun May 11, 2014 6:58 pm
PostPost subject: Tracing Vibrations on your helicopter
Reply with quote

Here's something you might find useful.

RC helicopters consist of numerous components that have the potential to generate vibrations at various amplitudes, by and large parts are prevented from being jettisoned by the ample use of CA and threadloc. When vibrations become apparent but elusive they can be very exasperating to find the cause. Any vibrations on the helicopter ought to be detectable with microphone and displayed on a spectrum analyser.
If you've got a mic here's a freeware application:

http://www.techmind.org/audio/specanaly.html

and here a list of vibration frequencies, components generating them and what to look for.

http://bart.ragesw.com/~cimfacom/CIMFA/cimfabuild3.html
By DMac

For instance:
"Frequency High 600-900 Hz
(12,000-18,000 or more RPM at the crankshaft, or Brushless Motor)
Destination
High frequency vibrations often cause a "blurring" of the horizontal and vertical tail fins, and on IC Helis, foaming of the fuel."

Spikes are easily seen with this spectrum analyser, the amplitude is adjustable, it's surprising just how may minor spikes do register.

It may not be possible to eliminate all vibrations, but at least here's a way to identify them and thereby work on reducing them. Once you've got your helicopter set-up and dialed-in, save a screen shot of the spectrum analyser display at some head speed for future reference.

Burgess
Back to top
View user's profile Send private message
tombo242
Admin
Admin


Joined: 04 Nov 2008
Posts: 4718
Location: Santo Estêvão, East Algarve, Portugal. Now 82, but still feels 22.

PostPosted: Tue May 13, 2014 4:38 pm
PostPost subject:
Reply with quote

That's really useful stuff Burgess.
Got it saved - thanks for posting

Tom
Back to top
View user's profile Send private message
Burgess
Extreme 3D
Extreme 3D


Joined: 27 Mar 2012
Posts: 1098
Location: Wales

PostPosted: Thu Dec 11, 2014 11:02 am
PostPost subject: Tool to check CG
Reply with quote

Here's an idea I had the other day for a simple tool to check CoG of 450 size helis, should work for flybarless heads too.

Large ball-link on a 3mm rod with M2 machine screw through the link-ball into the tapping in the rotor housing for the disk brake fitting.





That's my number 3 T-rex 450SEV2 which I did the experiment with the TeleBee gyro on the starboard main-frame.
Now equipped with a Assan GA250 paired with a GWS Park HPX F analog servo.

Spec:
Voltage 4.8v
Torque 3.0kg/cm
Speed 0.07s/60
dual ball-raced




Burgess
Back to top
View user's profile Send private message
Shaun96
Hopping Maniac
Hopping Maniac


Joined: 07 Jan 2015
Posts: 29
Location: San Fransisco

PostPosted: Wed Jan 14, 2015 6:50 pm
PostPost subject:
Reply with quote

"Burgess" is true Master of rc helis
Back to top
View user's profile Send private message
Display posts from previous:   
Electric Rc Helicopter Forum Index -> Tip and Tricks All times are GMT + 7 Hours
Post new topic   Reply to topic
Page 1 of 1
Jump to:  

 
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum




Electric Rc Helicopter topic RSS feed 

SmartFeedSmartFeed




Electric-RC-Helicopter.com