Well, folks, the unveiling is here.
Here are the first photos of my variable length
intake manifold designed based on the EDDIE analysis. The primary and
secondary of each rotor are merged into one runner (1 3/4" dia). These
two runners are composed of 1.854 dia tube in which the 1.75" dia tubes
slide. One set for each rotor. There is a small DC 50 rpm motor
(turns out this is a bit slow) that turns a jack screw. This jack screw
drives the throttle body mount and the two 1.75" dia tubes and changes the
length by 4" which is a range of approx 1500 rpm. I wanted to get a 6-7"
change, but this is a prototype, so I used what I had laying around in terms
of manifold parts which put the whole setup 3-4" higher than I
want. So depending on OAT the 1500
rpm range could give me the EDDIE from 5000 - 6500 rpm.
There is a controller with limit switches at the
upper and lower extension to independently stop the motor when limits are
reached. I have a small potentiometer with a gear on its shaft. A
rack is attached to the throttle body which moves up and down with it.
The teeth of the rack turn the pot which of course changes the voltage which
is indicated on the control box by 10 Red LEDs. There is a dual color
LED which is Green when the throttle body is extending and is Red when it is
retracting.
A few photos are attached. Hope to install
it on the aircraft tomorrow and within a day or two have it
running.
Ed Anderson
RV-6A N494BW Rotary
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Matthews, NC