Fun, Learning, Friendship and Mutual Respect START  HERE


Unregistered
Go Back   HeliFreak > R/C Helicopters > Main Forum - Helicopter Talk


Main Forum - Helicopter Talk R/C Helicopters and the people who fly them. VENDOR TOPICS DO NOT GO HERE. Full Scale Heli threads go in OT please


Reply
 
LinkBack Thread Tools Display Modes
Old 01-22-2013, 12:18 PM   #1 (permalink)
Registered Users
 
Posts: 122
 

Join Date: Dec 2012
Location: Paso Robles, California
Default Can an RC helicopter experience settling with power?

So I was out on my morning run this morning and was letting my mind wander, and for whatever reason I started to ponder whether or not an RC helicopter could experience settling with power. I would say it's theoretically possible, and a more accurate question might be, how big does an RC helicopter have to be to experience settling with power? I imagine some of the larger scale helicopters probably produce vortices large enough to cause settling with power under the right conditions.

Have any of you ever experienced settling with power with one of your RC helis?
__________________
Mikado Logo 700 Xxtreme, Synergy N5c, Blade 450X, Blade Nano CP X
Spektrum DX8
kennyd1gital is offline        Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 01-22-2013, 12:28 PM   #2 (permalink)
 
My HF Map location
Join Date: Mar 2010
Location: Winnipeg, MB
Default Can an RC helicopter experience settling with power?

Umm, what is settling with power?
gothicbunny is offline        Reply With Quote Quick reply to this message
Old 01-22-2013, 12:33 PM   #3 (permalink)
Registered Users
 
Posts: 162
 

Join Date: Apr 2011
Location: Eden Prairie, MN
Default

Same as vortex ring state? There are videos in you tube of an mCPx doing this. Try googling it.
__________________
TRex 450 Pro (now DFC with HC3SX) / Blade 130x / Blade mCPx / Blade nCPx / Hirobo Shuttle (out of service)
Khaag is offline        Reply With Quote Quick reply to this message
Old 01-22-2013, 12:33 PM   #4 (permalink)
Registered Users
 

Join Date: Nov 2004
Location: so.Cal
Default Settling with power

Short answer "Yes". When I was learning 29 years ago I had a Shuttle, I thought it was the worst ship in the world with approaches because of the settling problem but I soon learned the keep up my forward speed when landing and don't be afraid to really hit the power.
Junkpilot
__________________
junkpilot
junkpilot is offline        Reply With Quote Quick reply to this message
Old 01-22-2013, 12:35 PM   #5 (permalink)
Registered Users
 
Posts: 1,087
 

Join Date: Oct 2009
Location: Netherlands
Default

Smaller models also have this problem. Difference is we have so much power at out command we can just blast out of it.

Well, except my solopro. Its a 100 sized FP and it can plummet down pretty rapidly even under full power.
__________________
MSH miniPRTOS & PRTOS 500 a better way to fly
GAUI
Hurricane 425 night rig & 550 the monster
sp00fman is offline        Reply With Quote Quick reply to this message
Old 01-22-2013, 12:43 PM   #6 (permalink)
Registered Users
 
Posts: 1,777
 

Join Date: Jan 2011
Location: S„o Paulo, Brazil
Default

I think yes. When I started flying 450s, my Storm was set to a fairly low HS, and often happened to descend vertically until bouncing onto the ground. Pulling the collective all way up didn't help, indeed it looks like the heli descended even faster. After the bounce, the heli started to climb normally. And it never happened when the heli had some forward speed, only while hovering.

I think that any underpowered heli (as my Storm then, and the mCPx as Khaag said) is subject to this effect. Compared to the average RC heli, any full-scale heli is way underpowered, thus subject to the settling with power effect.

My 2 cents.

Cheers!
__________________
We are made of star stuff.

Compass 7HV / Atom 6HVU / Atom 5.5 / Align Trex 500L / Spektrum DX8
ARM_Coder is offline        Reply With Quote Quick reply to this message
Old 01-22-2013, 12:47 PM   #7 (permalink)
Registered Users
 
Posts: 1,661
 

Join Date: Aug 2012
Location: Clarksville, TN
Default Can an RC helicopter experience settling with power?

That video of the Mcpx shows nothing more than bogging.

Our helis have so much power that VRS is nothing to worry about.
Nologic is offline        Reply With Quote Quick reply to this message
Old 01-22-2013, 12:49 PM   #8 (permalink)
Registered Users
 
Posts: 1,246
 

Join Date: Oct 2010
Location: Norway
Default



Go to 9:26 or thereabout.
__________________
Blade 400, Blade CX2, Blade mCPx, Blade BL mCPx, Phoenix, RealFlight 7
DX8
.... and... err... a plank
If it ain't flyin, it's a downer,
LN400 is offline        Reply With Quote Quick reply to this message
Old 01-22-2013, 01:19 PM   #9 (permalink)
Registered Users
 
Posts: 3,715
 

Join Date: Dec 2010
Location: san jose, California
Default

neat. I learned something.
__________________
Greg
MSH USA Heli Flight Team
Mikado V Team
Lynx
el guapo is offline        Reply With Quote Quick reply to this message
Old 01-22-2013, 01:29 PM   #10 (permalink)
Registered Users
 
Posts: 12,081
 
My HF Map location
Join Date: May 2010
Location: Long Island, NY (Melville)
Default

Quote:
Originally Posted by Nologic View Post
That video of the Mcpx shows nothing more than bogging.

Our helis have so much power that VRS is nothing to worry about.
I didnít watch the video... but the mCPX sure does experience VRS. If you descend quickly with negative pitch (while stationary), you will not pull out of it. I tested this extensively, even after I did my BL mods.
__________________
~SAB~ Goblin 700 ~Compass~ Warp 360 ~Blade~ mCP X (BL)
AMA# 977012
**Team BOCA Bearings**
BaconRaygun is offline        Reply With Quote Quick reply to this message
Old 01-22-2013, 01:35 PM   #11 (permalink)
Registered Users
 
Posts: 3,911
 
My HF Map location
Join Date: May 2010
Location: Cincinnati,Ohio, USA
Default

That video explains what happened to my 450 a while back. I never did know what happened but I guess I now know.
dankcincy is offline        Reply With Quote Quick reply to this message
Old 01-22-2013, 01:42 PM   #12 (permalink)
Registered Users
 
Posts: 4,804
 
My HF Map location
Join Date: Jun 2011
Location: Seattle Area, East Side
Default

Quote:
Originally Posted by Nologic View Post
That video of the Mcpx shows nothing more than bogging.

Our helis have so much power that VRS is nothing to worry about.
+1
Most 3D-capable RC models running mid-high HS and 11į+ collective should have no trouble powering out of VRS. On the other hand, heavy scale ships (that video ^^ was awesome), running low HS, low pitch range, and skirting the low end of the power/weight band, or a 3D machine running low HS and low collective range, could easily get into VRS and smack the deck really hard in a steep approach.
__________________
CopterX 450 Black Angel FBL "Night Rig" | ZYX v4.0
PRTOS 500 FBL "Sky Whip" | Robird G31
Audacity P6 FBL "Phoenix" | MSH Brain | 12s
Goblin Speed | iKon
Dr. M is offline        Reply With Quote Quick reply to this message
Old 01-22-2013, 02:10 PM   #13 (permalink)
Registered Users
 
Posts: 122
Thread Starter Thread Starter
 

Join Date: Dec 2012
Location: Paso Robles, California
Default Re: Can an RC helicopter experience settling with power?

Come to think of it, my small coaxial experiences settling with power/vortex ring state. If I have it in a high hover and quickly reduce power to get a decent going, I can slam the power back on and it will fall through until it hits the ground.

As far as rc helis having an over abundance of power and being able to pull out of it, I don't fully agree. Without some forward airspeed, it shouldn't matter how much power you have on reserve. Adding power should only further increase the rate of decent because the helicopter will be pulling more pitch and generating larger vortices.
__________________
Mikado Logo 700 Xxtreme, Synergy N5c, Blade 450X, Blade Nano CP X
Spektrum DX8
kennyd1gital is offline        Reply With Quote Quick reply to this message
Old 01-22-2013, 02:13 PM   #14 (permalink)
Registered Users
 
Posts: 122
Thread Starter Thread Starter
 

Join Date: Dec 2012
Location: Paso Robles, California
Default Re: Can an RC helicopter experience settling with power?

Quote:
Originally Posted by Dr. M View Post
+1
Most 3D-capable RC models running mid-high HS and 11°+ collective should have no trouble powering out of VRS. On the other hand, heavy scale ships (that video ^^ was awesome), running low HS, low pitch range, and skirting the low end of the power/weight band, or a 3D machine running low HS and low collective range, could easily get into VRS and smack the deck really hard in a steep approach.
This isn't entirely correct. You have it backwards. More pitch and more power create larger vortices. Reduced pitch generates smaller vortices. That's why lowering the collective is one of the steps in the recovery procedure (for full scale helicopters).
__________________
Mikado Logo 700 Xxtreme, Synergy N5c, Blade 450X, Blade Nano CP X
Spektrum DX8
kennyd1gital is offline        Reply With Quote Quick reply to this message
Old 01-22-2013, 02:38 PM   #15 (permalink)
Registered Users
 
Posts: 12,081
 
My HF Map location
Join Date: May 2010
Location: Long Island, NY (Melville)
Default

^What he said...
__________________
~SAB~ Goblin 700 ~Compass~ Warp 360 ~Blade~ mCP X (BL)
AMA# 977012
**Team BOCA Bearings**
BaconRaygun is offline        Reply With Quote Quick reply to this message
Old 01-22-2013, 02:45 PM   #16 (permalink)
Registered Users
 
Posts: 2,010
 

Join Date: Feb 2009
Location: Ridgecrest CA
Default Can an RC helicopter experience settling with power?

You can see (or feel) settling with power with a RC helicopter. Bring the heli straight down with some positive pitch and you will notice it takes more positive pitch than normal to get the decent rate to zero. However, with 10 plus degrees of pitch and plenty of HP to keep the blades turning, it is hardly noticeable. There is not a full scale helicopter in the world that comes close to doing tic tocks.
Glenn Goodlett is online now        Reply With Quote Quick reply to this message
Old 01-22-2013, 04:25 PM   #17 (permalink)
Registered Users
 

Join Date: Aug 2010
Location: AZ
Default

Generally, if you are descending at a rate of 50% to 150% of your downwash velocity, at a horizontal velocity of less than 75% of your downwash velocity, you can see VRS. For a typical 450 in hover, downwash speed is approx 11mph, so you have to be descending at a velocity of 5mph to 15-ish mph to encounter it at all, and then only at horizontal speeds of less than 8mph.

Kenny, VRS is a function of descent rate vs downwash velocity. If you pull more power/pitch, you increase the downwash velocity, and if that changed ratio between descent rate and downwash velocity drops below the onset velocity (50% ish), you can fly out of it vertically. If pulling more pitch/power did what you say, it would be impossible to fly out of VRS vertically- something we do all the time, and even full scale machines with sufficient excess power (like the Skycrane) can do.
__________________
"The problem with quotes found on the internet is you have no way of confirming their authenticity." - Abraham Lincoln
extrapilot is offline        Reply With Quote Quick reply to this message
Old 01-22-2013, 04:34 PM   #18 (permalink)
Registered Users
 
My HF Map location
Join Date: Jan 2011
Location: Over The Hills and Far Away
Default

Well ....there ya go! Awsome info...I learned something cool today.
__________________
Trex700N2E
Trex500ESPTT(PRO head and Tail )
Trex500ESP (Belted)
HC500SE ....GO TEAM FLYBAR!
Blayd is offline        Reply With Quote Quick reply to this message
Old 01-22-2013, 04:48 PM   #19 (permalink)
Registered Users
 
Posts: 3,206
 
My HF Map location
Join Date: Dec 2007
Location: Raleigh, NC - USA
Default

I think most who think they are entering a VRS state in a mcpx are really just experiencing a loss of transitional lift. The rotor (spinning as a disc) will generate more lift in forward flight than hovering. If you are flying around in forward flight and pull back slightly on elevator to reduce your forward speed and do not touch collective you will drop, sometimes a little quick. This isn't really VRS. You are simply losing lift due to no airflow over the rotor disc, requiring more pitch to maintain a hover. While I'm sure there is a little recycling of the vorticies, a majority of that "sinking" is loss of transitional lift.
__________________
Blade 130X - Stock
mCPx v1 Brushless Stretch (125mm) - WK10A - 11000kv Inrunner - 550 mah - Full CNC Upgrades
Retired Helis - Outrage 550, Trex 500, Logo 400, Others
poor_red_neck is offline        Reply With Quote Quick reply to this message
Old 01-22-2013, 05:00 PM   #20 (permalink)
Registered Users
 

Join Date: Apr 2011
Location: Australia
Default

Quote:
Originally Posted by poor_red_neck View Post
I think most who think they are entering a VRS state in a mcpx are really just experiencing a loss of transitional lift.
You can get a mcpx or ncpx into VRS, in still air a fast descent cannot be powered out of (of you get it right). More collective just accelerates the descent speed, moving in any direction corrects and the heli rises. Seems like VRS to me.

Never seen it with a larger 3D heli though.


Quote:
Originally Posted by kennyd1gital View Post
Come to think of it, my small coaxial experiences settling with power/vortex ring state. If I have it in a high hover and quickly reduce power to get a decent going, I can slam the power back on and it will fall through until it hits the ground.
This has to be something else I think?
The rotors are rotating in opposite directions so I dont see how you can get the vortices rolling back into the rotor (the two would interfere with each other). You could have stalled the blades, i have done that before on a micro coax, then the motors did not have the power to accelerate quickly again.
__________________
-DX8
-MSH MiniProtos Stretched, SK720, DS95/DS95i, Hyp 4S 25C 2500mAh
-MSH Protos Stretched, Brain, Hyp DS16/BLS251, 6S 3000mAh
-Goblin 500, HC3SX, Hyp DH16/MKS980BL, Scorp 4015-1100
desertstalker is offline        Reply With Quote Quick reply to this message
Reply




Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the HeliFreak forums, you must first register.
Please enter your desired user name, your REAL and WORKING email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself. Use a real email address or you will not be granted access to the site. Thank you.
Email Address:
Location
Where do you live? ie: Country, State, City or General Geographic Location please.
Name and Lastname
Enter name and last name here. (This information is not shown to the general public. Optional)
Helicopter #1
Enter Helicopter #1 type and equipment.
Helicopter #2
Enter Helicopter #2 type and equipment.
Helicopter #3
Enter Helicopter #3 type and equipment.
Helicopter #4
Enter Helicopter #4 type and equipment.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On




Copyright © Website Acquisitions Inc. All rights reserved.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.

SEO by vBSEO 3.6.1