In the mid-70's, an engineer named Tony Criscimagna invented a
tachometer which still stands as one of the best in existence. Soon after, Tony
started a business and sold thousands of these excellent tachometers under the
tradename "TNC" (his initials).
Skyborn Electronics (Powerflite) acquired the TNC from Tony around 2003,
and continued to build the original design. Faced with the obsolescence of some
critical components, Skyborn started to work on updating the design, but never
completed this process.
July 2005:
FROMECO Scale Avionics was presented with the welcome
opportunity to acquire the TNC tachometer! We are exceptionally pleased to be
able to reintroduce this outstanding product to the RC modeller community.
What we Changed
Processing: The FROMECO TNC's "brain" has been totally revised,
incorporating current microprocessor technology for 0.05% accuracy and improved
functionality.
Durability: FROMECO has re-engineered the
tachometer's packaging. The FROMECO TNC fully protects the sensor element,
has an integrated battery compartment, and is more resistant to
damage.
ON/OFF control: The FROMECO TNC uses slider
switch to turn the tachometer.
High RPM hold: The
revised tach displays both the current RPM and the highest RPM attained.
There are 5 significant digits for each measurement, for easy
reading.
Upgraded components: The new TNC uses an upgraded
sensor element, easily capable of obtaining RPM measurements at 6 feet under
most lighting conditions. The components have been upgraded to surface
mount technology, for reduced size and better
durability.
Cost: We are able to offer the new FROMECO TNC
for only $95. (instead of the former price of $120.00)
What we didn't Change
Range: The new TNC uses the same optical front end (the part that
detects the propeller blades) as the original, with only minor revision for
modernization of the parts. A well-proven
design!
Performance: The readings are just as solid as one
could expect from a TNC, even though the processing method is different.
The range is still excellent. The accuracy is still outstanding. We
continually compared the revised design with about a half-dozen of the
originals, to make sure the new one meets or exceeds the standard set by the
original TNC tachometer.
"The Name": Thanks, Tony, for a
great tachometer! Also thanks to Skyborn Electronics, for allowing us to
bring this tool back to the RC community!
Not only is the TNC great for RC use, it also works very
well for checking what we call "Full Scale" or General Aviation (GA) props
as well. The TNC is an excellent device to keep you in dash Tach
honest. Or if you don't have a Tach at all.
NOTE: The Fromeco TNC Tachometer is not a FAA
certified instrument, nor will it ever be.
Works great for:
- Ultra Lights
- Light Sport
- GA "Limited to 2 Blade and 3 Blade Birds"
Testimonial
Dear Fromeco,
I own and fly a full scale airplane and am
also an avid RC pilot. With both real and model aircraft it is desirable to know
propeller speed to get a good idea of engine tuning and performance. In fact, a
panel mounted tachometer is a mandatory instrument in real
airplanes.
Recently, my aviation mechanic discovered that my aircraft
tachometer was in error. He used a several hundred dollar optical instrument
made for the job that looked similar in principle to the tachs used by RC
hobbyists. So after getting my aircraft panel mounted tachometer re-calibrated,
I found myself interested in occasionally checking its calibration. I was not
about to spend hundreds of dollars, but wondered if an RC hobby unit would work
as well. At first I tried a GloBee tach. I couldn't even make it work reliably
on my RC models. After some internet research, the TNC Tachometer sounded like
the most reliable unit so I ordered one. At just under $100, I'm glad to report
that it works wonderfully.
After verifying proper calibration under a
flourescent light, I went for a flight in my Cessna and pointed the unit through
the windshield at the prop. I tried it in various day light conditions and it
always reported values in close agreement with my mechanical tach. I say "close"
because while the TNC Tach reads in units of 1 RPM, my airplane tach reads in
increments of 50 RPMs. Light conditions included directly into the sun, away
from the sun, and late afternoon/early evening under a complete overcast. My
Cessna has a two bladed prop, but I also tried it in a friend's Cessna 182 with
3 blades and a very sophisticated G1000 glass panel avionics and engine
monitoring system. Again, the TNC Tach values were in very close agreement with
the C182's instrumentation which reported RPM in units of ten.
The
purpose built test tachometers that aviation mechanics use, have a display that
is bigger and better oriented for visibility. However, I found it convenient
enough to simply hold the TNC Tach sideways with its display toward me for
readability. The TNC tach immediately displays the highest RPM and the
instantaneous RPM. I found the instantaneous reading to agree precisely with the
airplane's tachometer and the high reading to be slightly high. I attribute this
to hand positioning artifacts when the unit is first pointed at the prop, both
numbers were useable. With in reason, the TNC Tach was very tolerant to hand
holding, angle, or where on the prop the unit was pointed.
Much of the RC
crowd probably already knows how good this tach is. The full scale, general
aviation crowd should get to know this device better.
--Jose
Velez