SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Dec 31, 2012, 04:04 PM
An Aussie in Chicago
Joined Apr 2012
1,286 Posts
Quote:
Originally Posted by TexasAggie View Post
  • Weight: around 73 oz.
  • Motor: 920 kv Emax BL2820/07 from HURC (http://www.headsuprc.com/servlet/the...ushless/Detail)
  • Prop size: 9x6, 10x5, 10x6, 10x7
  • ESC: Hobbywing 40A
  • Separate BEC: Castle 10A
  • Servos used: HS-82MG x4 on wings (noisy little buggers); HS-65HB x2 on tail
  • Flight battery: 1 Sky Lipo 4S 4000 mAh
  • Video battery: small 3S
  • Flight cam: RMRC 480
  • VTX: 400 mW Sunsky
  • VTX antena: DIY Cloverleaf
  • RX: Sunsky or Lawmate
  • RX antenna: DIY Virevent or Skew-planar wheel
  • Stabilizer: GWS PG-02 dual-gain, switchable via Tx
  • OSD: Remzibi OSD
  • Max wind: about 25 knots
  • Mods: flaps, motor mount, carbon ribbons in wings/stabilizers, proper hinges and control hardware.

Some prop data for my motor. Admittedly, it's not very helpful since I don't have a tachometer and therefore, have no way of measuring thrust.

10x5:
Max current: 29.59 A @ 15.88 V
Max power: 469.9 W
Min voltage: 15.64 V

10x6:
Max current: 34.98 A @ 15.77 V
Max power: 551.5 W
Min voltage: 15.45 V

10x7:
WILL UPDATE

You can measure static thrust using one of the light weight kitchen scales. The one I have has a max of 11 lb capacity and cost $10 from Amazon.

With a rear engine plane like the Skywalker. Just place the nose on the scales and hold it vertically up side down. The apply full thrust and check the scale, then just subtract the planes weight giving you thrust. Best with 2 people.

You don't need the wings attached or anything like that.
hendrnk is online now Find More Posts by hendrnk
Reply With Quote
Sign up now
to remove ads between posts
Old Dec 31, 2012, 04:29 PM
Gig 'Em!
TexasAggie's Avatar
United States, TX, College Station
Joined Nov 2010
647 Posts
Sounds like a nightmare as far as safety goes. I think I'll just buy a tachometer...
TexasAggie is offline Find More Posts by TexasAggie
Reply With Quote
Old Dec 31, 2012, 04:31 PM
Registered User
Daemon's Avatar
Lakewood, Colorado
Joined Aug 2002
28,395 Posts
Tachometer isn't going to tell you much about thrust.
Daemon is offline Find More Posts by Daemon
RCG Plus Member
Old Dec 31, 2012, 04:34 PM
Gig 'Em!
TexasAggie's Avatar
United States, TX, College Station
Joined Nov 2010
647 Posts
With the Flybrushless data it will. For instance, http://flybrushless.com/prop/view/78
TexasAggie is offline Find More Posts by TexasAggie
Reply With Quote
Old Dec 31, 2012, 04:36 PM
An Aussie in Chicago
Joined Apr 2012
1,286 Posts
Quote:
Originally Posted by TexasAggie View Post
Sounds like a nightmare as far as safety goes. I think I'll just buy a tachometer...
Its not hard or unsafe at all with 2 people. Anyway its the only way to get real static thrust figures.

You can also do this without the plane...just the motor and ESC & battery and some device to hold the engine @ full throttle.
hendrnk is online now Find More Posts by hendrnk
Reply With Quote
Old Dec 31, 2012, 04:44 PM
Gig 'Em!
TexasAggie's Avatar
United States, TX, College Station
Joined Nov 2010
647 Posts
I'd rather not take that risk. If the prop shatters it could end up in my chest or something. The less time the prop's plane of rotation spends intersecting me the better. For me, it's not worth that much to get a few numbers.

I updated my main post with more data.
TexasAggie is offline Find More Posts by TexasAggie
Last edited by TexasAggie; Dec 31, 2012 at 04:55 PM.
Reply With Quote
Old Apr 03, 2013, 12:27 AM
Registered User
United States, IL, Chicago
Joined Dec 2012
36 Posts
Hi guys
I need max flight time for a 1.8kg skywalker

should I use:
http://www.hobbyking.com/hobbyking/s...00kv_550w.html
OR
http://www.hobbyking.com/hobbyking/s...dProduct=18231

OR none of those ?

AND what prop ?
jasonyyd is online now Find More Posts by jasonyyd
Reply With Quote
Old Apr 03, 2013, 10:09 AM
Registered User
Shadrack's Avatar
Winnipeg
Joined Feb 2002
5,679 Posts
What type of flight time? You looking for an hour? I can get close to that with an OS 3820-1200kv and on a 3S 5100 I can glide along for 45 minutes with throttle management. Have had my amp use down to just over 3 amps in level flight. I run a 9 x 6 as a prop and never go much past half throttle except for launch.
Shadrack is online now Find More Posts by Shadrack
Reply With Quote
Old Apr 03, 2013, 06:00 PM
If it's to be, it's up to me.
subsonic's Avatar
Sydney, Australia
Joined Jan 2007
3,060 Posts
Quote:
Originally Posted by jasonyyd View Post
Hi guys
I need max flight time for a 1.8kg skywalker

should I use:
http://www.hobbyking.com/hobbyking/s...00kv_550w.html
OR
http://www.hobbyking.com/hobbyking/s...dProduct=18231

OR none of those ?

AND what prop ?
That's what this thread is for, isn't it? Have you read any of it?

You didn't mention what battery you are going to use. 3S? 4S? 12S?

The original Skywalker is pretty much limited to a 9" prop, unless you're keen on moving the motor up and accepting the slight handling compromise that goes with it.
subsonic is online now Find More Posts by subsonic
Reply With Quote
Old Apr 03, 2013, 10:53 PM
Registered User
Joined Oct 2012
2,164 Posts
FWIW, theres not much reason to install the motor on the plane to test it...

there is going to be little effect on its efficiency on the plane vs a simple wooden mount attached to whatever scale you have. It would certainly reduce measurement error and risk. When I see thrust measured in grams and the idea of balancing a 2kg plane in the mix... little sirens go off in my head.

For that matter, this thread could be as well applied to any plane... The design of planes may impede the airflow to the motor, but I should think this should be both negligible, and consistent between motor/props on the same plane. The most efficient motor and prop to push 1kg of thrust should be the most efficient for EVERYONE (desiring that amount of thrust anyway). but then, the individual units across production runs may not be so consistent for different people.
bauerbach is offline Find More Posts by bauerbach
Reply With Quote
Old Apr 03, 2013, 11:32 PM
Registered User
United States, IL, Chicago
Joined Dec 2012
36 Posts
Quote:
Originally Posted by subsonic View Post
That's what this thread is for, isn't it? Have you read any of it?

You didn't mention what battery you are going to use. 3S? 4S? 12S?

The original Skywalker is pretty much limited to a 9" prop, unless you're keen on moving the motor up and accepting the slight handling compromise that goes with it.
FYI:
I'm looking for the best "combination" for this much weight on the plane.
Doesn't matter if I end up using 3s, 4s....
Doesn't matter which prop, I knew the max is 9xX but isn't there still plenty of people are using bigger ones(thus I know I know it need to be modified...).

Again, there is only 1 thing can't be changed, is the weight of 1.8Kg....
That's why the weight is the only information I provided.
jasonyyd is online now Find More Posts by jasonyyd
Reply With Quote
Old Apr 04, 2013, 03:28 AM
Registered User
Daemon's Avatar
Lakewood, Colorado
Joined Aug 2002
28,395 Posts
Doesn't change the fact that the information you want is already in the thread.
Many people list their weight, and cruise amps. Look for the one that
best matches what you want. It's best to convert cruise amps to watts
Watts = volts (3S versus 4S nominal voltage) * amps, so you can
compare apples to apples. If want individual response, all you'll get
is people telling you that their own setup is best.

Besides, this thread is not for questions, it's for listing proven setups.
Daemon is offline Find More Posts by Daemon
RCG Plus Member
Old Apr 04, 2013, 03:37 AM
9W2DLR
Malaysia, Federal Territory of Putrajaya, Putrajaya
Joined Nov 2011
2,105 Posts
Quote:
Originally Posted by jasonyyd View Post
FYI:
I'm looking for the best "combination" for this much weight on the plane.
Doesn't matter if I end up using 3s, 4s....
Doesn't matter which prop, I knew the max is 9xX but isn't there still plenty of people are using bigger ones(thus I know I know it need to be modified...).

Again, there is only 1 thing can't be changed, is the weight of 1.8Kg....
That's why the weight is the only information I provided.
have search this thread? if you did you should find this post by subsonic what more do you need?

http://www.rcgroups.com/forums/showt...v#post21484280

as ian said this thread is not for questions, it's for listing proven setups. people need to learn how to use search button
skellator is offline Find More Posts by skellator
RCG Plus Member
Latest blog entry: ZMR/RCX Motor X Mount
Reply With Quote
Old Apr 06, 2013, 02:36 AM
Registered Loser
Canada, BC, Central Okanagan H
Joined Jun 2010
3,251 Posts
First the forum coders need to make a search that works well.
s_mack is offline Find More Posts by s_mack
Reply With Quote
Old Apr 06, 2013, 02:42 AM
Registered Loser
Canada, BC, Central Okanagan H
Joined Jun 2010
3,251 Posts
btw.. what does "proven" mean? I think a lot of the setups shown here are VASTLY over powered. I'm using this motor with mine with a dinky 18A ESC... something I got laughed at when I first suggested it. But it works, and I get far more flight time than someone using a 600W monster motor. Granted, I can't even dream of doing a flip or climbing at a steep rate... but that isn't (in my opinion) what this plane is all about.
s_mack is offline Find More Posts by s_mack
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Help! flyfly power set up ian.c Electric Ducted Fan Jet Talk 3 Aug 20, 2011 08:33 PM
Discussion STOL power set-up moes Power Systems 6 Aug 17, 2011 11:35 PM
Question Easy glider power set-up slowstick4ap Power Systems 1 Jul 07, 2011 07:23 AM
Help! GY401 SET-UP - DX7 - tail set up... help :( d1cky_kds Electric Heli Talk 16 Jun 27, 2011 06:10 PM
Discussion My XP9303/DragonLink and Skywalker Set Up Crist Rigotti FPV Talk 6 Apr 02, 2011 11:50 PM