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<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>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=dkrev@shaw.ca href="mailto:dkrev@shaw.ca">Dave Reaville</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=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
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>
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<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=trexlesh@msn.com href="mailto:trexlesh@msn.com">Rex LESHER</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=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>
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<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>
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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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