RunRyder RC
 6  Topic Subscribe
WATCH
 2 pages [ <<    <    ( 1 )     2     NEXT    >> ] 916 views POST REPLY
HelicopterMain Discussion › Cold and high altitude electric power (no power)
12-10-2017 08:29 PM  4 months agoPost 1
InvertedDude

rrVeteran

USA

My Posts: All  Forum  Topic

Flew in Flagstaff off a mountainside. The Trex 600esp in my opinion lost anywhere from 20% to 30% power. Temperature outside was 45 F.

Is this normal to be struggling flying at 5k altitude at 45F?

PM  EMAIL  GALLERY  Attn:RR  Quote
12-10-2017 09:04 PM  4 months agoPost 2
JuanRodriguez

rrProfessor

The Villages, Florida

My Posts: All  Forum  Topic

I would think that you would see less efficiency while flying at 5k in altitude at ANY temperature..... the air is thinner so I would suspect the efficiency of the blades suffers.....

The colder temp will probably effect the battery as well so what you are "feeling" is probably a combination of both.....

But, I'm sure the experts will provide more detailed, technical information.....

Been there, done that and old enough to know better.....

PM  EMAIL  GALLERY  Attn:RR  Quote
12-10-2017 10:49 PM  4 months agoPost 3
ICUR1-2

rrElite Veteran

Ottawa, Ontario

My Posts: All  Forum  Topic

Suspect the altitude had more effect than the cold. The higher up you are the thinner the air.

spending time, paying attention

PM  EMAIL  GALLERY  Attn:RR  Quote
12-10-2017 11:32 PM  4 months agoPost 4
co_rotorhead

rrVeteran

Centennial, CO, USA

My Posts: All  Forum  Topic

We fly regularly at 6K here in Colorado. Nitro and electric. We look forward to the colder temps because the nitro birds get a definite power increase. I've never heard anyone here flying 3D on an electric heli complain about power.

I suppose if you're used to flying at or near sea level, you would probably notice though. When we go to flying events at lower altitudes (especially 2K or less), there's a marked performance boost. And you actually have time to enjoy autorotations.

PM  EMAIL  GALLERY  Attn:RR  Quote
12-10-2017 11:40 PM  4 months agoPost 5
EEngineer

rrProfessor

TX

My Posts: All  Forum  Topic

I suppose if you're used to flying at or near sea level, you would probably notice though.
Definitely.......where I am, it's ~400' above sea level.

Went to the NATS at Lubbock, TX one year....~3000 above sea level.

Had to increase my control throws significantly on my pattern plane to have the same control "feel", due to the "thinner" air.

Logo 600SXs, 800XX, TDR IIs

PM  EMAIL  Attn:RR  Quote
12-11-2017 03:13 AM  4 months agoPost 6
InvertedDude

rrVeteran

USA

My Posts: All  Forum  Topic

Interesting
So thinner air will require more RPMS head speed? Say, I bump it from 1850 rpms to 2200 rpms?

what head speed are you guys flying at high altitudes?

My home is around 880 feet above sea level.

PM  EMAIL  GALLERY  Attn:RR  Quote
12-11-2017 03:16 AM  4 months agoPost 7
EEngineer

rrProfessor

TX

My Posts: All  Forum  Topic

I would guess more cyclic and collective throw, rather than head speed.

Logo 600SXs, 800XX, TDR IIs

PM  EMAIL  Attn:RR  Quote
12-11-2017 03:51 AM  4 months agoPost 8
co_rotorhead

rrVeteran

Centennial, CO, USA

My Posts: All  Forum  Topic

what head speed are you guys flying at high altitudes?
So the field I normally fly at is at 5500 ft. MSL. Headspeed and pitch settings are really not that much different from what people are using at lower altitudes. I think the guys flying 3D on 700 size helis are probably running between 1950-2100? Nothing too insane though. I think having good collective management goes a long way here too. I've see Matt Botos and Jaime Robertson fly awesome 3D routines in Fort Collins, which is right at 5K MSL.

PM  EMAIL  GALLERY  Attn:RR  Quote
12-11-2017 04:25 AM  4 months agoPost 9
EEngineer

rrProfessor

TX

My Posts: All  Forum  Topic

I've see Matt Botos and Jaime Robertson fly awesome 3D routines in Fort Collins, which is right at 5K MSL.
How much cyclic/collective were they using?

Do you know?

Logo 600SXs, 800XX, TDR IIs

PM  EMAIL  Attn:RR  Quote
12-11-2017 04:31 AM  4 months agoPost 10
InvertedDude

rrVeteran

USA

My Posts: All  Forum  Topic

co_rotorhead
A 700 Nitro/Electric are swinging much bigger and longer blades. The weight is not that much more than a porky 600ESP like mine. I am swinging 600mm CF blades.

+12/-12 pitch

7.5 degrees on cycle Ele/Ali

1850 rpms

PM  EMAIL  GALLERY  Attn:RR  Quote
12-11-2017 04:48 AM  4 months agoPost 11
rcscaleguy

rrNovice

CA, USA

My Posts: All  Forum  Topic

Head Speed
I suspect Jamie when he was last their in TX was running about 2200+. So between your 1850 and 2200 with your cyclic and collective numbers you're going to see and feel a difference. But don't bother comparing to other guys because they refresh packs once or twice a year. So get it flying the way you like and deal with what you have. Collective management was mentioned, and if you use it you'll be a happy guy. If you want to train, try a 30 nitro and do mild 3D. You'll quickly learn about collective management, or you get a bogged head and counting blades.

PM  EMAIL  GALLERY  Attn:RR  Quote
12-11-2017 12:23 PM  4 months agoPost 12
Heli_Splatter

rrElite Veteran

USA

My Posts: All  Forum  Topic

I lost a 450 due to the electronics burning up at 8000 feet in the Rockies. It struggled to fly and the air was just too thin.

PM  EMAIL  GALLERY  Attn:RR  Quote
12-11-2017 12:30 PM  4 months agoPost 13
co_rotorhead

rrVeteran

Centennial, CO, USA

My Posts: All  Forum  Topic

How much cyclic/collective were they using?

Do you know?
I don't know for sure, no. But I also don't remember either of them mentioning changing their setups to account for the altitude change. I'm guessing they were probably 12-13 on collective pitch and 8-9 on cyclic?

As mentioned, flying a nitro heli here you can rapidly improve your collective management. After flying nitro for a while, and then switching to electric, the difference is dramatic. You really feel like the heli is un-boggable. (is that a word?)

PM  EMAIL  GALLERY  Attn:RR  Quote
12-11-2017 12:34 PM  4 months agoPost 14
co_rotorhead

rrVeteran

Centennial, CO, USA

My Posts: All  Forum  Topic

I lost a 450 due to the electronics burning up at 8000 feet in the Rockies. It struggled to fly and the air was just too thin.
I may be attempting to fly a 15lb, 4-blade scale heli at 10-11k next week (I don't know for sure yet). If I do, I will report back with my experience.

PM  EMAIL  GALLERY  Attn:RR  Quote
12-11-2017 12:54 PM  4 months agoPost 15
Dan Minick

rrKey Veteran

Columbus, WI

My Posts: All  Forum  Topic

My guess would be absolutely the altitude messing with you as I fly here in Wisconsin in the cold, under 32 often closer to 0, and the helis love it. Cold air is thicker and the blades can really "bite". Right at 1000ft here

Team Synergy, Team FBL Rotors-------if its not broke...it will be!

PM  EMAIL  GALLERY  Attn:RR  Quote
12-11-2017 01:00 PM  4 months agoPost 16
co_rotorhead

rrVeteran

Centennial, CO, USA

My Posts: All  Forum  Topic

So here is a pic of a Raptor 50 nitro flying at 13k on Pike's Peak:

I knew the pilot -- he used to fly with us on occasion. If a heavy nitro Raptor can find the grunt to fly up there, a lighter electric with a higher power/weight ratio should be able to as well.*

* Note: by "fly" I mean forward flight, not smack 3D.

PM  EMAIL  GALLERY  Attn:RR  Quote
12-11-2017 02:37 PM  4 months agoPost 17
Heli_Splatter

rrElite Veteran

USA

My Posts: All  Forum  Topic

That is a great shot. They have made rescues from Everest at 21,000 I believe is the record.

In my case it was probably just not enough esc at 8000. No doubt that it can be done. I was not properly prepared.

PM  EMAIL  GALLERY  Attn:RR  Quote
12-11-2017 03:15 PM  4 months agoPost 18
Ladymagic

rrKey Veteran

South Korea

My Posts: All  Forum  Topic

It would seem that your perceived power loss stems more from the colder temps than the altitude.

While the higher altitude may affect your blade efficiency, you should still be capable of sustained flight with simple adjustments to your collective management habits. Where altitude would likely be a negative draw to a more noticeable extent, would be at an altitude where the air is thin enough to affect your ability to breathe normally...and I doubt you would want to fly at those extremes anyways. And since we aren't dealing with fuel/air mixtures, like you would with a nitro engine, I doubt what you are feeling is actually "power" loss but more performance feel changes in terms of responsiveness to your inputs.

On the other hand, most helis tend to do very well in colder temps; the air is more dense which leads to crisper cyclic response and your engine and motor temps run dramatically cooler, which translates to more power for both a N or an E heli.

Where you are likely feeling the performance drop is with your batteries. LiPos do not like dramatic temp variations; too cold or too hot and your battery's chemistry is affected. Current draw, IR, and battery age can all change the voltage output as your battery chemistry starts to be affected.

The E gurus could probably explain in greater detail and I might be totally misinterpreting your definition of power loss, but that's my guess.

Mellisa

PM  EMAIL  GALLERY  Attn:RR  Quote
12-11-2017 04:02 PM  4 months agoPost 19
Jeff polisena

rrElite Veteran

westpalmbeachflorida usa

My Posts: All  Forum  Topic

^^^^ Lipo batteries slow down the colder they get . Keep packs warm before flight and see if it helps .

I stole it ,flew it and gave it back ;)

PM  EMAIL  GALLERY  Attn:RR  Quote
12-11-2017 04:04 PM  4 months agoPost 20
Richardmid1

rrProfessor

Leeds, England

My Posts: All  Forum  Topic

Li-po's don't like the cold. If you can, warm them up in your car. We used to keep ours wrapped in a heated blanket while charging when it drops below 50F. Makes a huge difference in power.

The altitude won't help but 1850 rpm on a 600e with +/-12 collective is a fairly tame setup. I would look at running 2000+ and 13 degrees collective.

60% of the time, it works every time!

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
WATCH
 2 pages [ <<    <    ( 1 )     2     NEXT    >> ] 916 views POST REPLY
HelicopterMain Discussion › Cold and high altitude electric power (no power)
 Print TOPIC  Make Suggestion 

 6  Topic Subscribe

Saturday, April 21 - 3:21 am - Copyright © 2000-2018 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online