It  seems like fly-by wire is the current buzz  term.

And the advantage of  the throttle-by wire is??????, in  aircraft
applications.

Having been  the recipient of a possible  throttle jamming incident in the
air, with a  linkage that did not  give me good feedback of the actual
connection   of the throttle  and the throttle body, unless there is a
really  good
reason,   other than "that it is available",  in aircraft  application,  I
think I
would rather go with the push-pull  direct connection  variety of control.

Someone please straighten me   out

Rich

--

Rich, This is not to "straighten you out"  but  it's why I'm would like to
at least give it a go at doing   this.

Push/Pull direct connection is very nice, particularly when  it's  to an
engine just up front of you, however sometimes the engine  like in  my
case is behind you and the cable runs become quite long. I  need have  to
have 2 throttle controls linked together, it's a Tandem  Machine and  I
need enough space for people like me - 2 metres tall,  6'6" in the  old
measurements.

I really hate having connecting  rods on the left  side of the seats like
some others have done and the  machine is pretty  open. If I use a rod
system to join the throttle  controls then it sits out  in the open, is
easily damaged or tripped  over and makes it very hard to  get in/out the
left side of the  machine, I would really like to able to get  in/out the
left side of  the machine. So to avoid this issue and I really  want to
avoid it, I  need use at least one push/pull cable to link the  two
throttle levers  together so they operate together and then  another
cable from one of  the throttle controls to the throttle body, now  I'm
certainly able to  do that and if the electronic control does not  work
then I will be  doing just that.

However, TK insists that he  really wants to test  his throttle
controller design. He is also pretty  certain that it  will be perfectly
reliable, so one must give a fair go  after all, I  originally asked him
what he thought. He got interested in  doing  this, it would not be very
fair not to give a fair go. If it works   and I have no reason to doubt
that it won't then why not? For others  it  simply gives another option
for a throttle control system. I'm  already  completely reliant on all
sorts of other electronics and  electrical systems  for flying using
an RX-8 Engine, for instance  Tracy's EC3, Tracy's EM3,  fuel pumps,
trim system etc.

Apart  from anything else it is just  plain fun to see if it can or will
work  without spending too much time or  money on it, we've only spent  a
couple hours on it so far, I suspect that  it will go to a  working
prototype with only a very few more hours which is  pretty  good, it
would more than likely have taken me at least several hours   working out
how and where to run the push/pull cables as well as in   fabrication time
of a number or brackets and the like and to make sure  that  it would not
get damaged or bind going to the engine keep water  out of the  cables etc.

Regards David

--

Greetings  David.

I am also of the rear engine persuasion (aero canard SX). The  length of
the
cable is somewhat immaterial. It's been used in boats  (much longer run)
for
years, as well as virtually all twins, each of  which has  longer and more
tortuous runs.

The tandem throttle  arrangement does create some problems, but not
unsolvable with cables.  Merely run one cable from the front lever to a
fixture  at the aft  throttle control which connects this front cable to
the
rear cable (kind  of like a union with a perpendicular bolt to engage the
aft throttle lever.  This fixture (union) can be as simple as the
arrangement
used in the  locking mechanism of the canopy, or as sophisticated as  you
like.

With this arrangement, the forward throttle is directly  connected to the
engine, albeit through the fixture.

The cables can  be routed any way you please.
Good cables are lubricated, can be bent and  give a sturdy attachment.

This gives tactile feedback with the  throttle. Even the Airbus which is a
FBW craft syntheses feedback to the  pilot.  Direct  connection, indeed,
tells you throttle plate  position, binding and a myriad  of things which
you
can't get with  wire. Perhaps some feedback information  forewarning  of
some
possible impending malfunction (a bad place to have   one)

If You use TK's EC2 or 3, you have redundancy in spark, in go  juice, but
absolutely no redundancy in throttle position nor feedback  information, or
even  function.

Please don't get me wrong, I  really want to use the fly-by wire but I need
more info before I trust my  Glutei maximi to it

Rich


--

Hi, Rich - I'll try to  keep this shorter this time.

Agree the cable length does not really  matter. Tandem Throttle link-up
was always going to be cable. The Throttle  levers are designed for it,
so I'll use it. Good Cables are the only ones  to use :), Cables can
routed anywhere within reason but, wires are much  more flexible, the
limitations for cables are bend radius which forces some  space & minimum
distance limits. Wires with the Throttle body have  basically none.
Tactile feedback in this really comes from friction which  is built-in to
the throttle levers I'm using already. There are thousands  or millions of
these style or throttle systems in use today all around the  world. If the
throttle body was already designed for a cable, I simply  would use it
without a second thought.

Tracy Crook  (http://www.rotaryaviation.com) is the designer and seller
of the EC3 &  EM3.

T.K. is a friend of mine that used to work up until very recently  in R&D
in
the Auto industry designing and developing this sort of  stuff, He want to
do this now, I have have to give the fair  go.

Regards David


--Hi David,

I mistyped.

I meant Tracy Crook (TC) but used K instead of C. I agree with the
limitations of the radius of the cables. When I referred to tactile, I was
referring not specifically to the resistance of the lever, (as you correctly
stated a product of the friction), but the mechanical awareness of the
connection to the butterfly and it's actual position. With FBW, it is possible  to
think that you have full open throttle (because of full throttle position)
and actually have the butterfly (or whatever you use to shut down the
airflow)  closed giving you one more totally unknown in the event of an engine
problem.  Unknowns eat up valuable time when attempting to troubleshoot an
engine problem  at low altitude.

Case in point:

As I was approaching Peoria, IL about 4 years ago, in my dragonfly, less
than 1k AGL, my engine did not respond to advancing throttle. The linkage
that I  used was a cable(high quality) pulling against spring tension. The
spring opened  the throttle. the cable closed it. Seemed like a good idea at the
time. a cable  snap would yield a fully open throttle and a pull only cable
could be bent in a  smaller radius.

Descending for my approach to KPIA, upon leveling off, I advanced the
throttle, The lever felt normal, but the engine continued to idle. I spent
precious time trying to trouble shoot and correct the problem. The episode
resulted in the plane's destruction and my survival landing on the only  area,
way too small for a normal landing with a 40K tailwind with berms and
farming implements at what would be the end of my rollout. Not a good scene. The
only other place was into the wind on a freshly plowed wet field (did I
mention  it was rainy?)

Post accident (incident) investigation revealed nothing wrong with the
engine of the linkage. However, Post Post inspection (after dragging the corpus
home) revealed that a heat shield may have distorted with heat jamming the
throttle closed. (Idle) and when I added throttle, the relaxing cable had
no  effect since the spring tension was now counteracted by friction to the
heat  shield. I had no idea of this since from throttle position and
friction all  appeared normal. After "arrival" and cooling down, the heat shield
returned to  it's normal position and the throttle worked correctly.

This is not to justify the design error but to say that a solid throttle
connection would have notified me immediately that the throttle was jammed,
or  possibly given me the ability to muscle open the throttle yielding a
totally  different result. This event happened after 100 H TT.

Had I been aware that the throttle was not opening, or going to open,
perhaps I would not have wasted the precious moments trying to troubleshoot and
would have been able to put it down in a more hospitable place I had
passed.

When you have an engine failure at low altitude, although time flows like
molasses, every second is critical.

Rich

An electronic throttle needs a computer to control it.
What happens if the computer goes insane? :)
http://www.fear-of-flying.us/index.php?p=1_11_The-Robot-Plane
It can kill you long before you can do anything about it.

Current airplanes have carburetors, magnetos and throttle cables for
very good reasons.

Paul Lamar