Twin tachs

ROFL!
The heater huh? lots of free summer time hours! We actually have
another hobbs on the heater... for the heater

Well, the squat switch is a hydraulic by pass, but the hobbs should be wired
to the gear door switch or the gear up light.

Jim

"Kyler Laird" wrote in message
...
"Jim Burns" writes:

Yep. Got one of them also, but a previous owner wired it to the master
switch instead of the squat switch.

You have a squat switch?

BTW, we changed our Hobbes meter to run off of the heater.

--kyler

I've been talking to John at Diamondaire... Rochester totally dropped the
project, he's now working with Westach, but nothing forthcoming. His
solution for now is to use tach generators and electric tachs as the late F
model Aztecs and Barons had.

For now, I'll put in a twin needle mechanical and keep the tach cables
installed. If I blow a cable I'll think about my options once again. I'd
love a dual electronic tach from EI or Horizon... someday... but unless they
come out with a 3 1/8" model I'd have to redo the right panel

Jim

"Kyler Laird" wrote in message
...
"Jim Burns" writes:

One option is to simply get a mechanical dual tach and connect both tach
cables to the single tach but I don't know of a dual recording tach that
has
dual hour meters. Anybody?

I probably have the one we pulled from our Aztec in my junk box.

So far, I have not found a company that makes a dual electronic tach.
Neither E.I or Horizon seem to offer a dual tach.

I was told that Horizon would have a dual tach. "soon" when we were
looking in 2001.

Also, due to panel
configuration, I want a 3 1/8" dia tach not the smaller 2 1/4" tachs that
EI
or Horizon offer, I have no room for additional 2 1/4" gauges.

The Horizon P-1000 is a larger tach.

Another option is (always) on the horizon...
http://diamondaire.com/aztec.htm

Rochester engine instrumentation.We are currently working with
Rochester Gauges of Texas to introduce new 2-1/4" dual-needle
STC'd backlit gauges. [...] A 3-1/8" dual electric STC'd
tachometer will also be available.
(They've been saying that for awhile now.)

Is there anybody out there with any insight into this dilemma?

It's worth pursuing. I hate mechanical tachs. I've replaced those
damn cables way too many times. It makes no sense to have all that
crap in the plane just to provide a really lousy estimate of engine
speed. In a single it's o.k. but in a twin it's ridiculous. (I recall
the joy of yanking those cable housings out of my plane!)

You will love an electronic tach. I especially like the mag. failure
lights and the mag. drop feature. Having a tach. that always works and
is accurate without constant maintenance is pretty sweet too.

--kyler

Jim Burns wrote:
One option is to simply get a mechanical dual tach and connect both tach
cables to the single tach but I don't know of a dual recording tach that
has dual hour meters. Anybody?

This may be a totally goofy idea, but here goes. Install the mechanical
dual tach in the panel as above. Then get two Hobbs meters and wire one
to each engine. (I know Hobbs meter time is not tach hour meter time,
but play along.) Now, since you probably don't need to look at the
Hobbs meters every couple of minutes during your flight, you can stick
them in whatever available space you have behind the panel. (An LCD
Hobbs meter is only about 1"x2"x2".) You don't have to mount them so
that the numbers are normally visible; you just have to mount them so
that the numbers are visible when you want them.

If you have enough room, you can mount them on a hinged plate or flap
that can be swung down to read the meters and then swung back up out of
the way. Maybe install a captive thumbscrew or Dzus fastener to hold
the plate in the "stowed" position. Alternatively, mount the meters
without a hinge or flap, and mount small mirrors (like a mechanic's
inspection mirror, or a dental mirror) to bring the numbers out to
where you can see them. As long as you use an even number of mirrors,
you can read the numbers. The mirror closest to your eye probably needs
to be adjustable/removable/coverable, as it might reflect sunlight into
your face in certain situations.

If you believe that there's just no kill like an overkill, mount the
meters behind the panel as above, but also include a small LED or lamp
for illumination, a cheap webcam, and a small single-board computer with
video capture, OCR software, and audio output. Wire the output into an
aux input on your headphone system and wire a pushbutton to the board;
when you push the button it says something like "left engine three six
two point five hours, right engine three six one point seven hours" into
the audio system.

Matt Roberds

On Thu, 24 Aug 2006 00:36:11 GMT, wrote:

You don't have to mount them so
that the numbers are normally visible; you just have to mount them so
that the numbers are visible when you want them.

A Duchess I used to fly had the hobbs thing for the engines mounted in
the aft wall of the luggage compartment........

Peter Clark writes:

A Duchess I used to fly had the hobbs thing for the engines mounted in
the aft wall of the luggage compartment........

Is there any reason to have them in the cabin at all? Are there
approved clocks that can survive being in the engine compartment? Even
renters only look at them before each flight, right?

--kyler

On Tue, 29 Aug 2006 09:25:05 -0400, Kyler Laird
wrote:

Peter Clark writes:

A Duchess I used to fly had the hobbs thing for the engines mounted in
the aft wall of the luggage compartment........

Is there any reason to have them in the cabin at all? Are there
approved clocks that can survive being in the engine compartment? Even
renters only look at them before each flight, right?

Just so it can be read for filling out the tach/hobbs card handed into
the FBO so they know when MX is required.

On Tue, 29 Aug 2006 09:25:05 -0400, Kyler Laird
wrote:

Peter Clark writes:

A Duchess I used to fly had the hobbs thing for the engines mounted in
the aft wall of the luggage compartment........

Is there any reason to have them in the cabin at all? Are there
approved clocks that can survive being in the engine compartment? Even
renters only look at them before each flight, right?

Did a pre-buy on a Seminole one time that had 2 recording tachs and 2
independent aircraft hour meters. It had been used at a flight school,
all the "recording" devices had been changed multiple times.

Also, the maintenance records had random references to any/all of
them.

Probably one of the worst sets of logs that I've ever had to dig
through...

TC