Fun, Learning, Friendship and Mutual Respect
START  HERE


Unregistered
Go Back   HeliFreak > R/C Helicopter Support > Blade Helicopters (eFlite) > Blade 400


Blade 400 Blade Helicopters (eFlite) 400 Helicopters


Reply
 
Thread Tools Display Modes
Old 04-22-2008, 08:06 PM   #1
mituw16
Registered Users
 
Posts: 42
 

Join Date: Mar 2008
Location: Atlanta, Georgia
Default pitch question

hey guys,

a quick question about the pitch of the main blades...

in normal mode, at what throttle should the heli be lifting off? ( im still using the stock pitch curve) Mine takes off at about half, this is okay for normal mode because it keeps the head speed down and longer battery,

BUT, when i'm flying in stunt mode, i think the blades are set with too much positive pitch. When i do loops and rolls, i kick in full negative pitch, but i seems like there isnt enough negative collective to sustain an inverted hover, just enough to quickly counteract the falling and keep the heli level until it flips back over to right side up. I know you can adjust the pitch by adjusting the linkages between the swash and blades, but i dont know what they should be at.

basically.... I'm asking if i adjust the linkages to give the heli more collective at full negative, this means in normal mode i need more throttle to take off. is there a simple way where i can still take off in normal mode at about half to slightly above half, AND still be able to sustain inverted hovers?

I was thinking about changing the pitch curve for when its in normal mode to compensate, would this be a good idea or not?

Thanks to all who respond
__________________
"it ain't over till the fat pilot screams dead stick!"

B400: Align 325mm Carbon Pros, HS-65's, Align Carbon Tail Blades, Align indestructible blue landing skids
mituw16 is offline        Reply With Quote
Old 04-22-2008, 08:19 PM   #2
SeaComms
Registered Users
 

Join Date: Sep 2006
Location: Sunshine Coast, QLD, Australia
Default

Hi, jump on to finless's videos for the CCPM set up and that will explain everything. Basically the linkages are only adjusted for levelling of the swash, actual pitch ranges are controlled by the swash mix.

http://www.helifreak.com/showthread.php?t=11373

Just remember, the Trex is a leading edge control and the 400 is a trailing edge, so the swash will move in the opposite direction for pitch to that in the video.
__________________
Blade 400 - Hitec HS65KB's cyclic, Hitec 5000 + HSG5083 for tail, Hobbywing uBec.
Electrafun - overpowered with brushless and 11v lipo
F20 Delta wing EDF jet coming...

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
for Seamless Communications
SeaComms is offline        Reply With Quote
Old 04-22-2008, 08:50 PM   #3
mituw16
Registered Users
 
Posts: 42
Thread Starter Thread Starter
 

Join Date: Mar 2008
Location: Atlanta, Georgia
Default

the two linkages i'm referring to dont have anything to do with leveling the swash. they are the 2 links between the bottom of the swash that go all the way up the to blades and connect to the mixer arms that are attached to the blade grips.

if i unscrew (make them longer) i get less pitch at center stick, and if i screw in, i get more a center stick.....

it really comes down to, is there a happy medium where i can take off in normal mode without going to almost full throttle, but still have enough collective in stunt mode to sustain inverted hover. when i set the blades to 0 pitch at mid stick, sustaining inverted hovers are no problem, its only when the blades are at +2 that it becomes a problem. I set them at +2 so that it doesnt take almost full throttle to get it to lift off in normal mode.

if i have, or am doing something wrong with my setup. (all level swash, wash out block, and flybar cage) please tell me. i am new to helicopters and want to learn as much as possible
__________________
"it ain't over till the fat pilot screams dead stick!"

B400: Align 325mm Carbon Pros, HS-65's, Align Carbon Tail Blades, Align indestructible blue landing skids
mituw16 is offline        Reply With Quote
Old 04-22-2008, 09:02 PM   #4
SeaComms
Registered Users
 

Join Date: Sep 2006
Location: Sunshine Coast, QLD, Australia
Default

I understand where you are coming from, trust me !!

The finless videos will really do you a favour, trust me on that - I watched them several times and now have a pretty good understanding of it all - thanks in no small way to Bob.

But in a nutshell, centre all trims and subtrims, then set the heli for flight mode 1 (stunt mode) - centre the throttle stick, and make sure pitch curve is 50% at mid stick. To make it really easy, temporarily modify point 2 and 4 on the stunt pitch curve for 50% as well, this way the stick doesnt have to be dead on.

Now you straighten the servo arms using subtrim to get them exactly 90 degrees. Then, assuming your servo to swash links are close, adjust one or two slightly to get the swash perfectly level,

then adjust the short ones from the pitch slider / washout block to the flybar cage to get the arms on the washout block / pitch slider perfectly level,

then adjust the longer ones from swash to blades to get 0 pitch when the blades are at 90 degrees to the heli, check both blades.

Now you should have, with stock swash settings in the TX, about -10 to 0 to +10 in stunt mode and -3 to 0 to +10 in normal mode.

There are additional adjustments that can be made, such as adjusting servo endpoints (travel limits) to keep the swash level through the entire pitch range, and checking the elevator, aileron and total pitch settings and adjusting them with the swash mix in the TX. But from the quick description above, you only want to adjust the links for 0 pitch and level swash, all other range adjustments are done electronically with the swash menu.
__________________
Blade 400 - Hitec HS65KB's cyclic, Hitec 5000 + HSG5083 for tail, Hobbywing uBec.
Electrafun - overpowered with brushless and 11v lipo
F20 Delta wing EDF jet coming...

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
for Seamless Communications
SeaComms is offline        Reply With Quote
Old 04-22-2008, 09:27 PM   #5
Wolfpackin
HF Support
 
Posts: 11,340
 
My HF Map location
Join Date: Nov 2007
Location: Eagle, CO
Default

You do not want to lift at half stick, 3/4 stick would be better.
Half stick should be zero degrees of pitch in both modes, therefore no lift.

Typical curves and pitch should look something like:
Normal- 40-45-50-75-100 (-2d Low/0d Center/+10 High)
Idle up- 0-25-50-75-100 (-10 Low/0d Center/+10 High)

You'll hover upright at 3/4 stick and inverted at 1/4 stick, equal pitch and feel in both directions from center stick.
If your normal throttle curve matches or is close to the idle up curve, at center to high stick (Pos 3-5), you will have a smooth transition between the two modes and flying will be the same above half stick in both modes.

For example:
Normal- 0-40-80-90-100
Idle up- 100-90-80-90-100

You could increase the pitch using Swash Mix or bring the pitch in a little sooner with an S-Curve on pitch, 0-15-50-85-100.

If you want lower head speed keep the pitch curves standard and lower the throttle curve:
Wolfpackin is offline        Reply With Quote
Reply




Unregistered
Go Back   HeliFreak > R/C Helicopter Support > Blade Helicopters (eFlite) > Blade 400


Blade 400 Blade Helicopters (eFlite) 400 Helicopters

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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

Forum Jump


Copyright © 2004-2011 - William James - Helifreak.com