HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Oct 24, 2011, 04:49 AM
Registered User
Joined Dec 2010
180 Posts
Quote:
Originally Posted by kinderkram View Post
Sure you will. While the motors can handle 4S your HK ESCs are specified for 2-3S. So the fun won't last for long...
So much power and white smoke ok that was what I wanted to know!
I'm still struggling why there seems to be a lack of power, I have the idea it had more power before, but it all seems to got lost when I added the GPS and step-up boost converter.

So if I want to buy a new battery what do you recommend the Turnigy nano-tech? bigger mAh then 3000 or smaller? and just to be sure I'm going to order some 12" props from Paul.. any other recommendations?
rvbcrs is offline Find More Posts by rvbcrs
Reply With Quote
Sign up now
to remove ads between posts
Old Oct 24, 2011, 06:02 AM
Registered User
Joined Jul 2011
188 Posts
Quote:
Originally Posted by rvbcrs View Post
So much power and white smoke ok that was what I wanted to know!
I'm still struggling why there seems to be a lack of power, I have the idea it had more power before, but it all seems to got lost when I added the GPS and step-up boost converter.

So if I want to buy a new battery what do you recommend the Turnigy nano-tech? bigger mAh then 3000 or smaller? and just to be sure I'm going to order some 12" props from Paul.. any other recommendations?
Hi,

when buying a new battery keep an eye on the discharge current too! Not only the capacity counts.

I'm using 2200mAh 3S LiPos with 40C constant discharge rate on my tri and my flyduspider.

Rgds
aBUGSworstnightmare
aBUGSnightmare is offline Find More Posts by aBUGSnightmare
Reply With Quote
Old Oct 24, 2011, 06:10 AM
Registered User
Joined Dec 2010
180 Posts
Quote:
Originally Posted by aBUGSnightmare View Post
Hi,

when buying a new battery keep an eye on the discharge current too! Not only the capacity counts.

I'm using 2200mAh 3S LiPos with 40C constant discharge rate on my tri and my flyduspider.

Rgds
aBUGSworstnightmare
I'm flying my quadcopter to make video recordings, so I do not need the "wharthox" throttle is the discharge rate still a factor then?
rvbcrs is offline Find More Posts by rvbcrs
Reply With Quote
Old Oct 24, 2011, 06:18 AM
It wasn't me
r0sewhite's Avatar
Augsburg, Germany
Joined Mar 2010
428 Posts
Yesterday we had good weather so I went out to the fields for the first time after I exchanged the Keda 20-26M to Robbe Roxxy 2824-26.

WHAT A DIFFERENCE!!!

The Roxxy with 1380KV are incredible. Thrust and speed are brute. 4 seconds and the spider is out of sight.

They run much smoother than the Keda. The twitching I noticed in high speed turns is almost gone. I thought it was the props that start flapping due to the force but obviously the props hadn't much to do with this problem.

The Keda 20-26M really sucks compared to the Roxxy.
r0sewhite is offline Find More Posts by r0sewhite
Reply With Quote
Old Oct 24, 2011, 07:20 AM
OS Sponsor
kinderkram's Avatar
Germany, NRW, Dusseldorf
Joined Jun 2010
5,178 Posts
Yah, there must be a reason why you get 3 Kedas for the price of 1 Roxxy.

Quote:
Originally Posted by r0sewhite View Post
Yesterday we had good weather so I went out to the fields for the first time after I exchanged the Keda 20-26M to Robbe Roxxy 2824-26.

WHAT A DIFFERENCE!!!

The Roxxy with 1380KV are incredible. Thrust and speed are brute. 4 seconds and the spider is out of sight.

They run much smoother than the Keda. The twitching I noticed in high speed turns is almost gone. I thought it was the props that start flapping due to the force but obviously the props hadn't much to do with this problem.

The Keda 20-26M really sucks compared to the Roxxy.
kinderkram is offline Find More Posts by kinderkram
RCG Plus Member
Reply With Quote
Old Oct 24, 2011, 07:57 AM
Registered User
M4d_D's Avatar
Joined Dec 2006
845 Posts
which roxxys do you use ? 2824-26 ?
can you tell me a little about the comparison between the roxxys and the hacker a20-26m please ?







Quote:
Originally Posted by r0sewhite View Post
Yesterday we had good weather so I went out to the fields for the first time after I exchanged the Keda 20-26M to Robbe Roxxy 2824-26.

WHAT A DIFFERENCE!!!

The Roxxy with 1380KV are incredible. Thrust and speed are brute. 4 seconds and the spider is out of sight.

They run much smoother than the Keda. The twitching I noticed in high speed turns is almost gone. I thought it was the props that start flapping due to the force but obviously the props hadn't much to do with this problem.

The Keda 20-26M really sucks compared to the Roxxy.
M4d_D is offline Find More Posts by M4d_D
Reply With Quote
Old Oct 24, 2011, 08:41 AM
Registered User
Deutschland, Schleswig-Holstein, Kiel
Joined Jan 2011
431 Posts
Quote:
Originally Posted by M4d_D View Post
which roxxys do you use ? 2824-26 ?
can you tell me a little about the comparison between the roxxys and the hacker a20-26m please ?
+ ~30% KV

keda with 3S battery spins as fast as that roxxy does almost with 2S

more thrust is not surpising in that case....
alteskind is offline Find More Posts by alteskind
Reply With Quote
Old Oct 24, 2011, 09:25 AM
It wasn't me
r0sewhite's Avatar
Augsburg, Germany
Joined Mar 2010
428 Posts
Quote:
Originally Posted by M4d_D View Post
which roxxys do you use ? 2824-26 ?
can you tell me a little about the comparison between the roxxys and the hacker a20-26m please ?
Since I've got the Hacker A20-26M EVO on my quad and already flew the Roxxy 2824-26 on a quad, too: The Hacker have less speed (1130KV to 1380KV) but more thrust. If you flip the throttle stick to max position, the Hacker quad accelerates in almost no time to max speed while the Roxxy need a second or so.

On the spider, the Roxxy have less weight per motor to lift (compared to a quad), so you have full advantage of the speed without the disadvantage of less power.

Quote:
Originally Posted by alteskind View Post
+ ~30% KV

keda with 3S battery spins as fast as that roxxy does almost with 2S

more thrust is not surpising in that case....
More speed, not more thrust.
r0sewhite is offline Find More Posts by r0sewhite
Reply With Quote
Old Oct 24, 2011, 10:44 AM
Registered User
Goofy23's Avatar
Hamburg, Germany
Joined Jan 2011
1,074 Posts
how are the flight times now with almost 1400KV?
Have to say the Suppo 1100 are a good overall fit, more power then similar sized Kedas.
Goofy23 is online now Find More Posts by Goofy23
Reply With Quote
Old Oct 24, 2011, 10:46 AM
It wasn't me
r0sewhite's Avatar
Augsburg, Germany
Joined Mar 2010
428 Posts
Emptied a 3S 2200mAh battery with only speed flying (neither flips nor loops) in 5 minutes.
r0sewhite is offline Find More Posts by r0sewhite
Reply With Quote
Old Oct 24, 2011, 10:51 AM
Registered User
Goofy23's Avatar
Hamburg, Germany
Joined Jan 2011
1,074 Posts
looks fine, 5min is ok.
Goofy23 is online now Find More Posts by Goofy23
Reply With Quote
Old Oct 24, 2011, 12:42 PM
Registered User
Deutschland, Schleswig-Holstein, Kiel
Joined Jan 2011
431 Posts
Quote:
Originally Posted by r0sewhite View Post
Since I've got the Hacker A20-26M EVO on my quad and already flew the Roxxy 2824-26 on a quad, too: The Hacker have less speed (1130KV to 1380KV) but more thrust. If you flip the throttle stick to max position, the Hacker quad accelerates in almost no time to max speed while the Roxxy need a second or so.

On the spider, the Roxxy have less weight per motor to lift (compared to a quad), so you have full advantage of the speed without the disadvantage of less power.



More speed, not more thrust.
rosewhite, you mix up some vocabulary...and u compare apples with pears.
i ll try to explain, what i wanted to say above.


a motor doesnt make any thrust without a prop. .

for identical prop:
more spins per minute = more thrust (german: schub))

more spin--> more air is thrown --> more thrust (with bigger props more air is thrown per spin, with same result = more thrust)

thrust is the result of the total amount of moved air. no difference if little amounts are moved fast, or big amounts are moved slower, in total you move some kg air down, and that moves your copter up.
doesnt matter, if you use fast+small or bigger+slower props/motors

keda with 3S (11V) has ~12000 spins.
roxxy with 3S has ~15000 spins.

both with 3S, your roxxy makes 25% more thrust than the keda due its higher KV. it simply pushes 25% more air away, and drains the battery faster


btw - abilitiy to spin up fast/er = torque (german: drehmoment)
the roxxy takes more watts, it might have some more torque...



BUT a 2026m with 3S has similar thrust as a roxxy with 2S, as then both have almost the same power.

if compared correct, you had to use 2S battery for the roxxy, or use 6" props with it, or compare it to another motor with higher KV, as blue wonder 1300/1500KV.

motors with higher KV/same props do move more air - thats well known.

imho higher KV motors wont make the copter reacting faster - it just will fly faster forward.... think my slow-keda-spider reaches 60 to 70km/h.
thats enough for me, as i didnt learn to fly like warthox until now.
alteskind is offline Find More Posts by alteskind
Last edited by alteskind; Oct 24, 2011 at 01:15 PM.
Reply With Quote
Old Oct 24, 2011, 02:03 PM
Registered User
Joined Dec 2010
180 Posts
If I want longer flying times on my Jakub J Quadcopter is a 6000mAh battery overkill? Like this: http://www.hobbyking.com/hobbyking/s...Lipo_Pack.html
rvbcrs is offline Find More Posts by rvbcrs
Reply With Quote
Old Oct 24, 2011, 02:23 PM
It wasn't me
r0sewhite's Avatar
Augsburg, Germany
Joined Mar 2010
428 Posts
@alteskind: You're right, I took the wrong term.

What I meant is:
The Roxxy have more speed but less torque.
Keda 20-26M: 4-13A, max 15A
Roxxy 2824-26: 5-9A, max 11A

On a quad you feel that difference. The Keda accelerate a little faster than the Roxxy (both with same props) due to their higher torque. Only their max speed is lower due to lower KV. But on the spider, the weight each motor has to lift is less and the advantage of the Keda's higher torque is gone:
Spider: 890g / 6 motors = 148g per motor
Quad: 670g / 4 motors = 167g per motor

The acceleration feels the same on a spider. Maybe there is a non-noticeable difference to measure but that's not the point. All you feel is the higher speed of the Roxxy.
r0sewhite is offline Find More Posts by r0sewhite
Reply With Quote
Old Oct 24, 2011, 02:36 PM
Registered User
bob4432's Avatar
United States, AZ
Joined May 2010
1,820 Posts
Quote:
Originally Posted by rvbcrs View Post
So much power and white smoke ok that was what I wanted to know!
I'm still struggling why there seems to be a lack of power, I have the idea it had more power before, but it all seems to got lost when I added the GPS and step-up boost converter.

So if I want to buy a new battery what do you recommend the Turnigy nano-tech? bigger mAh then 3000 or smaller? and just to be sure I'm going to order some 12" props from Paul.. any other recommendations?
do you know how many flights have been logged on your batts? I have a setup that is similar in weight - ~1-1.1Kg w/ the rctimer 2830-14 750KV and have no issue w/ power using 10x4.7 apc props. I have not tried other props on it but would not think that is the issue since you have always used the same props. I use tgy 2200mA 25-30C batts fwiw. maybe your lipos have come to the end of the 'premium' part of their life?

From now on though, I am just going to buy the nano tech batts simply for the faster charging rate, the additional discharge will be a bonus and I will be interested to see if I even notice it.

Hope this helps,
Brian/bob4432
bob4432 is offline Find More Posts by bob4432
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
New Product Please let me introduce myself jimaquo Dock Talk 7 Oct 27, 2010 02:27 AM
Let me introduce the DEMON!!!! (Transparent covering and eliptical wing!!!) modest-master Sport Planes 7 Aug 25, 2002 11:46 PM
Let me introduce Angelis 280/400, Benjamin, Zombi (ARFs) modest-master Parkflyers 17 Mar 14, 2002 01:20 PM
Let me introduce the "NIKE" modest-master Electric Sailplanes 3 Mar 07, 2002 05:20 AM