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Feb 28, 2010, 03:42 PM
Registered User
Discussion

RC Lander 90MM design flaw?


I purchased a LEDF90-1A16 90mmm RC Lander fan unit for a scratch built U-2. Very nice piece of hardware, but two very weird features (see pics). As I understand their concept, there are grooves cut into the circumference around the fan so they can have a zero gap fan to shroud interface (OK). Problem is there is what can only be described as a sharp trip on the inlet lip. This detail at the lead in to the fan will turbulate the flow at the wall/ blade tip and negate any affect having no gap might have added. The second feature is a .2" sharp step directly after the fan instead of the typical gradual increase in area downstream.

In my application I'm sure it will work fine, but Lander should consider changing the design. At a bare minimum they might get a few more % thrust that they could advertise. I also wonder if this is the discrepancy I've seen in many posts about the actual thrust vs what is shown on the You-tube videos. Do any of you have the other versions of their 90mm fan and do they have these goofy details in the shroud?
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Feb 28, 2010, 04:18 PM
My project: FAIREY DELTA 1
Erik v. Schaik's Avatar
IMHO It's an unfinished shroud. For milling one needs a teethed cutter to remove volume and a normal cutter for precision tolerance. The Shroud needs to be volume milled from 2 sides and finish milled after that . If they pre mill and finish one side and the other side after that you'd end up with an oval shroud. There are at least 3 clamp repositions to make this shroud and they forgot the last one. You are luckey the rotor gap is so big your rotor does fit in this unfinished dia.

go cheap,buy twice
Mar 02, 2010, 07:12 AM
DominicM
DominicM's Avatar
I didn't think they were cheap compared to a wemo...
Mar 02, 2010, 09:15 AM
EDF all the way!
bruff's Avatar
My inlet is smooth, no sharp edges.
Bob
Mar 02, 2010, 09:19 AM
Registered User
Quote:
Originally Posted by ditchit
I didn't think they were cheap compared to a wemo...
Remains to be seen. It was 150$. It seems like roughly the same or less than wemo if i had the time to trudge through a thousand threads to find a good enough 6S 6lb thrust motor setup.

More on the fan: It's a new version of their LEDF-90 series fan. It looks like the motor housing and everthing up to the stators is the same, but the fan shroud directly around the fan and the rotor are different. The rotor is 85mm not 90 and all of that goofy inlet stuff seems to be the change. The other versions of their 90mm fan look like no kidding 90mm and they have nice inlet lips and no step after the fan. The videos on line show them running both versions at about the same thrust. I'm skeptical though. The older "nice inlet" version is shown powered off of 6s packs while this new version is run off of a power supply. I've used power supplies enough to know you set the amps/ volts you want and go test. If this motor/ fan/ shroud geom can't pull 85amps then the online test is bunk. I'm inclined to send this thing back and get the older version. Thoughts??
Mar 02, 2010, 09:38 AM
Pro Hoarder
turbonut's Avatar
A friend of my purchase one also! I did notice what you have posted! also it is not a 90mm as advertised it is 85mm..oops!
Scott
Mar 02, 2010, 09:41 AM
My project: FAIREY DELTA 1
Erik v. Schaik's Avatar
What power range are you looking for?
Mar 02, 2010, 10:14 AM
efflux RC's Avatar
Quote:
Originally Posted by plugandplay
But theirs works and yours dosen't.
Remind me to NEVER buy from any vendor who would make a post like yours above. Bashing a competitor's product and promoting your own. Very unprofessional.
I didn't bash anything.
Our EDFs work fine. We have run our 70mm rotor to 1250 watts. We now have a balancer and will see how much we can increase that.
We now offer the Skyworld EDF kits only. Add your own motor, or use one of our ARC or Mega motors. Sorry, it would'nt be plug and play.

You sure are dogmatic for your 6th post. Welcome to RCG.
Latest blog entry: Updated blog May 2017
Mar 02, 2010, 10:29 AM
Registered User
Quote:
Originally Posted by plugandplay
but theirs works and yours dosen't.
Remind me to never buy from any vendor who would make a post like yours above. Bashing a competitor's product and promoting your own. Very unprofessional.
. . .
Last edited by Socomon; Jun 28, 2010 at 07:26 PM.
Mar 02, 2010, 10:37 AM
Registered User
Quote:
Originally Posted by Erik v. Schaik
What power range are you looking for?
I'm after 6lbs of thrust in bursts. 4lbs continuous. The RC lander may get me there, but I've got a lot of reasons to question that it will actually produce the book #'s. FWIW it's got a 85mm fan and it has the exact same #'s as their no kidding 90mm fan. That plus all of the weird aero features doesn't pass the sniff test. I'm really worried I've got a 4 lb-thrust fan not a 6 lb-thrust fan as advertised.

I think the old version may work fine. It's the one that has many videos on you-tube and does have a nice duct.
Matt
Mar 02, 2010, 10:37 AM
another MONSTER ?
One Six Right's Avatar
oops wrong thread
Mar 02, 2010, 10:45 AM
Registered User
. . .
Last edited by Socomon; Jul 12, 2010 at 09:01 AM.
Mar 02, 2010, 11:05 AM
My project: FAIREY DELTA 1
Erik v. Schaik's Avatar
Quote:
Originally Posted by N178EZ
I'm after 6lbs of thrust in bursts. 4lbs continuous. Matt
for 6s, low/mid range power:
post1-6: 1600w/2.8kg
https://www.rcgroups.com/forums/show....php?t=1170649
1400W:
https://www.rcgroups.com/forums/show...postcount=1094
1700W
https://www.rcgroups.com/forums/show...=59940&page=43

the 1700w link was quite a search because Herb used a smaller fan initially
I think you'r good enough with a midi and the $19.95 turnegy

All the best,
Erik
Mar 02, 2010, 11:35 AM
efflux RC's Avatar
Quote:
Originally Posted by Socomon
Stop and consider the source of this post for a moment. "plugandplay" is Mr. Curtis Mattikow of EasyTiger models.
I don't keep up with the banned and relabeled users. (except Gene )
But I've read plenty about the name.

It was a pleasure meeting him.
Latest blog entry: Updated blog May 2017


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