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Heli Terms for Beginners

Old 07-25-2007, 05:36 PM
  #26  
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How about the meaning of the KV rating of brushless motors? It could either be its own item or added to the definition of Brushless Motor. It took me a bit of searching to find that it translates to RPM per volt applied. Being an EE by education (I'm a software engineer by trade), I immediately mistakenly translated it to kilovolt and wondered how you could generate 3000 kilovolts with a 11.1V battery and have enough current to drive a motor.
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Old 07-31-2007, 05:57 AM
  #27  
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Originally Posted by TheBum View Post
How about the meaning of the KV rating of brushless motors? It could either be its own item or added to the definition of Brushless Motor. It took me a bit of searching to find that it translates to RPM per volt applied. Being an EE by education (I'm a software engineer by trade), I immediately mistakenly translated it to kilovolt and wondered how you could generate 3000 kilovolts with a 11.1V battery and have enough current to drive a motor.
dude! you figure that out and you'll have solved ALL our power issues!
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Old 07-31-2007, 06:18 AM
  #28  
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Brushless motor Kv has been added to the definitions.
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Old 08-10-2007, 06:53 AM
  #29  
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Retreating Blade Stall
A dangerous situation resulting when in fast flight where the blade that is flying towards the helicopters tail looses enough airspeed to generate lift. This can result in loosing control of the helicopter.
More info on why the stall would be Relevant.

See-Saw Head
A form of rotor head where the two rotor blades are "connected" through a feathering shaft (thick wire) so that when one pitches up the other pitches down. This makes for a more stable helicopter an a simpler design, but does not hand le as well as a flapping head type.
I wouldn't confuse people on Feathering. it is Teetering. or flapping . If you liken it to an Airplane. It would be similar to Dihedral.

Dissymmetry of Lift
Describes how the advancing side of the rotor disk is moving faster and thus produces more lift than the retreating side. This causes the helicopter to bank in forward flight and is dampened by flapping blades.
you may want to Include the point of Cyclic action to Cause Symmetry (Relatively or Controlled) Flapping blades and Delta offset are a means of dampening un-commanded disk actions.

Feathering Shaft
A rod which helps support the rotor blades and give them more ridged strength. A flapping head has two feathering shafts (one for each blade) and a sea-saw head has one feathering shaft (running the span of the head)
I get confused when I read this. Are you trying to describe the Feathering Axis of the Blade (PITCH) or the Teetering action ??

Flapping
A type of rotor head where the two rotor blades are not connected directly through the feathering shaft (a thick wire), each blade can move somewhat independently of the other resulting in smoother control of the helicopter and the to some degree the feel of a .60 size heli.
Again you mention Feathering on this one. Are you referring to the Teetering action. or an Action of Blade flap on an axis inline with the chord line. if the later. then they are independent.


a shot in the dark here. if you can . could you contact me, re the latest issue(14). I wish to speak of the Vector angles mentioned on Page 107 Blade Articulation Maneuvering
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Old 08-10-2007, 04:12 PM
  #30  
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Unfortunately, there is one more term for beginner heli terms. One that nobody likes, but will all come to know.

Crash--Unintentional contact with the ground or other object that usually results in a financial expendature.
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Old 08-10-2007, 06:07 PM
  #31  
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Originally Posted by HX3D014 View Post
More info on why the stall would be Relevant.



I wouldn't confuse people on Feathering. it is Teetering. or flapping . If you liken it to an Airplane. It would be similar to Dihedral.

you may want to Include the point of Cyclic action to Cause Symmetry (Relatively or Controlled) Flapping blades and Delta offset are a means of dampening un-commanded disk actions.



I get confused when I read this. Are you trying to describe the Feathering Axis of the Blade (PITCH) or the Teetering action ??


Again you mention Feathering on this one. Are you referring to the Teetering action. or an Action of Blade flap on an axis inline with the chord line. if the later. then they are independent.
I didn't come up with the terms or descriptions. They were compiled from various heli sites and were written by experts, instructors or companies.
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Old 08-10-2007, 06:20 PM
  #32  
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Feathering Shaft
A rod which helps support the rotor blades and give them more ridged strength. A flapping head has two feathering shafts (one for each blade) and a sea-saw head has one feathering shaft (running the span of the head)
I get confused when I read this. Are you trying to describe the Feathering Axis of the Blade (PITCH) or the Teetering action ??
** The feathering shaft is what's being described. It is exactly as the description says, a one piece ridgied rod that connects the 2 blades together. This is not a description of "feathering". Again, I did not write these definitions as the previous post explains.

Flapping
A type of rotor head where the two rotor blades are not connected directly through the feathering shaft (a thick wire), each blade can move somewhat independently of the other resulting in smoother control of the helicopter and the to some degree the feel of a .60 size heli.
Again you mention Feathering on this one. Are you referring to the Teetering action. or an Action of Blade flap on an axis inline with the chord line. if the later. then they are independent.
**Flapping
A type of rotor head where the two rotor blades are not connected directly through the feathering shaft (a thick wire), each blade can move somewhat independently of the other resulting in smoother control of the helicopter and the to some degree the feel of a .60 size heli.

Again, this refers to the feathering shaft and NOT feathering. There is a difference between the two. Later in the the description it states flapping style heads have somewhat independent blades. This has nothing to do with teetering action or the see-saw. Read the post above as these definitions were not created by me.
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Old 08-10-2007, 06:31 PM
  #33  
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See-Saw Head
A form of rotor head where the two rotor blades are "connected" through a feathering shaft (thick wire) so that when one pitches up the other pitches down. This makes for a more stable helicopter an a simpler design, but does not hand le as well as a flapping head type.
Originally Posted by HX3D014 View Post
I wouldn't confuse people on Feathering. it is Teetering. or flapping . If you liken it to an Airplane. It would be similar to Dihedral.
Actually, it wouldn't be similar to dihedral. If the rotor blades were allowed to travel creating a concave rotor disk where the blades pitched up equally from the center to the tip then it would be similar to dihedral. Again, this was not a description for feathering OR the feathering shaft. It was for the see-saw and it simply included the feathering shaft to demonstrate how the see-saw head works.
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Old 08-10-2007, 08:52 PM
  #34  
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Originally Posted by brnyrbbl View Post
See-Saw Head
A form of rotor head where the two rotor blades are "connected" through a feathering shaft (thick wire) so that when one pitches up the other pitches down. This makes for a more stable helicopter an a simpler design, but does not hand le as well as a flapping head type.


Actually, it wouldn't be similar to dihedral. If the rotor blades were allowed to travel creating a concave rotor disk where the blades pitched up equally from the center to the tip then it would be similar to dihedral. Again, this was not a description for feathering OR the feathering shaft. It was for the see-saw and it simply included the feathering shaft to demonstrate how the see-saw head works.
correct. and so it is not feathering. the point is to look at one blade alone. and when it alone goes up. the direction is similar to the effect of adding dihedral. (Ignore the opposit blade for now) and so this example was given to indicate that there was no feathering of the Pitch. but the whole blade in the SAME way a wing is moved when adding anhedral or dihedral. I am fully aware of what is different. but as that blade Flaps or teeters up . it is moveing the same way a wing would if you added Dihedral.

Feathering is just for Pitch change.
teter or flap.
teeter has one hinge central to the Shaft axis. and Flaping has one hinge per blade.
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Old 08-10-2007, 08:57 PM
  #35  
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Yes, that's correct. The way you described it in the above post is perfect!
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Old 08-10-2007, 09:25 PM
  #36  
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Retreating Blade Stall
A dangerous situation resulting when in fast flight where the blade that is flying towards the helicopters tail looses enough airspeed to generate lift. This can result in loosing control of the helicopter.
Retreating blade stall is not when the heli goes to fast to cause not enough Relative airflow on the retreating side. it is
when the blade is at the retreating side, it is also at a Higher angle of attact (Because the comand from the swash is to get it High at the rear) and due to the AoA being to high. the blade stalls. <usualy at the tip> the area of the blade that is receiving a reverse flow is not stalled. it is just in reverse flow.

check out this one
you may want to ignore the red bit. it is hard for Pilots to understand and is commonly debated. but pictures are available. just cant find one at the moment. OK Found one.
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Old 08-25-2007, 03:05 AM
  #37  
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Back to page 1 again!
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Old 09-17-2007, 04:53 PM
  #38  
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Back to the top!!
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Old 10-08-2007, 04:35 AM
  #39  
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How would one recover from a Retreating blade stall?
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Old 10-08-2007, 04:51 AM
  #40  
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mostly. you will get warning signs of it about to happen.

But if you push into it. and it happens.

1st thing you must do is reduce collective
2ns thing is land and have a stiff drink and think about why it happened. IE why did you go there. (It is usually only going to happen if you exceed design limitations. IE VNE or VNE @ given Weight and Alt combination.)
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Old 04-02-2008, 09:16 PM
  #41  
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Question Please define different size terms

Could you explain what the different size designations mean. I understand that a T-rex 450 is smaller than a 600, but what do those numbers mean? What about a Raptor 50? What does that mean?

Thanks for clearing up a lot of terms.

Jackson Hawk
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Old 04-30-2008, 12:13 PM
  #42  
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This is great, Thanks! Lots of good info. I don't know what a stickie is but I'm all for it...
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Old 12-06-2008, 10:30 AM
  #43  
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From a beginner's viewpoint (mine), the description of the different sizes seems to be missing.

Again, I can't post links due to some forum rule, but you can find a description on www[DOT]rcheliwiki.com/Helicopter_sizes
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Old 12-15-2008, 01:18 AM
  #44  
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Great job, must hav taken ages, keep it up! very helpful
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Old 12-16-2008, 01:37 AM
  #45  
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Jackson,
Unfortunately, there isn't really accurate info that comes with numbers. Originally, the numbers related to engine size but with the electric helis moving in, those numbers have gone away. A 450 doesn't really tell you much except that it is smaller than a 600.

Originally Posted by JacksonH View Post
Could you explain what the different size designations mean. I understand that a T-rex 450 is smaller than a 600, but what do those numbers mean? What about a Raptor 50? What does that mean?

Thanks for clearing up a lot of terms.

Jackson Hawk
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Old 12-16-2008, 01:41 AM
  #46  
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Here is the info from http://www.rcheliwiki.com/Helicopter_sizes that Asperamanca was talking about but as I stated before, the sizes don't correspond to anything in particular anymore.

Sub-micro (<100g, <20cm rotor diameter)
Extremely small helicopters, often coaxial. Low total energy makes them suitable for flying indoors.
Micro (<500g, <50cm rotor diameter)
Small helicopters such as 350-sized electric helicopters.
Miniature (<1kg, <80cm rotor diameter)
400 - 450 sized electric helicopters, can be flow inside in large open spaces with care.
Small (<2kg, <100cm rotor diameter)
500 sized electric helicopters.
Normal (<4kg, <150cm rotor diameter)
30 and 50 sized nitro helicopters, 600-sized electric helicopters.
Large (<6kg, <200cm rotor diameter)
90 sized nitro helicopters

Originally Posted by Asperamanca View Post
From a beginner's viewpoint (mine), the description of the different sizes seems to be missing.

Again, I can't post links due to some forum rule, but you can find a description on www[DOT]rcheliwiki.com/Helicopter_sizes
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Old 01-26-2011, 03:26 AM
  #47  
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This is wonderful, Thanks! I don't know what a stickie is but sure stick it for the fun of it......
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Old 01-26-2011, 04:30 AM
  #48  
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that's cool this is a sticky. Aaron (aka brnyrbbl) would be glad that he left this behind as he passed away back in Aug 2010 ...Hope it stays up a long time and many add to it .
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Old 02-10-2011, 06:14 PM
  #49  
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Great Info !
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Old 08-12-2011, 08:33 PM
  #50  
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this is super helpful! thanks!
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