Cessna Skycatcher had the weirdest ?spoilers? or whatever they are
grafted on to the end of the trim tab. Any idea what they are about?
s dorr
They make the tab much more effective at the expense of a bit more drag.
It is like a so called spoiler on the trunk of a car generating down
force.
Why they did not make the tab larger is a bit of a mystery.
That may have caused a flutter problem. My guess is something like this
may
have added to the flutter potential.
Paul Lamar
Hmmmm, yes, flutter is always a potential problem. It is fun to
wander around a show like S n F and see all these weird little
aerodynamic tweaks they come up with to fix problems that crop up in
testing. I saw another airplane with oddly shaped fence tabs on the
ends of the ailerons .... obviously another afterthought patch to fix
a problem that would otherwise have required a major redesign.
Likely why an old friend used to refer to the subject as
"aero-god-damn-ics!"
SD
SD, did you see any rotary powered airplanes on the flight line this year?
They are usually parked on the first line on the left end. Facing the
airshow.
As I understand Tracy Crook did not make it but I can't get in touch with
him. Anybody know what happened?
Paul Lamar
Paul, Tracy Crook was there all day thursday with his RV8 3 rotor and I
talked with him a while in the auto engine conversion tent.. He is testing
the PSRU with no damper on the RX-8 two rotor of his RV4 operating for a
half hour continuous RPM in increments up to full power. There have been
no
resonance or other problems at 12 flight test hours. The hub is splined.
He
thinks the drive is actually smoother without the damper. Tracy has also
built his engine controller for 8 cylinder engines so I was incorrect in
my
statement that it worked up to 6 cylinders or rotors.
The only alternative engines in the tent were rotaries with a
display by the "Cozy Girls" Randy had an extensive pictured build log of
their Cozy4 and as usual fielded questions enthusiastically. Chrissie is
adding a few new products like an under engine turbocharger system and a
real nice looking intake manifold for a side port. She is addressing the
stock intake port cut on an angle making the port look taller than the
actual cross section by the height the runner enters the port. Nice stuff.
There was also a front housing water inlet/outlet similar to the RX-8
style but it looked like a new casting.
The twin engine velocity was apparently in flight testing and had
no winglets at the show. They added 4 sq ft of wing area per side up from
46 to 50 per side. Jan Eggenfeltner had his Honda 100 HP conversions
(viking engine) installed in several airframes and was doing runups after
the airshows.
Somehow we lost golf carts number 726 and 127 but got the other 19
returned on time. They may have been hijacked monday but we found out the
next Sunday.
I did a bunch of forums and several in the I-Pad3 apps for moving
map and in flight weather. The Mad-Elf was $99.99 per year and well
featured. Foreflight $726.00 with free weather WAAS and a few others with
prices in between.
The vendor locations were all occupied although some were at different
locations than in the past. Sonex lost their show displays and transporter
in a highway accident and were not there. Some of the display aircraft
were
moved from the FAM pavilion up near the flight line to fill in an open
area
where no vendor was located. Attendance by the public looked good to me
although that is not necessarily an indicator of people buying stuff. I
actually spent more on the homemade ice cream than tools this time since I
only bought things like carbide cutters. My wife was also a "volunteer"
this year riding trams. As usual it was a nice change of pace with no
drugs, drunks, or obnoxious people, just typical Sun-n-fun.
george grimes
An under engine turbo charger will not work unless there is a oil scavenge
pump.
The turbo must be mounted high enough so the oil drains back to the oil
sump by
gravity. The pressure in the bearing cavity must be atmospheric or below.
Paul Lamar
Paul, there is a scavenge pump. GG
What kind?
Paul Lamar
Paul, Not sure who makes the scavange pump. It just came out while
Chrissie was talking to someonr else about relocating a tube on her motor
mount for the turbo header to turn down under the oil pan. She says finding
the scavange pump was what made relocating the turbo possible. Her brand
new stock turbo manifold is for sale.
george grimes
Chuck Harbert used an electric scavenge pump way back in 1999 or there abouts on this
3 rotor turbo Velocity. Chrissie was on here in those days :) Dave Atkins was helping
him.
Paul Lamar
--
The Rotary Engine News Letter. Powered by Linux.
ACRE NL web site.
http://www.rotaryeng.net
You Tube key word PaulLamar2
Copyright 1998-2012 All world wide rights reserved.