Date: Wed, 18 Aug 1999 10:47:07 -0500
From: David Domeier <david010@earthlink.net>
Subject: COZY: Electric gizmos....

George and Carl,

    re "My manual pitch trim works perfectly, so I am interested in why
anyone
would want an electric one."

    My LEZ seemed to be just fine with manual trim, but for some reason
the MKIV is a bit more sensitive to manual trim.  It always needs a
little more tweaking. (I suspect the spring tension was not perfect or
balanced)

     This electric system provides for effortless, very fine tuning of
elevator trim.

    The primary reason I did it, however, is that I have ordered a
NavAid autopilot and a S-Tech stand alone altitude hold system.  The
S-Tech has a feature that turns on a light when the airplane is out of
trim, and in which direction.  The electric trim unit will provide for
very fine tuning while the altitude hold is on.  I guess one could do it
manually, but it is my opinion this will be more precise and easier,
plus I am going to use the original pitch trim bell crank for the
altitude hold servo with the motor mounted to the manual trim wood
bracket.  It should be a relatively easy installation with the sensor
and control unit mounted just aft of the lower instrument panel under my
seat.

    To answer your question, Carl, about back up trim if the unit runs
away, the answer is no.  It will require flying the airplane with
elevator stick force to over come the cylinder spring tension.  I do
have full elevator travel if the unit runs away in either direction.  It
is my opinion that the likelihood of a failure of the momentary
on-off-on switch is remote.  It is quite rugged and there are no
relays.  Also, I have it wired through a switch on the Lanza electric
panel, so if I can figure out what is going on in time, that switch will
kill power to the unit.

    As a side issue, the Steve Wright retraction system (another neat
electric gizmo) is controlled by relays and roller switches which if
failed will cause some structural damage since there are no internal
motor limit switches.  I am thinking about installing that same
momentary on-off-on switch to control it along with a light indication
of full up/down.  It would be a pain to have to hold that switch for
gear up and down, but it would provide a relatively simple fail/safe
system if one of the roller switches or a relay failed.

    I fly many short local flights and probably have over 150 retraction
cycles, with no problems, but I wonder if and when a relay or switch
will fail.  If Steve could figure out a way of installing internal limit
switches on that motor, and it is a powerful beast, I would be more
pleased, yet, with the unit.

dd

From: "Wilhelmson, Jack" <Wilhelmson@scra.org>
Subject: RE: COZY: Electric gizmos....
Date: Wed, 18 Aug 1999 14:55:47 -0400

David:

The motor gearbox does have a mechanical slip clutch in it to protect the
nylon
gears. This slipclutch is a last resort type of system and should not be
used as
a stop. Also, this clutch produces a lot of torque before it slips and may 
cause other damage.

A simple solution that has worked for me is:

Use a 10 amp circuit breaker. The motor is a DC motor and one of the
charateristics
of this type motor is that they draw current very proportional to their
load. Test the breaker
with a steady current to make sure it is close to the 10 amp holding limit.
Max current
during nose lifting is about  8 -- 9 amps on my system. You might want to
check this
on yours to make sure the 10 amp overload is ok. 

I have this type of protection on my airplane that use a nose lift system of
my own design
but uses the same motor and gear box and has worked several times when the
micro switches
where set to close.

Jack Wilhelmson N711CZ


> -----Original Message-----
> From:	David Domeier [SMTP:david010@earthlink.net]
> Sent:	Wednesday, August 18, 1999 4:47 PM
> To:	George A. Graham; Canard mail list; cdenk@ix.netcom.com
> Cc:	cozy_builders@canard.com
> Subject:	COZY: Electric gizmos....
> 
> George and Carl,
> 
>     re "My manual pitch trim works perfectly, so I am interested in why
> anyone
> would want an electric one."
> 
>     My LEZ seemed to be just fine with manual trim, but for some reason
> the MKIV is a bit more sensitive to manual trim.  It always needs a
> little more tweaking. (I suspect the spring tension was not perfect or
> balanced)
> 
>      This electric system provides for effortless, very fine tuning of
> elevator trim.
> 
>     The primary reason I did it, however, is that I have ordered a
> NavAid autopilot and a S-Tech stand alone altitude hold system.  The
> S-Tech has a feature that turns on a light when the airplane is out of
> trim, and in which direction.  The electric trim unit will provide for
> very fine tuning while the altitude hold is on.  I guess one could do it
> manually, but it is my opinion this will be more precise and easier,
> plus I am going to use the original pitch trim bell crank for the
> altitude hold servo with the motor mounted to the manual trim wood
> bracket.  It should be a relatively easy installation with the sensor
> and control unit mounted just aft of the lower instrument panel under my
> seat.
> 
>     To answer your question, Carl, about back up trim if the unit runs
> away, the answer is no.  It will require flying the airplane with
> elevator stick force to over come the cylinder spring tension.  I do
> have full elevator travel if the unit runs away in either direction.  It
> is my opinion that the likelihood of a failure of the momentary
> on-off-on switch is remote.  It is quite rugged and there are no
> relays.  Also, I have it wired through a switch on the Lanza electric
> panel, so if I can figure out what is going on in time, that switch will
> kill power to the unit.
> 
>     As a side issue, the Steve Wright retraction system (another neat
> electric gizmo) is controlled by relays and roller switches which if
> failed will cause some structural damage since there are no internal
> motor limit switches.  I am thinking about installing that same
> momentary on-off-on switch to control it along with a light indication
> of full up/down.  It would be a pain to have to hold that switch for
> gear up and down, but it would provide a relatively simple fail/safe
> system if one of the roller switches or a relay failed.
> 
>     I fly many short local flights and probably have over 150 retraction
> cycles, with no problems, but I wonder if and when a relay or switch
> will fail.  If Steve could figure out a way of installing internal limit
> switches on that motor, and it is a powerful beast, I would be more
> pleased, yet, with the unit.
> 
> dd

From: SWrightFLY@aol.com
Date: Wed, 18 Aug 1999 14:40:09 EDT
Subject: Re: COZY: Electric gizmos....

In a message dated 8/18/99 10:52:48 AM Central Daylight Time, 
david010@earthlink.net writes:

<<  I fly many short local flights and probably have over 150 retraction
 cycles, with no problems, but I wonder if and when a relay or switch
 will fail.  If Steve could figure out a way of installing internal limit
 switches on that motor, and it is a powerful beast, I would be more
 pleased, yet, with the unit. >>

Great question and one we were concerned about as the system was being 
developed. Bottom line........we have never had a relay or switch failure and 
the rated cycles for them will (we think) about equal the life of the 
airframe. The system does have an internal clutch which will slip and prevent 
serious damage should the system "run away". We considered "internal 
switches" but we chose to keep them external so we could keep the design 
simple and have them visible so they can be easily inspected. We were very 
concerned about dirt, water, etc., getting up in the tube where the ball 
screw functions so we chose to keep that sealed on the advice of theThompson 
Saginaw engineers.
Steve
 <A HREF="http://www.canard.com/noselift/">Wright Aircraft Works LLC: 
Electric Nose-Lift for EZEs</A> 

Date: Wed, 18 Aug 1999 07:44:10 -0400 (EDT)
From: "George A. Graham" <ca266@freenet.buffalo.edu>
Subject: COZY: Manual pitch trim


My manual pitch trim works perfectly, so I am interested in why anyone
would want an electric one.  I read the pilot reports on the canard/trim
website, and it appears that the greater "authority" of the unit is the
big bonus.

I followed Vance Atkinson's plans for his trim spring "cylinder", then
connected it to my pitch trim handle, instead of the electric motor.
See CSA Jan 95, page 11

My trim handle is in the center console, aft of the center mounted stick.


George Graham
RX-7 Powered Graham-EZ, N4449E
Homepage <http://freenet.buffalo.edu/~ca266>

From: "Nat Puffer" <cozy@extremezone.com>
Subject: COZY: pitch trim failure
Date: Wed, 18 Aug 1999 09:33:56 -0500

Builders,
There has been some fear expressed (needlessly) about what would happen if
Alex' pitch trim unit stuck or "ran away". I flight tested Alex first
prototype. It had a coarse thread on the lead screw, and a motor that
wasn't as powerful as currently, and also had a resistor wired in series.
On a long cross-country from Mesa to Arlington to St. Paul to Oshkosh, to
Mesa, with many stops in between, the trim stuck with the elevator set for
take-off. There was no problem overpowering it in cruise. Upon our return
to Mesa, I discussed this with Alex, and he modified his unit to a finer
pitch on the lead screw and a more powerful motor. It has worked just fine
since. Don't worry about imaginary problems!
Regards,
Nat

From: cdenk@ix.netcom.com
Date: Wed, 18 Aug 1999 16:30:52 -0500 (CDT)
Subject: COZY: Re: Electric gizmos....

Was said <if the unit runs away, the answer is no.  It will require flying the airplane with elevator stick force to over come 
the cylinder spring tension. >

I'll give 2 examples from last weeks flights to Wyoming:
  1: The plan was From Lincoln, Nebraska to stop a Rawlins, Wy. as a potty stop. A thunderstorm was setting over the airport 
(one of 3 we could see with 100 mile visibility) The nearest suitable airports probably were Rock Springs and Cheyenne, at 
least a half hour away. 

  2: On let down from 11,000' approaching home, passed through a cloud deck from 7000' to 4000' at 400 feet per minute for 
ear comfort took about a half hour. 

Try flying the plane for a half hour either enroute or preparing for an approach, while passing through a cloud deck. I am 
sure such a unit would not pass FAA certification funtionally, and I wouldn't have one on my airframe.

I believe the correct functionality: The trim system has an infinite motion, with a slip clutch. If runaway, open the breaker 
or fuse (easily accessible in flight), then (and the same if mechanism froze) normal adjustment by slipping clutch, just like 
the adjustable friction shown on the drawings.



Date: Thu, 19 Aug 1999 11:23:37 -0500
From: David Domeier <david010@earthlink.net>
Subject: Re: COZY: Re: Electric gizmos....

Carl,

    I disagree with your conclusion concerning this simple trim system
in an IFR airplane. (re ".... and I wouldn't have one on my airframe.")

    I have no interest in promoting the system, Carl, but I think we
should keep the total risk of single engine IFR flight in perspective.

      The momentary on-off-on switch controlling pitch trim is of very
high quality, not stressed by heat or vibration, and is of low usage.
The contacts are spring loaded open - even if the spring fails, moving
the switch to off should stop the motor.

    There are many more critical moving parts in the engine than in this
trim system.  I am more concerned about engine failure than failure of
the this trim system.



dd

From: cdenk@ix.netcom.com
Date: Thu, 19 Aug 1999 16:44:44 -0500 (CDT)
Subject: Re: COZY: Re: Electric gizmos....

was said <The momentary on-off-on switch controlling pitch trim is of very high quality>

I have had to replace numerous switches of various qualities from very cheap to expensive in the years that I have used 
various equipment, probably starting with a heathkit FM-1 tuner, but I wasn't thinking of only switch failure, but also such 
items as fuse or circuit breakers, motor, bearings, linkage type items, or whatever. Murphy's law controls. 

Re: Single Engine IFR: I respect that very seriously. On last weeks flights from Cleveland, to Pinedale, Wyoming, we stopped 
twice overnight due to weather, and filed IFR twice. The 1st IFR was Lincoln, Nebraska to Pinedale had a couple of 600 
overcast and 5 miles in fog reports. We went at 10,000', was in the clear with more than 20 mile visibility all the way. The 
2nd was also with a couple of 900' overcast and 3 miles and light rain. Climbed through 2800' to 4000' overcast layer on 
departure, on arrival it was into the clouds at 7000', and broke out at 4000' with 15 mile visibility. The lowest ceiling 
approach I have done with the Cosy was breaking out 1000' above the airport with at least 5 mile visibility. Though practice 
all the time down to minimums. The 2 weather stops were westbound 30 miles past Lincoln, Nebraska, visibility went from 30 
miles to 8 miles in a short period, widely scattered thunderstorms were reported. I could no longer assure myself (visually) 
that I wasn't going to fly into a thunderstorm, turned around and landed a Lincoln. The 2nd weather stop was, stopped at 
Lincoln for fuel, line of thunderstorms, rain, etc. would have stopped us after another half hour flying near Pella, Iowa. Not 
worth it to get into the air for that short time. Line too long to do an end run.

See future Central States Newsletter for full story. 

Date: Fri, 27 Aug 1999 15:38:26 -0700
From: "LCDR James D. Newman" <infaero@flash.net>
Subject: COZY: Re:  Electric gizmos....

Hi Dave and All,

    Sorry I didn't chime in sooner.  Been gone.

> David Domeier wrote:

> To answer your question, Carl, about back up trim if the unit runs
> away, the answer is no.  It will require flying the airplane with
> elevator stick force to over come the cylinder spring tension.  I do
> have full elevator travel if the unit runs away in either direction.  It
> is my opinion that the likelihood of a failure of the momentary
> on-off-on switch is remote.  It is quite rugged and there are no
> relays.  Also, I have it wired through a switch on the Lanza electric
> panel, so if I can figure out what is going on in time, that switch will
> kill power to the unit.

    I've mentioned this before (twice Oct. '97 & once May '98 - should be under 'Electric Trim' in
the archives), but I helped Todd Morgan come up with a trim system using a linear actuator that
spliced into his stock Cozy III trim system that could easily be removed by reaching under the panel
to pull a pit pin to drop a defective trim actuator, or you've lost all electrical, out of the way,
and the trim system immediately reverts back to manual.  Besides winning Osh Grand Champion that
year ('95), he won the Stan Ditzke Safety Award for this system using our grips.
    So, if you're really that concerned with actuator and/or electrical failure, the pit pin could
probably be incorporated into the really nice Strong Trim System.


Infinity's Forever,

        JD

