Today's Message Index:
----------------------
1. 01:35 AM - Re: use of toggle switch breakers (CardinalNSB@aol.com)
2. 02:59 AM - Re: Re: use of toggle switch breakers (FLYaDIVE@aol.com)
3. 05:13 AM - Re: Re: use of toggle switch breakers (OldBob Siegfried)
4. 06:03 AM - Re: AeroElectric-List Digest: 22 Msgs - 08/03/06 (Ernest Christley)
5. 06:38 AM - Re: Aero-Electric List: MPJA Speed Control (Hopperdhh@aol.com)
6. 07:59 AM - Re: Re: Aero-Electric List: MPJA Speed Control (Brian Lloyd)
7. 08:15 AM - Re: Re: Aero-Electric List: MPJA Speed Control (Hopperdhh@aol.com)
8. 08:44 AM - Re: Re: use of toggle switch breakers (Kelly McMullen)
9. 08:50 AM - Local Grounding Question (Charlie Kuss)
10. 09:26 AM - Re: Re: use of toggle switch breakers (Bill Denton)
11. 09:56 AM - Alternator seizure engine failure (Robert Sultzbach)
12. 09:58 AM - Re: Local Grounding Question (Harry Manvel)
13. 01:16 PM - Re: Local Grounding Question ()
14. 01:42 PM - Re: Re: Aero-Electric List: MPJA Speed Control (Brian Lloyd)
15. 01:48 PM - Re: Alternator seizure engine failure (Brian Lloyd)
16. 02:56 PM - Re: Re: Aero-Electric List: MPJA Speed (Robert L. Nuckolls, III)
17. 02:56 PM - Re: Local Grounding Question (Robert L. Nuckolls, III)
18. 03:45 PM - Re: Alternator seizure engine failure (Paul Messinger)
19. 05:09 PM - Re: Re: Aero-Electric List: MPJA Speed Control (Hopperdhh@aol.com)
20. 05:17 PM - Re: 8.33 kHz comms (Bruce McGregor)
21. 05:17 PM - Re: Re: use of toggle switch breakers (FLYaDIVE@aol.com)
22. 05:28 PM - Re: Alternator seizure engine failure (Brian Lloyd)
23. 05:42 PM - Re: Alternator seizure engine failure (Dave N6030X)
24. 05:42 PM - Re: Local Grounding Question (John Swartout)
25. 07:53 PM - Re: Alternator seizure engine failure (Charlie Kuss)
26. 08:22 PM - Re: Alternator seizure engine failure (Dave N6030X)
27. 08:42 PM - Re: Alternator seizure engine failure (OldBob Siegfried)
28. 08:48 PM - Re: Alternator seizure engine failure (OldBob Siegfried)
29. 08:55 PM - Re: Alternator seizure engine failure (Paul Messinger)
30. 10:20 PM - EFIS - BMA or GRT? (Dan Beadle)
31. 11:09 PM - Re: EFIS - BMA or GRT? (Bruce Gray)
Message 1
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| Subject: | Re: use of toggle switch breakers |
My certified aircraft uses little square cheap type breakers, and rocker
switches for certain items. I plan to replace the breaker and rocker switch
with a Potter and Brumfield "toggle switch/breaker combination". I plan to use
the same amp toggle switch breaker as the circuit breaker I am replacing. I
plan to do this for the landing light, taxi light, nav lights, beacon, pitot
heat, and fuel pump. My ap is ok with this as a minor modification.
Does anyone recommend against this plan, and why? Thank you, Skip Simpson
Message 2
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| Subject: | Re: use of toggle switch breakers |
--> AeroElectric-List message posted by: FLYaDIVE@aol.com
In a message dated 8/4/06 4:39:00 AM Eastern Daylight Time,
CardinalNSB@aol.com writes:
> My certified aircraft uses little square cheap type breakers, and rocker
> switches for certain items. I plan to replace the breaker and rocker
> switch with a Potter and Brumfield "toggle switch/breaker combination". I
plan to
> use the same amp toggle switch breaker as the circuit breaker I am
replacing.
> I plan to do this for the landing light, taxi light, nav lights, beacon,
> pitot heat, and fuel pump. My ap is ok with this as a minor modification.
>
> Does anyone recommend against this plan, and why? Thank you, Skip Simpson
=======================================
Skip:
Not at all. It is a good way to kill two birds with one stone. Maybe even
three birds:
1 - You replace old switches with new.
2 - You eliminate an old style fuse/breaker and replace with new
3 - And you also eliminate an additional failure point.
As far as it being Minor Modification ... I don't think so. but, the
important part is your A&P does thin it is. You will find out about that when
you
submit the 337. I would write it up as a Minor and let the FAA sort it out.
REMEMBER! You will have to change the wiring at the Old CB / Fuse You will have
to bypass the old and remove the Old and also add placards for the switches
showing CB Amperage.
Barry
"Chop'd Liver"
"Show them the first time, correct them the second time, kick them the third
time."
Yamashiada
Message 3
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| Subject: | Re: use of toggle switch breakers |
--> AeroElectric-List message posted by: OldBob Siegfried <oldbob@beechowners.com>
Good Morning Barry,
If you don't mind, may I make a small comment?
I will not attempt to make a determination as to
whether or not the proposed alteration is minor or
major, but will add that no 337 needs to be filed for
a minor alteration.
The determination can be made by the appropriately
certificated technician making the change.
He or she is required to state what has been done by
making an entry in the appropriate ship's papers.
There is always the possibility that some authorized
person such as an A&P holding an IA may later decide
that the installation is not minor and refuse to
declare the aircraft as airworthy. I would, therefor,
suggest that whoever is going to annual the airplane
be consulted. If the A&P who is going to authorize the
change is also the IA who is going to perform the
annual inspection, forget the 337!
Happy Skies,
Old bob
--- FLYaDIVE@aol.com wrote:
> --> AeroElectric-List message posted by:
> FLYaDIVE@aol.com
>
> In a message dated 8/4/06 4:39:00 AM Eastern
> Daylight Time,
> CardinalNSB@aol.com writes:
>
> > My certified aircraft uses little square cheap
> type breakers, and rocker
> > switches for certain items. I plan to replace
> the breaker and rocker
> > switch with a Potter and Brumfield "toggle
> switch/breaker combination". I
> plan to
> > use the same amp toggle switch breaker as the
> circuit breaker I am
> replacing.
> > I plan to do this for the landing light, taxi
> light, nav lights, beacon,
> > pitot heat, and fuel pump. My ap is ok with this
> as a minor modification.
> >
> > Does anyone recommend against this plan, and why?
> Thank you, Skip Simpson
> =======================================
> Skip:
>
> Not at all. It is a good way to kill two birds with
> one stone. Maybe even
> three birds:
> 1 - You replace old switches with new.
> 2 - You eliminate an old style fuse/breaker and
> replace with new
> 3 - And you also eliminate an additional failure
> point.
>
> As far as it being Minor Modification ... I don't
> think so. but, the
> important part is your A&P does thin it is. You
> will find out about that when you
> submit the 337. I would write it up as a Minor and
> let the FAA sort it out.
> REMEMBER! You will have to change the wiring at the
> Old CB / Fuse You will have
> to bypass the old and remove the Old and also add
> placards for the switches
> showing CB Amperage.
>
> Barry
> "Chop'd Liver"
>
> "Show them the first time, correct them the second
> time, kick them the third
> time."
> Yamashiada
>
>
>
>
> browse
> Subscriptions page,
> FAQ,
> http://www.matronics.com/Navigator?AeroElectric-List
>
>
> Admin.
>
>
>
>
>
>
>
>
>
>
>
Message 4
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| Subject: | Re: AeroElectric-List Digest: 22 Msgs - 08/03/06 |
--> AeroElectric-List message posted by: Ernest Christley <echristley@nc.rr.com>
AeroElectric-List Digest Server wrote:
>Hi Ernest,
>Yes, I'm using the MPJA pwm speed controller for dimming LED's. In the
>attached jpg. you can see the string of led's across the top of my panel
>which are controlled by a single MPJA speed controller. I too
>repositioned the potentiometer with a remote unit of higher quality. All
>of my circuits were configured from the manufacturer to operate on 12v
>as the MPJA pwm speed controller is designed to operate a 12v motor.
>Works great with no noticeable flicker.
>
>Mark S.
>
>
>
Thanks, guys. As often happens, I must've done something wrong. I'll
need to double check again that I got all the resistors in the right
places, and then schedule some time with the O-scope.
BTW, just for the record, I drilled a second 3/32" anti-rotation hole
for the supplied potentiometer so that I could stick it through in the
other direction. I did this AFTER checking that it was a simple,
center-tapped pot. This lets all the jelly bean parts go inside the
supplied box (drill ventilation holes) which I can then bolt up to the
backside of my panel with the control knob sticking through.
--
,|"|"|, Ernest Christley |
----===<{{(oQo)}}>===---- Dyke Delta Builder |
o| d |o http://ernest.isa-geek.org |
Message 5
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| Subject: | Re: Aero-Electric List: MPJA Speed Control |
Ernest,
Apparently this speed control/dimmer uses a PWM (pulse width modulation)
technique to dim the LEDs. LEDs are very fast responding unlike an incandescent
bulb which stays hot between pulses. You can get some weird effects with
this kind of dimming. When you glance across the panel you can probably see
the lights as a series of bright spots rather than solid lights. In older
calculators with 7 segment LED readouts you could move the calculator downward
across your field of vision and get a stairstep effect due to multiplexing of
the display. In other words, only one of the numbers is on at any given time.
This requires less circuitry to drive all of the display segments. In a
panel dimmer it conserves power, and the dimmer dissipates far less power.
I have yet to see an aircraft radio with LED displays that uses multiplexing
for the display, probably to avoid the effect described above. I would
think that a linear dimmer circuit would be a better choice for an aircraft
panel. I am very happy with the A and T Labs K11 Panel Dimmer although I
substituted a less massive heat convector. Just my opinion, YMMV.
http://www.a-and-t-labs.com/K11_Dimmer
Dan Hopper
RV-7A
In a message dated 8/4/2006 9:06:28 A.M. Eastern Daylight Time,
echristley@nc.rr.com writes:
AeroElectric-List Digest Server wrote:
>Hi Ernest,
>Yes, I'm using the MPJA pwm speed controller for dimming LED's. In the
>attached jpg. you can see the string of led's across the top of my panel
>which are controlled by a single MPJA speed controller. I too
>repositioned the potentiometer with a remote unit of higher quality. All
>of my circuits were configured from the manufacturer to operate on 12v
>as the MPJA pwm speed controller is designed to operate a 12v motor.
>Works great with no noticeable flicker.
>
>Mark S.
>
>
>
Thanks, guys. As often happens, I must've done something wrong. I'll
need to double check again that I got all the resistors in the right
places, and then schedule some time with the O-scope.
BTW, just for the record, I drilled a second 3/32" anti-rotation hole
for the supplied potentiometer so that I could stick it through in the
other direction. I did this AFTER checking that it was a simple,
center-tapped pot. This lets all the jelly bean parts go inside the
supplied box (drill ventilation holes) which I can then bolt up to the
backside of my panel with the control knob sticking through.
--
,|"|"|, Ernest Christley |
----===<{{(oQo)}}>===---- Dyke Delta Builder |
o| d |o http://ernest.isa-geek.org |
Message 6
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| Subject: | Re: Aero-Electric List: MPJA Speed Control |
--> AeroElectric-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
On Aug 4, 2006, at 9:31 AM, Hopperdhh@aol.com wrote:
> Apparently this speed control/dimmer uses a PWM (pulse width
> modulation) technique to dim the LEDs. LEDs are very fast
> responding unlike an incandescent bulb which stays hot between
> pulses. You can get some weird effects with this kind of dimming.
Persistence of vision averages the on/off time to effect the dimming
of the LEDs. The average energy that the LED emits is reduced so that
the eye has fewer photons to respond to.
So, yes, PWM will dim LEDs too.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
Message 7
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| Subject: | Re: Aero-Electric List: MPJA Speed Control |
In a message dated 8/4/2006 11:05:15 A.M. Eastern Daylight Time,
brian-yak@lloyd.com writes:
On Aug 4, 2006, at 9:31 AM, Hopperdhh@aol.com wrote:
> Apparently this speed control/dimmer uses a PWM (pulse width
> modulation) technique to dim the LEDs. LEDs are very fast
> responding unlike an incandescent bulb which stays hot between
> pulses. You can get some weird effects with this kind of dimming.
Persistence of vision averages the on/off time to effect the dimming
of the LEDs. The average energy that the LED emits is reduced so that
the eye has fewer photons to respond to.
So, yes, PWM will dim LEDs too.
Brian Lloyd
Brian,
You didn't get the point of my message. Persistence of the eye does what
you say, until you move your eyes. Then your eyes are fooled, and you see dots
(or lines) instead of steady lights.
Dan
Message 8
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| Subject: | Re: use of toggle switch breakers |
--> AeroElectric-List message posted by: Kelly McMullen <kellym@aviating.com>
P&B's were used for years in Mooney's. They do become weak and trip
early, after, oh say 30+ years. ;-) Otherwise, much easier to use. Be
certain of physical dimension fit, both front to back and side to side.
Read Part 43 Appendix A carefully as to minor vs major mod. Consult
with the IA you plan to use for your next annual. He is the person
that you need to buy into the project. Or at a minimum, have your A&P
discuss it with him.
Minor modifications are not written up on 337s. If you have doubt, at
least in your FSDO area, have your A&P write it up as a 337 field
approval and submit to FSDO for signature before any work starts. That
way you get approval or told not needed from your FSDO.
Quoting FLYaDIVE@aol.com:
> Skip:
>
> Not at all. It is a good way to kill two birds with one stone. Maybe even
> three birds:
> 1 - You replace old switches with new.
> 2 - You eliminate an old style fuse/breaker and replace with new
> 3 - And you also eliminate an additional failure point.
>
> As far as it being Minor Modification ... I don't think so. but, the
> important part is your A&P does thin it is. You will find out about
> that when you
> submit the 337. I would write it up as a Minor and let the FAA sort it out.
> REMEMBER! You will have to change the wiring at the Old CB / Fuse
> You will have
> to bypass the old and remove the Old and also add placards for the switches
> showing CB Amperage.
>
> Barry
> "Chop'd Liver"
>
> "Show them the first time, correct them the second time, kick them the third
> time."
> Yamashiada
>
>
Message 9
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| Subject: | Local Grounding Question |
--> AeroElectric-List message posted by: Charlie Kuss <chaztuna@adelphia.net>
Bob & listers,
I'm installing 4 locking cigarette lighter power recepticles in my
RV-8A project. These will be used to power things like rear seater
GPS, heated clothing, cell phone re-charger, Monroy traffic alerter &
music source. Can these units be grounded locally, or should the
grounds be run up to the terminal block?
Charlie Kuss
Message 10
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| Subject: | Re: use of toggle switch breakers |
--> AeroElectric-List message posted by: "Bill Denton" <bdenton@bdenton.com>
RE: "...also add placards for the switches showing CB Amperage."
The P&B W31 Toggle Switch/Breakers have the amp rating engraved on the end
of the toggle...
-----Original Message-----
[mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of
FLYaDIVE@aol.com
Sent: Friday, August 4, 2006 4:49 AM
--> AeroElectric-List message posted by: FLYaDIVE@aol.com
In a message dated 8/4/06 4:39:00 AM Eastern Daylight Time,
CardinalNSB@aol.com writes:
> My certified aircraft uses little square cheap type breakers, and rocker
> switches for certain items. I plan to replace the breaker and rocker
> switch with a Potter and Brumfield "toggle switch/breaker combination". I
plan to
> use the same amp toggle switch breaker as the circuit breaker I am
replacing.
> I plan to do this for the landing light, taxi light, nav lights, beacon,
> pitot heat, and fuel pump. My ap is ok with this as a minor
modification.
>
> Does anyone recommend against this plan, and why? Thank you, Skip
Simpson
=======================================
Skip:
Not at all. It is a good way to kill two birds with one stone. Maybe even
three birds:
1 - You replace old switches with new.
2 - You eliminate an old style fuse/breaker and replace with new
3 - And you also eliminate an additional failure point.
As far as it being Minor Modification ... I don't think so. but, the
important part is your A&P does thin it is. You will find out about that
when you
submit the 337. I would write it up as a Minor and let the FAA sort it out.
REMEMBER! You will have to change the wiring at the Old CB / Fuse You will
have
to bypass the old and remove the Old and also add placards for the switches
showing CB Amperage.
Barry
"Chop'd Liver"
"Show them the first time, correct them the second time, kick them the third
time."
Yamashiada
Message 11
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| Subject: | Alternator seizure engine failure |
--> AeroElectric-List message posted by: Robert Sultzbach <endspeed@yahoo.com>
Hi Brian, I have meant to throw cudos your way on the
predicted bearing failure/seizure's catastrophic
effect on an engine. I thought this was a very remote
failure possibility when you postulated about it.
Then, sure enough it goes and happens to one of our
posters. Good forethought on your part. Bob
Sultzbach
__________________________________________________
Message 12
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| Subject: | Re: Local Grounding Question |
--> AeroElectric-List message posted by: "Harry Manvel" <hmanvel@manvel.com>
Charlie,
I am interested in those "locking" recepticles. I have some which I have
velcroed together but that is kindof clunky. Where do you get those?
Harry Manvel
Defiant N2HM
PTK / Pontiac, MI
----- Original Message -----
Sent: Friday, August 04, 2006 11:39 AM
> --> AeroElectric-List message posted by: Charlie Kuss
> <chaztuna@adelphia.net>
>
> Bob & listers,
> I'm installing 4 locking cigarette lighter power recepticles in my RV-8A
> project. These will be used to power things like rear seater GPS, heated
> clothing, cell phone re-charger, Monroy traffic alerter & music source.
> Can these units be grounded locally, or should the grounds be run up to
> the terminal block?
> Charlie Kuss
>
>
> http://www.matronics.com/Navigator?AeroElectric-List
> http://wiki.matronics.com
>
>
>
Message 13
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| Subject: | Re: Local Grounding Question |
--> AeroElectric-List message posted by: <chaztuna@adelphia.net>
Harry,
Craig Payne from this list told me about these. They are made by Marinco. Model
# 12VPK. I got mine at my local Boat Owners Warehouse. Here is a web link.
http://www.marinco.com/scpt/ProdPage.php?loadItem=12VPK_Marinco%20Shore%20Power
They are great. They lock positively. Twist 30 degrees in either direction to
release the lock mechanism. They are waterproof. The male end contains a fuse
which you can use to protect the cable. I've found that even the male cigarette
connector from my Noika cell phone is retained quite well.
Charlie
---- Harry Manvel <hmanvel@manvel.com> wrote:
> --> AeroElectric-List message posted by: "Harry Manvel" <hmanvel@manvel.com>
>
> Charlie,
>
> I am interested in those "locking" recepticles. I have some which I have
> velcroed together but that is kindof clunky. Where do you get those?
>
> Harry Manvel
> Defiant N2HM
> PTK / Pontiac, MI
> ----- Original Message -----
> Sent: Friday, August 04, 2006 11:39 AM
>
>
> > --> AeroElectric-List message posted by: Charlie Kuss
> > <chaztuna@adelphia.net>
> >
> > Bob & listers,
> > I'm installing 4 locking cigarette lighter power recepticles in my RV-8A
> > project. These will be used to power things like rear seater GPS, heated
> > clothing, cell phone re-charger, Monroy traffic alerter & music source.
> > Can these units be grounded locally, or should the grounds be run up to
> > the terminal block?
> > Charlie Kuss
> >
> >
> >
> >
> >
> > http://www.matronics.com/Navigator?AeroElectric-List
> > http://wiki.matronics.com
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
>
>
>
>
>
>
>
>
>
>
>
>
>
Message 14
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| Subject: | Re: Aero-Electric List: MPJA Speed Control |
--> AeroElectric-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
On Aug 4, 2006, at 11:11 AM, Hopperdhh@aol.com wrote:
> Brian,
>
> You didn't get the point of my message. Persistence of the eye
> does what you say, until you move your eyes. Then your eyes are
> fooled, and you see dots (or lines) instead of steady lights.
That is true when looking at the LEDs themselves. But if your LEDs
are working as flood lights, the lighted area will not do what you
are suggesting as the light covers such a large area.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
Message 15
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| Subject: | Re: Alternator seizure engine failure |
--> AeroElectric-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
On Aug 4, 2006, at 12:52 PM, Robert Sultzbach wrote:
> --> AeroElectric-List message posted by: Robert Sultzbach
> <endspeed@yahoo.com>
>
> Hi Brian, I have meant to throw cudos your way on the
> predicted bearing failure/seizure's catastrophic
> effect on an engine. I thought this was a very remote
> failure possibility when you postulated about it.
> Then, sure enough it goes and happens to one of our
> posters. Good forethought on your part. Bob
> Sultzbach
Thanks. I certainly didn't want to be proved right in the way that it
happened.
On to the details, you probably want a belt that will fail and allow
the engine to keep running rather than kill the engine.
A 50A 14V alternator is producing 700W at full output. If the
alternator is 90% efficient it needs 770W of mechanical input. One HP
is 760W. So you need a belt that will handle 1HP. That is not a very
big belt. You sure don't need dual belts. If the alternator seizes
the smaller belt will fail and your engine keeps running to carry you
to a safe landing.
Now someone who knows belts should jump in here with belt sizing
information to cover the transmission of 1HP.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
Message 16
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|
| Subject: | Re: Aero-Electric List: MPJA Speed |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 09:31 AM 8/4/2006 -0400, you wrote:
>
>Ernest,
>
>Apparently this speed control/dimmer uses a PWM (pulse width modulation)
>technique to dim the LEDs. LEDs are very fast responding unlike an
>incandescent bulb which stays hot between pulses. You can get some weird
>effects with this kind of dimming. When you glance across the panel you
>can probably see the lights as a series of bright spots rather than solid
>lights. In older calculators with 7 segment LED readouts you could move
>the calculator downward across your field of vision and get a stairstep
>effect due to multiplexing of the display. In other words, only one of
>the numbers is on at any given time. This requires less circuitry to
>drive all of the display segments. In a panel dimmer it conserves power,
>and the dimmer dissipates far less power.
>
>I have yet to see an aircraft radio with LED displays that uses
>multiplexing for the display, probably to avoid the effect described
>above. I would think that a linear dimmer circuit would be a better
>choice for an aircraft panel. I am very happy with the A and T Labs K11
>Panel Dimmer although I substituted a less massive heat convector. Just
>my opinion, YMMV.
The few cases where I've selected duty-cycle dimming
parameters or multiplexing for LED displays, the switching
rate was ALWAYS in the hundreds of Hz. The PWM modulator
under discussion can no doubt be modified . . .find the
frequency selection capacitor and cut it to say 1/10th
the present value. The probable outcome is equivalent
functionality with no visible flicker or "beading" at
any intensity.
Bob . . .
Message 17
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| Subject: | Re: Local Grounding Question |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 11:39 AM 8/4/2006 -0400, you wrote:
>--> AeroElectric-List message posted by: Charlie Kuss <chaztuna@adelphia.net>
>
>Bob & listers,
> I'm installing 4 locking cigarette lighter power recepticles in my RV-8A
> project. These will be used to power things like rear seater GPS, heated
> clothing, cell phone re-charger, Monroy traffic alerter & music source.
> Can these units be grounded locally, or should the grounds be run up to
> the terminal block?
If they are potential victims, then protected grounding is
not a 'bad' idea . . . but still not always necessary.
If the accessories you're plugging into these outlets
are designed to run from the automotive cigar lighter
-OR- are obviously NOT potential victims like heaters,
then risks are very small for local grouding.
Bottom line is . . . try it. You won't have to do anything
worst than fix it later.
Bob . . .
Message 18
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| Subject: | Re: Alternator seizure engine failure |
--> AeroElectric-List message posted by: "Paul Messinger" <paulm@olypen.com>
First 90% efficiency (for a 1970 alternator design) is in your dreams, try
in the mid 70's but the main point is with "V" belts the belt tension needs
to be high with an engine rpm of 6,000 and a single "V" based on the design
of belts available 15-20 years ago. The subject engine is an EA81 that needs
a light belt tension to prevent water pump bearing failure from too high but
common belt tension. The tension must be high enough so there is no slippage
under any expected load condition. Also remember the water pump is part of
the belt load and finally you must consider the pulley to belt contact arc
to transmit the load from the crank to the pump and alternator in a 3 pulley
setup.
Thus the manufacturer of the conversion decided on dual belts with light
tension as friction did the rest. This was to prevent a common failure at
the time of water pump bearing wear and loss of coolant.
Its not easy to design a "V" belt that will slip on the one hand and not
require high belt tension for its friction drive. Also consider in this
application the crank to alternator pulley ratio is around 1-1.4 . Further
throttled back it does not take much and with a "Sprague" clutch driving the
prop (no inertial help here) and a very light flywheel there is little
inertia to help. The specific belts are narrow with machined sides not the
cloth covered ones of the era. There is no way the belt will snap if its in
good condition until its been heated and burned thru. Again there was no
chance of this here as the engine stopped immediately.
In addition there are around 700+ such dual belt conversions with over
100,000 flight hours (some with over 4,000 hours) and this is the first
known failure of its type. Hardly a bad design based on actual performance.
I have the specific dual belt system on my own engine so I do know the
actual situation.
Good luck in finding a belt that acts like a fuse and instantly self
destructs at 200% of design load but lasts 1,000 hours at 100% of design
load.
The very common cogged timing belt widely used in modern auto engines can
fail and if it does the engine stops. If the idler fails the belt slips the
cogs and the engine fails. On an aircraft engine if an accessory case driven
unit fails and locks up the engine likely will fail fast from major metal
parts internal to the accessory case.
I believe the "result of the failure" is being addressed by your comment and
you are missing the "real likely cause" which is a bad bearing from the use
of a rebuilt alternator. 80 hours was the total time on the engine and also
the alternator since rebuild where is not common to replace the bearings.
Paul
----- Original Message -----
Sent: Friday, August 04, 2006 1:45 PM
> --> AeroElectric-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
>
>
> On Aug 4, 2006, at 12:52 PM, Robert Sultzbach wrote:
>
>> --> AeroElectric-List message posted by: Robert Sultzbach
>> <endspeed@yahoo.com>
>>
>> Hi Brian, I have meant to throw cudos your way on the
>> predicted bearing failure/seizure's catastrophic
>> effect on an engine. I thought this was a very remote
>> failure possibility when you postulated about it.
>> Then, sure enough it goes and happens to one of our
>> posters. Good forethought on your part. Bob
>> Sultzbach
>
> Thanks. I certainly didn't want to be proved right in the way that it
> happened.
>
> On to the details, you probably want a belt that will fail and allow the
> engine to keep running rather than kill the engine.
>
> A 50A 14V alternator is producing 700W at full output. If the alternator
> is 90% efficient it needs 770W of mechanical input. One HP is 760W. So
> you need a belt that will handle 1HP. That is not a very big belt. You
> sure don't need dual belts. If the alternator seizes the smaller belt
> will fail and your engine keeps running to carry you to a safe landing.
>
> Now someone who knows belts should jump in here with belt sizing
> information to cover the transmission of 1HP.
>
> Brian Lloyd 361 Catterline Way
> brian-yak AT lloyd DOT com Folsom, CA 95630
> +1.916.367.2131 (voice) +1.270.912.0788 (fax)
>
> I fly because it releases my mind from the tyranny of petty things . . .
> Antoine de Saint-Exupry
>
>
> http://www.matronics.com/Navigator?AeroElectric-List
> http://wiki.matronics.com
>
>
>
Message 19
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| Subject: | Re: Aero-Electric List: MPJA Speed Control |
Brian,
Oh. I'll have to give it a try. I can see that covering a large area may
change things. I was thinking of my own panel where I have two bright whit
e
LEDs in the artificial horizon light bar connected to the panel dimmer. Wi
th
PWM, I could just imagine seeing multiple AHs as I scanned the panel! Or i
f
I had a row of LEDs on the underside of the glare shield, seeing lights
dancing all over the inside of the airplane as I look around outside at nig
ht.
do not archive
Thanks,
Dan
In a message dated 8/4/2006 7:20:02 P.M. Eastern Daylight Time,
brian-yak@lloyd.com writes:
--> AeroElectric-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
On Aug 4, 2006, at 11:11 AM, Hopperdhh@aol.com wrote:
> Brian,
>
> You didn't get the point of my message. Persistence of the eye
> does what you say, until you move your eyes. Then your eyes are
> fooled, and you see dots (or lines) instead of steady lights.
That is true when looking at the LEDs themselves. But if your LEDs
are working as flood lights, the lighted area will not do what you
are suggesting as the light covers such a large area.
Brian Lloyd 361 Catterline Way
brian-yak AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
=94 Antoine de Saint-Exup=C3=A9ry
=========================
==========
=========================
==========
=========================
==========
=========================
==========
Message 20
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| Subject: | Re: 8.33 kHz comms |
--> AeroElectric-List message posted by: "Bruce McGregor" <bruceflys@comcast.net>
Be careful, IFR qualified GPS units must meet TSO 129a standards. The
Garmin 430/530/480 and King KLN series do. I have read nothing about GRT
certifying their equipment.
Regards, Bruce McGregor
************************************************
Anyone know when the new channelization is going to become mandatory in
the US? I hear it's coming, someday. What are some good options for
current production nav-comms that offer this feature already? I don't
need a gps/nav/comm unit since I plan to run GRT's gps as a stand-alone
IFR unit, so the 430, 530, 480 are all too much radio for my needs.
Thanks.
-Bill B.
Message 21
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|
| Subject: | Re: use of toggle switch breakers |
--> AeroElectric-List message posted by: FLYaDIVE@aol.com
In a message dated 8/4/06 12:31:26 PM Eastern Daylight Time,
bdenton@bdenton.com writes:
> RE: "...also add placards for the switches showing CB Amperage."
>
> The P&B W31 Toggle Switch/Breakers have the amp rating engraved on the end
> of the toggle...
>
=========================
True, there is an engraving but it is not very visible ... Not to these old
eyes and very difficult to see at night.
I just redid all the placards on the RV-6A with a brother P-Touch and black
tape. WOW looks very nice. Maybe not OSH 1st place quality but very nice.
Barry
"Chop'd Liver"
"Show them the first time, correct them the second time, kick them the third
time."
Yamashiada
Message 22
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|
| Subject: | Re: Alternator seizure engine failure |
--> AeroElectric-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
Paul Messinger wrote:
> --> AeroElectric-List message posted by: "Paul Messinger"
> <paulm@olypen.com>
>
> First 90% efficiency (for a 1970 alternator design) is in your dreams,
> try in the mid 70's but the main point is with "V" belts the belt
> tension needs to be high with an engine rpm of 6,000 and a single "V"
> based on the design of belts available 15-20 years ago. The subject
> engine is an EA81 that needs a light belt tension to prevent water pump
> bearing failure from too high but common belt tension. The tension must
> be high enough so there is no slippage under any expected load
> condition. Also remember the water pump is part of the belt load and
> finally you must consider the pulley to belt contact arc to transmit the
> load from the crank to the pump and alternator in a 3 pulley setup.
Well I was thinking in terms of a Lycoming engine wherein the belt
drives the alternator and only the alternator.
But, I am glad you chimed in here because, frankly, I don't know squat
about belt drives beyond the obvious and would not pretend otherwise.
--
Brian Lloyd 361 Catterline Way
brian-yak at lloyd dot com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
- Antoine de Saint-Exupery
Message 23
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|
| Subject: | Re: Alternator seizure engine failure |
--> AeroElectric-List message posted by: Dave N6030X <N6030X@DaveMorris.com>
Sounds like a more reliable approach for vehicles
that can't "pull over to the side of the road" in
case of failure would be to mount 2 alternators
with 1/2 the current capacity each, driven by 2
separate belts neither of which require the kind
of tension that would seize the engine or burn out the bearings.
Dave Morris
At 05:36 PM 8/4/2006, you wrote:
>--> AeroElectric-List message posted by: "Paul Messinger" <paulm@olypen.com>
>
>First 90% efficiency (for a 1970 alternator
>design) is in your dreams, try in the mid 70's
>but the main point is with "V" belts the belt
>tension needs to be high with an engine rpm of
>6,000 and a single "V" based on the design of
>belts available 15-20 years ago. The subject
>engine is an EA81 that needs a light belt
>tension to prevent water pump bearing failure
>from too high but common belt tension. The
>tension must be high enough so there is no
>slippage under any expected load condition. Also
>remember the water pump is part of the belt load
>and finally you must consider the pulley to belt
>contact arc to transmit the load from the crank
>to the pump and alternator in a 3 pulley setup.
>
>Thus the manufacturer of the conversion decided
>on dual belts with light tension as friction did
>the rest. This was to prevent a common failure
>at the time of water pump bearing wear and loss of coolant.
>
>Its not easy to design a "V" belt that will slip
>on the one hand and not require high belt
>tension for its friction drive. Also consider in
>this application the crank to alternator pulley
>ratio is around 1-1.4 . Further throttled back
>it does not take much and with a "Sprague"
>clutch driving the prop (no inertial help here)
>and a very light flywheel there is little
>inertia to help. The specific belts are narrow
>with machined sides not the cloth covered ones
>of the era. There is no way the belt will snap
>if its in good condition until its been heated
>and burned thru. Again there was no chance of
>this here as the engine stopped immediately.
>
>In addition there are around 700+ such dual belt
>conversions with over 100,000 flight hours (some
>with over 4,000 hours) and this is the first
>known failure of its type. Hardly a bad design based on actual performance.
>
>I have the specific dual belt system on my own
>engine so I do know the actual situation.
>
>Good luck in finding a belt that acts like a
>fuse and instantly self destructs at 200% of
>design load but lasts 1,000 hours at 100% of design load.
>
>The very common cogged timing belt widely used
>in modern auto engines can fail and if it does
>the engine stops. If the idler fails the belt
>slips the cogs and the engine fails. On an
>aircraft engine if an accessory case driven unit
>fails and locks up the engine likely will fail
>fast from major metal parts internal to the accessory case.
>
>I believe the "result of the failure" is being
>addressed by your comment and you are missing
>the "real likely cause" which is a bad bearing
>from the use of a rebuilt alternator. 80 hours
>was the total time on the engine and also the
>alternator since rebuild where is not common to replace the bearings.
>
>Paul
>
>
>----- Original Message ----- Sent: Friday, August 04, 2006 1:45 PM
>
>
>>--> AeroElectric-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
>>
>>
>>On Aug 4, 2006, at 12:52 PM, Robert Sultzbach wrote:
>>
>>>--> AeroElectric-List message posted by:
>>>Robert Sultzbach <endspeed@yahoo.com>
>>>
>>>Hi Brian, I have meant to throw cudos your way on the
>>>predicted bearing failure/seizure's catastrophic
>>>effect on an engine. I thought this was a very remote
>>>failure possibility when you postulated about it.
>>>Then, sure enough it goes and happens to one of our
>>>posters. Good forethought on your part. Bob
>>>Sultzbach
>>
>>Thanks. I certainly didn't want to be proved
>>right in the way that it happened.
>>
>>On to the details, you probably want a belt
>>that will fail and allow the engine to keep
>>running rather than kill the engine.
>>
>>A 50A 14V alternator is producing 700W at full
>>output. If the alternator is 90% efficient it
>>needs 770W of mechanical input. One HP is
>>760W. So you need a belt that will handle 1HP.
>>That is not a very big belt. You sure don't
>>need dual belts. If the alternator seizes the
>>smaller belt will fail and your engine keeps
>>running to carry you to a safe landing.
>>
>>Now someone who knows belts should jump in here
>>with belt sizing information to cover the transmission of 1HP.
>>
>>Brian Lloyd 361 Catterline Way
>>brian-yak AT lloyd DOT com Folsom, CA 95630
>>+1.916.367.2131 (voice) +1.270.912.0788 (fax)
>>
>>I fly because it releases my mind from the tyranny of petty things . . .
>> Antoine de Saint-Exupry
>>
>>
>>
>>
>>
>>
>>
>>http://www.matronics.com/Navigator?AeroElectric-List
>>http://wiki.matronics.com
>>
>>
>>
>>
>>
>>
>>
>>
>
>
Message 24
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|
| Subject: | Local Grounding Question |
--> AeroElectric-List message posted by: "John Swartout" <jgswartout@earthlink.net>
Charlie, where do you get "locking" cigarette lighter sockets? I've got two
of the regular kind, from AS&S, IIRC, that I plan to install. The plugs
seem pretty secure in them. Also, I put the sockets behind the panel,
easily reached *deliberately* but out of the way of knees, kneeboards, etc.
John
-----Original Message-----
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Charlie
Kuss
Sent: Friday, August 04, 2006 11:40 AM
--> AeroElectric-List message posted by: Charlie Kuss
<chaztuna@adelphia.net>
Bob & listers,
I'm installing 4 locking cigarette lighter power recepticles in my
RV-8A project. These will be used to power things like rear seater
GPS, heated clothing, cell phone re-charger, Monroy traffic alerter &
music source. Can these units be grounded locally, or should the
grounds be run up to the terminal block?
Charlie Kuss
Message 25
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|
| Subject: | Re: Alternator seizure engine failure |
Dave,
This is one of those, "it looked good on paper"
ideas. The reality is that if both alternators
are driven off the front of the engine, losing
the belt on one, generally takes out the other
alternator. When a belt fails, it often gets
tangled up in any near by pulleys and belts. This
will derail or destroy the belt for the second alternator.
Bob N's recommendation of a rear drive
(Lycoming engine) secondary alternator (like the B&C units) is a safer bet.
Charlie Kuss
>--> AeroElectric-List message posted by: Dave N6030X
<N6030X@DaveMorris.com>
>
>Sounds like a more reliable approach for
>vehicles that can't "pull over to the side of
>the road" in case of failure would be to mount 2
>alternators with 1/2 the current capacity each,
>driven by 2 separate belts neither of which
>require the kind of tension that would seize the
>engine or burn out the bearings.
>
>Dave Morris
>
>
>At 05:36 PM 8/4/2006, you wrote:
>>--> AeroElectric-List message posted by: "Paul Messinger"
<paulm@olypen.com>
>>
>>First 90% efficiency (for a 1970 alternator
>>design) is in your dreams, try in the mid 70's
>>but the main point is with "V" belts the belt
>>tension needs to be high with an engine rpm of
>>6,000 and a single "V" based on the design of
>>belts available 15-20 years ago. The subject
>>engine is an EA81 that needs a light belt
>>tension to prevent water pump bearing failure
>>from too high but common belt tension. The
>>tension must be high enough so there is no
>>slippage under any expected load condition.
>>Also remember the water pump is part of the
>>belt load and finally you must consider the
>>pulley to belt contact arc to transmit the load
>>from the crank to the pump and alternator in a 3 pulley setup.
>>
>>Thus the manufacturer of the conversion decided
>>on dual belts with light tension as friction
>>did the rest. This was to prevent a common
>>failure at the time of water pump bearing wear and loss of coolant.
>>
>>Its not easy to design a "V" belt that will
>>slip on the one hand and not require high belt
>>tension for its friction drive. Also consider
>>in this application the crank to alternator
>>pulley ratio is around 1-1.4 . Further
>>throttled back it does not take much and with a
>>"Sprague" clutch driving the prop (no inertial
>>help here) and a very light flywheel there is
>>little inertia to help. The specific belts are
>>narrow with machined sides not the cloth
>>covered ones of the era. There is no way the
>>belt will snap if its in good condition until
>>its been heated and burned thru. Again there
>>was no chance of this here as the engine stopped immediately.
>>
>>In addition there are around 700+ such dual
>>belt conversions with over 100,000 flight hours
>>(some with over 4,000 hours) and this is the
>>first known failure of its type. Hardly a bad
>>design based on actual performance.
>>
>>I have the specific dual belt system on my own
>>engine so I do know the actual situation.
>>
>>Good luck in finding a belt that acts like a
>>fuse and instantly self destructs at 200% of
>>design load but lasts 1,000 hours at 100% of design load.
>>
>>The very common cogged timing belt widely used
>>in modern auto engines can fail and if it does
>>the engine stops. If the idler fails the belt
>>slips the cogs and the engine fails. On an
>>aircraft engine if an accessory case driven
>>unit fails and locks up the engine likely will
>>fail fast from major metal parts internal to the accessory case.
>>
>>I believe the "result of the failure" is being
>>addressed by your comment and you are missing
>>the "real likely cause" which is a bad bearing
>>from the use of a rebuilt alternator. 80 hours
>>was the total time on the engine and also the
>>alternator since rebuild where is not common to replace the bearings.
>>
>>Paul
>>
>>
>>----- Original Message ----- Sent: Friday, August 04, 2006 1:45 PM
>>
>>
>>>--> AeroElectric-List message posted by: Brian Lloyd
<brian-yak@lloyd.com>
>>>
>>>
>>>On Aug 4, 2006, at 12:52 PM, Robert Sultzbach wrote:
>>>
>>>>--> AeroElectric-List message posted by:
>>>>Robert Sultzbach <endspeed@yahoo.com>
>>>>
>>>>Hi Brian, I have meant to throw cudos your way on the
>>>>predicted bearing failure/seizure's catastrophic
>>>>effect on an engine. I thought this was a very remote
>>>>failure possibility when you postulated about it.
>>>>Then, sure enough it goes and happens to one of our
>>>>posters. Good forethought on your part. Bob
>>>>Sultzbach
>>>
>>>Thanks. I certainly didn't want to be proved
>>>right in the way that it happened.
>>>
>>>On to the details, you probably want a belt
>>>that will fail and allow the engine to keep
>>>running rather than kill the engine.
>>>
>>>A 50A 14V alternator is producing 700W at full
>>>output. If the alternator is 90% efficient it
>>>needs 770W of mechanical input. One HP is
>>>760W. So you need a belt that will handle 1HP.
>>>That is not a very big belt. You sure don't
>>>need dual belts. If the alternator seizes the
>>>smaller belt will fail and your engine keeps
>>>running to carry you to a safe landing.
>>>
>>>Now someone who knows belts should jump in
>>>here with belt sizing information to cover the transmission of 1HP.
>>>
>>>Brian Lloyd 361 Catterline Way
>>>brian-yak AT lloyd DOT com Folsom, CA 95630
>>>+1.916.367.2131 (voice) +1.270.912.0788 (fax)
>>>
>>>I fly because it releases my mind from the tyranny of petty things . . .
>>>=97 Antoine de Saint-Exup=E9ry
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>http://www.matronics.com/Navigator?AeroElectric-List
>>>http://wiki.matronics.com
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
=========================
==========
=========================
==========
=========================
==========
=========================
==========
>
>
Message 26
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|
| Subject: | Re: Alternator seizure engine failure |
--> AeroElectric-List message posted by: Dave N6030X <N6030X@DaveMorris.com>
So, what happens in the case of a gear-driven
alternator when it seizes up? Does it shred the
whole back end of the Lycoming?
Dave
At 09:45 PM 8/4/2006, you wrote:
>Dave,
> This is one of those, "it looked good on
> paper" ideas. The reality is that if both
> alternators are driven off the front of the
> engine, losing the belt on one, generally takes
> out the other alternator. When a belt fails, it
> often gets tangled up in any near by pulleys
> and belts. This will derail or destroy the belt for the second alternator.
> Bob N's recommendation of a rear drive
> (Lycoming engine) secondary alternator (like the B&C units) is a safer bet.
>Charlie Kuss
>
>
>>--> AeroElectric-List message posted by: Dave N6030X <N6030X@DaveMorris.com>
>>
>>Sounds like a more reliable approach for
>>vehicles that can't "pull over to the side of
>>the road" in case of failure would be to mount
>>2 alternators with 1/2 the current capacity
>>each, driven by 2 separate belts neither of
>>which require the kind of tension that would
>>seize the engine or burn out the bearings.
>>
>>Dave Morris
>>
>>
>>At 05:36 PM 8/4/2006, you wrote:
>>>--> AeroElectric-List message posted by: "Paul Messinger" <paulm@olypen.com>
>>>
>>>First 90% efficiency (for a 1970 alternator
>>>design) is in your dreams, try in the mid 70's
>>>but the main point is with "V" belts the belt
>>>tension needs to be high with an engine rpm of
>>>6,000 and a single "V" based on the design of
>>>belts available 15-20 years ago. The subject
>>>engine is an EA81 that needs a light belt
>>>tension to prevent water pump bearing failure
>>>from too high but common belt tension. The
>>>tension must be high enough so there is no
>>>slippage under any expected load condition.
>>>Also remember the water pump is part of the
>>>belt load and finally you must consider the
>>>pulley to belt contact arc to transmit the
>>>load from the crank to the pump and alternator in a 3 pulley setup.
>>>
>>>Thus the manufacturer of the conversion
>>>decided on dual belts with light tension as
>>>friction did the rest. This was to prevent a
>>>common failure at the time of water pump bearing wear and loss of coolant.
>>>
>>>Its not easy to design a "V" belt that will
>>>slip on the one hand and not require high belt
>>>tension for its friction drive. Also consider
>>>in this application the crank to alternator
>>>pulley ratio is around 1-1.4 . Further
>>>throttled back it does not take much and with
>>>a "Sprague" clutch driving the prop (no
>>>inertial help here) and a very light flywheel
>>>there is little inertia to help. The specific
>>>belts are narrow with machined sides not the
>>>cloth covered ones of the era. There is no way
>>>the belt will snap if its in good condition
>>>until its been heated and burned thru. Again
>>>there was no chance of this here as the engine stopped immediately.
>>>
>>>In addition there are around 700+ such dual
>>>belt conversions with over 100,000 flight
>>>hours (some with over 4,000 hours) and this is
>>>the first known failure of its type. Hardly a
>>>bad design based on actual performance.
>>>
>>>I have the specific dual belt system on my own
>>>engine so I do know the actual situation.
>>>
>>>Good luck in finding a belt that acts like a
>>>fuse and instantly self destructs at 200% of
>>>design load but lasts 1,000 hours at 100% of design load.
>>>
>>>The very common cogged timing belt widely used
>>>in modern auto engines can fail and if it does
>>>the engine stops. If the idler fails the belt
>>>slips the cogs and the engine fails. On an
>>>aircraft engine if an accessory case driven
>>>unit fails and locks up the engine likely will
>>>fail fast from major metal parts internal to the accessory case.
>>>
>>>I believe the "result of the failure" is being
>>>addressed by your comment and you are missing
>>>the "real likely cause" which is a bad bearing
>>>from the use of a rebuilt alternator. 80 hours
>>>was the total time on the engine and also the
>>>alternator since rebuild where is not common to replace the bearings.
>>>
>>>Paul
>>>
>>>
>>>----- Original Message ----- Sent: Friday, August 04, 2006 1:45 PM
>>>
>>>
>>>>--> AeroElectric-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
>>>>
>>>>
>>>>On Aug 4, 2006, at 12:52 PM, Robert Sultzbach wrote:
>>>>
>>>>>--> AeroElectric-List message posted by:
>>>>>Robert Sultzbach <endspeed@yahoo.com>
>>>>>
>>>>>Hi Brian, I have meant to throw cudos your way on the
>>>>>predicted bearing failure/seizure's catastrophic
>>>>>effect on an engine. I thought this was a very remote
>>>>>failure possibility when you postulated about it.
>>>>>Then, sure enough it goes and happens to one of our
>>>>>posters. Good forethought on your part. Bob
>>>>>Sultzbach
>>>>
>>>>Thanks. I certainly didn't want to be proved
>>>>right in the way that it happened.
>>>>
>>>>On to the details, you probably want a belt
>>>>that will fail and allow the engine to keep
>>>>running rather than kill the engine.
>>>>
>>>>A 50A 14V alternator is producing 700W at
>>>>full output. If the alternator is 90%
>>>>efficient it needs 770W of mechanical input.
>>>>One HP is 760W. So you need a belt that will
>>>>handle 1HP. That is not a very big belt. You
>>>>sure don't need dual belts. If the alternator
>>>>seizes the smaller belt will fail and your
>>>>engine keeps running to carry you to a safe landing.
>>>>
>>>>Now someone who knows belts should jump in
>>>>here with belt sizing information to cover the transmission of 1HP.
>>>>
>>>>Brian Lloyd 361 Catterline Way
>>>>brian-yak AT lloyd DOT com Folsom, CA 95630
>>>>+1.916.367.2131 (voice) +1.270.912.0788 (fax)
>>>>
>>>>I fly because it releases my mind from the tyranny of petty things . . .
>>>> Antoine de Saint-Exupry
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>http://www.matronics.com/Navigator?AeroElectric-List
>>>>http://wiki.matronics.com
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
>>
>>
>>
>>
>>===================================
>>AeroElectric-List Email Forum -
>>;
>>http://www.matronics.com/Navigator?AeroElectric-List
>>===================================
>>; - NEW MATRONICS LIST WIKI -
>>;
>>http://wiki.matronics.com
>>===================================
>>; - List Contribution Web Site -
>>; -Matt Dralle, List Admin.
>>http://www.matronics.com/contribution
>>===================================
>>
>>
>>
>>
>>
>>
Message 27
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| Subject: | Re: Alternator seizure engine failure |
--> AeroElectric-List message posted by: OldBob Siegfried <oldbob@beechowners.com>
Good Evening Dave,
I do not remember for sure, but I think B&C uses a
shear coupling on their alternator that is designed to
be driven off of an accessory pad on the Lycoming
which otherwise generally drives a vacuum pump.
Anyone know for sure?
Happy Skies,
Old Bob
--- Dave N6030X <N6030X@DaveMorris.com> wrote:
> --> AeroElectric-List message posted by: Dave N6030X
> <N6030X@DaveMorris.com>
>
> So, what happens in the case of a gear-driven
> alternator when it seizes up? Does it shred the
> whole back end of the Lycoming?
>
> Dave
>
> At 09:45 PM 8/4/2006, you wrote:
> >Dave,
> > This is one of those, "it looked good on
> > paper" ideas. The reality is that if both
> > alternators are driven off the front of the
> > engine, losing the belt on one, generally takes
> > out the other alternator. When a belt fails, it
> > often gets tangled up in any near by pulleys
> > and belts. This will derail or destroy the belt
> for the second alternator.
> > Bob N's recommendation of a rear drive
> > (Lycoming engine) secondary alternator (like the
> B&C units) is a safer bet.
> >Charlie Kuss
> >
> >
> >>--> AeroElectric-List message posted by: Dave
> N6030X <N6030X@DaveMorris.com>
> >>
> >>Sounds like a more reliable approach for
> >>vehicles that can't "pull over to the side of
> >>the road" in case of failure would be to mount
> >>2 alternators with 1/2 the current capacity
> >>each, driven by 2 separate belts neither of
> >>which require the kind of tension that would
> >>seize the engine or burn out the bearings.
> >>
> >>Dave Morris
> >>
> >>
> >>At 05:36 PM 8/4/2006, you wrote:
> >>>--> AeroElectric-List message posted by: "Paul
> Messinger" <paulm@olypen.com>
> >>>
> >>>First 90% efficiency (for a 1970 alternator
> >>>design) is in your dreams, try in the mid 70's
> >>>but the main point is with "V" belts the belt
> >>>tension needs to be high with an engine rpm of
> >>>6,000 and a single "V" based on the design of
> >>>belts available 15-20 years ago. The subject
> >>>engine is an EA81 that needs a light belt
> >>>tension to prevent water pump bearing failure
> >>>from too high but common belt tension. The
> >>>tension must be high enough so there is no
> >>>slippage under any expected load condition.
> >>>Also remember the water pump is part of the
> >>>belt load and finally you must consider the
> >>>pulley to belt contact arc to transmit the
> >>>load from the crank to the pump and alternator in
> a 3 pulley setup.
> >>>
> >>>Thus the manufacturer of the conversion
> >>>decided on dual belts with light tension as
> >>>friction did the rest. This was to prevent a
> >>>common failure at the time of water pump bearing
> wear and loss of coolant.
> >>>
> >>>Its not easy to design a "V" belt that will
> >>>slip on the one hand and not require high belt
> >>>tension for its friction drive. Also consider
> >>>in this application the crank to alternator
> >>>pulley ratio is around 1-1.4 . Further
> >>>throttled back it does not take much and with
> >>>a "Sprague" clutch driving the prop (no
> >>>inertial help here) and a very light flywheel
> >>>there is little inertia to help. The specific
> >>>belts are narrow with machined sides not the
> >>>cloth covered ones of the era. There is no way
> >>>the belt will snap if its in good condition
> >>>until its been heated and burned thru. Again
> >>>there was no chance of this here as the engine
> stopped immediately.
> >>>
> >>>In addition there are around 700+ such dual
> >>>belt conversions with over 100,000 flight
> >>>hours (some with over 4,000 hours) and this is
> >>>the first known failure of its type. Hardly a
> >>>bad design based on actual performance.
> >>>
> >>>I have the specific dual belt system on my own
> >>>engine so I do know the actual situation.
> >>>
> >>>Good luck in finding a belt that acts like a
> >>>fuse and instantly self destructs at 200% of
> >>>design load but lasts 1,000 hours at 100% of
> design load.
> >>>
> >>>The very common cogged timing belt widely used
> >>>in modern auto engines can fail and if it does
> >>>the engine stops. If the idler fails the belt
> >>>slips the cogs and the engine fails. On an
> >>>aircraft engine if an accessory case driven
> >>>unit fails and locks up the engine likely will
> >>>fail fast from major metal parts internal to the
> accessory case.
> >>>
> >>>I believe the "result of the failure" is being
> >>>addressed by your comment and you are missing
> >>>the "real likely cause" which is a bad bearing
> >>>from the use of a rebuilt alternator. 80 hours
> >>>was the total time on the engine and also the
> >>>alternator since rebuild where is not common to
> replace the bearings.
> >>>
> >>>Paul
> >>>
> >>>
> >>>----- Original Message ----- Sent: Friday, August
> 04, 2006 1:45 PM
> >>>
> >>>
> >>>>--> AeroElectric-List message posted by: Brian
> Lloyd <brian-yak@lloyd.com>
> >>>>
> >>>>
> >>>>On Aug 4, 2006, at 12:52 PM, Robert Sultzbach
> wrote:
> >>>>
> >>>>>--> AeroElectric-List message posted by:
> >>>>>Robert Sultzbach <endspeed@yahoo.com>
> >>>>>
> >>>>>Hi Brian, I have meant to throw cudos your way
> on the
> >>>>>predicted bearing failure/seizure's
> catastrophic
> >>>>>effect on an engine. I thought this was a very
> remote
> >>>>>failure possibility when you postulated about
> it.
> >>>>>Then, sure enough it goes and happens to one of
> our
> >>>>>posters. Good forethought on your part. Bob
> >>>>>Sultzbach
> >>>>
> >>>>Thanks. I certainly didn't want to be proved
> >>>>right in the way that it happened.
> >>>>
> >>>>On to the details, you probably want a belt
> >>>>that will fail and allow the engine to keep
> >>>>running rather than kill the engine.
> >>>>
> >>>>A 50A 14V alternator is producing 700W at
> >>>>full output. If the alternator is 90%
> >>>>efficient it needs 770W of mechanical input.
> >>>>One HP is 760W. So you need a belt that will
> >>>>handle 1HP. That is not a very big belt. You
> >>>>sure don't need dual belts. If the alternator
> >>>>seizes the smaller belt will fail and your
> >>>>engine keeps running to carry you to a safe
> landing.
> >>>>
> >>>>Now someone who knows belts should jump in
> >>>>here with belt sizing information to cover the
> transmission of 1HP.
> >>>>
> >>>>Brian Lloyd 361
> Catterline Way
> >>>>brian-yak AT lloyd DOT com Folsom, CA
> 95630
> >>>>+1.916.367.2131 (voice)
> +1.270.912.0788 (fax)
> >>>>
> >>>>I fly because it releases my mind from the
> tyranny of petty things . . .
> >>>> Antoine de Saint-Exupry
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
>
>>>>http://www.matronics.com/Navigator?AeroElectric-List
> >>>>http://wiki.matronics.com
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>
> >>
> >>
>
=== message truncated ==
Message 28
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| Subject: | Re: Alternator seizure engine failure |
--> AeroElectric-List message posted by: OldBob Siegfried <oldbob@beechowners.com>
Good Evening Once Again Dave,
Just checked and the B&C does include a shear drive
unit.
Happy Skies,
Old Bob
--- Dave N6030X <N6030X@DaveMorris.com> wrote:
> --> AeroElectric-List message posted by: Dave N6030X
> <N6030X@DaveMorris.com>
>
> So, what happens in the case of a gear-driven
> alternator when it seizes up? Does it shred the
> whole back end of the Lycoming?
>
> Dave
>
> At 09:45 PM 8/4/2006, you wrote:
> >Dave,
> > This is one of those, "it looked good on
> > paper" ideas. The reality is that if both
> > alternators are driven off the front of the
> > engine, losing the belt on one, generally takes
> > out the other alternator. When a belt fails, it
> > often gets tangled up in any near by pulleys
> > and belts. This will derail or destroy the belt
> for the second alternator.
> > Bob N's recommendation of a rear drive
> > (Lycoming engine) secondary alternator (like the
> B&C units) is a safer bet.
> >Charlie Kuss
> >
> >
> >>--> AeroElectric-List message posted by: Dave
> N6030X <N6030X@DaveMorris.com>
> >>
> >>Sounds like a more reliable approach for
> >>vehicles that can't "pull over to the side of
> >>the road" in case of failure would be to mount
> >>2 alternators with 1/2 the current capacity
> >>each, driven by 2 separate belts neither of
> >>which require the kind of tension that would
> >>seize the engine or burn out the bearings.
> >>
> >>Dave Morris
> >>
> >>
> >>At 05:36 PM 8/4/2006, you wrote:
> >>>--> AeroElectric-List message posted by: "Paul
> Messinger" <paulm@olypen.com>
> >>>
> >>>First 90% efficiency (for a 1970 alternator
> >>>design) is in your dreams, try in the mid 70's
> >>>but the main point is with "V" belts the belt
> >>>tension needs to be high with an engine rpm of
> >>>6,000 and a single "V" based on the design of
> >>>belts available 15-20 years ago. The subject
> >>>engine is an EA81 that needs a light belt
> >>>tension to prevent water pump bearing failure
> >>>from too high but common belt tension. The
> >>>tension must be high enough so there is no
> >>>slippage under any expected load condition.
> >>>Also remember the water pump is part of the
> >>>belt load and finally you must consider the
> >>>pulley to belt contact arc to transmit the
> >>>load from the crank to the pump and alternator in
> a 3 pulley setup.
> >>>
> >>>Thus the manufacturer of the conversion
> >>>decided on dual belts with light tension as
> >>>friction did the rest. This was to prevent a
> >>>common failure at the time of water pump bearing
> wear and loss of coolant.
> >>>
> >>>Its not easy to design a "V" belt that will
> >>>slip on the one hand and not require high belt
> >>>tension for its friction drive. Also consider
> >>>in this application the crank to alternator
> >>>pulley ratio is around 1-1.4 . Further
> >>>throttled back it does not take much and with
> >>>a "Sprague" clutch driving the prop (no
> >>>inertial help here) and a very light flywheel
> >>>there is little inertia to help. The specific
> >>>belts are narrow with machined sides not the
> >>>cloth covered ones of the era. There is no way
> >>>the belt will snap if its in good condition
> >>>until its been heated and burned thru. Again
> >>>there was no chance of this here as the engine
> stopped immediately.
> >>>
> >>>In addition there are around 700+ such dual
> >>>belt conversions with over 100,000 flight
> >>>hours (some with over 4,000 hours) and this is
> >>>the first known failure of its type. Hardly a
> >>>bad design based on actual performance.
> >>>
> >>>I have the specific dual belt system on my own
> >>>engine so I do know the actual situation.
> >>>
> >>>Good luck in finding a belt that acts like a
> >>>fuse and instantly self destructs at 200% of
> >>>design load but lasts 1,000 hours at 100% of
> design load.
> >>>
> >>>The very common cogged timing belt widely used
> >>>in modern auto engines can fail and if it does
> >>>the engine stops. If the idler fails the belt
> >>>slips the cogs and the engine fails. On an
> >>>aircraft engine if an accessory case driven
> >>>unit fails and locks up the engine likely will
> >>>fail fast from major metal parts internal to the
> accessory case.
> >>>
> >>>I believe the "result of the failure" is being
> >>>addressed by your comment and you are missing
> >>>the "real likely cause" which is a bad bearing
> >>>from the use of a rebuilt alternator. 80 hours
> >>>was the total time on the engine and also the
> >>>alternator since rebuild where is not common to
> replace the bearings.
> >>>
> >>>Paul
> >>>
> >>>
> >>>----- Original Message ----- Sent: Friday, August
> 04, 2006 1:45 PM
> >>>
> >>>
> >>>>--> AeroElectric-List message posted by: Brian
> Lloyd <brian-yak@lloyd.com>
> >>>>
> >>>>
> >>>>On Aug 4, 2006, at 12:52 PM, Robert Sultzbach
> wrote:
> >>>>
> >>>>>--> AeroElectric-List message posted by:
> >>>>>Robert Sultzbach <endspeed@yahoo.com>
> >>>>>
> >>>>>Hi Brian, I have meant to throw cudos your way
> on the
> >>>>>predicted bearing failure/seizure's
> catastrophic
> >>>>>effect on an engine. I thought this was a very
> remote
> >>>>>failure possibility when you postulated about
> it.
> >>>>>Then, sure enough it goes and happens to one of
> our
> >>>>>posters. Good forethought on your part. Bob
> >>>>>Sultzbach
> >>>>
> >>>>Thanks. I certainly didn't want to be proved
> >>>>right in the way that it happened.
> >>>>
> >>>>On to the details, you probably want a belt
> >>>>that will fail and allow the engine to keep
> >>>>running rather than kill the engine.
> >>>>
> >>>>A 50A 14V alternator is producing 700W at
> >>>>full output. If the alternator is 90%
> >>>>efficient it needs 770W of mechanical input.
> >>>>One HP is 760W. So you need a belt that will
> >>>>handle 1HP. That is not a very big belt. You
> >>>>sure don't need dual belts. If the alternator
> >>>>seizes the smaller belt will fail and your
> >>>>engine keeps running to carry you to a safe
> landing.
> >>>>
> >>>>Now someone who knows belts should jump in
> >>>>here with belt sizing information to cover the
> transmission of 1HP.
> >>>>
> >>>>Brian Lloyd 361
> Catterline Way
> >>>>brian-yak AT lloyd DOT com Folsom, CA
> 95630
> >>>>+1.916.367.2131 (voice)
> +1.270.912.0788 (fax)
> >>>>
> >>>>I fly because it releases my mind from the
> tyranny of petty things . . .
> >>>> Antoine de Saint-Exupry
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
>
>>>>http://www.matronics.com/Navigator?AeroElectric-List
> >>>>http://wiki.matronics.com
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>
> >>
> >>
> >>
>
=== message truncated ==
Message 29
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| Subject: | Re: Alternator seizure engine failure |
--> AeroElectric-List message posted by: "Paul Messinger" <paulm@olypen.com>
I agree that a LYC belt drive is a different issue and not likely to be a
problem with a frozen bearing.
My point is the specific subject auto engine conversion is very different.
Lots of trades to consider and no perfect solution.
But as you pointed out some time ago bearing failure in a locked failure
mode can happen however rare it might be.
I might point out the Subaru engine has demonstrated the ability to run for
as long as 30 min with No coolant so if the engine can be kept running its
possible to land safely. The key is using the prop inertia of a non clutch
drive and / or a reasonable sized flywheel to force the belt to start
slipping. In this case the manufacturer chose to assume the bearing lock up
was less likely than a belt failure and or the pump leaking from belt side
load.
Since the original design the use of dual belts has been questionable in
auto engine conversions including the belt reduction designs. Stratus for
example has had several dual belt failures where one belt failed and then
took out the other belt and went to a single wider belt. Eggenfelner
recently had a multi belt reduction unit fail all the belts from a single
FOD starting with a single belt that progressed to the rest of the belts and
dropped the design.
Perhaps a single belt under slightly more tension is a better way to go and
risk water pump leakage on this specific application. I have considered this
and am considering a single belt as its simple to do and pump shaft leakage
is a slow failure and thus simple to detect the loss of coolant before its a
serious risk to the engine. In any event its better than a locked engine and
becoming a glider where I live. Lets see; 95% of the time its a stump farm,
high trees, rough mountain sides, or cold seas for landing sites.
The trades in an auto engine conversion are many. Here the Sprague clutch
allowed a saving of 20 pounds of flywheel to reduce the torsional loads from
a 4 cyl engine. Much the same as the flywheel on Lyc vs no flywheel on the
Cont where the torsionals are different due to basic engine design. Or the
Cont trade of accessory gear drive for the alternator vs the Lyc belt drive.
Different solutions from different designers.
No criticism of your comments just a clarification of the exact
configuration of the failure and its effects. I would not expect that 99% of
this list members know the specific design of the subject system.
Just as we would not consider using a used crank with out magniflux etc, we
should not use a repaired alternator without new HI quality bearings.
Paul
----- Original Message -----
Sent: Friday, August 04, 2006 5:25 PM
> --> AeroElectric-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
>
> Paul Messinger wrote:
>> --> AeroElectric-List message posted by: "Paul Messinger"
>> <paulm@olypen.com>
>>
>> First 90% efficiency (for a 1970 alternator design) is in your dreams,
>> try in the mid 70's but the main point is with "V" belts the belt
>> tension needs to be high with an engine rpm of 6,000 and a single "V"
>> based on the design of belts available 15-20 years ago. The subject
>> engine is an EA81 that needs a light belt tension to prevent water pump
>> bearing failure from too high but common belt tension. The tension must
>> be high enough so there is no slippage under any expected load
>> condition. Also remember the water pump is part of the belt load and
>> finally you must consider the pulley to belt contact arc to transmit the
>> load from the crank to the pump and alternator in a 3 pulley setup.
>
> Well I was thinking in terms of a Lycoming engine wherein the belt
> drives the alternator and only the alternator.
>
> But, I am glad you chimed in here because, frankly, I don't know squat
> about belt drives beyond the obvious and would not pretend otherwise.
>
> --
> Brian Lloyd 361 Catterline Way
> brian-yak at lloyd dot com Folsom, CA 95630
> +1.916.367.2131 (voice) +1.270.912.0788 (fax)
>
> I fly because it releases my mind from the tyranny of petty things . . .
> - Antoine de Saint-Exupery
>
>
>
Message 30
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|
| Subject: | EFIS - BMA or GRT? |
Does anyone have recommendations on GRT vs BMA-Lite? I am looking for a
reliable IFR unit. I will go with Dual AHRS, separate avionics
buss/battery, etc. The real decision is which vendor - prices turn out to
be pretty similar.
Thanks
Dan
Message 31
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|
| Subject: | EFIS - BMA or GRT? |
My feelings on low cost non-certified EFIS systems are fairly well
known.
favor
and install a third separate attitude reference steam gauge.
Bruce
www.glasair.org
-----Original Message-----
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Dan
Beadle
Sent: Saturday, August 05, 2006 1:14 AM
Does anyone have recommendations on GRT vs BMA-Lite? I am looking for a
reliable IFR unit. I will go with Dual AHRS, separate avionics
buss/battery, etc. The real decision is which vendor - prices turn out
to
be pretty similar.
Thanks
Dan
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