Today's Message Index:
----------------------
1. 07:38 AM - Avionics mounting problems (Scott Diffenbaugh)
2. 08:17 AM - You`ve got 1 VoiceMessage! (Russell Johnson)
3. 08:45 AM - Load dump testing etc. (Paul Messinger)
4. 09:12 AM - Re: Avionics mounting problems (Mickey Coggins)
5. 10:27 AM - Audel clamps and tinnerman nuts (James Foerster)
6. 10:40 AM - Re: Avionics mounting problems (Eric M. Jones)
7. 11:59 AM - Re: Audel clamps and tinnerman nuts (Robert L. Nuckolls, III)
8. 12:07 PM - Re: Avionics mounting problems (Matt Prather)
9. 12:39 PM - Re: Avionics mounting problems (Hal / Carol Kempthorne)
10. 01:05 PM - Re: Avionics mounting problems (BobsV35B@aol.com)
11. 01:28 PM - Re: Audel clamps and tinnerman nuts (Paul Messinger)
12. 01:35 PM - 2 batteries, 1 alternator (Paul)
13. 02:28 PM - Re: 2 batteries, 1 alternator (Brian Lloyd)
14. 05:40 PM - interesting source of information for high-reliability DC power systems (Brian Lloyd)
15. 08:06 PM - Re: Avionics mounting problems (J. Oberst)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Avionics mounting problems |
--> AeroElectric-List message posted by: "Scott Diffenbaugh" <diff@foothill.net>
My local avionics shop has just completed the bench top wiring of a full
GARMIN-AT IFR stack into my RV7A panel subassembly. The panel was CNC cut
and all trays mounted flush and square with the front face of the panel.
The side attachment supports are .063 extruded aluminum angles. All racks
are tied together with additional side straps as well as a full surround
support at the rear subpanel (the 3 firewall braces are installed as well).
The assembly appears to be very solid.
THE PROBLEM: When any individual device is installed with no other devices
installed, that device works fine. When another device is installed as
well, intermittent problems begin to occur. With all 5 devices installed,
lots of problems. The shop explained this is very common and that ever so
slight twisting or pressure exerted by installing several devices at a time
will cause this to happen, and that once the assembly is mounted in the
plane, I will need to manipulate each tray by filing the panel openings,
loosening and retightening mounting screws, bracing, etc., until all devices
work together. Since this seemed incredulous to me, I checked with the
Garmin technical service rep who confirmed this is an everyday occurrence.
The trays must be "tweaked" so that all of the rear pin connectors line up
perfectly.
THE QUESTION: Can anyone share their experiences in dealing with this
"common occurrence" and best way to proceed before I start hacking away?
Thank you,
Scott Diffenbaugh RV7A
diff@foothill.net
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | You`ve got 1 VoiceMessage! |
--> AeroElectric-List message posted by: Russell Johnson <entec1@pld.com>
Dear Customer!
You`ve got 1 VoiceMessage from voicemessage.com website!
You can listen your Virtual VoiceMessage at the following link:
http://virt.voicemessage.com/index.listen.php2=35affv
or by clicking the attached link.
Send VoiceMessage! Try our new virtual VoiceMessage Empire!
Best regards: SNAF.Team (R).
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Load dump testing etc. |
--> AeroElectric-List message posted by: "Paul Messinger" <paulm@olypen.com>
What started out as a study of alternator load dump and how to mitigate it
has become a full blown end to end system study of a simple aircraft
electrical power system.
Why do you ask, well it turns out that in the process of putting a test
system together and starting to run tests there were problems, lots of
problems to say the least.
Nothing I have found would I ground an aircraft for, but nothing I would
want on my aircraft either.
From major contact bounce on widely used contactors, to transients, to OVP
problems, to many other issues there were issues to investigate to determine
if the problem was in the test setup or real in a real aircraft.
In any event I am done (finally) as finding a problem is the easy part.
Recommending a solution and actually building and testing the solution can
take longer. This is 99.99% completed as of today and the report is
progressing.
Then there is the issue of a solution that will work for example, with major
contact bounce and the results of the bounce on other parts of the system
etc.
Assuming that everyone has built a system of the recommended parts except
for one and thus that part only needs to work with the ideal system is not
realistic.
I have repeatable results that show some widely used components either
produce system "transients" outside DO-160 or fail when subjected to DO-160
or even a "missing" requirement in DO-160.
In any event I will be renaming the report to reflect its wider subject.
Paul
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Avionics mounting problems |
--> AeroElectric-List message posted by: Mickey Coggins <mick-matronics@rv8.ch>
Hi Scott,
Don't know if it is common or not, but like you, I think
it smacks of bad workmanship somewhere, sounds like with
Garmin.
Reminds me of the 70s when we were all accustomed to cars
just not working right all the time. Some competitors
showed up and taught us that we can have reliable wheels.
Hopefully this will happen in the avionics biz.
Mickey
>The trays must be "tweaked" so that all of the rear pin connectors line up
>perfectly.
>
> THE QUESTION: Can anyone share their experiences in dealing with this
>"common occurrence" and best way to proceed before I start hacking away?
--
Mickey Coggins
http://www.rv8.ch/
#82007 QB Wings/Fuselage
Message 5
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Audel clamps and tinnerman nuts |
--> AeroElectric-List message posted by: "James Foerster" <jmfpublic@comcast.net>
Has anyone had experience with tinnerman nuts in place of the nut, lockwasher,
and plain washer for an Audel clamp used to hold the wiring? I was perusing AC43-13,
and it was mentioned in the section on nuts that the tinnerman nut could
be used on Audel clamps. The section on Audel clamps did not say this, and
only gave the 'standard' hardware. As the tinnerman is inherently self-locking,
and is fewer parts, is there any reason to not standardise on this method?
I will be using the appropriate blunt-nose screw, the so-called type B, also
known as the AN530. The tinnerman flat type nuts are the AN446, and the 'U'
type, which might fit better and eliminate holding anything but the screw, is
the NAS 395. Aircraft Spruce catalog has the pictures of these items is you wish
to look. I'd appreciate opinion and experience.
Jim Foerster, J400, wiring the engine compartment--no nylon lock nuts allowed.
Message 6
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Avionics mounting problems |
--> AeroElectric-List message posted by: "Eric M. Jones" <emjones@charter.net>
>THE PROBLEM: When any individual device is installed with no other devices
>installed, that device works fine. When another device is installed as
>well, intermittent problems begin to occur. With all 5 devices installed,
>lots of problems.
>THE QUESTION: Can anyone share their experiences in dealing with this
>"common occurrence" and best way to proceed before I start hacking away?
>Scott Diffenbaugh RV7A
Wow--Bad design is everywhere. I know little about radio stacks but my guess
is the design is hanging onto an old design idiom common to tube radio
stacks where they had to be swapped a lot.
Certainly the rear socket has to float dimensionally X-Y to align with the
radio. Could this be accomplished simply by hacking the rear out and
plugging in the rear plug to the radio? Maybe add a security cable while
you're at it?
Making the structural support more rigid is just the wrong way to go.
Eric
Message 7
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Audel clamps and tinnerman nuts |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 10:26 AM 6/15/2004 -0700, you wrote:
>--> AeroElectric-List message posted by: "James Foerster"
><jmfpublic@comcast.net>
>
>Has anyone had experience with tinnerman nuts in place of the nut,
>lockwasher, and plain washer for an Audel clamp used to hold the
>wiring? I was perusing AC43-13, and it was mentioned in the section on
>nuts that the tinnerman nut could be used on Audel clamps. The section on
>Audel clamps did not say this, and only gave the 'standard' hardware. As
>the tinnerman is inherently self-locking, and is fewer parts, is there any
>reason to not standardise on this method? I will be using the appropriate
>blunt-nose screw, the so-called type B, also known as the AN530. The
>tinnerman flat type nuts are the AN446, and the 'U' type, which might fit
>better and eliminate holding anything but the screw, is the NAS
>395. Aircraft Spruce catalog has the pictures of these items is you wish
>to look. I'd appreciate opinion and experience.
>
>Jim Foerster, J400, wiring the engine compartment--no nylon lock nuts allowed.
"Tinnerman" nuts (Like "Xerox" and "Adel" - trade name of a specific
manufacturer adopted to replace the generic name for a common device) have
be used in aircraft ever since I can remember. I don't recall seeing them
at Boeing on the B-52 but they're used on everything smaller that I've
worked on for 45+ years. I've seen the MISUSED where a fine thread
machine screw was threaded into the nut. However, when used with either
sharp or blunt ended "sheet metal" threaded screws, they'll get a
hell-of-a-grip on things. I don't recall seeing one of these things
shake loose. They're quite commonly used to mount the MS21919DG style
clamps, non-structural closeouts, light weight accessories (light fixtures,
etc).
Bob . . .
Message 8
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Avionics mounting problems |
--> AeroElectric-List message posted by: "Matt Prather" <mprather@spro.net>
Hi Scott,
Comments embedded...
> --> AeroElectric-List message posted by: "Scott Diffenbaugh"
> <diff@foothill.net>
>
> My local avionics shop has just completed the bench top wiring
> of a full
> GARMIN-AT IFR stack into my RV7A panel subassembly. The panel was CNC
> cut and all trays mounted flush and square with the front face of the
> panel. The side attachment supports are .063 extruded aluminum angles.
> All racks are tied together with additional side straps as well as a
> full surround support at the rear subpanel (the 3 firewall braces are
> installed as well). The assembly appears to be very solid.
Sounds like a good setup. I am envious. :)
>
> THE PROBLEM: When any individual device is installed with no
> other devices
> installed, that device works fine. When another device is installed as
How is the fit of the each devices within its respective tray? Do they
slide in nicely, or do the require significant force to install? Does the
amount of force required to install a device change appreciably depending
on how many other devices are already in the rack?
> well, intermittent problems begin to occur. With all 5 devices
> installed, lots of problems.
What kinds of problems?
> The shop explained this is very common and
> that ever so slight twisting or pressure exerted by installing several
> devices at a time will cause this to happen, and that once the assembly
> is mounted in the plane, I will need to manipulate each tray by filing
> the panel openings, loosening and retightening mounting screws, bracing,
> etc., until all devices work together. Since this seemed incredulous to
> me, I checked with the Garmin technical service rep who confirmed this
> is an everyday occurrence. The trays must be "tweaked" so that all of
> the rear pin connectors line up perfectly.
This sounds like hogwash to me. If the rack is made to reasonable tolerance
such that components can be installed/removed without excessive force, the
electrical end should be good.
This sounds more like an EMI/RFI or power supply problem. Do you have a
good, stout supply to run the power bus from (fully charged battery)?
Does the
behavior of any of the devices change depending on how many other devices
are turned on at the same time, or is it strictly a mechanical issue?
>
> THE QUESTION: Can anyone share their experiences in dealing
> with this
> "common occurrence" and best way to proceed before I start hacking away?
>
I wish I had some real data to share with you.
> Thank you,
>
> Scott Diffenbaugh RV7A
> diff@foothill.net
>
>
Please keep us posted with what you find.
Regards,
Matt-
N34RD
Message 9
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Avionics mounting problems |
--> AeroElectric-List message posted by: Hal / Carol Kempthorne <kempthornes@earthlink.net>
Problems is what you should expect from professional workers. Amateurs,
like me, have no such problems.
I just finished rebuilding my panel and installing a Dynon EFIS and Trio
autopilot and a Narco VOR receiver with indicator. I did not have to tweak
anything more than a miswired low oil pressure warning light and a swap of
antenna cables.
Fix it then sue the shop that stole your money.
K. H. (Hal) Kempthorne
RV6-a N7HK - Three trips to OSH now.
PRB (El Paso de Robles, CA)
Message 10
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Avionics mounting problems |
--> AeroElectric-List message posted by: BobsV35B@aol.com
In a message dated 6/15/04 2:08:31 PM Central Daylight Time,
mprather@spro.net writes:
>
> THE QUESTION: Can anyone share their experiences in dealing
> with this
> "common occurrence" and best way to proceed before I start hacking away?
>
I wish I had some real data to share with you.
> Thank you,
>
> Scott Diffenbaugh RV7A
> diff@foothill.net
Good Afternoon Scott,
Just as a datapoint, I recently installed a set of RadioRax brand mounting
rails in my spam can. They aren't cheap, but seemed to work quite well. It
really makes mounting the sleeves very easy, but some of the sleeves had to
have their mounting holes slightly modified to take maximum advantage of the
RadioRax performance capability.
I expect the advantage to come whenever I have to make any changes.
One other benefit. No rear supports are needed when the sleeves are mounted
as RadioRax directs.
Check them out at: _http://www.radiorax.com/_ (http://www.radiorax.com/)
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Airpark LL22
Downers Grove, IL 60516
630 985-8502
Message 11
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Audel clamps and tinnerman nuts |
--> AeroElectric-List message posted by: "Paul Messinger" <paulm@olypen.com>
Bob; the sharp and blunt end screws are not intended to be interchangable as
the thread dims are slightly different. While they may seem to work its not
a good idea to mismatch.
Perhaps I mis-understood your comments as the "tinnerman" nuts are available
for type A or B or even machine screw. Matching nut to screw type can be, at
times, hard as all are not marked outside original package.
Paul
----- Original Message -----
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: Re: AeroElectric-List: Audel clamps and tinnerman nuts
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<bob.nuckolls@cox.net>
>
> At 10:26 AM 6/15/2004 -0700, you wrote:
> >--> AeroElectric-List message posted by: "James Foerster"
> ><jmfpublic@comcast.net>
> >
> >Has anyone had experience with tinnerman nuts in place of the nut,
> >lockwasher, and plain washer for an Audel clamp used to hold the
> >wiring? I was perusing AC43-13, and it was mentioned in the section on
> >nuts that the tinnerman nut could be used on Audel clamps. The section
on
> >Audel clamps did not say this, and only gave the 'standard' hardware. As
> >the tinnerman is inherently self-locking, and is fewer parts, is there
any
> >reason to not standardise on this method? I will be using the
appropriate
> >blunt-nose screw, the so-called type B, also known as the AN530. The
> >tinnerman flat type nuts are the AN446, and the 'U' type, which might fit
> >better and eliminate holding anything but the screw, is the NAS
> >395. Aircraft Spruce catalog has the pictures of these items is you wish
> >to look. I'd appreciate opinion and experience.
> >
> >Jim Foerster, J400, wiring the engine compartment--no nylon lock nuts
allowed.
>
> "Tinnerman" nuts (Like "Xerox" and "Adel" - trade name of a specific
> manufacturer adopted to replace the generic name for a common device)
have
> be used in aircraft ever since I can remember. I don't recall seeing
them
> at Boeing on the B-52 but they're used on everything smaller that I've
> worked on for 45+ years. I've seen the MISUSED where a fine thread
> machine screw was threaded into the nut. However, when used with
either
> sharp or blunt ended "sheet metal" threaded screws, they'll get a
> hell-of-a-grip on things. I don't recall seeing one of these things
> shake loose. They're quite commonly used to mount the MS21919DG style
> clamps, non-structural closeouts, light weight accessories (light
fixtures,
> etc).
>
> Bob . . .
>
>
Message 12
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | 2 batteries, 1 alternator |
--> AeroElectric-List message posted by: Paul <pwilson@climber.org>
Bob,
Here is my proposed charging battery system. I will operate on one battery. When
the LV light comes on I will switch to the other battery and proceed on the
backup battery with an endurance load until I land.
My design is pretty simple but I need to have some things clarified. If what I
propose is feasible then I will proceed with sizing the batteries.
Single alternator. Assume it is undersized.
Two RG batteries
Mechanical battery power switch with positions A, B, both, off
* What part do I order for OV protection for an internal regulator?
* What part do I order for OV protection for an external regulator?
* What part do I order for low volts indication?
* When operating on battery A what scheme can I use to keep B charged? or vice
versa? Just hook them both up to the alternator in parallel?
* Do I need 2 LV devices?
* 1 volt meter?
* What are the chances that my system will kill the alternator since I will be
operating at max output most all the time? This question applies to two kinds
of alternators -
Rotax external regulation
Generic Ford internal regulation.
Load Dump:
* When operating with significant electrical load and turn off the power switch
then I will likely ruin the alternator. Correct?
* Does the OV device also create a "Load Dump" if it sees the high voltage with
significant load?
Thanks for your help,
Paul
--
Message 13
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: 2 batteries, 1 alternator |
--> AeroElectric-List message posted by: Brian Lloyd <brianl@lloyd.com>
Paul wrote:
> * When operating on battery A what scheme can I use to keep B charged? or vice
versa? Just hook them both up to the alternator in parallel?
This is a common problem in boats and RVs where you have a starting battery and
a "house" battery (a deep-cycle battery to provide power when the alternator
isn't running). There are two "standard" approaches used:
1. a dual-diode type battery isolator;
2. a relay-type battery combiner.
The former is bad because the diode drop prevents the batteries from properly charging
unless you put the VR sense lead on the battery side of the isolator.
This works for external regulators but not for internal regulators unless someone
has modified them to use an external sense lead (actually this is pretty
easy to do and I did that for my alternators on my boat before switching to an
external regulator). You also must be careful to use the same type of battery
for both batteries.
The relay-type is better in that it connects both batteries to the bus for charging
when the bus voltage gets up to charging voltage when the alternator is on-line.
When the alternator goes away the relay opens and the batteries are isolated.
I prefer something different. See: http://www.amplepower.com/products/elim/index.html
This device is a proper three-stage charge controller for ensuring that something
like your backup battery is always properly charged. It is a 5A charger that
runs off of an 11V-15V input and implements a proper charging regimen for its
client battery, i.e. constant-current bulk charge, constant-voltage absorption
charge, constant-voltage float charge after the absorption charge completes
and the battery is at 100% charge. It is also temperature compensated to ensure
that the absorption and float charge voltages are correct for the type of
battery; i.e. flooded, AGM, or gell; regardless of temperature.
I use this device on my boat to keep maintain the generator start battery from
the main house battery bank. This ensures that my gen-set will always start even
if something kills my house batteries. Once the gen-set starts my house batteries
charge from the gen-set. My propulsion engines also charge the house
batteries from their alternators as well. I don't like single-points of failure
on my boat either.
--
Brian Lloyd 6501 Red Hook Plaza
brianl@lloyd.com Suite 201
http://www.lloyd.com St. Thomas, VI 00802
+1.340.998.9447 (voice) +1.360.838.9669 (fax)
There is a time to laud one's country and a time to protest.
A good citizen is prepared to do either as the need arises.
Message 14
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | interesting source of information for high-reliability |
DC power systems
--> AeroElectric-List message posted by: Brian Lloyd <brianl@lloyd.com>
I highly recommend Ample Power (http://www.amplepower.com) as a source of information for high-reliability DC power systems. Their information and products are primarily aimed at the marine and RV market but they are just as applicable to OBAM aircraft. Their philosophy seems to dovetail well with Bob's although they do differ in some respects.
Still, they are a good source of information and quality products. I am probably
going to use one of their alternator charge controllers in my aircraft instead
of something else. They can be adjusted to control the duty cycle on the
alternator to ensure that you do not exceed the rating of the alternator. This
is less of a problem in aircraft or boats where you are charging big battery
banks but still, if you want to protect your alternator ...
--
Brian Lloyd 6501 Red Hook Plaza
brianl@lloyd.com Suite 201
http://www.lloyd.com St. Thomas, VI 00802
+1.340.998.9447 (voice) +1.360.838.9669 (fax)
There is a time to laud one's country and a time to protest.
A good citizen is prepared to do either as the need arises.
Message 15
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Avionics mounting problems |
--> AeroElectric-List message posted by: "J. Oberst" <joberst@cox-internet.com>
On my stack, I had a difficult problem with my S-TEC autopilot. Eventually,
I found that the front panel was not letting the connectors seat fully. By
filing the panel so the unit could slide all the way in, I eliminated the
problem.
Jim Oberst
----- Original Message -----
From: "Matt Prather" <mprather@spro.net>
Subject: Re: AeroElectric-List: Avionics mounting problems
> --> AeroElectric-List message posted by: "Matt Prather"
<mprather@spro.net>
>
> Hi Scott,
>
> Comments embedded...
>
> > --> AeroElectric-List message posted by: "Scott Diffenbaugh"
> > <diff@foothill.net>
> >
> > My local avionics shop has just completed the bench top wiring
> > of a full
> > GARMIN-AT IFR stack into my RV7A panel subassembly. The panel was CNC
> > cut and all trays mounted flush and square with the front face of the
> > panel. The side attachment supports are .063 extruded aluminum angles.
> > All racks are tied together with additional side straps as well as a
> > full surround support at the rear subpanel (the 3 firewall braces are
> > installed as well). The assembly appears to be very solid.
>
> Sounds like a good setup. I am envious. :)
>
> >
> > THE PROBLEM: When any individual device is installed with no
> > other devices
> > installed, that device works fine. When another device is installed as
>
> How is the fit of the each devices within its respective tray? Do they
> slide in nicely, or do the require significant force to install? Does the
> amount of force required to install a device change appreciably depending
> on how many other devices are already in the rack?
>
> > well, intermittent problems begin to occur. With all 5 devices
> > installed, lots of problems.
>
> What kinds of problems?
>
> > The shop explained this is very common and
> > that ever so slight twisting or pressure exerted by installing several
> > devices at a time will cause this to happen, and that once the assembly
> > is mounted in the plane, I will need to manipulate each tray by filing
> > the panel openings, loosening and retightening mounting screws, bracing,
> > etc., until all devices work together. Since this seemed incredulous to
> > me, I checked with the Garmin technical service rep who confirmed this
> > is an everyday occurrence. The trays must be "tweaked" so that all of
> > the rear pin connectors line up perfectly.
>
> This sounds like hogwash to me. If the rack is made to reasonable
tolerance
> such that components can be installed/removed without excessive force, the
> electrical end should be good.
>
> This sounds more like an EMI/RFI or power supply problem. Do you have a
> good, stout supply to run the power bus from (fully charged battery)?
> Does the
> behavior of any of the devices change depending on how many other devices
> are turned on at the same time, or is it strictly a mechanical issue?
>
> >
> > THE QUESTION: Can anyone share their experiences in dealing
> > with this
> > "common occurrence" and best way to proceed before I start hacking away?
> >
>
> I wish I had some real data to share with you.
>
> > Thank you,
> >
> > Scott Diffenbaugh RV7A
> > diff@foothill.net
> >
> >
>
> Please keep us posted with what you find.
>
> Regards,
>
> Matt-
> N34RD
>
>
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|