Today's Message Index:
----------------------
1. 06:24 AM - speaking of solenoids (Charlie England)
2. 07:37 AM - Re: How many connections are too many (prestonkavanagh)
3. 08:01 AM - Re: "Contactor Questions" , battery in the trunk, now Ground power plug (Robert L. Nuckolls, III)
4. 08:27 AM - Re: M43435/II/B Lacing tape (prestonkavanagh)
5. 08:32 AM - Re: speaking of solenoids (Jeff Luckey)
6. 09:03 AM - Re: speaking of solenoids (Robert L. Nuckolls, III)
7. 02:14 PM - Re: speaking of solenoids (Robert L. Nuckolls, III)
8. 04:58 PM - Re: Re: Magnetized Dynon D100 Display (n1dw)
9. 05:51 PM - Re: speaking of solenoids (Robert L. Nuckolls, III)
10. 06:28 PM - Re: Re: Magnetized Dynon D100 Display (Bill Boyd)
Message 1
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| Subject: | speaking of solenoids |
My neighbor sourced a starter solenoid online (I forget if it was ebay or
Amazon) and it worked for about 2 flights before going intermittent. When
he disassembled it, he saw this method of grounding the coil wire. I'm not
immune to using 'generic' parts, but this does show that it makes sense to
verify quality on parts with unknown pedigree.
Message 2
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| Subject: | Re: How many connections are too many |
I stumbled into doing what Charlie recommends.
The instrument panel is a single piece with a 90 degree bend, the bend forming
a shelf on top of the leg holes. (What's the technical term for "leg holes"?)
4 AWG comes to the back of the passenger side of the instrument panel. The
ground, main distribution and a brown out buss are all there, mounted on the back
of the panel or top of the leg hole shelf. I also have a 12-conductor expansion
bus, currently empty but available for future use.
To get the panel out I detach the several busses and remove a dozen screws holding
panel to airplane structure. It takes about 10 minutes, but it's not complex.
(The passenger side of the busses is an ipad frame. If I had avionics spilling
over to the passenger side I would need a larger leg hole shelf.)
--------
PBK3
PA-12, BD-4, RV6a, gliders
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=502051#502051
Attachments:
http://forums.matronics.com//files/ip_busses_142.jpg
Message 3
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| Subject: | Re: "Contactor Questions" , battery in the trunk, |
now Ground power plug
At 04:59 PM 5/24/2021, you wrote:
>Is this external power receptacle on a Western airplane?=C2 Or a Yak/CJ?
There have been a number of connector styles adapted
to ground power service on aircraft. The military
was fond of the 3-pin configuration with wiring as
illustrated in View-A of:
http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z31K.pdf
The small pin is shorter than the other two
power conducting pins. This pin was used to control
a ground power contactor such that the contactor
would NOT close until the main power pins were engaged.
Conversely, upon disengagement the contactor WOULD
open before the main power pins broke contact.
This prevented arcing/burning of the power pins
should connect/disconnect operations be conducted
with a potential for high current flows.
View-B illustrates a more pedestrian approach
to ground power. This single pin connector was
common to terrestrial vehicles manufactured
by Cole-Hersee and perhaps others. I think
Piper was the first to offer this connector
on their product line.
Virtually every FBO ground power cart I've encountered
has two cart-to-aircraft cables: One with the mil-spec
3-terminal plug, a second with the Mack-truck style
plug.
I'm aware of a short-lived, single pin ground power
connector that Beech used for a time waaayyy back
when.
http://www.aeroelectric.com/Pictures/Connectors/AeroStart/
I think this ground power combo was offered on
some Beech models. A 'jumper cable' was supplied
with each airplane 'cause few if any FBOs had
mating plugs on their ground power carts.
The clips are kinda flimsy for engine cranking
currents. I suspect this cable's primary utility
was to charge the ship's battery from a nearby
vehicle whereupon the engine could be started
using internal battery power.
There may be others out there but the two
styles illustrated in Z31 are the most prevalent
in the wild.
Bob . . .
Un impeachable logic: George Carlin asked, "If black boxes
survive crashes, why don't they make the whole airplane
out of that stuff?"
Message 4
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| Subject: | Re: M43435/II/B Lacing tape |
The thread started with Bob N. identifying the lacing we should be using. Coincidentally
I had already purchased that EBay offering. This morning the seller
wrote
"Hi Preston, Thank you for contacting us. Yes we have about 65 spools more, how
many do you want to purchase? please let us know"
I don't want to be the go-between but if someone volunteers I'm guessing you can save a few dollars per spool. You can see the item in his EBay store by clicking through on https://www.ebay.com/str/mycyberoffice?_bkw=MilSpec+AA52081
Regards, PK
--------
PBK3
PA-12, BD-4, RV6a, gliders
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=502053#502053
Message 5
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| Subject: | Re: speaking of solenoids |
That kind of thing makes me wonder if and how, cheap low-quality look-alik
es might infiltrate legitimate supply chains.=C2-=C2-
Makes me kinda nervous but also makes me feel a little better about spendin
g 2x or 3x as much for a "genuine Ford (or whatever manufacturer)" part.
Caveat Emptor and you get what you pay for (how do you say that in Latin?;)
-Jeff
On Tuesday, May 25, 2021, 06:35:23 AM PDT, Charlie England <ceengland7@
gmail.com> wrote:
My neighbor sourced a starter solenoid online (I forget if it was ebay or
Amazon) and it worked for about 2 flights before going intermittent. When h
e disassembled it, he saw this method of grounding the coil wire. I'm not i
mmune to using 'generic' parts, but this does show that it makes sense to v
erify quality on parts with unknown pedigree.
Message 6
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| Subject: | Re: speaking of solenoids |
At 08:21 AM 5/25/2021, you wrote:
>My neighbor sourced a starter solenoid online (I forget if it was
>ebay or Amazon) and it worked for about 2 flights before going
>intermittent. When he disassembled it, he saw this method of
>grounding the coil wire. I'm not immune to using 'generic' parts,
>but this does show that it makes sense to verify quality on parts
>with unknown pedigree.
Yup . . .
There are many sources for form-fit-function
contactors that would appear to fill the need.
Fortunately, most are probably of good value
and will perform well. It is not DIFFICULT
to avoid pot-holes in design such as you've
discovered. But design isn't always the
problem.
Check out the illustrations at:
http://www.aeroelectric.com/Pictures/Contactors/70%20Series%20Contactors/
In particular, this image at
http://www.aeroelectric.com/Pictures/Contactors/70%20Series%20Contactors/70%20Series%20Failure%20(circa%202000)/TearDown_10.jpg
This contactor failed for lack of due diligence
in assembly . . . which can happen to anybody.
All of the products illustrated in this series
of pictures were nominally well suited to task
by manufacturers with good track records.
For those interested in such things, here's the
after market electrical/ignition parts catalog
from Standard (caution . . . it's a big one ~190MB).
http://www.aeroelectric.com/Mfgr_Data/Standard/Ignition%20and%20Electrical%20Illustrated%20Parts%20Guide.pdf
On page 1513 we find the SS-598 Starter 'Solenoid".
This device probably has the largest applications
list of all Standard contactors. I've been
citing this part (and it's close cousins) for
decades. As you can see from the catalog, Standard
is one of the 'big dogs' in the after market parts
business. If anyone has had both time and incentive
to get it right, Standard is a good place to start.
One thing I did notice while browsing the catalog is
no mention of diode suppression on the coil. I
used to sell a contactor with the necessary
diode and if memory serves, it was a Standard
part but 20+ years have stretched the gray matter
thin.
I'll check with B&C to see if they're selling
the diode suppressed product and identify
its pedigree.
If the device is not specifically marked
as 'diode suppressed', you can test it
(I'll need to do a video on how) or simply
add a diode for the heck of it. Two diodes
is not 'better' than one . . . but no diode
is not a good thing. Coil energy release
in starter contactors is particularly wicked.
Bob . . .
Un impeachable logic: George Carlin asked, "If black boxes
survive crashes, why don't they make the whole airplane
out of that stuff?"
Message 7
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| Subject: | Re: speaking of solenoids |
>
> I'll check with B&C to see if they're selling
> the diode suppressed product and identify
> its pedigree.
Dave at B&C assures me that their S702-1 DOES
include the coil suppression diode although it's
no longer cited on either the box -or- the part
itself.
My goof - their website DOES call out this
feature.
https://bandc.com/product/intermittent-duty-starter-contactor/
Electrical testing for existence of the
diode is not difficult . . . but it's something
that it would be nice not to worry about.
At the same time, lacking specific knowledge
of it's presence kinda encourages one to add
it to the outside . . . just-in-case. Also
a PITA.
I'll pray over this a bit.
Bob . . .
Un impeachable logic: George Carlin asked, "If black boxes
survive crashes, why don't they make the whole airplane
out of that stuff?"
Message 8
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| Subject: | Re: Magnetized Dynon D100 Display |
A little late getting this info (had said last Thursday but didn't go to the
airport until today), but here goes:
I have a SIRS floating magnetic compass mounted on top of my glareshield in
a Glastar. I also have a Dynon D10A which was removed from the panel a
couple years ago (and has been sitting in a cabinet at home since) and which
had no electrical connections to it for the following experiment. Aircraft
power was off. Both left and right sides of the D10A screen were placed in
proximity to the compass with the following results:
D10A right side: No effect at 4". Abt 1 deg at 2" and abt 2-3 deg in
contact with the compass.
D10A left side: No effect at 6", abt 1 deg at 4", abt 2 deg at 2" and 11
deg in contact with the compass. So the left side has more impact than the
right side.
The location of the D10A when installed in the aircraft was over 6" from the
compass, so I never noticed any impact from the installation arrangement.
Not sure what the meaning of the above is, but there is some magnetic affect
not associated with current passing through the D10A (and probably other
similar display devices). It is apparent also that separating a magnetic
compass from display screens of any sort, and steel aircraft frames, is
probably a prudent move.
Doug Windhorn
From: owner-aeroelectric-list-server@matronics.com
<owner-aeroelectric-list-server@matronics.com> On Behalf Of Robert L.
Nuckolls, III
Sent: Tuesday, May 18, 2021 11:07 AM
Subject: Re: AeroElectric-List: Re: Magnetized Dynon D100 Display
At 02:28 PM 5/17/2021, you wrote:
<mailto:fransew@gmail.com> >
Upon further investigation, I don't think my D-180 display is magnetized
after
all. I pulled the D-180 part way out of the instrument panel without
disconnecting any cables. Then I moved the compass around. The magnetic
interference seemed to be stronger under the instrument panel. Eventually I
determined that the control stick is magnetized and attracts the south end
of
the compass needle. As I moved the compass around the control stick, the
needle always pointed at the stick. Sorry about posting an incorrect data
point yesterday.
It is worth a try for Chris to try demagnetizing the steel locking rod with
a soldering gun.
https://www.youtube.com/watch?v=g2sFp5Blg_g
I received this note from John this morning:
================== received from John Torode 5/18/20 ===============
bob,
we have repeated the experiment with one of our d100s with the same result:
the magnetic fields emanating from the d100
cause significant compass errors. we believe this is from currents inside
the device, not from any material becoming magnetized.
in fact we would try not to include much ferrous material (d-subs i guess).
my electronic compass has a definite signature from the pulsating current in
the power leads to the strobe, which are some distance
away.
what is puzzling is his claim that it used to work fine. one idea is that
the power wire to the d100 has moved.
we have spoken with him before (i am disappointed that any query from a
customer goes unanswered), and have concluded that
the panel is a bad place for a compass because of the many currents around.
we do not think there is a reliable solution besides moving the compass to a
magnetically quiet place.
sorry,
john
==========================================================================
Compass interference issues can be difficult to track down.
When Beech began offering the B&C SD-20 variants on the
A36, we encountered a situation where turning the aux
alternator on/off caused an unacceptable swing in the
cowl mounted wet compass. We had to move it up onto the
windshield.
The distance moved was but a few inches but more toward
the fringes of the magnetic field emanating from the
rear of an energized alternator which was on the OTHER
side of the firewall!
Strength of magnetic forces vary with both
distance and position. The forces do not radiate
in uniformly dispersed spherical pattern. To make
matters more complex, they can be strongly
influenced by passive features located within
the field.
Steel tube airplanes were subject to magnetization
of structure . . . sometimes difficult to neutralize.
It was a rare instance that some interference
was mitigated by demagnetizing some rogue source
of magnetic force. The 'fix' nearly always called
for a design change.
We also know that the distance over which
a given field has influence has a profound
effect on strength.
Bob . . .
Un impeachable logic: George Carlin asked, "If black boxes
survive crashes, why don't they make the whole airplane
out of that stuff?"
Message 9
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| Subject: | Re: speaking of solenoids |
> If the device is not specifically marked
> as 'diode suppressed', you can test it
> (I'll need to do a video on how) or simply
> add a diode for the heck of it. Two diodes
> is not 'better' than one . . . but no diode
> is not a good thing. Coil energy release
> in starter contactors is particularly wicked.
I've got a idea for a stone-simple,
'catch diode sniffer' for contactors.
I need to proof it on the bench but I'm
pretty sure I can post a bill-of-materials
and schematic presently. Need to replace
shocks on the truck first.
Bob . . .
Un impeachable logic: George Carlin asked, "If black boxes
survive crashes, why don't they make the whole airplane
out of that stuff?"
Message 10
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| Subject: | Re: Magnetized Dynon D100 Display |
And now we have to worry about pilots being magnetized by Moderna and
Johnson & Johnson. It never ends.
On Tue, May 25, 2021 at 8:05 PM n1dw <n1deltawhiskey@comcast.net> wrote:
> A little late getting this info (had said last Thursday but didn=99
t go to
> the airport until today), but here goes:
>
>
> I have a SIRS floating magnetic compass mounted on top of my glareshield
> in a Glastar. I also have a Dynon D10A which was removed from the panel
a
> couple years ago (and has been sitting in a cabinet at home since) and
> which had no electrical connections to it for the following experiment.
> Aircraft power was off. Both left and right sides of the D10A screen wer
e
> placed in proximity to the compass with the following results:
>
>
> D10A right side: No effect at 4=9D. Abt 1 deg at 2=9D and a
bt 2-3 deg in
> contact with the compass.
>
> D10A left side: No effect at 6=9D, abt 1 deg at 4=9D, abt 2
deg at 2=9D and 11
> deg in contact with the compass. So the left side has more impact than t
he
> right side.
>
>
> The location of the D10A when installed in the aircraft was over 6
=9D from
> the compass, so I never noticed any impact from the installation
> arrangement.
>
>
> Not sure what the meaning of the above is, but there is some magnetic
> affect not associated with current passing through the D10A (and probably
> other similar display devices). It is apparent also that separating a
> magnetic compass from display screens of any sort, and steel aircraft
> frames, is probably a prudent move.
>
>
> Doug Windhorn
>
>
> *From:* owner-aeroelectric-list-server@matronics.com <
> owner-aeroelectric-list-server@matronics.com> *On Behalf Of *Robert L.
> Nuckolls, III
> *Sent:* Tuesday, May 18, 2021 11:07 AM
> *To:* aeroelectric-list@matronics.com
> *Subject:* Re: AeroElectric-List: Re: Magnetized Dynon D100 Display
>
>
> At 02:28 PM 5/17/2021, you wrote:
>
>
> Upon further investigation, I don't think my D-180 display is magnetized
> after
> all. I pulled the D-180 part way out of the instrument panel without
> disconnecting any cables. Then I moved the compass around. The magnetic
> interference seemed to be stronger under the instrument panel. Eventuall
y
> I
> determined that the control stick is magnetized and attracts the south en
d
> of
> the compass needle. As I moved the compass around the control stick, the
> needle always pointed at the stick. Sorry about posting an incorrect dat
a
> point yesterday.
> It is worth a try for Chris to try demagnetizing the steel locking rod
> with a soldering gun.
> https://www.youtube.com/watch?v=g2sFp5Blg_g
>
>
> I received this note from John this morning:
>
> ================== received from John
Torode 5/18/20 ==============
> bob,
>
> we have repeated the experiment with one of our d100s with the same
> result: the magnetic fields emanating from the d100
> cause significant compass errors. we believe this is from currents insid
e
> the device, not from any material becoming magnetized.
> in fact we would try not to include much ferrous material (d-subs i guess
).
>
> my electronic compass has a definite signature from the pulsating current
> in the power leads to the strobe, which are some distance
> away.
>
> what is puzzling is his claim that it used to work fine. one idea is that
> the power wire to the d100 has moved.
>
> we have spoken with him before (i am disappointed that any query from a
> customer goes unanswered), and have concluded that
> the panel is a bad place for a compass because of the many currents aroun
d.
>
> we do not think there is a reliable solution besides moving the compass t
o
> a magnetically quiet place.
>
> sorry,
>
> john
>
> ========================
>
> Compass interference issues can be difficult to track down.
> When Beech began offering the B&C SD-20 variants on the
> A36, we encountered a situation where turning the aux
> alternator on/off caused an unacceptable swing in the
> cowl mounted wet compass. We had to move it up onto the
> windshield.
>
> The distance moved was but a few inches but more toward
> the fringes of the magnetic field emanating from the
> rear of an energized alternator which was on the OTHER
> side of the firewall!
>
> Strength of magnetic forces vary with both
> distance and position. The forces do not radiate
> in uniformly dispersed spherical pattern. To make
> matters more complex, they can be strongly
> influenced by passive features located within
> the field.
>
> Steel tube airplanes were subject to magnetization
> of structure . . . sometimes difficult to neutralize.
>
> It was a rare instance that some interference
> was mitigated by demagnetizing some rogue source
> of magnetic force. The 'fix' nearly always called
> for a design change.
>
> We also know that the distance over which
> a given field has influence has a profound
> effect on strength.
>
>
> Bob . . .
>
> Un impeachable logic: George Carlin asked, "If black boxes
> survive crashes, why don't they make the whole airplane
> out of that stuff?"
>
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