Congratulations on the progress on both
the aircraft and career, Chris.
What signal source are you using to drive
your Tach? From the tailing coils? I presume.
Not having a scope on the line, its hard
to tell, but here are two possibilities.
- The
pulsed tach signal from the coil is becoming distorted at higher rpm
for some reason (Not too likely, but could happen)
- The
Tach unit is failing to capture the higher rpm (pulse train frequency)
properly. There are a number of different type inputs that Tachs
have to match today. IF your tach is not designed for the specific
type of pulse train put out by the rotary trailing coils, then it may not
function properly.
If you could borrow a scope and see what the
signal looks like that could eliminate one possible cause. If it
looks fairly clean and steady in frequency an amplitude then its likely a
problem with the Tach. Check your Tach literature – there are some
that require a different number of pulses per revolution out from the tach
signal. I can not recall for certain, but it seems that the rotary puts
out a two pulse per rev signal.
Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com
http://www.andersonee.com
http://members.cox.net/rogersda/rotary/configs.htm#N494BW
http://www.dmack.net/mazda/index.html
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On Behalf
Of Christopher Barber
Sent: Wednesday, July 09, 2008
1:45 AM
To: Rotary
motors in aircraft
Subject: [FlyRotary] Saga vids on
utube and MORE checking the basics
Submitted for your consideration....
http://www.youtube.com/watch?v=qsndDKG1OuE
http://www.youtube.com/watch?v=86fy3qNCVJs
Right after both of these runs we discovered
the reason for some of the roughness
present in these runs. The nut
holding the crank angle sensor was not tightened properly. GOTTA
check
That is me at the controls and my buddy, Russell, on
cam. (he discovered the infinity focus feature
just AFTER these videos were taken
<g>. He is actually the smartest guy I know.
I am coming to the conclusion that many/most of my
current concerns are
electrically based. So, I will be running and
checking wires AGAIN. I
am really annoyed by the RPM indicator going to zero
when I go over
about 5400ish rpm (usually). I still have some power
to go but do not know what I
actually achieve. Actually, today, in
the second video, it got to 5000 but then went to zero.
When I backed off the throttle, it went to a
couple erratic numbers then went back to normal
Still lots more to discover and tweak. However,
did you notice my plane
is actually moving under its own power <G>. Wow,
who'd of thunk it.
Oh, btw, on an unrelated note, I was promoted to
corporal yesterday at work.
(we only have corporal's and sergeants on the
streets). FWIW.
All the best,
Chris
Velocity SE N17010
New 2nd gen 13b turbo block,
Medium street port,by Mazdatrix
Mistral intake
RWS 2.17 Redrive
RWS EM2
RWS EC2
IVO in flight adjustable Magnum 3 blade prop
Aeroelectic Z-14 duel alt/duel bat
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