Fun, Learning, Friendship and Mutual Respect
START  HERE


Unregistered
Go Back   HeliFreak > R/C Helicopter Support > 250 Class Electric Helicopters


250 Class Electric Helicopters 250 Class Electric Helicopters manufactured by Align, Tarot, SYMA, Airhog, Chaos, HK and similar.


Reply
 
Thread Tools Display Modes
Old 08-07-2009, 08:04 AM   #1
ttruttmann
Registered Users
 
Posts: 337
 
My HF Map location
Join Date: Feb 2009
Location: Chicago
Default Throttle Curves - does this make sense?

I'm trying to avoid any sudden RPM changes when switching from normal to IdleUp1. I noticed that if I was in hover - somewhere between center and 3/4 stick - and switched to IdleUp1, that it would jump.

I'm trying these settings:

Normal 0-50-65-80-95
IdleUp1 95-80-65-80-95

This makes the power curve (line) identical above center stick...is there any reason not to fly this way? IdleUp2 will still be flat. Thanks
__________________
TJ
- MT 325SE | DS287mg | GY401 w/9257 | Beam Carbon Tail Pushrod
- Trex 250se | D201HB | GY520 w/3500 | FS Carbon Tail Pushrod
- FBL UH-1 Huey | Thunder Tiger kit with RJX head & Skookum 720 - Current project
- JR 9303 TX
ttruttmann is offline        Reply With Quote
Old 08-07-2009, 08:17 AM   #2
jockstrap
Registered Users
 
Posts: 1,853
 

Join Date: Dec 2006
Location: Sydney, Australia
Default

the jump may actually be a change in pitch not throttle..

My 450s change HS on idle-up but do not jump in height at all...
There is a little kick in my tail thou on my new 450 pro as the HS chages quite a bit on that one.. but once again, no change in helight..
__________________
DX7 Mode-1 | 450 pro 6s | 450 pro | Schweizer 300C Gasser Scale | T-Rex550e | Aeolus 50 | HeliX T-Rex700 fbl Gasser | HWC600 Gasser | Henseleit MPXLe | Henseleit 3DNT | Suzi-Janis 700 | Gaui NX4 | Gaui X5 | Blade 350QX
jockstrap is offline        Reply With Quote
Old 08-07-2009, 08:28 AM   #3
ttruttmann
Registered Users
 
Posts: 337
Thread Starter Thread Starter
 
My HF Map location
Join Date: Feb 2009
Location: Chicago
Default

hmm...my pitch curves are identical above center stick. It seems to reason that if you're at a given pitch...say 3 degrees at hover...that a sudden jump in headspeed will generate more lift. Maybe it's just more noticeable on my little 250 than on your heavier bird?

I see you have some smaller helis too...can I ask how you have your curves set up for them?
__________________
TJ
- MT 325SE | DS287mg | GY401 w/9257 | Beam Carbon Tail Pushrod
- Trex 250se | D201HB | GY520 w/3500 | FS Carbon Tail Pushrod
- FBL UH-1 Huey | Thunder Tiger kit with RJX head & Skookum 720 - Current project
- JR 9303 TX
ttruttmann is offline        Reply With Quote
Old 08-07-2009, 08:33 AM   #4
halley
Registered Users
 
Posts: 2,152
 
My HF Map location
Join Date: Apr 2009
Location: Central Connecticut, USA
Default

Those throttle curves have an identical center stick. Yes. That does what you want.

But the curves seem really low. 65% throttle on the stock equipment is not enough for a good response. I'd make your common point at least 80%.
halley is offline        Reply With Quote
Old 08-07-2009, 12:06 PM   #5
Jasmine2501
Registered Users
 
Posts: 3,528
 
My HF Map location
Join Date: Jun 2008
Location: In deep space, abandoned. Any crew? Negative.
Default

Forget all that... set throttle to 100% and go balls-out until the battery dies
__________________

jazzyflight.blogspot.com
Jasmine2501 is offline        Reply With Quote
Old 08-07-2009, 12:30 PM   #6
ferret30
Registered Users
 
Posts: 1,184
 
My HF Map location
Join Date: Apr 2007
Location: Seattle
Default

You really don't want to have throttle changes past mid stick for normal mode, and also you don't want a v-curve for idle up. Many people on this forum have found that the 250 wags/kicks on throttle changes.

So use flat throttle curves, something like:

N: 0-80-80-80-80
1: 80-80-80-80-80
2: 90-90-90-90-90

Also, for normal mode, having your throttle and pitch changing around the hover point (i.e. 65%) makes the heli especially jumpy. When you move the stick down, the headspeed drops *and* the pitch changes, which makes it drop fast. By keeping headspeed constant and only changing pitch, the heli is more predictable and flyable.
ferret30 is offline        Reply With Quote
Old 08-07-2009, 05:05 PM   #7
ttruttmann
Registered Users
 
Posts: 337
Thread Starter Thread Starter
 
My HF Map location
Join Date: Feb 2009
Location: Chicago
Default

Thanks! I completely rebuilt the heli profile in my DX7 last weekend and I was suddenly getting a wag...I think we should start a list of things that don't cause a 250 to wag...

Maybe these new throttle curves are the culprit!

Hopefully I'll have a nice weather day this weekend to try it out.

Thanks everyone!
__________________
TJ
- MT 325SE | DS287mg | GY401 w/9257 | Beam Carbon Tail Pushrod
- Trex 250se | D201HB | GY520 w/3500 | FS Carbon Tail Pushrod
- FBL UH-1 Huey | Thunder Tiger kit with RJX head & Skookum 720 - Current project
- JR 9303 TX
ttruttmann is offline        Reply With Quote
Old 08-07-2009, 06:08 PM   #8
Jasmine2501
Registered Users
 
Posts: 3,528
 
My HF Map location
Join Date: Jun 2008
Location: In deep space, abandoned. Any crew? Negative.
Default

Quote:
Originally Posted by ttruttmann View Post
I think we should start a list of things that don't cause a 250 to wag...
That would be a very short list... all I can think of is Tuesday.
__________________

jazzyflight.blogspot.com
Jasmine2501 is offline        Reply With Quote
Old 08-07-2009, 07:34 PM   #9
ttruttmann
Registered Users
 
Posts: 337
Thread Starter Thread Starter
 
My HF Map location
Join Date: Feb 2009
Location: Chicago
Default

Quote:
Originally Posted by Jasmine2501 View Post
That would be a very short list... all I can think of is Tuesday.
hehehe!
__________________
TJ
- MT 325SE | DS287mg | GY401 w/9257 | Beam Carbon Tail Pushrod
- Trex 250se | D201HB | GY520 w/3500 | FS Carbon Tail Pushrod
- FBL UH-1 Huey | Thunder Tiger kit with RJX head & Skookum 720 - Current project
- JR 9303 TX
ttruttmann is offline        Reply With Quote
Old 08-08-2009, 05:47 PM   #10
helidude3
Registered Users
 
Posts: 904
 
My HF Map location
Join Date: Jan 2009
Location: Tiburon, CA, 94920
Default

Quote:
That would be a very short list... all I can think of is Tuesday.
sorry, but what?!?
__________________
T-rex 250 Super Combo w/ hs-65mg's
Blade cp pro: spectrum receiver, BL main, DD tail, Gyro
www.bladecpupgrades.co.nr
Blade cx2
E-flite 4-site
helidude3 is offline        Reply With Quote
Old 08-08-2009, 10:42 PM   #11
Jasmine2501
Registered Users
 
Posts: 3,528
 
My HF Map location
Join Date: Jun 2008
Location: In deep space, abandoned. Any crew? Negative.
Default

Quote:
Originally Posted by helidude3 View Post
sorry, but what?!?
http://en.wikipedia.org/wiki/Deadpan

It's just my style I guess.
__________________

jazzyflight.blogspot.com
Jasmine2501 is offline        Reply With Quote
Old 08-08-2009, 11:13 PM   #12
ttruttmann
Registered Users
 
Posts: 337
Thread Starter Thread Starter
 
My HF Map location
Join Date: Feb 2009
Location: Chicago
Default

<grin> as if your sig pic doesn't say it all...my puppy gets that exact same expression occasionally, usually when he's about to clear the room
__________________
TJ
- MT 325SE | DS287mg | GY401 w/9257 | Beam Carbon Tail Pushrod
- Trex 250se | D201HB | GY520 w/3500 | FS Carbon Tail Pushrod
- FBL UH-1 Huey | Thunder Tiger kit with RJX head & Skookum 720 - Current project
- JR 9303 TX
ttruttmann is offline        Reply With Quote
Old 08-11-2009, 08:15 AM   #13
jockstrap
Registered Users
 
Posts: 1,853
 

Join Date: Dec 2006
Location: Sydney, Australia
Default

@ttruttmann - here are my t-rex250 curves

250 = stock motor, 16 tooth pinion, 410 servos, spartan 760 gyro 3000g tail servo
batt = zippy 20c 800mah, align 800mah 20c
blades = align 205D carbons

Throttle:

norm: 0,40,65,75,85
st1: 100,inh,80,inh,100
st2: flat 100%

pitch:

norm:45,inh,50,inh,100
st1: 0,inh,50,inh,100
st2: 0,inh,50,inh,100
__________________
DX7 Mode-1 | 450 pro 6s | 450 pro | Schweizer 300C Gasser Scale | T-Rex550e | Aeolus 50 | HeliX T-Rex700 fbl Gasser | HWC600 Gasser | Henseleit MPXLe | Henseleit 3DNT | Suzi-Janis 700 | Gaui NX4 | Gaui X5 | Blade 350QX
jockstrap is offline        Reply With Quote
Old 08-27-2009, 01:14 PM   #14
ttruttmann
Registered Users
 
Posts: 337
Thread Starter Thread Starter
 
My HF Map location
Join Date: Feb 2009
Location: Chicago
Default

Quote:
Originally Posted by ferret30 View Post
You really don't want to have throttle changes past mid stick for normal mode, and also you don't want a v-curve for idle up. Many people on this forum have found that the 250 wags/kicks on throttle changes.

So use flat throttle curves, something like:

N: 0-80-80-inh-80
1: 80-inh-80-inh-80
2: 100-inh-100-inh-100

Also, for normal mode, having your throttle and pitch changing around the hover point (i.e. 65%) makes the heli especially jumpy. When you move the stick down, the headspeed drops *and* the pitch changes, which makes it drop fast. By keeping headspeed constant and only changing pitch, the heli is more predictable and flyable.
I've been playing around with these and you're spot on that that higher headspeeds improved stability. I did find that I could hear my headspeed drop off a bit as the rotor pitch bit into the air.

Now I'm trying:

N: 0-40-80-inh-85
1: 85-inh-80-inh-85
2: 100-inh-95-inh-100
__________________
TJ
- MT 325SE | DS287mg | GY401 w/9257 | Beam Carbon Tail Pushrod
- Trex 250se | D201HB | GY520 w/3500 | FS Carbon Tail Pushrod
- FBL UH-1 Huey | Thunder Tiger kit with RJX head & Skookum 720 - Current project
- JR 9303 TX
ttruttmann is offline        Reply With Quote
Old 08-28-2009, 07:16 PM   #15
TMoore
Registered Users
 

Join Date: Apr 2004
Location: Cookeville, TN
Default

Quote:
Originally Posted by ferret30 View Post
You really don't want to have throttle changes past mid stick for normal mode, and also you don't want a v-curve for idle up. Many people on this forum have found that the 250 wags/kicks on throttle changes.

So use flat throttle curves, something like:

N: 0-80-80-80-80
1: 80-80-80-80-80
2: 90-90-90-90-90

Also, for normal mode, having your throttle and pitch changing around the hover point (i.e. 65%) makes the heli especially jumpy. When you move the stick down, the headspeed drops *and* the pitch changes, which makes it drop fast. By keeping headspeed constant and only changing pitch, the heli is more predictable and flyable.
I see no reason to use a flat line curve on the throttle as this elimnates the head room that the esc needs to absorb pitch changes. My tail doesn't wag and I'm running 3 different flight modes depending on the batttery I'm running and its power capacity.

TM
TMoore is offline        Reply With Quote
Old 08-28-2009, 09:38 PM   #16
watdazit
Registered Users
 
Posts: 1,030
 

Join Date: Jan 2009
Location: Braidwood NSW Australia
Default

Quote:
Originally Posted by helidude3 View Post
sorry, but what?!?
It's a sense of humour thing, either you get it or you don't. I like it Jasmine, keep them confused.
__________________
A geriatric flier pushing the brain cells and reaction time.
RC addict with lots of helis, planks and cars.
watdazit is offline        Reply With Quote
Reply




Unregistered
Go Back   HeliFreak > R/C Helicopter Support > 250 Class Electric Helicopters


250 Class Electric Helicopters 250 Class Electric Helicopters manufactured by Align, Tarot, SYMA, Airhog, Chaos, HK and similar.

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 © 2004-2015 by RCGroups.com, LLC except where otherwise indicated. The HeliFreak.com logo is a trademark of RCGroups.com, LLC.