Fun, Learning, Friendship and Mutual Respect START  HERE


Unregistered
Go Back   HeliFreak > R/C Helicopters > RC Helicopter Flight School


RC Helicopter Flight School Instructional Flying Tips, Tricks, Videos, and Q&A


Reply
 
LinkBack Thread Tools Display Modes
Old 04-28-2011, 12:24 PM   #1 (permalink)
Registered Users
 

Join Date: Feb 2011
Default Rethink on trottle/pitch curves on electric heli

I went out flying yesterday and crashed my 500 electric . The wind was blowing about 10knots but the 500 handled well in normal fig8 flights. The problem came in at landing time. Brought the heli nose into wind slow FF to heli pad. 2Meters form the ground on it's way to the helipad it flipped right and crashed hard. At that time I had to bring the throttle down to 1/4 stick. When the heli flipped it was if I had no aileron stick control. At first I thought one of the aileron servo's failed, at home confirmed it did not.


My throttle/pitch curves I was using are TH-0%,50%,70%,85%,100% PI-30%,40%,50%,75%,100% which relates to -4,-2,0,+5,+10 degrees.

I had to drop the throttle stick to 1/4 to get the heli down from 15m. The wind just kept it in the air. @ 1/4 stick the blades are @ about -3 but the head speed dropped to 50% of 2200rpm or less. @ that speed and below you lose cyclic and tail control. The reason why it went to the right was the advancing blade created more lift when a gust blown over it, tilted right and just dropped down.

On Nitos you normally have a governor that keeps the head speed constant and you can use the full pitch curve range. On a TH curve like I had, you an only use pitch range when head speed is above 1800rpm which was effectively 50% and upwards.
On clam days this would not apply as I land the heli just below 3/4 stick.
I am going to change my Idleup1 to be more flat, running from about 70% to 100%. Only then can I realy use the pitch range from 0 to -4. I think of stating in normal mode, then once in hover change to Idleup1, Idleup2 stuntmode only

Any other pilot with the same kind of experience?
ChrisGB is offline        Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 04-28-2011, 01:31 PM   #2 (permalink)
Registered Users
 
Posts: 5,196
 

Join Date: Nov 2008
Default

Idle up with soft start at start of flight
Hover 2' above ground in idle up when landing and hit throttle hold.
Never even need normal mode.

That is the best combo I have found on the T500.
The 500 loves HS and idle up is the best way to get it.

Idle up 1 is flat at 90%
Idle up 2 is flat at 100%
Or use a gov at somewhere between 2600-2800 RPM's
fastflyer20 is offline        Reply With Quote Quick reply to this message
Old 04-30-2011, 03:58 PM   #3 (permalink)
Registered Users
 
Posts: 1,020
 

Join Date: Mar 2010
Default

Anyway, if you're not slamming down throttle stick when in trouble, make TC at 1/4 70%. If supported by your TX you may also want to move the 2nd point anticipating it at 10% stick.
ziper_it is offline        Reply With Quote Quick reply to this message
Old 05-01-2011, 05:10 AM   #4 (permalink)
Registered Users
Thread Starter Thread Starter
 

Join Date: Feb 2011
Default

Thanks guys, it makes sense, I changed my Idleup 1 all 70% for a start, will go to 80% or more once my flying demand increase. I start the heli in N mode, in hover change to Idle1 to fly around. At landing and can hit the Th-Hold/or switch to N mode switch to stop the motor.

Great.
ChrisGB is offline        Reply With Quote Quick reply to this message
Old 05-01-2011, 08:11 AM   #5 (permalink)
Registered Users
 
Posts: 5,196
 

Join Date: Nov 2008
Default

Perfect, you got it.
Two more ideas
1) You can increase head speed even higher, try 90% too, the 500 loves HS.
If you can't tell the difference, just decrease it.
2) Make sure soft start is enabled on ESC, you can then flip to idle up 1 on the ground, motor will safely and slowly spool up. Now normal will be rarely used, and saves some switch flipping while in the air.
fastflyer20 is offline        Reply With Quote Quick reply to this message
Old 05-03-2011, 05:25 AM   #6 (permalink)
Registered Users
 
Posts: 1,489
 

Join Date: Oct 2009
Default

My NORM mode is setup the same as IDLE1 and IDLE2, w/ slightly different head speeds. Works great.
__________________
Rush 750 w/ Xera 4530-500 (12T), YGE160HV, WR S.BEC, Torq 9180/9188, AR7200BX
Outrage 550 w/ Scorp 4020-1390 (13T), YGE120, CC BEC Pro, Quark, MKS BLS980, Futaba BLS451
wolfdown 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


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 © 2021 DragonByte Technologies Ltd.

SEO by vBSEO 3.6.1