Model Forum / Radio Controlled / Air Models / November 2005

OOPS ... messed up the copy and paste for the Wattage motor link. It should
be   http://www.hobbypeople.net/gallery/131480.asp

I'm flying a KMS 31/12 on a sport plane at about 250 sq in and 22 oz, and
it powers the plane quite nicely.  Not quite unlimited vertical, but it's
close.  I'm usually flying it with a 3cell 1550 LiPo.  

Now, for your situation - the KMS would probably outperform the 400, but
it really won't be happy on a 7 cell nicad.  If you can run it on 9
cells, you'll be a lot happier, and a 3 cell LiPo would be better still.  
The Tanic 3 cell 1550 is on sale tomorrow, too, for $50.  The Tanics are
kinda pricey, but they're very good packs.  

So, for your plane, try the KMS 31/12 with a 3 cell 1550 pack, an APC 9x6
slow flyer prop, and a Castle Creations Thunderbird 18 speed control.  I
haven't tried a KMS ESC, but the TBird is from Castle Creations, and I'm
a big fan of theirs.  The Tbird's regular price is $35, which is only $5
more than the super-sale KMS price.  Unfortunately, the Hobby People site
says it's not in stock, so if you want to fly this weekend, you may have
to go with something like the KMS.  

That setup should pull the plane around pretty well, but you won't have
huge vertical with it if you really are coming in at 30+ oz.  Of course,
the KMS is an ounce less than the 400 (ignore the box.  The KMS 31/12 and
31/09 weigh 65 gm each) and the Kokam LiPo would be about 3 oz less than
that Nicad pack.

If the plane comes with a 7" prop, better make sure you have clearance
for a 9".  When I tried an 8" on the KMS, the performance suffered quite
a bit.

One last warning about that KMS - it doesn't come with a real radial
mount.  It has two (or 4?) screws that go into threaded holes in the
backplate, but there's almost no practical way to mount the engine like
that unles you have a radial mount that you got elsewhere.  The
'standard' radial mount that comes with, say, an EssKay or Himaxx
outrunner will fit just fine, and GWSExpert sold me a few radial mount
sets for $5 each, but you'll need something.  

The ungeared cobalt is a complete mismatch.

Its a good motor, but not with a 7x4 stuck on it.

On 8 cells a permax 450 turbo is a far far better animal in that class.

the cobalt needs gears and a lot of amps, Then it really delivers.

...

Hej Forrest

Here you have a lot of links about (DIY) Brushless DC-Motors &
Speedcontrollers for Model-Aircrafts:

Peters LRK Site:
http://www.torcman.de/peterslrk/index_eng.html
http://www.torcman.de/peterslrk/SPEEDY-BL.html

machinedesign.com: Do-it-yourself brushless:
http://www.machinedesign.com/ASP/strArticleID/56118/strSite/MDSite/viewSelectedA
rticle.asp

Citat: "...Authors report good results using 1-mm wire with a polyamide
lacquer coating able to take up to 250°C...efficiencies of around 90% or
better. Typical prop motors generally weigh less than 5 oz and those
built to date produce outputs ranging from 20 W to 2 kW. Some reportedly
run at around 15,000 rpm..."

List of my Super Magnets for Motor Builders:
http://www.engconcepts.net/List_Of_Motor_Magnets.asp

DIY Controller Schematic.
It is at www.bldc.de but is poor quality...I have redrawn it more
clearly. The source is also posted at this site but you need to register
first:
http://www.rcgroups.com/forums/showthread.php?t=181247

Tornado N-Kanal:
http://www.bldc.de/
"...
Aufgrund der Schwierigkeiten, die wir mit den verwendeten Treibern
(TC4427) hatten, haben wir nun einen reinen N-Kanal Steller entworfen.
Dieser basiert auf dem Atmel Mega8 Mikrocontroller. Als Treiber kommen
hier IR2102 zur Anwendung.
..."

brushless LRK motor:
http://hjem.get2net.dk/Modelfly_Lars_Kroll/lrk8.htm
http://www.aerodesign.de/peter/2001/LRK350/SPEEDY-BL.html
http://www.speedy-bl.com/electr-e.htm
http://www.speedy-bl.com/schema-e.htm

Simpel: Speedcontroller 2:
http://www.speedy-bl.com/minireg2-e.htm
Speed Controller Speedy-2 with Microcontroller PIC16F84-04/SO:
http://www.speedy-bl.com/spdy1684-e.htm

Speedy-BL - Drehzahlsteller für bürstenlose Modell-Motoren:
http://www.geocities.com/SouthBeach/Port/1592/speedybl.htm

http://www.ele.tut.fi/~peni/speedy_sprint/speedy_sprint.html

http://mitglied.lycos.de/brushless/
http://home.versanet.de/~b-konze/
http://gb97816.bei.t-online.de/
http://www.rcgroups.com/forums/showthread.php?s=&threadid=140454

http://www.industrialnewsroom.com/fullstory/30087

http://www.radetzki.info/html/sbl_micro.html

seven diy brushless ESC designs:
http://www.rcgroups.com/forums/showthread.php?s=&threadid=140454
http://www.rcgroups.com/forums/showthread.php?s=&threadid=157193

Brushless Motor:
http://wiki.oliverbetz.de/owiki.php/BrushlessMotor

A Brushless Motor You Can Build:
http://www.rcmicroflight.com/library/motor1.asp

regards, Glenn