Wrathall Mark wrote:

Mark Wrathall wrote:

Butch, do you mean the pitch is locked in whatever

pitch you set by the

motor leadscrew?. What happens if you have just

commanded finer pitch with

your pitch switch, and the switch fails on. This

would drive the motor till

it hits a physical stop. It is desirable that this

be a ground adjustable

stop, which is set to control static RPM.

*********************************************************

Hi Mark;

The attached illustration will make it easier for me to
explain. There are two (2) pitch positions shown;

--Minimum Pitch, 07 deg. against a mechanical stop (Yoke
slots).
--Maximum Pitch, 32  "      "    "     "       "   (Yoke
Bearing Bushing)

The Pitch is VERNIER ADJUSTABLE from MAX-MIN, a net
range of 25 deg. via two (2) 10-32 ss pins easily
accessible by removing the Gearmotor Cover, and
employing a "T" allen wrench. After MAX adjustment is
attained (set), these then become the MAX mechanical
stop, The MIN adjustment isn't externally adjustable.

BTW, I've personally always had access to a Kill switch
or circuit breaker that shuts off power to the prop in
case of a "RunAway"......Never had to use it, or heard
of anyone who has.

The LAEV can (Will?) be equipped with electronic limits
which sense instantanious motor overloads which are self
re-setting......Paul, chime in on this.

                               Did I forget anything?
                                       Butch

They call them Raychem PolySwitch Resettable Fuses.
They reset automatically when they cool off. 75 cents each at
DigiKey. Watch your tach. When the RPM stops changing let up
on the pitch change toggle switch.

Paul Lamar

Mark Wrathall wrote:

Glad to see all this was thought through in advance.

Mark.

We had a committee :-) If you want to go high buck you can use
a toggle switch type aircraft circuit breaker. My circuit breaker

of

choice.

Paul Lamar

There has been a lot of posts on the Aeroelectric Connection forum

on the

use of these circuit breakers.  Check out what Bob says about them.

Rick Girard
13B + LEZ

   Bob Nuckolls decided long ago that fuse blocks and automotive fuses
(ATO?) were the only way to go for most applications in aircraft. One

thing

about Bob, once he's decided something no amount of arguing or

discussion

will ever convince him otherwise.

  Bob's arguments in favor of fuse blocks made sense to me and thats

what I

used on the RV. Convenient, cheap, and easy. But switch-breakers are a

nice

choice if you dont mind spending the $.

Mike Wills

Despite Bob's argument (and they do have merit), from my thousand of hours
of flying in military aircraft, I can tell you that numerous times I have
had equipment pop a circuit breaker from a temporary overload and was able
to reset the equipment and get it functioning again.  Can't do that with the
normal fuse.  These automatically resetable fuses are probably OK - I just
like something I can pull and push on {:>) so as I know when I pull it - the
power is not there and when I push it in, the power is there.  But, then I
fly with steam gauges.

Ed Anderson

Neat Ed. I like those steam guages as well as the pop out resettable CB's.
Royce

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