Today's Message Index:
----------------------
1. 04:45 AM - Re: D-Sub High Density 78 female - solfder or crimp contacts (rd2)
2. 12:33 PM - Re: Power distribution parts (Robert L. Nuckolls, III)
3. 12:44 PM - Re: Monarch EE Anti-Plugging Field Accelerating? (Robert L. Nuckolls, III)
4. 12:45 PM - Where to put the Cross-Feed Contactor? (Dan)
5. 04:12 PM - Re: Where to put the Cross-Feed Contactor? (C&K)
6. 06:27 PM - Re: Monarch EE Anti-Plugging Field Accelerating? (rparigoris)
7. 06:40 PM - Revmaster R2300 PMA (dj_theis)
8. 08:50 PM - Re: Where to put the Cross-Feed Contactor? (Robert L. Nuckolls, III)
Message 1
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| Subject: | Re: D-Sub High Density 78 female - solfder or crimp |
contacts
Thanks to all who responded, advice from this list is invaluable.
Even if soldering skills are good, crimping seems the better choice in the
case of high density, especially for the inner rows and aging eyes <g>R
----- Original Message -----
From: Charlie England <ceengland7@gmail.com>
Sent: Tue, 05 Jan 2021 08:55:18 -0500 (EST)
Subject: Re: AeroElectric-List: D-Sub High Density 78 female - solfder or c
rimp contacts
If you're having trouble crimping subD pins, you likely have the wrong tool
s for the task. I've been soldering for over 50 years (a lot of them profes
sionally), and crimping is still easier/faster (though more expensive) than
soldering for me. Harder for me is accurately stripping the wire to prep f
or the crimp. A decent quality stripping tool with dies sized for each gaug
e wire (I like this style) seems essential, and a good eye for strip length
helps (to ensure full depth of bare wire into the terminal, without leavin
g excess bare wire exposed). I've never had good luck with the 'automatic'
strippers, but I've never invested in a new, really high quality version. T
he crimp itself is 'automatic'; as long as the terminal is the proper depth
into the crimper, the tool forces you to make a full crimp before releasin
g. BTW, you really don't need to spend $hundreds on a production crimper fo
r one project. Stein and others sell this tool which many of us have used t
o wire entire a/c. Since you're using HD pins, you might want the optional
HD positioner, though I've had good success manually positioning the pin wh
en I've only needed to do a couple at a time.
I'll bet you will have much more trouble depinning the old shell (you need
this tool) than crimping the new pins.
Charlie
On Tue, Jan 5, 2021 at 7:28 AM rd2 <rd2@dejazzd.com> wrote:
Excellent advice, as usual, thanks Stein. Crimped it'll be.
The problem was my soldering skills are much better than my crimping skills
(almost none).
Thanks for bringing up the questions, Bob:
--snip--
Do you already have the connector to which you want
add wires? How many wires total in your task?
---snip---
I already have the female connector - it is populated from another applicat
ion. I assume that I can reuse it - just need to remove the populated conta
ct sockets, crimp the new ones and repopulate.
I don't now the exact number of wires yet, I expect most (or more than 1/2)
of the positions to be used.
I will visit Stein's web site to order sockets and tools, but first I need
to find some mp4 on youtube that will guide me through the process instead
of asking questions.
Thanks again.
Rumen
----- Original Message -----
From: SteinB <stein@steinair.com>
Sent: Mon, 04 Jan 2021 17:45:07 -0500 (EST)
Subject: RE: AeroElectric-List: D-Sub High Density 78 female - solfder or c
rimp contacts
We generally try to avoid solder cup connectors on aircraft because typical
ly the average builder doesn=99t have a good high temp yet small iron
able to successfully use the solder cups (wires often end up cold soldered
and fall off in with future vibration), or they end up wicking tons of sol
der up into the wire that inevitably leads to wire breakage. On top of that
, in a 78 pin arrangement the solder cups would be incredibly densely packe
d, and it=99s likely the end result would not be pretty. It also take
s longer than simply crimping on a pin and inserting it into a connector. A
lso, if you need to =9Cmove=9D a wire in the middle of that lar
ge 78 pin connector, it=99s pretty easy to do with crimp pins, not so
much with solder cups. Lastly, the 78 pin crimp connectors aren=99t
that terribly expensive (we stock and sell them for about $17 each), standa
rd crimp tooling works well. Just my 2 cents as usual! Cheers,Stein From:o
wner-aeroelectric-list-server@matronics.com <owner-aeroelectric-list-server
@matronics.com> On Behalf Of rd2
Sent: Monday, January 4, 2021 3:38 PM
To:aeroelectric-list@matronics.com
Subject: AeroElectric-List: D-Sub High Density 78 female - solfder or crimp
contacts Hi Group.What type contacts would you recommend for a 78 female c
onnector - solder or crimp, and why?It seems that solder type are easier to
find and less expensive. The connector will be used for a relays box to se
lect VHF nav signals to an HSI.Rumen....
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| Subject: | Re: Power distribution parts |
At 03:04 PM 1/6/2021, you wrote:
>Bob
>
>If you want to handle splitting the shipment,
>I'll take one of the 10 fuse blocks.=C2 Please
>advise what cost you desire.=C2 You can send the
>information privately=C2 to
><mailto:Paul@eckenroth.com>Paul@eckenroth.com.=C2
>If it is all too much hassle=C2 for you , that's
>no problem.=C2 I'm good either way.=C2 Thanks
I'm sorta in a housecleaning mode and had a choice
to pitch 'em or get them into hands that have
more time and will to distribute. John is the
da man!
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 3
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| Subject: | Re: Monarch EE Anti-Plugging Field Accelerating? |
At 09:00 PM 1/5/2021, you wrote:
>
>Hi Bob Perhaps you can enlighten me a little more how Monarch
>controls speed on my EE with their hocus pocus. Here's a link to the
>only schematic I have:
>https://1drv.ms/b/s!Ah1S270Nwg9V4St1iHBVNSihPNyL?e=Y3H4UJ
>The huge Ohmite-A-1925 Rheostat (size of a volley ball) controls the
>field for the motor and generator at the same time. Why not just
>control the generator field?
>At the top of the schematic there is Field Accelerating using a CXG
>2105-B and Anti-Plugging using a SD4-2-S-14. What is Field
>Accelerating? What is Anti-Plugging?
I'm taking a guess based on what I know about
motor characteristics. Motor speeds in this machine
are adjusted based on field excitation of the parallel
wound motors. The stronger the field, the slower the
motor. This is kinda cool because the field excitation
control has no effect on armature supply current/volage,
hence a minimal effect on available torque at the
selected speed.
"Plugging" is a motor stopping technique that calls
for reversing power to the armature for milliseconds
after initiating the stop command. It's easy to see
that the initial current flow is quite high . . .
higher than inrush. Further, timing is very important.
If the 'plugging' interval is too long, the motor comes
to a stop before REVERSING until the plugging configuration
is discontinued. I suspect that in this case, anti-plugging
\ features are added so that should the lathe operator
quickly switch from FWD to REV rotation (a clasic
plugging situation), the opposite polarity of motor
drive current is delayed until after normal dynamic
breaking has completed.
This is just a guess. Wiring diagrams for this machine
are not exactly lucid illustrations of functionality.
While no doubt accurate, they are not exactly great
teaching tools! This is a common condition across
a spectrum of suppliers of electrically driven systems
from lawn mowers to . . . well . . . really nice
old lathes!
Are the speed control rheostats on a common shaft?
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: | Where to put the Cross-Feed Contactor? |
I have A-14 with rear batteries. Finishing the wiring right now. My
thought was that the cross-feed contactor would go on the inside of the
firewall so that only one fat wire has to go through (I have the brass
ground block that bolts through the firewall, and of course, there are a
bunch of smaller wires that go through, probes and such and wires from the
alternator controllers, which are on the engine side). The person helping
me thinks it would be better to locate the cross feed contactor on the
engine side because maintenance is easier. But if it is on the engine
side, more fat wires go through the firewall.
Does anyone have an opinion on this? I understand it is a pain to crawl
under the panel and get at the firewall. On the other hand, it seems to me
there is a benefit to minimizing the number of fat wires through the
firewall.
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| Subject: | Re: Where to put the Cross-Feed Contactor? |
Mine sits beside the batteries and batteryr contactor. Maintenance is
largely a non issue. It is in a relatively benign area. It conducts
significant current during cranking but doesn't actually switch high
current like a starter contactor.
Ken
On 07/01/2021 3:39 PM, Dan wrote:
> I have A-14 with rear batteries. Finishing the wiring right now. My
> thought was that the cross-feed contactor would go on the inside of
> the firewall so that only one fat wire has to go through (I have the
> brass ground block that bolts through the firewall, and of course,
> there are a bunch of smaller wires that go through, probes and such
> and wires from the alternator controllers, which are on the engine
> side). The person helping me thinks it would be better to locate the
> cross feed contactor on the engine side because maintenance is
> easier. But if it is on the engine side, more fat wires go through
> the firewall.
>
> Does anyone have an opinion on this? I understand it is a pain to
> crawl under the panel and get at the firewall. On the other hand, it
> seems to me there is a benefit to minimizing the number of fat wires
> through the firewall.
Message 6
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| Subject: | Re: Monarch EE Anti-Plugging Field Accelerating? |
Hi Bob
Yes the speed control rheostats are on a common shaft.
I found this link:
https://www.practicalmachinist.com/vb/monarch-lathes/field-acceleration-relay-226109/
I believe it's Field Accelerating that is the hocus pocus I never fully understood
too much that I believe helps increase torque?
I read the post in practical machinist several times, still don't fully understanding
it.
If the chat and Motor-Generator and Control System Design Schematic help you understand
what's going on, an interpretation would be appreciated.
What is Base Speed?
Thx. Ron P.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=500076#500076
Message 7
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| Subject: | Revmaster R2300 PMA |
Hello all,
This is a revisiting of the dual integrated PMA that Revmaster (VW derivative)
implements on their latest engine design.
There's a lot here so my apologies in advance.
Attached is a scematic of how I've implemented control using a variation of the
Z drawings. I've included the current front page with shows the full control
scheme with the alternator and a second drawing that I simply redrew to show
only the charging circuit. I've done enough checking to convince myself that
the regulator / rectifier (R/R) is depicted in a way that at least "losely" shows
it's function. Specifically, it is a half wave rectifier with a control circuit
controlling an SCR. This SCR opens the path to ground for the alternator
to limit charging. The circuit is actually pretty sophisticated in that it
will not "turn on" the SCR unless it first senses a battery is present in the
circuit. US patent 4,220,909 describes in more detail the safe guards of the
circuit that go beyond insuring a battery connection.
My goal with this post is to solicit comments on a failure mode that a few of these
engines have had, particularly over the last few years. One strong suggestion
the engine supplier has made is to avoid running both stators at the same
time AND avoid using the AGM style batteries. My initiial goal was to find
evidence (for or against) use of the AGM (Odessey PC680).
The third drawing is the setup I assembled to test the rectifying circuit, independent
of the Revmaster alternator. This uses a small 3 phase motor I had along
with a 120, single phase input, 3 phase output VFD to drive the motor - coupled
to a John Deere, 20 amp 6 pole alternator (very close in performance and
characteristics to 1/2 the Revmaster). I plan on expanding testing to verify
open circuit and short circuit performance of the full Remaster alternator and
RR (in my engine) once I am comfortable withk the design and have enough data
to support the use (or not) of an AGM battery.
Sorry for this being so long, almost done setting up the question...
The next two plots are of a couple of the many scope traces I have of the alternator
/RR test assembly. The slow speed run up at 30 hz / 875 rpm shows the RR
not "turning on" and basically an open circuit voltage measurement of the low
rpm alternator with a well charged battery. The 42 hz (1200 rpm) shows the
charging circuit just beginning to inject current to the battery at a voltage
of 13.52 volts (not this is on the negative trace of the sine wave due to my scope
orientation in the charging circuit but it was a positive voltage to the
battery.
A few notes. The trace is using a 10x probe. The blue trace is the current measured
across the 100 mv @ 30 amp shunt. The values on the horizontal lines on
the scope trace are on the bottom right of the printout.
The John Deere alternator runups were done using a large, wet, lead acid battery
(donated by my '64 Pontiac that's resting for the winter). The regulator will
not activate without a working battery attached. More on that if anyone is
interested.
Finally, the last photo is of one of the stators on the Revmaster engine AFTER
it failed. I'm told by the pilot (Glen Bradley) that his two stator failures
occurred in flight under higher rpms and after the battery (the Odessey AGM) was
worked over during a hard start.
HERE IS MY Thesis: I suspect that the stators are experiencing "turn to turn short
circuits." This fault mode was suggested to me by another engineer where
I work (experienced in these failures) and in his words, "a short between two
adjacent wires in the stator is common and one of the most rapid ways a stator
will self destruct." (as opposed to a phase to ground fault on a stator)
After a bit of reading I've come up with what I think are justifying equations
that would predict the result of shorting a single loop of the stator wire. A
single loop of wire on a permanent magnet alternator experiences a circulating
current that is at least an order of magentude greater than the complete coil.
This rotating conductor (attached to the upstream and down stream stator wiring
at a single point) quickly overheats and initiates a cascading failure of
adjacent insulation.
If you look at the photo of the burned stator, the 12 O'clock and 6 )'clock coils
are stand a lone stators for the redundent CDI ignition. The right five from
1 O'clock to 5 O'clock make up the right stator for the PMA. The left five
from 7 to 11 O'clock are the other PMA stator, making up the dual alternator.
I find it more than interesting that only one of the coils making up the left stator
is burned while the other 4 appear perfect. Also, the CDI ignition coil
failed as well and of course, it is in no way connected to the AGM battery.
I'll stop there and wait for comment
--------
Scratch building Sonex #1362
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=500077#500077
Attachments:
http://forums.matronics.com//files/cx5_r2300_stator_failure_211.jpg
http://forums.matronics.com//files/42_hz_1200_rpm_113.pdf
http://forums.matronics.com//files/30_hz_875_rpm_no_charging_394.pdf
http://forums.matronics.com//files/revmaster_r2300_electrical_test_163.pdf
http://forums.matronics.com//files/revmaster_2300_alternator_ckt_214.pdf
http://forums.matronics.com//files/z16m_revmaster_2300_r13_pg1_183.pdf
Message 8
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| Subject: | Re: Where to put the Cross-Feed Contactor? |
>The person helping me thinks it would be better to locate the cross
>feed contactor on the engine side because maintenance is easier.
The cross-feed contactor becomes the forward power
distribution point for energy from the two systems.
Having it on the cabin side probably simplifies
wiring to the busses and reduces volume of wire
through the firewall.
This contactor has a VERY low operating stress profile.
Maintenance should be the lowest of all the contactors.
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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