HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Dec 04, 2012, 11:58 PM
Registered User
Australia, VIC, Melbourne
Joined Nov 2006
11,766 Posts
I have to go and find the exact numbers, but my Lander 5 blade alloy 6S does approx 2.1kb thrust for 60A, and the HET 2W30 CS10 2.0Kg for 66A.... something like that. it was a notable shortfall in outputs versus their input powers. Not negligible, or even minor.... enough to be saddening.... (it was somewhere from 5% to 10% area)
But I stick with CS10/12's!! Well worth it for the sound.
PeterVRC is offline Find More Posts by PeterVRC
RCG Plus Member
Sign up now
to remove ads between posts
Old Dec 05, 2012, 12:02 AM
Registered User
Joined Jan 2011
1,062 Posts
A lot of bearing talk going on. I'd just buy a new motor, unless it was one of those 350 dollar motor's that heli direct sells for 700 size helis.....
stingeragents is offline Find More Posts by stingeragents
Reply With Quote
Old Dec 05, 2012, 12:09 AM
Registered User
WhalleyB0Y's Avatar
Canada, BC, Surrey
Joined Jul 2011
923 Posts
Where'd you even go to find high quality replacement bearings?
WhalleyB0Y is offline Find More Posts by WhalleyB0Y
Reply With Quote
Old Dec 05, 2012, 12:12 AM
Extreme CNC Alloy EDF
Extreme_RC's Avatar
Australia
Joined Mar 2006
11,756 Posts
Quote:
Originally Posted by PeterVRC View Post
Well that is a 'weeny' plane. And F-16's (like that design) would be the fastest 'shape' you can use. So put those two factors together and it will be FAST on any power system.
But none of the videos mean much without recorded speeds (truly accurate) seeing videos make any plane look 1.5x faster than when you are there anyway. My 900W Vampire flies as fast as that!! LOL. In video... (well, not really.. but it looks FAST in video!)
And for whatever power they are using, a Wemo would do that bit more thrust/speed for that same power. Typically 1000W in a CS10 will be 0.2Kg sort of area lower than the same in a low blade count Lander or Wemo. That is more what counts in the comparisons mentioned.
The CS10 costs power... some amount.
Plus I think Efflux said more that the CS10 runs out of power (1800w area? Kaboom), when the Wemo is still going over 2000W, to even 2400W.... alive.
Now the CS12-70.... that solves that power limit problem, but (same as the CS10) it will still not give the same result as the Wemo for the same power input.
Nothing but conjecture here, I have already posted up the wemo and the CS10 setups for this particular F16 months ago, all the data and comparisons, and I know the speed of the model as I have had it radared and dopplered with 4 different setups in it now. Its currently pulling around 60w more than it was with the wemo in it, and its just as fast. Actual back to back testing and results are worth something, not conjecture and guesstimation.

The CS10 is not 200g below the wemo at 1000w, it is around 30-40g below the wemo at 800-900w.

The wemo will spin to 70K before exploding, and I have it running at 63,800rpm with the 1W40, pulling only 2060w but producing 2.8kg thrust, actual test results.

Where is your 900w vampire video? Mine is posted up so lets see yours and compare, mine is at 900w odd as well.
Extreme_RC is offline Find More Posts by Extreme_RC
Reply With Quote
Old Dec 05, 2012, 12:21 AM
Registered User
Australia, VIC, Melbourne
Joined Nov 2006
11,766 Posts
In the Vampire thread....
(My only video for now... but hopefully decent videos of all aircraft coming over the next weeks).
You might have to follow 'blurred blob' for a lot of it! LOL. But there are enough clearish periods to see speed.
Of course, just any small zoom change means an even 'faster' plane.... so there is no true reference. Only radar, GPS or RCspeedo etc can tell a usefully accurate speed.

Oh, after take-off it is about 70% to 80% throttle all flight. Though 100% is not any huge leap ahead in speed.

...

Vampire01 (2 min 16 sec)
PeterVRC is offline Find More Posts by PeterVRC
RCG Plus Member
Last edited by PeterVRC; Dec 05, 2012 at 12:41 AM.
Reply With Quote
Old Dec 05, 2012, 12:56 AM
It should fly at least once
clive45's Avatar
Australia, NSW, Grenfell
Joined Mar 2006
2,607 Posts
http://www.bocabearings.com/

Buying another cheap motor may give you the same problem(bad bearings), how many do you buy before you get a good one. Replace bearings and it should be good to go for quite a while.
clive45 is offline Find More Posts by clive45
Reply With Quote
Old Dec 05, 2012, 01:10 AM
chuck
santa barbara, CA
Joined May 2009
4,319 Posts
Quote:
Originally Posted by clive45 View Post
http://www.bocabearings.com/

Buying another cheap motor may give you the same problem(bad bearings), how many do you buy before you get a good one. Replace bearings and it should be good to go for quite a while.
unfortunately, as noted before, some of the cheap motors suffer from undersized shafts that will still be a issue w/ good bearings.
chas650r is offline Find More Posts by chas650r
Reply With Quote
Old Dec 05, 2012, 01:28 AM
Registered User
Australia, VIC, Melbourne
Joined Nov 2006
11,766 Posts
How about..... Loctitie and good bearings... hehe
(or just loctite and oil)
PeterVRC is offline Find More Posts by PeterVRC
RCG Plus Member
Old Dec 05, 2012, 01:59 AM
Registered User
Australia, VIC, Melbourne
Joined Nov 2006
11,766 Posts
The Lander 6S 5 blade versus CS10 HET 2W30 numbers:
Sort of sustained, after 20secs approx. (not peaks)

CS10 HET2W30-2200kv 6S 4000Mah 30C 63.7A 19.8V 1260W 1.9Kg

DPS 70mm 2550KV 6S 4000mAH 30C 51.4A 21.8V 1120W 1.95Kg

Exact same battery (recharged for each test).
You can see that the Lander did the same thrust (a bit MORE really) for 140W less power.
12 Amps less.
The voltage drop on the CS10/HET probably shows how much more load it was under, whilst the Lander had a pretty easy job with its load.
Even allowing for a bit of error here or there, the difference is so large it will always still be a very clear win for the Lander. And applies to all low blade count fans versus CS10/12.

The Lander motor is obviously capable.
The HET 2W30 is also a capable CS10 6S motor.
But it is the LOAD difference... FAN... that is the cause of the major part of the result difference

I should have used two Landers in the plane these were tested for (rather than 2 CS10 HET's) as the CS10's, in this aircraft's case, don't even help the sound (jet-like) much at all. So the power 'cost' is not even giving anything else back in any form of sound benefit really! The ducting system just doesn't help that almost at all.

...
Oh.. and the Lander CS10-70....
CS10 Lander 2960-2200kv 6S 4000mAH 30C 64.0A 19.9V 1274W 1.82Kg

Again the same battery, but obviously a bit of motor difference (KV error and/or design) to the HET CS10...... but very much the same area of result.
So those two back each other up, seeing they do give those close numbers with CS10's.
PeterVRC is offline Find More Posts by PeterVRC
RCG Plus Member
Old Dec 05, 2012, 02:18 AM
Registered User
anlucas's Avatar
Greece, Attica, Athens
Joined May 2011
3,553 Posts
Quote:
Originally Posted by PeterVRC View Post
CS10 HET2W30-2200kv 6S 4000Mah 30C 63.7A 19.8V 1260W 1.9Kg
DPS 70mm 2550KV 6S 4000mAH 30C 51.4A 21.8V 1120W 1.95Kg

Exact same battery (recharged for each test).
You can see that the Lander did the same thrust (a bit MORE really) for 140W less power.
12 Amps less.
The voltage drop on the CS10/HET probably shows how much more load it was under, whilst the Lander had a pretty easy job with its load.
Even allowing for a bit of error here or there, the difference is so large it will always still be a very clear win for the Lander. And applies to all low blade count fans versus CS10/12.
This test also shows if a better battery was used the CS10 numbers could go much higher (albeit at more amps/watts).

The battery in theory can deliver 4x30Amps but clearly in practice it can only deliver around 50amps and hold voltage at 22v.

The 2V difference is very significant and I don't know if 2200kv is the best kv to compare with the lander's 2550kv.

Although the results speak and the conclusion is valid, I don't think we can generalise that it will hold true with other motor choices.

I cannot see how the Lander 5blade wins hands down since it most probably would not benefit much by a better battery. I have the same Lander and I get the same thrust results(1.95-2Kg) irrespective of battery.

The specific CS10/HET combo on the other hand would provide much more
thrust with a better battery.

My Lander 10Blade 6S pulls 2.4Kg with a battery that holds 21.5V.
anlucas is offline Find More Posts by anlucas
Reply With Quote
Old Dec 05, 2012, 04:35 AM
Registered User
Australia, VIC, Melbourne
Joined Nov 2006
11,766 Posts
You have only pointed out more info on what shows the CS is less efficient.
"The specific CS10/HET combo on the other hand would provide much more
thrust with a better battery."
That means you are saying that would hold a higher voltage.... Which then must use a total of more power, because more Volts will cause more Amps, meaning a total or more Watts.
It is already using more power... by 140W... to achieve less thrust than the 5 blade.

The issue isn't what a CS10 COULD do... but what it DOES do for X Power. And that is LESS OUTPUT than a low blade count fan.

It is actualy a nice fluke that these three setups I used do have close to the same thrust outputs... thus making it very easy to see and highlight how the CS10 is a measurable amount worse than a low blade count fan.
The 2550kv to 2200kv difference is an expected requirement of a low blade count versus a 10 blade. The lower blade area will be need more RPM to move the same air - which is what it shows. (Not that the exact same amount has to be moved... just the same total thrust, however it does that).

It seems you are thinking of how to prove the CS10 CAN produce more thrust... but that is not the issue. The issue is what it COSTS to make the SAME thrust with a CS10 instead of a low blade count fan.
You are PAYING for its only real benefit of being a QUIETER fan, which then allows the "whoosh" (White Noise) to be heard above "leaf blower noise".
There is no other benefit of using a higher blade count at all.... just to be a quiter fan.
"Faster and more Micro Cuts" of air are much quieter than "Slowerand less Large Chunks" of air.
PeterVRC is offline Find More Posts by PeterVRC
RCG Plus Member
Old Dec 05, 2012, 04:59 AM
Registered User
The43rdHammer's Avatar
United Kingdom
Joined May 2010
382 Posts
More conjecture here as I have no numbers other than power at the moment.

Last night I removed the CS10 fan and replaced it with the 6904 (four blade). Both ran on the same motor (HET 2W-25 2660kv) with the same battery (5S 3000 MaH 40C).

The Wattmeter was reading roughly 1100w for both fans, slightly higher amp draw on the CS10. What was evident though was that the 6904 has noticably more punch. I would consider myself a pureist and have a totally open mind regarding which fan might be better, but I really don't need a thrust tester to be able to tell the difference here. The 6904 on this setup wins hands down.

One thing that does perhaps bias the above results is that this setup may not be optimal for the CS10 as this motor is undoubtedly a better match for the 6904.

I flew the F-4 on the Changesun last weekend, will do so on the 6904 this weekend and hopefully have some video to post.

Caveat emptor: Thrust test was not made on a dedicated thrust meter but by simply by hanging the model by it's nose. 'Tis what know as testing o'natural!
The43rdHammer is offline Find More Posts by The43rdHammer
Reply With Quote
Old Dec 05, 2012, 05:05 AM
Registered User
anlucas's Avatar
Greece, Attica, Athens
Joined May 2011
3,553 Posts
Quote:
Originally Posted by PeterVRC View Post
You have only pointed out more info on what shows the CS is less efficient.
"The specific CS10/HET combo on the other hand would provide much more
thrust with a better battery."
That means you are saying that would hold a higher voltage.... Which then must use a total of more power, because more Volts will cause more Amps, meaning a total or more Watts.
It is already using more power... by 140W... to achieve less thrust than the 5 blade.

The issue isn't what a CS10 COULD do... but what it DOES do for X Power. And that is LESS OUTPUT than a low blade count fan.
I don't think I mentioned the word efficiency anywhere so, indeed we are talking about two different objectives. My intention was not to prove or disprove your theory/tests rather than provide more information from a different angle that could help the casual observer.

Some people in here have provided test results that show the CS10 to be comparable to other fans in terms of efficiency. Your experience is different.

I have been able to get these results in my 4S and 5S models.

In reality I would like to have more motor options for the 10 and 12 blade fans to find the kv/length of can for each application. The motor choices are a but limited now.
anlucas is offline Find More Posts by anlucas
Reply With Quote
Old Dec 05, 2012, 05:24 AM
Life begins at transition
Australia, VIC, Sale
Joined May 2007
3,593 Posts
I think comparing a well-designed, low blade count fan to a "I'm assuming it's been designed?" high blade count fan is a bit of apples/oranges.

Stu's fans outperform a Wemo, yet have more blades?

Likewise, choice of motor will have a huge effect. A Haoye being spun by a Neu will probably do fairly well!
Odysis is offline Find More Posts by Odysis
Reply With Quote
Old Dec 05, 2012, 05:34 AM
Registered User
Australia, VIC, Melbourne
Joined Nov 2006
11,766 Posts
This is the CS10 Lander using a Nano-Tech 65C battery.
I do a number of battery tests across fans, but try to keep comparisons grouped. But also mainly with combo's (motor/fan/battery) that I have decided to use in an actual aircraft I am setting up.

CS10 Lander 2960-2200kv 6S 5000mAH 65C 74.7A 22.32V 1668W 2.14Kg
(It does 1820W peak (79A), for 2.25Kg thrust)
Quite a few of my EDF tests are on my YouTube page:
-- http://www.youtube.com/playlist?list...ature=view_all --

If you were to use that combo in a plane you would be very prone to ending up with motor failure, because you are likely to "over-do" WOT usage and even at the lower sustained numbers the motor gets very hot. Use WOT coming off "rests" and it will be more towards the 1800W area for those runs.
Also any plane with that power would be excessive anyway.... just a fun "Wow! Look at my fast plane!" sort of thing. Fine to do if you want, but thus in those higher failure areas.
30C to 40C is plenty for this combo and "auto limits" the max powers, whilst the battery is still not over-specced and will cope fine. The 4000mAH 30C doesn't even get very warm, which shows it is totally fine doing its lower power job.
PeterVRC is offline Find More Posts by PeterVRC
RCG Plus Member
Last edited by PeterVRC; Dec 05, 2012 at 05:40 AM.
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
New Product Change Sun 12 blade 90mm Flip Flop Electric Ducted Fan Jet Talk 7112 Nov 30, 2014 12:33 PM
New Product Change Sun 120mm and new 10 blade 70mm fans Flip Flop Electric Ducted Fan Jet Talk 131 Apr 27, 2012 08:07 PM
Sold Change Sun electric retracts Flip Flop Aircraft - Electric - Jets (FS/W) 3 May 23, 2011 07:20 AM
Sold Change Sun Electronic retracts w/Lander struts hole digger Aircraft - Electric - Jets (FS/W) 2 May 06, 2011 02:27 PM
Sold Change Sun Electric retracts NIB 75.00 jzuniga Aircraft - Electric - Jets (FS/W) 2 Sep 03, 2010 10:36 AM