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some stats on heli inertia
 Moderated by: colin, admin, AdeH
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 Posted: 10 April 2010 12:52 pm
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AdeH
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Mana: 
 lets take a look at some of the forces and velocities involved in a 30 size helicopter with average wood blades at 1800 rpm...
  • Each spindle, blade holder and nylon nut screwed to it has to hold 270 pounds (122Kg) to keep the blades from flying away!
  • The tip speed of each blade is about 250 MPH or 413 KPH!
  • If your a person who can throw about 50mph (81 KPH) that's equivalent to hitting something with the tip of an 8 ft (2.5m) ruler as hard as you can. It would HURT!
  • If one blade seperates and the other is still attatched, the helicopter will have to sustain the force of a somewhat large man jumping on it from every direction 30 times per second. It won't last the blink of an eye and peices will fly hundreds of feet in every directoin.
  • Remember, these statistics are for 30 sized helicopter blades. 60 Sized helicopters are much more powerful, and they're blades are considerably longer and heavier.
Thansks to Heliguy.com for those statistics.



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 Posted: 10 April 2010 09:40 pm
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Phil Fearn
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Hello Ade . Its frightening to think about it ! but put into perspective , if all said nuts , bolts and fitting  are in good order and checked regularly then all will be fine :? . I once read stats on the forces generated by propellers . These were frightening but all parts are hopefully designed  to withstand these forces..

Phil

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 Posted: 13 April 2010 05:12 pm
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Ian M

 

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Phil, If the components are not up to scratch, as we all hope they are, we should invest in one of the 'new MWMFC jackets' mentioned in the Caption wanted article, the one that has the 2 vents at the rear, they most certainly will be needed.

About 5 years ago I saw a carbon rotor blade fail on a model, the bits spread over a very large area and one shard cut the flight pack i had on charge in half and this was about 30m from the model. It was quite a sobering experience.

This was not down to bad maintenance or lack of TLC the model had been well maintained and was checked just prior to flight, for whatever reason one blade just let go. Did it hit a flying beetle, large bumble bee or something else we will never know but they do make quiet a bang when they fail under full load.

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 Posted: 13 April 2010 07:52 pm
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AdeH
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Ian

I had a brand new rotor blade fail on my Raptor 60. It does happen. Fortunately not that often.

It was put down to manufacturers fault.

It happens to the best of us:shock:

 

Ade



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