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Aerial Photography and Video > Main-blade-induced vibration ....?
 
 
Hogster
Key Veteran
Location: Surrey, UK

What exactly is a head loader Ace? Literally a weighted bar that you slide into the rotorhead in place of the spindle and blade grips?

That's a neat idea Might have to make up one of those! ... by hand ... if only I had a lathe

Cheers


David
05-12-2008 12:33 AM
HOMEPAGE  
 
 
Oyley
Heliman
Location: Manchester (UK)

Headloaders

Hi David...30/50 size headloaders at Revolution for £21/22 very useful,they replace you blades and offer no lift for setting up engines and pretty good for finding vibes.
05-12-2008 01:19 AM
 
 
AceBird
Elite Veteran
Location: Utica, NY USA

Quote 
What exactly is a head loader Ace?

I used clear oak but ash would be the best, like an axe handle. Make / buy a metal bushing for the blade grip screw so the wood doesn’t split out and I wrapped the end grain with fiberglass and epoxy. These will likely be lighter than your actual blades and put less stress on the head.



http://www.runryder.com/helicopter/...1/?p=3467790#RR

In your other post a stronger mast can definitely solve your problem. A flybarless head is going to have a much more aggressive reaction than a flybar head unless you changed the linkage geometry to compensate for that. A stiffer main shaft will change the resonate frequency of the cyclic control so the vibration is not that obvious.

Ace
What could be more fun?
05-12-2008 05:56 PM
 
 
Hogster
Key Veteran
Location: Surrey, UK

Thanks for the explanation and photos Ace!

Well, it gives me great pleasure to say I've more or less got the vibration problem under control now! After close inspection of the rotor head components last night, I found that one of the spindle bolts was belt ... I also balanced the rotors as per this thread:

http://runryder.com/helicopter/t431298p1/

However, even after all this there was still a noticeable vibration when I tested the heli this morning, so I tried swapping the blades over and, after noticing that the tracking was out, adjusting the length of one of the grip control-rods.

Although there's still a little vibration during spool up, it's not nearly as bad as it was, and it more or less disappears once the heli is airborne (apart from a little up/down judder every now and then).

Here's the first successful video I've managed to take from the heli since "upgrading" from my original front-mount

http://www.vimeo.com/1009645

I've now reinstalled the braces to give some extra support to the front mount and will fly again later ...

Looks like I'm reaching the end of the tunnel with this problem!

Cheers,


David
05-13-2008 04:41 PM
HOMEPAGE  
 
 
AceBird
Elite Veteran
Location: Utica, NY USA

Super! I like it. I like the little car too.

Ace
What could be more fun?
05-13-2008 05:49 PM
 
 
Hogster
Key Veteran
Location: Surrey, UK

Hehe thanks

By the way, after putting the two triangulation braces on between the underside of the front mount and the undercarriage, the vibration came back .... interesting how something like that can affect the vibration .....

Cheers


David
05-13-2008 10:34 PM
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Advantage Hobby . Revolution Models . CarbonXtreme

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Aerial Photography and Video > Main-blade-induced vibration ....?
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