Espritmodel.com Telemetry Radio
Reply
Thread Tools
Old Oct 23, 2002, 03:54 PM
York Electronics
Gary Warner's Avatar
Dallas Tx USA
Joined Apr 1999
2,505 Posts
What motor for Eco Fan (older fan)

Ok, I caved and bought several of these close-out Eco fans from HL. I couldn't resist at $29.00 each. The fan calls for a 20 turn car motor (540 type), but todays motors don't use this turn anymore. The selection of motors made and distributed for the car-guys is mind boggling.

What turn car motor works well with this fan?

I expect about 250 watts on 7 cells.

On a pair of Speed 600 Graupner fans I have (also discontinued - boy can I pick'em or what ) I use 14x4 turn motors and they are just right for these fans. But, I can't find any 14x4 motors anymore. . Any ideas short of BL motors or buying one of everything to try them out?
Gary Warner is offline Find More Posts by Gary Warner
Last edited by Gary Warner; Oct 23, 2002 at 03:57 PM.
Reply With Quote
Sign up now
to remove ads between posts
Old Oct 23, 2002, 06:41 PM
Registered User
St. Mary, Maryland, United States
Joined Dec 1996
8,189 Posts
I used to use an Astro "Turbo 05" which is really a 6 turn Astro cobalt 035. Kv is about 3225, I would use 8 cells which draws right around 40 amps. Two of these would ROG a 7 pound 550 square inch twin from grass with the ailerons drooped as flaps. 40 amps is a bit of an overload though so you want to fly at partial throttle a lot once you are off the ground.
Chris True is offline Find More Posts by Chris True
Reply With Quote
Old Oct 23, 2002, 06:55 PM
2014 EDF JET JAM We be Jamming
Kevin Cox's Avatar
St. Louis Intl, Missouri, United States
Joined Jan 1997
6,754 Posts
I used the Cermark Cobalt 05 in my Plenum AF http://wemotec.com/englisch/customer...m3.jpg*449+200

It required 10 cells and I think the current draw was about 42-45 amps (lots of sparks ) But worked well....how many years ago was that twin you made Chris? Seems like a long time ago!
Kevin Cox is offline Find More Posts by Kevin Cox
Reply With Quote
Old Oct 24, 2002, 11:55 AM
Registered User
St. Mary, Maryland, United States
Joined Dec 1996
8,189 Posts
Hmm, good question! I flew it at KRC in Allentown, think it was the last year KRC took place. That would be 3 NEAT's ago + 1 year without KRC + 1 so 4 years - 5 years?

It is a light year technology wise . 1250's were brand new now replaced by CP-1700's and the Midi / HW series either didn't exist or were just annouced at the time. Brushless motors were rarely in common use etc.
Chris True is offline Find More Posts by Chris True
Reply With Quote
Old Oct 24, 2002, 12:23 PM
York Electronics
Gary Warner's Avatar
Dallas Tx USA
Joined Apr 1999
2,505 Posts
Thanks Guys

Chris,

That's cool! 7 pounds and off grass. That's about 650 watts (under the cardinal 100 watts per pound for ROG). I like the idea of Astro motors in the fans for long life. Still, the $$$ causes me to shutter.

I was looking for 500 watts on 4.5 pounds and will be very happy if it just ROG's from pavement. I haven't yet decided on the airframe yet, but I was considering the Westwind (boxy corp. jet). With 53 ounces just for motors and batteries this only leaves 19 ounces for everything else. I know, wishful thinking, but I'm good a building very light.

Kevin,

It's encouraging to see a 60 ounce plane fly on one of these fans. I guess you are getting about 30 ounces of thrust. I forgot about the Cermark motors. Maybe I'll check into them. Thanks.

Update: I went to the LHS today and got a couple of 13x2 motors for $39.95 each. I'll get one in a fan tonight. Keeping fingers crossed.

Last night I set up a fan on a new cheap can 05 ($1.95 surplus). I was quite surprised to see 250 watts at 10 volts and 35 amps. Efflux off the 70MPH scale of mind meter. If it were not for the cheap brushes, this would work.

Also, wow, it sure takes a lot of work to get these fans to run true.

I had to trim the outer faces of the blade mounts so as not to interfere with the spinner (was causing it to run off center by lifting the spinner off it's seat).

I had to trim (grind) down the end of the adaptor shaft as inner post inside spinner was contacting it before the spinner was fully seated.

I had to balance rotor assembly with 4 pieces of clear tape added to the back of two blades.

I had to remove “flash” from all leading and trailing edges on blades.

I had to replace the spinner screw (made off-center).

I had to manufacture a "true" rod to use with magnetic balancer from an old armature assembly (original one had off-center points on the ends of the rod and was slightly bent (was new - never used).

I had to true the back face of the spinner to perfect on-center running (indexed the spinner), etc., etc...

Had to add a very small piece of duct tape inside spinner for final “exact” balance.

It took 6 hours, but I have a very smooth running fan now. About the only thing made with exacting tolerances is the shaft adaptors on-center trueness and the size of the motor input shaft bore.
Gary Warner is offline Find More Posts by Gary Warner
Reply With Quote
Old Oct 24, 2002, 01:10 PM
Registered User
St. Mary, Maryland, United States
Joined Dec 1996
8,189 Posts
Re: Thanks Guys

Quote:
Originally posted by Gary Warner
Chris,

That's cool! 7 pounds and off grass. That's about 650 watts (under the cardinal 100 watts per pound for ROG). I like the idea of Astro motors in the fans for long life. Still, the $$$ causes me to shutter.
Yup, and it wasn't putting green grass either. A big part of that success I think was the airfoil which worked really well with flaperons drooped 30 degrees or so. The airfoil was an MH-45 and the ailerons were about 2 inches wide. Without flaps it needed pavement for enough speed buildup.
Chris True is offline Find More Posts by Chris True
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Question Mini Fan and 3s: What motor for 600+ watts? ChrisAttebery Electric Ducted Fan Jet Talk 20 May 16, 2006 10:27 PM
What motor for Midi fan? FHHOBBIES Electric Ducted Fan Jet Talk 2 Feb 14, 2005 09:21 PM
What motor for about 600watts on 3s for a Midi fan? YZYgold Electric Ducted Fan Jet Talk 0 Dec 12, 2004 07:24 AM
What motor for Tanic 6S and 609 fan? sblack Electric Ducted Fan Jet Talk 5 May 27, 2004 12:01 PM
What model motor for this fan? isaac-bees Electric Ducted Fan Jet Talk 3 Aug 19, 2002 06:12 AM