HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Aug 19, 2012, 05:44 PM
speedin n da weeds :)
sikky's Avatar
USA, AZ, Glendale
Joined Feb 2008
595 Posts
Are the blades the same as the haoye 7 blade fans?
sikky is offline Find More Posts by sikky
Reply With Quote
Sign up now
to remove ads between posts
Old Aug 19, 2012, 06:16 PM
Extreme CNC Alloy EDF
Extreme_RC's Avatar
Australia
Joined Mar 2006
11,537 Posts
I ran the wemo up to 3.6kg thrust to see how far it could go, used a 2858-1 on 8s, hit around 3200w from memory, but not enough clearance and second run it blew. Never bothered to try it again as the 3.17 shafts at the time were not replaceable! But with the new 1W40 and 7s it could be interesting. Soon as the new housings are in I want to test this out again.
Extreme_RC is offline Find More Posts by Extreme_RC
Reply With Quote
Old Aug 19, 2012, 09:17 PM
Registered User
United States, GA, Alpharetta
Joined Feb 2009
403 Posts
Quote:
Originally Posted by Extreme_RC View Post
I ran the wemo up to 3.6kg thrust to see how far it could go, used a 2858-1 on 8s, hit around 3200w from memory, but not enough clearance and second run it blew. Never bothered to try it again as the 3.17 shafts at the time were not replaceable! But with the new 1W40 and 7s it could be interesting. Soon as the new housings are in I want to test this out again.
The 4mm shaft ARC 2858-1 aren't replaceable either. The magnet carrier/rotor is one piece machined steel.
rfodor is offline Find More Posts by rfodor
Reply With Quote
Old Aug 19, 2012, 09:50 PM
Registered User
United States, OH, Cuyahoga Falls
Joined Apr 2006
224 Posts
I have a typhoon 2w20, can I use it with the change sun 10 blades? Am I going to fry my motor?

Thanks,

Le fou
le fou is offline Find More Posts by le fou
Reply With Quote
Old Aug 19, 2012, 10:14 PM
Extreme CNC Alloy EDF
Extreme_RC's Avatar
Australia
Joined Mar 2006
11,537 Posts
I thought the magnet carriers were alloy with the shaft pressed and bonded in?
Extreme_RC is offline Find More Posts by Extreme_RC
Reply With Quote
Old Aug 19, 2012, 10:46 PM
Registered User
Australia, VIC, Melbourne
Joined Nov 2006
10,910 Posts
Le Fou, I assume you mean only using 4S? (higher volts is too many RPM that it will attempt to do - and fail, lol)
And even at 4S it would be under heavy duress I expect, so I would really think it is a 3S motor for the CS10.
PeterVRC is offline Find More Posts by PeterVRC
RCG Plus Member
Latest blog entry: FPV Cameras & fixed or pan/tilt
Reply With Quote
Old Aug 19, 2012, 10:52 PM
Registered User
Joined Oct 2009
1,050 Posts
Quote:
Originally Posted by le fou View Post
I have a typhoon 2w20, can I use it with the change sun 10 blades? Am I going to fry my motor?

Thanks,

Le fou
Its better to use a high torque, rather than high rpm motor for CS-10, on 3S you should be safe, but it wont make much thrust..
nighthawk0077 is offline Find More Posts by nighthawk0077
Reply With Quote
Old Aug 20, 2012, 03:29 AM
John
jk671's Avatar
United States, NV, Las Vegas
Joined Mar 2011
436 Posts
Hey Mark,
Thanks for getting those units out to me! Here's what they're going in to!

Freewing SU-35 what's in the box and pre-build (5 min 53 sec)
jk671 is offline Find More Posts by jk671
Reply With Quote
Old Aug 20, 2012, 03:32 AM
Big gov never Works
St. Martin's Avatar
Skunk Water, Rhode Island
Joined Jul 2002
12,322 Posts
Quote:
Originally Posted by le fou View Post
I have a typhoon 2w20, can I use it with the change sun 10 blades? Am I going to fry my motor?

Thanks,

Le fou
Depends on how many watts you need. As noted, it will only last on a 3s. Most users on this thread are shooting for 1000W+. I only go for high watt numbers when powering 90mm LIGHT Wt jets with 70mm fans. So, see this post: http://www.rcgroups.com/forums/showp...postcount=4776

If you use the fan, in what used to be mid power range, even the little HET 4W or Mega 16/15/4 (2250Kv) will work. Since I assembled this fan, I have ran it up 6 times on 4s-2200 40c packs. An it has more than enough thrust for an RBC Skyhawk, that will recieve it. But, I like seeing a scale jet fly realistically, not be a blur.

Fuzz
St. Martin is offline Find More Posts by St. Martin
Reply With Quote
Old Aug 20, 2012, 05:35 AM
Extreme CNC Alloy EDF
Extreme_RC's Avatar
Australia
Joined Mar 2006
11,537 Posts
Quote:
Originally Posted by jk671 View Post
Hey Mark,
Thanks for getting those units out to me! Here's what they're going in to!
Sweeeet! Nice finish on it, is that an LX model? Its pretty big, and gonna have some grunt too! Fans will pull 70A easy with the packs, and dont worry about the ESC's I run that model at 100A constant on 6s with a 90mm fan and run 7 servos off the built in BEC too, no issues at all, real tough speedies.
Extreme_RC is offline Find More Posts by Extreme_RC
Reply With Quote
Old Aug 20, 2012, 05:42 AM
John
jk671's Avatar
United States, NV, Las Vegas
Joined Mar 2011
436 Posts
Quote:
Originally Posted by Extreme_RC View Post
Sweeeet! Nice finish on it, is that an LX model? Its pretty big, and gonna have some grunt too! Fans will pull 70A easy with the packs, and dont worry about the ESC's I run that model at 100A constant on 6s with a 90mm fan and run 7 servos off the built in BEC too, no issues at all, real tough speedies.
Freewing SU-35
jk671 is offline Find More Posts by jk671
Reply With Quote
Old Aug 20, 2012, 06:22 AM
Registered User
Australia, VIC, Melbourne
Joined Nov 2006
10,910 Posts
My pair of 2W30/CS10 in the Su-35 are only pulling 110Amps total. The limitation must be the ducting structure, because on a Zippy 6S 5800mAH 30C (174Amp theoretical ability) they each do 70A for 2.1Kg thrust on the bench.
This is typical to what happens in-plane, for most aircraft.... quite a lot of loss due to the ducting design.
4.2Kg on the bench, but only 3.1Kg or so in the plane.

When testing in a Durafly Vampire, running without a hatch on - which makes for a huge total static test inlet ability - it hardly helps the CS10 gain any thrust. As much as it is a 'messy shape' in total, for the inlet, you could say that it is like having some HUGE inlet that still 'tapers' into a somewhat nicer flow path as it gets nearer to the fan. So it should not be the same loss problem, and reason, like using a fan with no inlet lip. It won't be 'perfect' like a nice nacelle could give, but it should still be quite good.
So this suggests the inlet side is not the problem in most typical cases.
And thus not in the Su either.
It will be the exhaust side causing the main problem.
PeterVRC is offline Find More Posts by PeterVRC
RCG Plus Member
Latest blog entry: FPV Cameras & fixed or pan/tilt
Reply With Quote
Old Aug 20, 2012, 07:00 AM
Extreme CNC Alloy EDF
Extreme_RC's Avatar
Australia
Joined Mar 2006
11,537 Posts
Quote:
Originally Posted by PeterVRC View Post
My pair of 2W30/CS10 in the Su-35 are only pulling 110Amps total. The limitation must be the ducting structure, because on a Zippy 6S 5800mAH 30C (174Amp theoretical ability) they each do 70A for 2.1Kg thrust on the bench.
This is typical to what happens in-plane, for most aircraft.... quite a lot of loss due to the ducting design.
4.2Kg on the bench, but only 3.1Kg or so in the plane.

When testing in a Durafly Vampire, running without a hatch on - which makes for a huge total static test inlet ability - it hardly helps the CS10 gain any thrust. As much as it is a 'messy shape' in total, for the inlet, you could say that it is like having some HUGE inlet that still 'tapers' into a somewhat nicer flow path as it gets nearer to the fan. So it should not be the same loss problem, and reason, like using a fan with no inlet lip. It won't be 'perfect' like a nice nacelle could give, but it should still be quite good.
So this suggests the inlet side is not the problem in most typical cases.
And thus not in the Su either.
It will be the exhaust side causing the main problem.
First up a fan on the bench running alone cannot be compared to a pair running on the same battery. The fans need to be run individually in the airframe in order to ascertain any ducting losses, and ducting losses come from the inlet side.

Amp draw is not much use without the voltage, 110A at what voltage? The simple figure of voltage will show us whether the battery likes running at 110A. Knowing how one single fan runs both inside and outside the fuse is the important information.

The vampire; take the canopy off and there is a HUGE difference in the available power, my vampire with 4s 10 blade setup and stock ducting would not hold itself up with the canopy on, removed and it climbs out of my hand strongly. By opening up the inlets as much as possible and removing 3 of the bars in the cheater I have managed to get it to climb out of my hand just, its still starving a little but infinitely better than it was.

The inlet is most always the issue, no air in = no air out, I have experimented with inlet size and cheater holes on many models, and the same results show in every case.
Extreme_RC is offline Find More Posts by Extreme_RC
Reply With Quote
Old Aug 20, 2012, 07:51 AM
Registered User
United States, GA, Alpharetta
Joined Feb 2009
403 Posts
Quote:
Originally Posted by Extreme_RC View Post
I thought the magnet carriers were alloy with the shaft pressed and bonded in?
I bent the shaft on my 4mm 2858-1 and thought oh well I'll just replace it. When I opened up the motor and pulled the rotor I found a solid piece of machined steel with the magnets glued on (I asume) and wrapped with fiber glass. No way to replace just the shaft.... unlike the Neu 1112/1Y and RC Lander 4000KV that I have replaced the shafts in. Apparently you have to replace the complete rotor assembly on the ARC motor - if you can find one. I was able to straighten the shaft in my drill press with a dial indicator and it is working in a CS10/Lander shroud but I worry about it being weakened.

I would have thought that the magnet carrier would have to be nonmagnetic and maybe it is. I can't see the base of the magnets through the fiber glass wrapping. Mu metal would make an excellent magnetic shield and could be wrapped around the steel.... I just can't tell.
rfodor is offline Find More Posts by rfodor
Reply With Quote
Old Aug 20, 2012, 07:56 AM
Registered User
Australia, VIC, Melbourne
Joined Nov 2006
10,910 Posts
I measured the Vampire on scales. 100g more thrust for no hatch. 2A more current draw.
A pathetic change for the huge area/volume addition.
1030g thrust in plane. 1.35g out of plane. Just 100g 'regain' shows it is not dropping off due to the inlet side.
I found the same in the EPO F-15.... opening out the EXHAUST side gave huge gains to the CS10. It is not quite the same situation, but a lot of it is still just from rear impedance - not the flow path/pattern.

If you have a much more capable combo, then it would need more airflow and then the hatch removal would show more difference. But not many people are even running 5S, so not many would be using combo's that do over 1.35Kg on the bench anyway. So it is more useful info to the majority to see lower power region results.

Same for the Su... which I had mentioned EDF's results in and out of the plane.
2 batteries in parallel don't help the in-plane result... again, just 100g sort of area for the gain of the two. So that shows my single battery is close enough to capable to drive both on its own just fine. (174 Amp capable). I did this to test whether it would be worthwhile spending a LOT more money on higher C batteries.
But also, a 'better' battery, with lower IR, would do some amount better... but that is irrevant to this topic. Because the test using dual batteries shows how little change there is.
4.2Kg becomes 3.1KG in the plane, so the issue is IN the plane - not the power source.
It has very long ducting, and not enough area for CS10's either. And you can't fix that - or not to any overly useful degree. Due to the TV design at the rear.

One weird thing I have been noting across all tests of various aircraft, is that the notable loss seen from bench to aircraft - which must be due to airflow (inlet or exhaust) - does not actually waste power. You just get, and use, less.... you get less thrust, but use less Amps. Not far off being a linear relationship - so at least it is not burning power for nothing, on the lower output cases. And often it ends up that the thrust result is a more useful 'forced limitation' on you - you are forced to have less thrust, but a sensible amount that is more suited to the typical model aircraft's weight seen, and you get the bonus of forced lower current draw with that.
It is much like there is some automatic regulation of "This scale model would have this amount of weight and thrust, so the limitations of ducting etc will just make this end result be what occurs".

And it is only people that want 'excessive' thrust that need to head to more costly - in motor, battery, ducting solutions - to 'beat' that 'automatic limiting' and have to pay a lot in current then. Of course useful if you could improve the ducting, to make it easier on the combo than having to feed it with power, but often you can't do a lot about that.
The Su-35 is a case that just needs 'more power thrown at it' to beat the ducting shortfalls. You can't beat, or remove (easily), the TV exhaust narrowing. But I would think that a better suited fan system - one that runs more off high efflux speed than volume - would be the way to improve it easier. Very high speed 3 blade fan? I have never tried tests on those.
PeterVRC is offline Find More Posts by PeterVRC
RCG Plus Member
Last edited by PeterVRC; Aug 20, 2012 at 08:01 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 7081 Jul 28, 2014 08:25 AM
New Product Change Sun 120mm and new 10 blade 70mm fans Flip Flop Electric Ducted Fan Jet Talk 131 Apr 27, 2012 07:07 PM
Sold Change Sun electric retracts Flip Flop Aircraft - Electric - Jets (FS/W) 3 May 23, 2011 06:20 AM
Sold Change Sun Electronic retracts w/Lander struts hole digger Aircraft - Electric - Jets (FS/W) 2 May 06, 2011 01:27 PM
Sold Change Sun Electric retracts NIB 75.00 jzuniga Aircraft - Electric - Jets (FS/W) 2 Sep 03, 2010 09:36 AM