HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Sep 10, 2001, 11:40 AM
Electriaddict
dorysch1's Avatar
Melville Saskatchewan Canada
Joined Mar 2001
1,579 Posts
spinner or not

spinner or no spinner? I am in the process of building a new duct\fuse for my tutor should I eliminate the spinner on the rotor ?
dorysch1 is offline Find More Posts by dorysch1
Reply With Quote
Sign up now
to remove ads between posts
Old Sep 10, 2001, 04:41 PM
EDF Head
Haldor's Avatar
Stavanger, Norway
Joined Feb 2000
7,999 Posts
Only if the spinner represent a problem for you. There must be some loss without it but to what extent isnt sure. Scott Black flies hit F86 without and it dont appear to miss it. I guess YMMV.

So its flying now - great!
-Haldor
Haldor is offline Find More Posts by Haldor
Reply With Quote
Old Sep 10, 2001, 04:43 PM
Use The Force Jim
Jim Walker's Avatar
Las Cruces, NM USA
Joined Jul 2001
2,340 Posts
I'm no expert on flow dynamics and I'm new to EDF, but from what I've read so far on this forum, everything that smooths airflow through the duct is very important.

Without the spinner, air will have to change direction very suddenly as it hits the hub face vs. flowing smoothly around the spinner into the fan blades.

I've learned that small things like this can take a huge toll on fan efficiency. Just my .02 worth, by all means get a second opinion....

Jim
Jim Walker is offline Find More Posts by Jim Walker
Reply With Quote
Old Sep 10, 2001, 05:12 PM
Electriaddict
dorysch1's Avatar
Melville Saskatchewan Canada
Joined Mar 2001
1,579 Posts
I was thinking of making a tubular director inside the ducting to direct air away from the hub? or am I just wasting time and server space heheeheh
dorysch1 is offline Find More Posts by dorysch1
Reply With Quote
Old Sep 10, 2001, 08:43 PM
2014 EDF JET JAM We be Jamming
Kevin Cox's Avatar
St. Louis Intl, Missouri, United States
Joined Jan 1997
6,728 Posts
I also fly without a spinner. You could balance it but it always seem to run smoother without it and at a little more RPMs so did I win or lose? It flys just as fast and makes less noise. I'm happy
Kevin Cox is offline Find More Posts by Kevin Cox
Reply With Quote
Old Sep 13, 2001, 06:56 PM
Scott Black, Montreal
sblack's Avatar
montreal quebec Canada
Joined Sep 1999
1,254 Posts
I fly mine with no spinner (HW609 fan). It does not seem to be nearly as critical as the inlet lip. Maybe I am losing 1 or 2% eff. but I can't notice it. I just couldn't get the darn thing to run smoothly so I took it off. Vibration will also cost you power.

sb
sblack is offline Find More Posts by sblack
Reply With Quote
Old Sep 14, 2001, 10:03 AM
Electriaddict
dorysch1's Avatar
Melville Saskatchewan Canada
Joined Mar 2001
1,579 Posts
that will be more weight I can shed Thanks ! hopefully I can get it up again (the plane that is) before it snows here I want to build something to put my speed600 motor in to fly around in the winter not sure what though
dorysch1 is offline Find More Posts by dorysch1
Reply With Quote
Old Sep 14, 2001, 01:29 PM
Lithium Member
Herb's Avatar
Irvine, Calif USA
Joined Feb 1999
12,015 Posts
My experience is that it depends on the model, and in particular on the inlet ducting. If the airflow has already a slight turbulence at and around the spinner location, it won't matter much whether it's on or off. It seems the air will create its own spinner... I was quite astonished on some of my earlier models to notice the absence of any detectable effect when you took the spinner off. If the ducting is really straight & smooth I have noticed though some significant changes in sound when you take the spinner off, ie increased turbulence.

If you do have the time and patience, I would suggest though to painstakingly balance the prop and spinner, it's worth the effort,

http://aeneas.ps.uci.edu/edf/fan/balancer_1.jpg

One thing that seems to have very little effect (around less than 1/2 oz of st thrust in a HW-609) is the streamlined carbon fiber cone aft of the motor,

http://aeneas.ps.uci.edu/edf/mig17/p3010006.jpg
Herb is offline Find More Posts by Herb
Last edited by Herb; Sep 14, 2001 at 01:34 PM.
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Mini480 to spinner or not to spinner oilman Electric Ducted Fan Jet Talk 8 Sep 10, 2004 03:39 AM
Kyosho fan spinner? Need or not? kwan Electric Ducted Fan Jet Talk 4 Oct 02, 2001 05:30 AM
gear drive or not? sms Parkflyers 4 Jul 12, 2001 02:11 PM
Speed 280BB - direct drive or not? Tyson Electric Plane Talk 9 Jun 04, 2001 06:12 AM
P-40 Warhawk FLY or NOT Cosmic Shane Parkflyers 0 May 17, 2001 12:54 AM