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<= font size=3D2 face=3DArial>

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=3DqsndDKG1OuE

http://www.youtube.com/watch?v=3D86fy3qNCVJs

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

the basics. = DOH!

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

&= nbsp;

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