Tach Attack

[Ron Wanttaja[_2_]]

A month or so back, I asked about re-setting the reading of a standard
aircraft tach to reflect the time the airplane spent with a temporary
replacement.

Unfortunately, as it turns out, there was nothing wrong with my
tach...or with the tach cable. The tach-drive section on the engine
itself (Continental C85) was bad.

Once I was convinced the engine-side tach drive was munged, I started
looking into the options for electronic tachs. Most installed a
transducer on the engine tach drive...which I figured wouldn't work in
my case, since they probably would have the same problems with my
damaged drive head. Others connected to a Bendix or Slick
magneto...neat option, but I have Eisemans.

Finally, I noticed the "Tiny Tach" on the Aircraft Spruce web page.
Seemed pretty good...got its signal by wrapping a wire around a spark
plug cable. From the description, I wasn't completely sure which model
to buy. But when I went to the company's web page, I found they had a
universal "Commercial" model that also updated faster than the standard
units.

http://www.tinytach.com/tinytach/commercial.php

Only $65, so I went ahead and ordered one. It had both a tach function
as well as an hourmeter and two service timers. It didn't need ANY
other connection other than to wrap the sensor wire around a spark plug
cable. It has a built-in battery.

When it came in, I went to the airport and tried a temporary
installation. No go...tach read zero. I suspected the shielding on the
tach cables, and a call to the tach vendor confirmed it. The tech
recommended peeling the shielding back near a plug, but I didn't want to
run my tach wire out into the slipstream.

One of my spark plug wires is about 9" too long, and a previous owner
had wrapped up the excess and tie-wrapped it to the engine mount. I
figured I'd modify the wire there, so if I botched it, there'd still be
enough cable to connect to the mag. So I picked at the shielding with a
toothpick to make some openings, then carefully plucked away at it with
an exacto knife. A few minutes work, and I had a 1" long section of
cable free of the braid.

The tach instructions said to wrap the red wire around the cable 3-4
times. I gave that a shot, and the tachometer worked.

I made a mount for the Tiny Tach from some leftover 1/8" plywood. I
could have just used a flat sheet to attach behind the panel, but I
ended up with a "sandwich" construction where the outer face was
circular with the diameter just less than a standard instrument hole. I
felt this gave a lot nicer look to the installation....it looked more
like an instrument sitting "in the hole" than just a flat sheet behind
the panel.

http://www.bowersflybaby.com/tech/tach_done.jpg

One thing I had to do was plug off the old tach cable port on the back
of the engine. Aircraft Spruce had a cap for Lycomings that had the
same thread sizes, so I took a chance that it'd fit my Continental.

It did, but the hardest part was safety-wiring it in place. The cap
sits between the generator and the right mag, and there aren't any good
places nearby to connect the safety-wire to. I finally settled on a
fitting eight or so inches away, and fed in a long piece of safety wire
through pre-drilled holes in the end of the cap.

I was wiggling the wire around, trying to curve the other end back
around, when I heard a crackling sound. I stepped back and saw smoke
rising. The loose end of the safety wire had flipped up and had shorted
a +12V terminal to ground!

My arm shot out and I grabbed the wire. Bad move. It was a 0.032
stainless steel wire with about 20 amps flowing through it. I turned it
loose and grabbed a pair of pliers.

Problem solved...but now I had a nice little burn across the last joint
of one of my fingers. Got a beau-ti-ful blister, now.

http://www.bowersflybaby.com/tech/tach_owie.jpg

The cap was finally safetied, and I ran the tach wire ran over the same
route as the old tach drive cable. Wrap the red sensor wire around the
open area between the braid four times, then lay the sensor wire
parallel to the spark plug wire and wrap the whole area in copper tape.
I was concerned about the open braid causing radio noise.

No radio noise...but no operation of the tach, either.

I figured it was the copper tape, so I stripped it away and straightened
the sensor wire.

The tach worked now, but was very erratic at low RPM. I wrapped the end
of the sensor wire around the plug wire one more time, and the problem
got better. So I wrapped the rest of the red wire around the plug
(about six turns). The idle was now stable, except it would glitch
momentarily every five or ten seconds.

http://www.bowersflybaby.com/tech/tach_coil.jpg

I'd brought a headset with, and noticed that the open section in the
braid produced only a very minor bit of popping into the radio. But I'd
started to wonder if maybe my copper tape wrapping HADN'T been the
problem, earlier. I had laid the rest of the sensor wire horizontally
along the plug wire under the copper tape. The diagram from the tach
manufacturer shows the sensor wire coming straight away from the plug
wire, instead. So I re-wrapped the section with copper tape, taking
care to let the sensor go directly away from the plug wire instead of
wrapping it in the copper tape.

And lo and behold, it worked.

http://www.bowersflybaby.com/tech/tach_copper.jpg

Wrap the area in electrical tape for a bit of durability, then re-secure
the spark plug wire to the motor mount with tie-wraps, as before.

http://www.bowersflybaby.com/tech/tach_wrap.jpg

A test flight produced very nice operation. There's still a bit of
instability at low power settings, but once the RPM crosses 1000, the
tach is rock-steady. The copper tape shielding is working great; no
ignition noise is audible.

Since it's connected to the left magneto, conventional "Mag checks" are
a thing of the past. When the mag switch goes to "R", the tach goes to
zero...it can't register if the magneto isn't firing.

I don't see this as much of a drawback. I've been less concerned with
the actual RPM drop during a mag check than with rough running, instead.
I figure that any real problem will manifest itself as missing and
stumbling, rather than hitting 155 RPM on a mag drop.

In any case, I own a small handheld tach, and will use it at annual time
to make sure things are hunky-dory.

The hourmeter function is pretty slick; it registers hours until the
engine starts, then automatically switches to the tach mode. However,
the hour meter shows hours and minutes only until the tach reaches
199:59; after that, it reads whole hours only.

Not a real drawback, as the tach also includes a secondary counter that
can still be used to keep track of minutes. However, 200 hours is about
five years of flying for me, and the built-in battery of the Tiny Tach
is only good for 5-8 years. At that point, I'd better hope the company
is still operating...or come up with some other solution.

Ron Wanttaja

[Scott[_7_]]

Ron Wanttaja wrote:

>
> I was wiggling the wire around, trying to curve the other end back
> around, when I heard a crackling sound. I stepped back and saw smoke
> rising. The loose end of the safety wire had flipped up and had shorted
> a +12V terminal to ground!
>
> My arm shot out and I grabbed the wire. Bad move. It was a 0.032
> stainless steel wire with about 20 amps flowing through it. I turned it
> loose and grabbed a pair of pliers.
>
> Problem solved...but now I had a nice little burn across the last joint
> of one of my fingers. Got a beau-ti-ful blister, now.
>
> http://www.bowersflybaby.com/tech/tach_owie.jpg

Ouch. Now I have another argument to put in my bag of retorts when
people bash me for not having an electrical system in my plane! I've
never shorted the battery supply to ground in any of MY planes! ;)

Hope your finger gets better soon...you may need it for driving! ;)

[Rich S.[_2_]]

On Aug 7, 9:52*pm, Ron Wanttaja > wrote:

> . . . Unfortunately, as it turns out, there was nothing wrong with my
> tach...or with the tach cable. *The tach-drive section on the engine
> itself (Continental C85) was bad. . . .

And, what do you plan to do about the stray pieces of the old tach
drive which are floating around in your oil? :))

Rich S.

[Ron Wanttaja[_2_]]

Rich S. wrote:
> On Aug 7, 9:52 pm, Ron Wanttaja > wrote:
>
>> . . . Unfortunately, as it turns out, there was nothing wrong with my
>> tach...or with the tach cable. The tach-drive section on the engine
>> itself (Continental C85) was bad. . . .
>
> And, what do you plan to do about the stray pieces of the old tach
> drive which are floating around in your oil? :))

That's why the engine has the oil screen, right? :-)

Actually, the tach drive is external to the engine. It's at the end of
a longish shaft on an idler gear inside the accessory case.

Ron Wanttaja

[Stealth Pilot[_2_]]

On Fri, 07 Aug 2009 21:52:49 -0700, Ron Wanttaja >
wrote:


>Finally, I noticed the "Tiny Tach" on the Aircraft Spruce web page.
>Seemed pretty good...got its signal by wrapping a wire around a spark
>plug cable. From the description, I wasn't completely sure which model
>to buy. But when I went to the company's web page, I found they had a
>universal "Commercial" model that also updated faster than the standard
>units.
>
>http://www.tinytach.com/tinytach/commercial.php
>
>Only $65, so I went ahead and ordered one. It had both a tach function
>as well as an hourmeter and two service timers. It didn't need ANY
>other connection other than to wrap the sensor wire around a spark plug
>cable. It has a built-in battery.
>

it is indeed a pity that tinytach cant be given the hint that a
replaceable lithium battery would see an aviation market open up for
them. two lithium batteries so that they can be replaced individually
without loss of power would seem a simple mod to make the tach really
useful.
my hp calculators have used the two battery idea for ages.(ever since
I bought them :-) )

Stealth Pilot

[Ron Wanttaja[_2_]]

Stealth Pilot wrote:
> On Fri, 07 Aug 2009 21:52:49 -0700, Ron Wanttaja >
> wrote:
>
> it is indeed a pity that tinytach cant be given the hint that a
> replaceable lithium battery would see an aviation market open up for
> them. two lithium batteries so that they can be replaced individually
> without loss of power would seem a simple mod to make the tach really
> useful.

They're losing the vast aviation market? :-)

From what I can see, the product is mostly aimed at the industrial
engine market, especially rental equipment. They know it's being used
on aircraft engines, but I suspect the number of actual installations in
airplanes is pretty small. Probably mostly in the ultralight world,
since anything with a Lycoming or Continental is already going to have a
tach drive.

As far as the non-replaceability of the battery, we'll see when the time
comes. The case is sealed plastic, so it should be possible to cut it
open. If nothing else, adding an external pack for a battery shouldn't
be tough.

It looks like Tiny Tach did, in fact, recently upgrade its commercial
tach from using external power to using solely the internal battery.
The version of their installation instruction that's online shows a
battery connection....

http://www.tinytach.com/tinytach/images/com_instructions.pdf

When I ordered the tach, I thought I'd have to supply power to it.
Since I thought I'd have to deliver power to the meter, I figured I'd
add a small voltmeter as well, since my voltmeter is a short-arc analog
gauge mounted just above the floor (tough to read).

I ordered the Martel Tools QM-100V....

http://www.martelmeters.com/pdf/QM_100V.pdf

....and this is one slick device. Self-contained LCD voltmeter in a
package the size of two postage stamps, less than a quarter inch thick,
surface mounts using a 7/32" stud on the back of the package. Didn't
use it, since the tach didn't need power after all, but I'll probably
add it the next time I rework the power.

Ron Wanttaja

[canuck_bob]

Gee Ron,

Your on a slippery slope. Digital displays and already planning your
next electrical upgrade! Could be evidence of that dreaded
psychological disorder known as Airventure Syndrome. We'll keep an
eye out for the major symptoms, obsessive urges to install IFR glass
panels, researching the installation of autopilot systems and weather
radar, and the most serious sympton requiring medication a small
little black box that costs more than your last house.

There is only one cure. Quick, rush to the airport and throw that
generator and starter into the bush, recycle the battery, and strip
all that tangled wire. Think back to the days when your electrical
system was 2 wires to a switch. There is hope still for a complete
recovery! ;-)

Bob

[Scott[_7_]]

Ron Wanttaja wrote:

They know it's being used
> on aircraft engines, but I suspect the number of actual installations in
> airplanes is pretty small. Probably mostly in the ultralight world,
> since anything with a Lycoming or Continental is already going to have a
> tach drive.

Except yours!!! ;)

Scott
Corben Junior Ace WITH built in tach drive (so far)!!!

[Scott[_7_]]

canuck_bob wrote:
Think back to the days when your electrical
> system was 2 wires to a switch. ;-)
>
> Bob
>

And some of us STILL do! ;)

Scott
Corben Junior Ace
We don't need no steeenkin' electrical system ;)

[John Kimmel[_2_]]

Ron Wanttaja wrote:
>
> Not a real drawback, as the tach also includes a secondary counter that
> can still be used to keep track of minutes. However, 200 hours is about
> five years of flying for me, and the built-in battery of the Tiny Tach
> is only good for 5-8 years. At that point, I'd better hope the company
> is still operating...or come up with some other solution.
>
> Ron Wanttaja

Here is a picture of the insides of a tiny tach. The gray stuff is soft potting compound similar to BMS5-95. The battery was a common
3v Lithim Ion button cell welded to the tabs before potting. If I ever find another tiny tach that needs a new battery, I will cut a
hole right over the battery with a rotabroach or a mill instead of splitting the case. You can't open the case without breaking it

http://tinyurl.com/tinytach

--
John Kimmel


So in this world
Of the simple and odd,
The bent and plain,
The unbalanced bod,
The imperfect people
And differently pawed,
Some live without love...
That's how they're flawed.

[Morgans[_7_]]

"John Kimmel" > wrote

> Here is a picture of the insides of a tiny tach. The gray stuff is soft
> potting compound similar to BMS5-95. The battery was a common 3v Lithim
> Ion button cell welded to the tabs before potting. If I ever find another
> tiny tach that needs a new battery, I will cut a hole right over the
> battery with a rotabroach or a mill instead of splitting the case. You
> can't open the case without breaking it
>
> http://tinyurl.com/tinytach

My tactic for splitting plastic cases is to use a dremmel tool with a thin
cut-off wheel, and cut right on the seam. Don't bother trying to pry it
apart, since they always crack like you have observed. When putting it back
together, I use JB Weld on the seam and quickly put electrical tape over the
seam. This holds the case together while the JB sets up and the tape will
later peel off, leaving a nice slick seam of JB. On a black case is
difficult to see that it has been taken apart, since the JB Weld becomes a
smooth surface that matches the plastic case amazingly well.

I have used this method to replace cells in power tool battery packs, and
the repair holds up to the extreme abuse they are subjected to.
--
Jim in NC

[Ron Wanttaja[_2_]]

John Kimmel wrote:
> Ron Wanttaja wrote:
>>
>> Not a real drawback, as the tach also includes a secondary counter
>> that can still be used to keep track of minutes. However, 200 hours
>> is about five years of flying for me, and the built-in battery of the
>> Tiny Tach is only good for 5-8 years. At that point, I'd better hope
>> the company is still operating...or come up with some other solution.
>
> Here is a picture of the insides of a tiny tach. The gray stuff is soft
> potting compound similar to BMS5-95. The battery was a common 3v Lithim
> Ion button cell welded to the tabs before potting.

OooooOooo, thank you! I've saved that shot for future reference.

Ron Wanttaja

[Ron Wanttaja[_2_]]

canuck_bob wrote:
> Gee Ron,
>
> Your on a slippery slope. Digital displays and already planning your
> next electrical upgrade! Could be evidence of that dreaded
> psychological disorder known as Airventure Syndrome. We'll keep an
> eye out for the major symptoms, obsessive urges to install IFR glass
> panels, researching the installation of autopilot systems and weather
> radar, and the most serious sympton requiring medication a small

I probably shouldn't confess this, but ever since the Dynon folks gave a
presentation at the EAA Chapter, I've really had the urge to install one
of their EFIS boxes on my Fly Baby. Just for the jaw-dropping
incongruity of it, if nothing else....

Ron Wanttaja

[Philippe[_2_]]

Scott a écrit:

>> Think back to the days when your electrical
>> system was 2 wires to a switch. ;-)

but now, electrical system may be more reliable. I read my old
continental engine health on an EIS 4000.
For my tach, I use two magnet on the flywheel, a reed contact and two
wires.

You know small continental d'nt have flywheel but a french guy make a
conversion for A65 with kubota permanent magnet alternator and
automotive starter. This kit may fit O200 too.
http://mdlaurent.free.fr/

I also use the magnets for CDI electronic ignition. no more magnetos,
no more cable for tach, no more copper tube for oil pressure...

By
--
« Si tous les poètes voulaient se donner la main, ils toucheraient enfin
des doigts d'auteur! »
Philippe Vessaire Ò¿Ó¬

[Stealth Pilot[_2_]]

On Sun, 09 Aug 2009 21:11:48 -0700, John Kimmel >
wrote:

>Ron Wanttaja wrote:
>>
>> Not a real drawback, as the tach also includes a secondary counter that
>> can still be used to keep track of minutes. However, 200 hours is about
>> five years of flying for me, and the built-in battery of the Tiny Tach
>> is only good for 5-8 years. At that point, I'd better hope the company
>> is still operating...or come up with some other solution.
>>
>> Ron Wanttaja
>
>Here is a picture of the insides of a tiny tach. The gray stuff is soft potting compound similar to BMS5-95. The battery was a common
>3v Lithim Ion button cell welded to the tabs before potting. If I ever find another tiny tach that needs a new battery, I will cut a
>hole right over the battery with a rotabroach or a mill instead of splitting the case. You can't open the case without breaking it
>
>http://tinyurl.com/tinytach


John
this is incredibly funny. they go to all the trouble of sealing up the
case and filling it to make it bullet proof and what is it that the
second reader of ron's post does?

pull one apart to see what's inside :-) :-) :-)

I love it!

Stealth Pilot

[Dan[_12_]]

Stealth Pilot wrote:
> On Sun, 09 Aug 2009 21:11:48 -0700, John Kimmel >
> wrote:
>
>> Ron Wanttaja wrote:
>>> Not a real drawback, as the tach also includes a secondary counter that
>>> can still be used to keep track of minutes. However, 200 hours is about
>>> five years of flying for me, and the built-in battery of the Tiny Tach
>>> is only good for 5-8 years. At that point, I'd better hope the company
>>> is still operating...or come up with some other solution.
>>>
>>> Ron Wanttaja
>> Here is a picture of the insides of a tiny tach. The gray stuff is soft potting compound similar to BMS5-95. The battery was a common
>> 3v Lithim Ion button cell welded to the tabs before potting. If I ever find another tiny tach that needs a new battery, I will cut a
>> hole right over the battery with a rotabroach or a mill instead of splitting the case. You can't open the case without breaking it
>>
>> http://tinyurl.com/tinytach
>
>
> John
> this is incredibly funny. they go to all the trouble of sealing up the
> case and filling it to make it bullet proof and what is it that the
> second reader of ron's post does?
>
> pull one apart to see what's inside :-) :-) :-)
>
> I love it!
>
> Stealth Pilot

I think most of us have done that at one time or another. The hard
part is putting it back together with no parts left over.

Dan, U.S. Air Force, retired

[John Ammeter]

Install the EFIS and double the value of your Flybaby.... grin...

John

Ron Wanttaja wrote:
> canuck_bob wrote:
>> Gee Ron,
>>
>> Your on a slippery slope. Digital displays and already planning your
>> next electrical upgrade! Could be evidence of that dreaded
>> psychological disorder known as Airventure Syndrome. We'll keep an
>> eye out for the major symptoms, obsessive urges to install IFR glass
>> panels, researching the installation of autopilot systems and weather
>> radar, and the most serious sympton requiring medication a small
>
> I probably shouldn't confess this, but ever since the Dynon folks gave a
> presentation at the EAA Chapter, I've really had the urge to install one
> of their EFIS boxes on my Fly Baby. Just for the jaw-dropping
> incongruity of it, if nothing else....
>
> Ron Wanttaja

[Brian Whatcott]

Morgans wrote:

> My tactic for splitting plastic cases is to use a dremmel tool with a
> thin cut-off wheel, and cut right on the seam. Don't bother trying to
> pry it apart, since they always crack like you have observed. When
> putting it back together, I use JB Weld on the seam and quickly put
> electrical tape over the seam. This holds the case together while the
> JB sets up and the tape will later peel off, leaving a nice slick seam
> of JB. On a black case is difficult to see that it has been taken
> apart, since the JB Weld becomes a smooth surface that matches the
> plastic case amazingly well.
>
> I have used this method to replace cells in power tool battery packs,
> and the repair holds up to the extreme abuse they are subjected to.


I was already predisposed to believe the efficiency of this method.
Scaled up to an angle grinder with a thin cut-off blade (which are
amazingly rugged these days) I have opened an impromptu inspection
panel in a car door to replace the electric window winder clutch,
saving a whole bunch of hand wriggling in a narrow door space;
Carved a notch in a big bale carrier strut to put the load further
forward (If you ever had 1200 lbs of hay trailer wriggling a truck
like a girl with a hula hoop, you'd want to do this...) and cut off
a sink drain stopper funnel securing ring, long since corroded
to immobility. I am a believer!

Brian W

[Brian Whatcott]

Philippe wrote:
....
> I also use the magnets for CDI electronic ignition. no more magnetos,
> no more cable for tach, no more copper tube for oil pressure...
>
> By

Not sure if this is what you mean, but a few high energy magnets
spinning on a plate do a great job producing pulses in a few coils
spaced close to the spinning magnets.

Seems like you could easily arrange two sets of coils to provide a
double source for a CD ignition, as well as timing it....
Or perhaps more compact, a source (if rectified and smoothed)
for one of those electronic ignition modules that fit inside the car
distributor, these days....

Either way that really amounts to a magneto I suppose - but so few
components, and double redundant so no battery would be involved.....

Brian W

[Peter Dohm]

"brian whatcott" > wrote in message
...
> Philippe wrote:
> ...
>> I also use the magnets for CDI electronic ignition. no more magnetos,
>> no more cable for tach, no more copper tube for oil pressure... By
>
> Not sure if this is what you mean, but a few high energy magnets spinning
> on a plate do a great job producing pulses in a few coils spaced close to
> the spinning magnets.
>
> Seems like you could easily arrange two sets of coils to provide a double
> source for a CD ignition, as well as timing it....
> Or perhaps more compact, a source (if rectified and smoothed)
> for one of those electronic ignition modules that fit inside the car
> distributor, these days....
>
> Either way that really amounts to a magneto I suppose - but so few
> components, and double redundant so no battery would be involved.....
>
> Brian W

I admit that I don't recall who manufactures and sells them; but I seem to
recall that Steve Wittman used a "self sufficient distributor" fitting that
description, as part of his V8 conversion for the Tailwind, at least 25
years ago.

Peter

[Scott[_7_]]

Peter Dohm wrote:

>
> I admit that I don't recall who manufactures and sells them; but I seem to
> recall that Steve Wittman used a "self sufficient distributor" fitting that
> description, as part of his V8 conversion for the Tailwind, at least 25
> years ago.
>
> Peter
>
>
>
Would that really be a Vertex magneto that fits into the distributor
hole? They use Vertex mags on VW engines sometimes...

Scott

[Peter Dohm]

"Scott" > wrote in message
.. .
> Peter Dohm wrote:
>
>>
>> I admit that I don't recall who manufactures and sells them; but I seem
>> to recall that Steve Wittman used a "self sufficient distributor" fitting
>> that description, as part of his V8 conversion for the Tailwind, at least
>> 25 years ago.
>>
>> Peter
>>
>>
>>
> Would that really be a Vertex magneto that fits into the distributor hole?
> They use Vertex mags on VW engines sometimes...
>
> Scott

You are probably correct, although I no longer recall the name and do not
recall where my copy of the V8 conversion plans might be stored.

That was just one of several projects that never came to fruition. And
today there are additional choices in the same range of power, weight, and
displacement--that would not require the resurection of a 45 year old
engine.

Peter

[Brian Whatcott]

Peter Dohm wrote:
> "brian whatcott" > wrote in message
> ...
>> Philippe wrote:
>> ...
>>> I also use the magnets for CDI electronic ignition. no more magnetos,
>>> no more cable for tach, no more copper tube for oil pressure... By
>> Not sure if this is what you mean, but a few high energy magnets spinning
>> on a plate do a great job producing pulses in a few coils spaced close to
>> the spinning magnets.
>>
>> Seems like you could easily arrange two sets of coils to provide a double
>> source for a CD ignition, as well as timing it....
>> Or perhaps more compact, a source (if rectified and smoothed)
>> for one of those electronic ignition modules that fit inside the car
>> distributor, these days....
>>
>> Either way that really amounts to a magneto I suppose - but so few
>> components, and double redundant so no battery would be involved.....
>>
>> Brian W
>
> I admit that I don't recall who manufactures and sells them; but I seem to
> recall that Steve Wittman used a "self sufficient distributor" fitting that
> description, as part of his V8 conversion for the Tailwind, at least 25
> years ago.
>
> Peter
>
>
>
Something that fits in the distributor hole and looks like a
distributor, with no battery lead however, is the VW type magneto.
Kinda expensive, and sticks up on a VW cowl, but does the job.

Kinda like the Wittman approach??

Brian W

[flash]

"Dan" > wrote in message
...
> Stealth Pilot wrote:
>> On Sun, 09 Aug 2009 21:11:48 -0700, John Kimmel >
>> wrote:
>>
>>> Ron Wanttaja wrote:
>>>> Not a real drawback, as the tach also includes a secondary counter that
>>>> can still be used to keep track of minutes. However, 200 hours is
>>>> about five years of flying for me, and the built-in battery of the Tiny
>>>> Tach is only good for 5-8 years. At that point, I'd better hope the
>>>> company is still operating...or come up with some other solution.
>>>>
>>>> Ron Wanttaja
>>> Here is a picture of the insides of a tiny tach. The gray stuff is soft
>>> potting compound similar to BMS5-95. The battery was a common 3v Lithim
>>> Ion button cell welded to the tabs before potting. If I ever find
>>> another tiny tach that needs a new battery, I will cut a hole right over
>>> the battery with a rotabroach or a mill instead of splitting the case.
>>> You can't open the case without breaking it
>>>
>>> http://tinyurl.com/tinytach
>>
>>
>> John
>> this is incredibly funny. they go to all the trouble of sealing up the
>> case and filling it to make it bullet proof and what is it that the
>> second reader of ron's post does?
>>
>> pull one apart to see what's inside :-) :-) :-)
>>
>> I love it!
>>
>> Stealth Pilot
>
> I think most of us have done that at one time or another. The hard part
> is putting it back together with no parts left over.
>
> Dan, U.S. Air Force, retired

And making sure that the magic smoke doesn't EVER escape.

Flash

[John Kimmel[_2_]]

Stealth Pilot wrote:
> On Sun, 09 Aug 2009 21:11:48 -0700, John Kimmel >
> wrote:
>
>> Ron Wanttaja wrote:
>>> Not a real drawback, as the tach also includes a secondary counter that
>>> can still be used to keep track of minutes. However, 200 hours is about
>>> five years of flying for me, and the built-in battery of the Tiny Tach
>>> is only good for 5-8 years. At that point, I'd better hope the company
>>> is still operating...or come up with some other solution.
>>>
>>> Ron Wanttaja
>> Here is a picture of the insides of a tiny tach. The gray stuff is soft potting compound similar to BMS5-95. The battery was a common
>> 3v Lithim Ion button cell welded to the tabs before potting. If I ever find another tiny tach that needs a new battery, I will cut a
>> hole right over the battery with a rotabroach or a mill instead of splitting the case. You can't open the case without breaking it
>>
>> http://tinyurl.com/tinytach
>
>
> John
> this is incredibly funny. they go to all the trouble of sealing up the
> case and filling it to make it bullet proof and what is it that the
> second reader of ron's post does?
>
> pull one apart to see what's inside :-) :-) :-)
>
> I love it!
>
> Stealth Pilot

I pulled it apart years ago.

--
John Kimmel







So in this world
Of the simple and odd,
The bent and plain,
The unbalanced bod,
The imperfect people
And differently pawed,
Some live without love...
That's how they're flawed.

[Philippe[_2_]]

brian whatcott a écrit:

>> I also use the magnets for CDI electronic ignition. no more magnetos,
>> no more cable for tach, no more copper tube for oil pressure...
>>
>> By
>
> Not sure if this is what you mean, but a few high energy magnets
> spinning on a plate do a great job producing pulses in a few coils
> spaced close to the spinning magnets.

I have two simple magnets one north face and the other south face glue
at 0° and 180°.
The sensor is one AH287 and I use two automotive CDI boxes as power
stage for ignition #2.
I use one distributorless box from M&W ignition for #1.

For the electric wiring, I copy the following schematic:
http://www.jodel.com/index.asp?p=potezwiring&engines

My electronics devices are in the the point and distributor ignition
place.
In fact, I built 2 distributorless ignittions like today cars but
still have fix timing.

The wish list is one microcontroler for variable timing.

No way to built a small generator with my magnets. A batteryless
ignition like Jabiru require more start energy than my ignition.



By
--
« Si tous les poètes voulaient se donner la main, ils toucheraient enfin
des doigts d'auteur! »
Philippe Vessaire Ò¿Ó¬

[Stealth Pilot[_2_]]

On Tue, 11 Aug 2009 09:26:15 +0200, Philippe >
wrote:

>brian whatcott a écrit:
>
>>> I also use the magnets for CDI electronic ignition. no more magnetos,
>>> no more cable for tach, no more copper tube for oil pressure...
>>>
>>> By
>>
>> Not sure if this is what you mean, but a few high energy magnets
>> spinning on a plate do a great job producing pulses in a few coils
>> spaced close to the spinning magnets.
>
> I have two simple magnets one north face and the other south face glue
>at 0° and 180°.
> The sensor is one AH287 and I use two automotive CDI boxes as power
>stage for ignition #2.
> I use one distributorless box from M&W ignition for #1.
>
> For the electric wiring, I copy the following schematic:
>http://www.jodel.com/index.asp?p=potezwiring&engines
>
> My electronics devices are in the the point and distributor ignition
>place.
> In fact, I built 2 distributorless ignittions like today cars but
>still have fix timing.
>
> The wish list is one microcontroler for variable timing.
>
>No way to built a small generator with my magnets. A batteryless
>ignition like Jabiru require more start energy than my ignition.
>

the trick with the magnets is to understand that it is the collapsing
magnetic field that produces the pulse to the spark plug.
if you look at a jabiru magnet there are 3 poles. as the magnet goes
whizzing past the coil the coil sees North-South then suddenly
South-North. the second magnet orientation is designed to accelerate
the collapse of the field through the coil core.
The two outer poles are , say, South and the centre one, say, North or
vice versa.

it is not just magnets on a plate but magnetic pole orientation as
well that makes it work.

Stealth Pilot

[Peter Dohm]

"brian whatcott" > wrote in message
...
> Peter Dohm wrote:
>> "brian whatcott" > wrote in message
>> ...
>>> Philippe wrote:
>>> ...
>>>> I also use the magnets for CDI electronic ignition. no more magnetos,
>>>> no more cable for tach, no more copper tube for oil pressure... By
>>> Not sure if this is what you mean, but a few high energy magnets
>>> spinning on a plate do a great job producing pulses in a few coils
>>> spaced close to the spinning magnets.
>>>
>>> Seems like you could easily arrange two sets of coils to provide a
>>> double source for a CD ignition, as well as timing it....
>>> Or perhaps more compact, a source (if rectified and smoothed)
>>> for one of those electronic ignition modules that fit inside the car
>>> distributor, these days....
>>>
>>> Either way that really amounts to a magneto I suppose - but so few
>>> components, and double redundant so no battery would be involved.....
>>>
>>> Brian W
>>
>> I admit that I don't recall who manufactures and sells them; but I seem
>> to recall that Steve Wittman used a "self sufficient distributor" fitting
>> that description, as part of his V8 conversion for the Tailwind, at least
>> 25 years ago.
>>
>> Peter
>>
>>
>>
> Something that fits in the distributor hole and looks like a distributor,
> with no battery lead however, is the VW type magneto.
> Kinda expensive, and sticks up on a VW cowl, but does the job.
>
> Kinda like the Wittman approach??
>
> Brian W

I believe so.

Peter

[Morgans[_7_]]

"Scott" > wrote


> Would that really be a Vertex magneto that fits into the distributor hole?
> They use Vertex mags on VW engines sometimes...

I think it was this beast that I read some very unflattering things about,
concerning reliability, about a month ago. It made me wonder if I would
want to depend on one of these while above the NC mountains.

Anyone else remember anything like that?
--
Jim in NC

[cavelamb[_2_]]

Morgans wrote:
>
> "Scott" > wrote
>
>
>> Would that really be a Vertex magneto that fits into the distributor
>> hole? They use Vertex mags on VW engines sometimes...
>
> I think it was this beast that I read some very unflattering things
> about, concerning reliability, about a month ago. It made me wonder if
> I would want to depend on one of these while above the NC mountains.
>
> Anyone else remember anything like that?

Especially considering there is only one of them...

[Scott[_7_]]

cavelamb wrote:
> Morgans wrote:
>>
>> "Scott" > wrote
>>
>>
>>> Would that really be a Vertex magneto that fits into the distributor
>>> hole? They use Vertex mags on VW engines sometimes...
>>
>> I think it was this beast that I read some very unflattering things
>> about, concerning reliability, about a month ago. It made me wonder
>> if I would want to depend on one of these while above the NC mountains.
>>
>> Anyone else remember anything like that?
>
> Especially considering there is only one of them...

True, but even the normal distributor goes dead when the battery goes
dead, so unless you have a charging system, the same thing could happen.
Mr. "Morgans" COULD move up to IL or IN to escape those pesky
mountains! ;)

Scott

[Morgans[_7_]]

"Scott" > wrote
>
> True, but even the normal distributor goes dead when the battery goes
> dead, so unless you have a charging system, the same thing could happen.
> Mr. "Morgans" COULD move up to IL or IN to escape those pesky mountains!
> ;)

Been there, done that. I grew up in Northern Ohio. Flat, flat, FLAT!
<ggg>
--
Jim in NC

[Scott[_7_]]

Morgans wrote:
>
> "Scott" > wrote
>>
>> True, but even the normal distributor goes dead when the battery goes
>> dead, so unless you have a charging system, the same thing could
>> happen. Mr. "Morgans" COULD move up to IL or IN to escape those pesky
>> mountains! ;)
>
> Been there, done that. I grew up in Northern Ohio. Flat, flat, FLAT!
> <ggg>

Flat is good (except in the case of women)!!! Double grin!