Paul Wrote:
SNIP
if you want to run Tracy's EFI I think
you will need this display to allow you to taylor the EFI system to your
airplane.
I could be wrong. Tracy may be supplying some crude indicators to
substitute
for this display. I saw a column type LED indicating something on his
instrument
panel (I forgot what its function was. I think it was mixture.) when he
took
me for a ride. Tracy?
The only thing you need to set up the EC2 is a mixture monitor (O2 sensor &
readout) available in many speed equipment catalogs (or I can supply). The
EC2 will run right out of the box but mixture needs to be optomized at
various power settings. This can be done with EGT gauges too but it is MUCH
easier and faster with the mixture monitor. The problem with doing the
initial tuning with EGT gauges is that they respond slowly and (as one
example) you don't know for sure if the EGT is low because the mixture is
too lean or too rich. The mixture monitor gives you an instant indication
and is not ambiguous. BTW, that column LED display Paul mentioned is the
monitor and it is hooked to the original O2 sensor installed long ago. It's
still ticking even after a lot of 100LL use.
It is becoming necessary for me to do more strategic business planning if I
am going to retain my sanity. In the long term it looks like I need two
versions of the display, one that just does the basics (fuel flow, fuel
total, MAP, rpm, inlet air temp) and a second "page" for the programming
parameters since these only need to be displayed on rare occasions. The
other version would add all the other engine monitor functions (temps,
pressures, etc.).
I've also had so many requests for a redrive that will handle metal props
that I have a new design on the drawing board that will allow these.
Conventional constant speed props will also be possible later on. Will be
testing the prototype in a few months. The current drive can be
retrofitted. The prop shaft is a lot more expensive to do on this model so
the price will be higher. I didn't know it was that big a concern but many
wanted the metal prop just because of the "all weather" capability they
offer. I get no damage in the rain with my wood prop by throttling back to
4000 engine rpm. There was minor pitting when I ran at 4600 rpm and a wood
prop gets pretty chewed up when run at 75% power settings (5200 - 5500
depending on altitude) in the rain. Not sure how the composite props would
do, never flew my IVO in the rain.
Tracy Crook
rws@altavista.net
www.rotaryaviation.com
Seems to me a metal blade is a sledge hammer approach to the problem
not to mention the extra weight of PSRU and blades.
Composite props usually require an electro formed compound curved nickel cuff.
These are quite expensive but a thin stainless cuff could be made and bonded on.
The trick is welding the 0.016 inch thin SS parts together so they fit
a compound curve prop blade leading edge. Good argument for a straight
taper blade instead. That way the SS cuff can be merely bent and glued on.
(Bill, joa & Perry are you listening?:-))
Rubber or urethane also seems to work. Bonding it on seems to be the problem.
The blades will have to be routed out for the 0.016 inch thickness of
the cuffs. Perhaps joa can accommodate that in the mold that he is making
on a 3D mill. Bill and Perry are still working on the exact design of the
blades for the ACRE NL CS prop.
Paul Lamar
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