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<DIV
style="FONT-WEIGHT: normal; FONT-SIZE: 12pt; COLOR: #000000; FONT-FAMILY: Lucida Sans">
<DIV>George</DIV>
<DIV> </DIV>
<DIV>It's kind of a long story, but I know a guy that designs/builds props for
tug boats.. I got the corkscrew prop idea from him. The whole
idea</DIV>
<DIV>behind it is to force the air to the center of the backplate.
The tapered spokes made it a lot easier to help accomplish the shape.
It's</DIV>
<DIV>just been an experiment to see if it would work. I haven't done any
sort of elaborate testing. I have put it on a drill motor and spun
it. It definitely moves air. I also put it on my magnetic balancer
outside in a breeze, and it spun right up on its own. The whole problem,
in my opinion, is that there is a lot of resistance to airflow within the motor
itself. As it spins, I'm sure it creates a sort of vortex within, and
makes </DIV>
<DIV>it resistant to internal airflow. Thus, the need for creating a high
pressure area in front , and forcing the air through.</DIV>
<DIV>The only other thing that I've been thinking about doing is to form a
tunnel around the motor, and force feed the air through it via the cheek</DIV>
<DIV>cowls. But, right now, I'm thinking it would be much easier to
just get the EVO motor. I could use the extra power... lol</DIV>
<DIV>Actually the standard 30-10 has plenty of power, but in the higher winds,
I'm really pushing the motor to its limits. The extra few hundred rpms and
the ability to turn a higher pitch prop with the EVO would be very
beneficial.</DIV>
<DIV> </DIV>
<DIV>Rex</DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV style="FONT: 10pt arial"><B>From:</B> <A title=mailto:geobet@gis.net
href="mailto:geobet@gis.net">george w. kennie</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=mailto:nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">NSRCA Mailing List</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Sunday, December 17, 2006 10:18
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion] Cooling
outrunners</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>Rex,</FONT></DIV>
<DIV><FONT face=Arial size=2>Sounds similar to a small outrunner that I have
in which the cooling holes in the end-bell of the can are drilled at a 45
degee angle in order to scoop some air into the core of the motor.
</FONT></DIV>
<DIV><FONT face=Arial size=2>The spinner fan-blade/vane thing probably has a
cross-over point where the force generated by the full compliment of vanes is
offset by the larger holes realized by removing</FONT></DIV>
<DIV><FONT face=Arial size=2>
spokes. Of course this could be
bench measured by run-testing the two variations blowing against a spring
loaded sail positioned behind the motor and recording the deflection
angle. </FONT></DIV>
<DIV><FONT face=Arial size=2>G.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=mailto:trexlesh@msn.com href="mailto:trexlesh@msn.com">Rex
LESHER</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=mailto:nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">NSRCA Mailing List</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Sunday, December 17, 2006 12:24
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion] Cooling
outrunners</DIV>
<DIV><BR></DIV><!--[gte IE 5]><?xml:namespace prefix="v" /><?xml:namespace prefix="o" /><![endif]-->
<DIV
style="FONT-WEIGHT: normal; FONT-SIZE: 12pt; COLOR: #000000; FONT-FAMILY: Lucida Sans">
<DIV>Wayne</DIV>
<DIV> </DIV>
<DIV>Take a look at the D8 website, electrics link.... It has photos
of my experiment. I actually did more than just shaping like a
prop. I actually carved the spokes into a curve on the back side,
similar to the prop on a tug boat. The curved spoke is placed "just
so" over the openings</DIV>
<DIV>in the motor. The cupped portion of the spoke forces air directly
into the motor. The curve in the carved portion in the spoke is
intended to force the air towards the hub by trapping the air further
out on the spoke first. The spinner is louvered, somewhat like a
squirrel cage fan.</DIV>
<DIV>The intention of the louver is to "chop" the air and force feed it into
the spinner, creating a high pressure area that will feed air to the prop
shaped</DIV>
<DIV>backplate. To be honest, after doing all this
work, I was somewhat disappointed with the results. Turned out,
that I didn't have enough cooling</DIV>
<DIV>exhaust outlet area in the aft fuselage. After I pretty much
doubled that opening, all my cooling problems went away. This summer
will tell for </DIV>
<DIV>sure as to wether or not it works as well as intended. Last
summer was spent actually getting to this point....</DIV>
<DIV>I'm contemplating removing every other spoke on the back plate, but as
I said, I'm going to wait and see how my temps are running as the summer
heat gets here. Like Dave, I'm concerned with removing too much
material. If the spokes are left "stock", it's not a problem.
But, with as much material as I have removed, there might be a
concern. I'm guessing that it would be ok. I use a nylon 10-32
bolt to hold the spinner to the</DIV>
<DIV>adapter, and it's just snugged up, so there isn't much pressure against
the backplate. We aren't using using a starter on the cone, so there
doesn't </DIV>
<DIV>have to be much structural strength there. Just make sure you do
a good rebalance after you get done with whatever carving you do....</DIV>
<DIV> </DIV>
<DIV>Rex</DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV style="FONT: 10pt arial"><B>From:</B> <A title=mailto:dkrev@shaw.ca
href="mailto:dkrev@shaw.ca">Dave Reaville</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=mailto:nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">NSRCA Mailing List</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Sunday, December 17, 2006 8:53
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion]
Cooling outrunners</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial>Hi Wayne</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>Actually Chad and Rex (I think???) had already done
that but I was a little concerned with leaving sufficient material
after the spoke removal :-) so I decided not to. I am not sure just
how much additional flow would be created but it's certainly worth
considering. </FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>Dave</FONT></DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=mailto:wgalligan@texasairnet.com
href="mailto:wgalligan@texasairnet.com">Wayne Galligan</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=mailto:nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">NSRCA Mailing List</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Saturday, December 16, 2006
8:23 PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion]
Cooling outrunners</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>Dave,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>You could go one step further and grind an
airfoil in the remaining spokes to aid in pulling the air
in.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Wayne G. </FONT></DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=mailto:dkrev@shaw.ca href="mailto:dkrev@shaw.ca">Dave
Reaville</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=mailto:nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">NSRCA Mailing List</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Saturday, December 16, 2006
2:09 PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion]
Cooling outrunners</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>Re: Outrunner Cooling</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>FWIW I have made some other changes to the
spinner that have helped a little. I removed three of the spokes of my
backplate to assist in weight loss :-) as well as increase flow
through the motor. Picture here </FONT><FONT face=Arial><A
title=http://members.shaw.ca/patternwestnews/pictures/planes/tttrim.htm
href="http://members.shaw.ca/patternwestnews/pictures/planes/tttrim.htm">http://members.shaw.ca/patternwestnews/pictures/planes/tttrim.htm</A></FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>I am also going to make some minor changes to
the spinner itself by increasing the prop cut-out forward. These
openings coupled with the ducting that Chad used towards the rear
of the motor should provide adequate cooling for the Plett. I
understand the Evo has bigger openings to assist in cooling but I
think it's very important to make sure that the backplate spokes,
when mounted, align properly to allow unrestricted flow through the
openings. It's possible to block the flow if improperly installed or
if it rotates on it's own.</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>I have seen Rex's spinner in action and it
appears to me to assist in cooling.</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>Dave R</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV>----- Original Message ----- </DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=mailto:trexlesh@msn.com href="mailto:trexlesh@msn.com">Rex
LESHER</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=mailto:nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">NSRCA Mailing
List</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Saturday, December 16,
2006 9:52 AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion]
Cooling outrunners</DIV>
<DIV><BR></DIV><!--[gte IE 5]><?xml:namespace prefix="v" /><?xml:namespace prefix="o" /><![endif]-->
<DIV style="FONT-SIZE: 10pt; COLOR: #000000; FONT-FAMILY: Arial">
<DIV>Hi guys, I've been without power for the last couple
days.... The mods I did to the spinner are on the D8
website. I'm not sure how effective my process really
is. I can tell you that it works much better than not having
any opening at all. I did that experiment.... Chad
touched on the real problem and I believe he is right on. The
spokes in the backplate and the closed sides between the openings in
the spinner create too much resistance (spinning disc) for the
appropriate amount of air to get directly into the
motor. I first tried just opening the sides of the
spinner, and used that for my baseline. Then, I used the
modification as shown on the D8 website. I figure that I
dropped somewhere around 20 degrees on average. After a few
flights, I took the spinner off, and the motor cooled much
better. That tells me that in order to get the greatest
cooling, you'd have to create a high pressure area in front of the
motor... </DIV>
<DIV>Now, I'm playing with ducting, forcing air around the
can.... Time will tell, if I don't demag the motor!!!</DIV>
<DIV> </DIV>
<DIV>Rex</DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV style="FONT: 10pt arial"><B>From:</B> <A
title=mailto:AtwoodDon@aol.com
href="mailto:AtwoodDon@aol.com">AtwoodDon@aol.com</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=mailto:nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">nsrca-discussion@lists.nsrca.org</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Friday, December 15,
2006 6:16 PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re:
[NSRCA-discussion] Cooling outrunners</DIV>
<DIV><BR></DIV><FONT id=role_document face=Arial color=#000000
size=2>
<DIV>
<DIV>Jim, </DIV>
<DIV> </DIV>
<DIV>I think Rex Lesher modified a True Turn spinner to have
'inlet slits' to pull air into the spinner and back thru the
motor. I don't know if there were any tests to indicate if
was effective. Maybe Rex can comment here.</DIV>
<DIV> </DIV>
<DIV>I also believe there are some NASA airflow studies that
indicate the area around the prop hub and some small amount of the
prop as well as the spinner create an cone like airflow around
that area that basically prevents air from entering the spinner
slots, etc.</DIV>
<DIV> </DIV>
<DIV>Hacker has a fan like attachment on the back of the large
outrunners than creates a negative pressure area inside the motor
and draws air in thru the front of the motor for cooling.
there have been some tests retrofitting a similar fan on the back
of other outrunners with similar success. Basically a trade
off in weight for cooling effectiveness.</DIV>
<DIV> </DIV>
<DIV>As you know, I run an AXI 5330/F3A with the chin cowl opening
ducted to divert incoming air upward across the AXI. It
seems to work even on the hottest summer days. No air from
the cheek cowls is ducted toward the motor, it just passes thru
toward the ESC and batteries.</DIV>
<DIV> </DIV>
<DIV>Don</DIV>
<DIV> </DIV>
<DIV>In a message dated 12/15/2006 4:14:26 P.M. Pacific Standard
Time, joddino@socal.rr.com writes:</DIV>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px solid"><FONT
style="BACKGROUND-COLOR: transparent" face=Arial color=#000000
size=2>
<DIV>It would seem the best way to cool outrunners that have
holes in the case on the end that faces the nose ring,
would be to bring air in through the spinner and through holes
in the backplate. Wondering if anyone has really thought
about the optimum design. I can picture internal vanes but
perhaps cutting off the nose of the spinner and leaving a big
hole would be adequate. Anyone tried anything like
this?</DIV>
<DIV> </DIV>
<DIV>Jim
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