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Old Apr 28, 2010, 10:20 PM
Some call me the other guy!
DoctorAudio's Avatar
Milwaukie , Oregon
Joined Feb 2003
4,394 Posts
I don't want to argue with you guys, It just seems as your bent on it.
You have to do some testing yourself.
Nobody is claiming of trying to break a record. So what's the big deal?
I had had good luck with these motors and that is the fact!
I have blown 6 ESC's and the motors still work!
I just don't get it.

This is a test!
2836/3700 KV
2836 3700KV motor test! (1 min 22 sec)


This is not the first or the last flight of this bird.

Super Stryker Speed test #2 (6 min 54 sec)


2836/2350 KV 4S
http://www.youtube.com/watch?v=Vqjvl4DrAic

Look guys, If I did it you can too.
I am not saying that your going to run all over everyone at the field.
I have projects for days over here, if I were to spend 150 bucks on a motor for my stryker. It would make it less fun for me!
So, what if I say they are super fast motors. For less than 20 bucks they are super fast. Plus if I would blow one up, I would not think twice about throwing it into the garbage and buy another.
Thanks.
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Last edited by DoctorAudio; Apr 28, 2010 at 10:35 PM.
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Old Apr 28, 2010, 11:53 PM
Registered User
GryphonRCU's Avatar
United States, CA, SF
Joined Mar 2008
3,820 Posts
johnnyrocco123,

One of the motors that I wasted money on spins 4.75X4.75 at 212 MPH pitch speed.
(by far the weakest prop that was installed on that motor before we propped up by 50+% load).

The above prop should be tested against a larger prop with 1:1 diameter to pitch ratio (same brand motor of same size or 1 size smaller motor but lower KV to reduce power big time).

We can ensure that the larger prop has 200-300W less power.

We can then see which one flies faster.

I will o.k. that only the small prop gets allowed to do a dive...a big one.
Large prop setup needs to fly level, only level.

The motor swap will be on a fixed plane with fixed ESC and fixed battery....just motor/prop swaps (different KV for different prop)...while ensuring the small prop has 200-300W more power.


Any guesses in advance of the outcome?


I need help from 1 friend to get it all done....I hope he agrees.


p.s. no one woke up one morning and said lets put on larger props...every time we hit a wall, we had to go to larger props...., then we started seeing which motors could swing the bigger ones and which ones couldn’t....then bigger props ....at the end we were left with few brands.....bigger props for even higher speed was needed but NO 28mm could swing those....then Custom motors were built...it has been a progression with many lessons learned along the way.


Gryphon
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Old Apr 29, 2010, 12:58 AM
BUILDnFLY
jphong's Avatar
Edmonton, Alberta, Canada
Joined Apr 2006
146 Posts
Quote:
Originally Posted by DoctorAudio View Post
I agree with above.
With the 2836/2350 KV motor I am getting about 9 mins of flight.
The 2836/3200 KV close to 7 mins.
The 2836/ 3700 KV motor gives the least of flight time, 6 mins!
Ill try out those flight times on my new setup with the 3200 KV motor. I said about 3min on the 2700KV inrunner because my packs were puffing and getting hot at about 5-7 min of flying and that setup is only pulling about 30-35 amps so Im surprised you can get close to 7min when you are drawing almost twice as much amperage.

Ill do some test runs and let you guys know how it goes once it stops raining.

Here are some pics of the new bird, black paint and colored stripe decals.
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Old Apr 29, 2010, 03:12 AM
Livin it UP when Im goin DOWN
Arcteryxxx's Avatar
Norway, Telemark, Skien
Joined Feb 2010
4,261 Posts
Nice bird, jphong!
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Old Apr 29, 2010, 06:44 AM
Registered User
Melbourne, Australia
Joined Mar 2009
370 Posts
Hi folks

I'm a big fan of the blue & red Turnigy motors. I've got a 2836-2350 in a hobbyking Stryker clone (The Skyfun, which is really a skyartec funjet) running on turnigy 4s 1800mAh 40c lipos.

I've flown it on a 4.75x4.25 and 5.5x4.5 APC prop, which drew around 590w/38A and 800w/52A respectively. 4.75x4.25 was nice, but not enough vertical nor speed. 5.5x4.5 is pretty sweet at both, but I wouldnt mind just a little more speed.


Assuming that the skyfun and stryker are aerodynamically very similar, how would a 2836-3200 perform with a 4.5x4.1 apc prop?

DriveCalc has been very accurate on specs for the 2350kv, and for the 3200kv it gives the following stats:

64A, 947w, 1415g static thrust, 129mph Vopt (not pitch speed) at 75% efficiency

stats for 2350kv with 5.5x4.5 are:

52A, 789w, 1510g static thrust, 107mph Vopt at 69% efficiency.


On paper, it looks like a no brainer that the 3200kv would be better.... but is a stryker-esque airframe going to need more thrust than a 4.5x4.1 prop can provide to get to ~130mph?
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Old Apr 29, 2010, 07:19 AM
Crashing into the sky!
jackosmeister's Avatar
Auckland NZ
Joined Aug 2007
7,179 Posts
Quote:
This is a test!
2836/3700 KV
Not its not...

This is a test

5S 4.75x5.5 (0 min 16 sec)


Turnigy 2600kV inrunner rotor explodes on 6S (0 min 31 sec)


Results of test... Dont run 6S

I 100% agree with gryphon, unless you have an uber slippery plane (molded pylon racer and the like) your wasting your time with sub 5" props, as you dont have enough thrust to achieve your pitch speed. Think superbike engine trying to pull a semi trailer and you have the idea. You can make a semi trailer go fast, but it takes lotsa thrust to go along with the pitch speed. It may sound like its going a squillion miles an hour, but its stuck in top gear and the clutch is slipping.
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Old Apr 29, 2010, 08:39 AM
Slow Flyer
Bombay's Avatar
Richmond, TX
Joined Apr 2008
3,235 Posts
Quote:
Assuming that the skyfun and stryker are aerodynamically very similar, how would a 2836-3200 perform with a 4.5x4.1 apc prop?

DriveCalc has been very accurate on specs for the 2350kv, and for the 3200kv it gives the following stats:

64A, 947w, 1415g static thrust, 129mph Vopt (not pitch speed) at 75% efficiency

stats for 2350kv with 5.5x4.5 are:

52A, 789w, 1510g static thrust, 107mph Vopt at 69% efficiency.


On paper, it looks like a no brainer that the 3200kv would be better.... but is a stryker-esque airframe going to need more thrust than a 4.5x4.1 prop can provide to get to ~130mph?

NinetySix:
So what do your calcs tell you about running the 3200kv on a 6x4 prop? Is that a feasible solution?
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Old Apr 29, 2010, 08:45 AM
Registered User
Melbourne, Australia
Joined Mar 2009
370 Posts
Quote:
Originally Posted by Bombay View Post
NinetySix:
So what do your calcs tell you about running the 3200kv on a 6x4 prop? Is that a feasible solution?
its on its limit for 3s, but I'm running 4s.

63a, 680w, 1577g static thrust, 81mph Vopt, 70% efficiency
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Old Apr 30, 2010, 03:28 AM
Registered User
Melbourne, Australia
Joined Mar 2009
370 Posts
Quote:
Originally Posted by NinetySix View Post
drivecalc stats for 2350kv with 5.5x4.5 are:

52A, 789w, 1510g static thrust, 107mph Vopt at 69% efficiency.
How is this for freaky.... took the skyfun out today with my HowFast air speed meter taped on, 5mph wind....

with a fresh battery she did 107mph!

Tried a few props out - all with a fresh lipo. results are:
  • 5.5x4.5E APC - 107mph
  • 5.25x4.75E APC - 103mph
  • 5x5E APC - 97mph
  • 5x5E TGS - 100mph

All props drew nearly the same current, the 5.5x4.5 drawing slightly more though. The 5.5x4.5 certainly is the pick of the lot, fastest, quietest and best vertical.... very surprised by the TGS 5x5E though, as noisy as it is... Did not expect the APC 5x5E to work very well, but worth a shot.

Only the batteries were slightly warm after a hard flight.
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Old Apr 30, 2010, 04:01 AM
Livin it UP when Im goin DOWN
Arcteryxxx's Avatar
Norway, Telemark, Skien
Joined Feb 2010
4,261 Posts
Quote:
Originally Posted by NinetySix View Post
How is this for freaky.... took the skyfun out today with my HowFast air speed meter taped on, 5mph wind....

with a fresh battery she did 107mph!

Tried a few props out - all with a fresh lipo. results are:
  • 5.5x4.5E APC - 107mph
  • 5.25x4.75E APC - 103mph
  • 5x5E APC - 97mph
  • 5x5E TGS - 100mph

All props drew nearly the same current, the 5.5x4.5 drawing slightly more though. The 5.5x4.5 certainly is the pick of the lot, fastest, quietest and best vertical.... very surprised by the TGS 5x5E though, as noisy as it is... Did not expect the APC 5x5E to work very well, but worth a shot.

Only the batteries were slightly warm after a hard flight.
This was on 4S, right?
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Old Apr 30, 2010, 05:11 AM
Registered User
Melbourne, Australia
Joined Mar 2009
370 Posts
Yes, turnigy 4s 1800mAh 40c lipo, 2836-2350, AUW 26.5oz.
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Old Apr 30, 2010, 05:34 AM
Livin it UP when Im goin DOWN
Arcteryxxx's Avatar
Norway, Telemark, Skien
Joined Feb 2010
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Quote:
Originally Posted by NinetySix View Post
Yes, turnigy 4s 1800mAh 40c lipo, 2836-2350, AUW 26.5oz.
I'm quite impressed with these results, and I think this is about max you can get with a sub-6 prop...
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Old Apr 30, 2010, 06:29 AM
Crashing into the sky!
jackosmeister's Avatar
Auckland NZ
Joined Aug 2007
7,179 Posts
Ditch the 5.5x4.5, bolt on a 6x4 sport. In flight the 6x4 sport will draw LESS current than the 5.5x4.5 and go faster.
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Old Apr 30, 2010, 08:12 AM
Slow Flyer
Bombay's Avatar
Richmond, TX
Joined Apr 2008
3,235 Posts
Yeah, I am surprised you didn't try the 6x4.

BTW - who sells the 6x4 sport?
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Old Apr 30, 2010, 10:17 AM
You down with EPP?
johnnyrocco123's Avatar
Houston, Tx
Joined May 2009
6,678 Posts
Quote:
Originally Posted by NinetySix View Post
Yes, turnigy 4s 1800mAh 40c lipo, 2836-2350, AUW 26.5oz.
Thank you for posting actual numbers/props/ and specific battery. Now we are getting somewhere.
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