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<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=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> 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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