 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
gordonrsmith921(at)yahoo.
Guest
|
 Posted: Mon Jun 29, 2009 2:17 am Post subject: Electric dependent Engine - Pucker Factor? |
 |
|
I have been following the posts on this list for a year or so and ‘Lectric Bob’s writings for maybe 10 years. This has led to my understanding of failure tolerant design, so that if any part fails (as any part can and will) you go to plan”B” with out needing to raise a sweat. Not considered as possible failures in this case are such things as prop bolts, wing struts, connecting rods and the like.
I am considering the use of an Eggenfellner E6.0 Subaru Auto conversion. The electrical system architecture will basically be Z-19.
There are electrical system designs that are very failure tolerant even for electrically dependent engines. And there are more and more of these electrically dependent engines being used all the time. But usually you have 2 fuel pumps, 2 electrical paths to the fuel injection/electronic ignition, etc.
The Egg has 1 ECU (Engine Control Unit) computer. Without it functioning the fan out front does not rotate. It is a computer whose heart is a microprocessor.
Is a microprocessor in the same league as a prop bolt for reliability?
This is a single point of failure regardless of how many electrical feed paths are designed to feed it. What is the reliability of a microprocessor; does it approach a zero failure rate similar to a prop bolt or an RG battery?
What is the answer for this? Simply accept it and increase the pucker factor?
Also, I think that I have seen Bob mention that he might be publishing a Z-19 modification, specific to the Egg requirements and also some potential pre-flight checklist recommendations for Z-19 and perhaps other designs, Has this been done and I have missed it?
[quote][b]
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
 |
Ed Anderson
Joined: 10 Jan 2006
Posts: 475
|
| Posted: Mon Jun 29, 2009 4:17 am Post subject: Electric dependent Engine - Pucker Factor? |
|
|
Hi Gordon,
Been flying with my all-electric rotary for over 10 years I originally used an aftermarket HALTECH F3 unit (single CPU, but did have a mixture control) – it failed after 2 ˝ years – fortunately while doing a run-up on the ground. I have since flow with a dual CPU EFI system and while I firmly believe a microchip (if operated within its intended environment is about as safe and reliable as anything can be), I feel more comfortable, knowing at the flick of a switch I have a back up. The backup does reduce the pucker factor -even thought I’ve never had to use it.
So probably does not answer your question, but just wanted to share real-world experience with you.
Ed
Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson(at)carolina.rr.com
http://www.andersonee.com
http://www.dmack.net/mazda/index.html
http://www.flyrotary.com/
http://members.cox.net/rogersda/rotary/configs.htm#N494BW
http://www.rotaryaviation.com/Rotorhead%20Truth.htm[url=http://www.dmack.net/mazda/index.html][/url]
From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Gordon Smith
Sent: Monday, June 29, 2009 5:55 AM
To: aeroelectric-list(at)matronics.com
Subject: AeroElectric-List: Electric dependent Engine - Pucker Factor?
I have been following the posts on this list for a year or so and ‘Lectric Bob’s writings for maybe 10 years. This has led to my understanding of failure tolerant design, so that if any part fails (as any part can and will) you go to plan”B” with out needing to raise a sweat. Not considered as possible failures in this case are such things as prop bolts, wing struts, connecting rods and the like.
I am considering the use of an Eggenfellner E6.0 Subaru Auto conversion. The electrical system architecture will basically be Z-19.
There are electrical system designs that are very failure tolerant even for electrically dependent engines. And there are more and more of these electrically dependent engines being used all the time. But usually you have 2 fuel pumps, 2 electrical paths to the fuel injection/electronic ignition, etc.
The Egg has 1 ECU (Engine Control Unit) computer. Without it functioning the fan out front does not rotate. It is a computer whose heart is a microprocessor.
Is a microprocessor in the same league as a prop bolt for reliability?
This is a single point of failure regardless of how many electrical feed paths are designed to feed it. What is the reliability of a microprocessor; does it approach a zero failure rate similar to a prop bolt or an RG battery?
What is the answer for this? Simply accept it and increase the pucker factor?
Also, I think that I have seen Bob mention that he might be publishing a Z-19 modification, specific to the Egg requirements and also some potential pre-flight checklist recommendations for Z-19 and perhaps other designs, Has this been done and I have missed it?
| Quote: | | http://www.matronics.com/Navigator?AeroElectric-List |
0123456789
__________ Information from ESET NOD32 Antivirus, version of virus signature database 3267 (20080714) __________
The message was checked by ESET NOD32 Antivirus.
<![if !supportAnnotations]> <![endif]>
[quote][b]
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
_________________
Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com |
|
| Back to top |
|
|
Sam
Joined: 18 May 2008
Posts: 135
|
| Posted: Mon Jun 29, 2009 4:18 am Post subject: Electric dependent Engine - Pucker Factor? |
|
|
Gordon. Tracy Crook has his EC3 fuel injection/ignition controller and he may have a version that will work for you. The EC3 has two independent controllers mounted on a single board in a single box. Here is the link: http://www.rotaryaviation.com/eficont.html
Tracy is out of town through the end of July, but his business partner, Laura, is providing some support while he's gone.
Regards,
Sam Hoskins
On Mon, Jun 29, 2009 at 4:55 AM, Gordon Smith <gordonrsmith921(at)yahoo.com (gordonrsmith921(at)yahoo.com)> wrote:
[quote]
I have been following the posts on this list for a year or so and Lectric Bobs writings for maybe 10 years. This has led to my understanding of failure tolerant design, so that if any part fails (as any part can and will) you go to planB with out needing to raise a sweat. Not considered as possible failures in this case are such things as prop bolts, wing struts, connecting rods and the like.
I am considering the use of an Eggenfellner E6.0 Subaru Auto conversion. The electrical system architecture will basically be Z-19.
There are electrical system designs that are very failure tolerant even for electrically dependent engines. And there are more and more of these electrically dependent engines being used all the time. But usually you have 2 fuel pumps, 2 electrical paths to the fuel injection/electronic ignition, etc.
The Egg has 1 ECU (Engine Control Unit) computer. Without it functioning the fan out front does not rotate. It is a computer whose heart is a microprocessor.
Is a microprocessor in the same league as a prop bolt for reliability?
This is a single point of failure regardless of how many electrical feed paths are designed to feed it. What is the reliability of a microprocessor; does it approach a zero failure rate similar to a prop bolt or an RG battery?
What is the answer for this? Simply accept it and increase the pucker factor?
Also, I think that I have seen Bob mention that he might be publishing a Z-19 modification, specific to the Egg requirements and also some potential pre-flight checklist recommendations for Z-19 and perhaps other designs, Has this been done and I have missed it?
| Quote: |
ist" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
tp://forums.matronics.com
_blank">http://www.matronics.com/contribution
|
[b]
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
_________________
Sam Hoskins
www.samhoskins.blogspot.com |
|
| Back to top |
|
|
khorton01(at)rogers.com
Guest
|
| Posted: Mon Jun 29, 2009 9:11 am Post subject: Electric dependent Engine - Pucker Factor? |
|
|
If the microchip is operating in suitable physical (temperature,
vibration, moisture, etc) and electrical environments, and it comes
from a microchip manufacturer with a proven track record, then it
should be extremely reliable.
My bigger concern would be software. Is the software simple, with
predictable response to all possible combinations of inputs, or is it
complex? Complex software often fails in unexpected ways, as FADEC
manufacturers for engines on large transport category aircraft keep
discovering (by failure I mean the software produces an unacceptable
output). Sometimes sensors fail in ways that has not been predicted.
What is the response to single and multiple sensor failures?
Kevin Horton
On 29 Jun 2009, at 12:24, jon(at)finleyweb.net wrote:
[quote] Hi Gordon,
I don't have any facts or answers for you, only a few additional
thoughts.
I fly a home-brew Subaru EJ-22 engine. It is controlled by a Real
World Solutions EC2 EFI system (two controllers in a single box, as
previously mentioned). I have crafted an electrical system that is
redundant and "protective" and that I am comfortable with. That
said; there are lots of single points of failure (as you have
already noted - propellor, engine mount, wing, canopy, crankshaft,
camshaft belt, etc... - it is a long list). In my opinion, the
chance of in-flight failure of any of these items is very, very
low. I believe the chance of my dual-controller ECU failing fits
into the same category. I make a living in the electronics/computer
world and have lots of faith AND experience with such systems. I
fully understand that there are MANY people that don't trust their
electronic Timex watch let alone anything more important/complex.
I am of the opinion that (any manufacturers) late model stock ECU is
not a good option for aircraft use due to extreme complexity
(require "faking out" a large number of sensors, operational
parameters specific to automobile use, etc...). However; I do
believe that they are VERY reliable. It is hard (probably
impossible) to find actual numbers but some very unscientific
research will show you that automotive ECU's just don't fail without
some sort of help (out of spec voltage, impact, etc...). I know -
nothing scientific or measurable in this entire paragraph. So, I
think you are correct - it really comes down to personal comfort
level. This is not a good thing, IMO, as it delays "progress" (a
whole different thread that always gets heated for the very reason
mentioned here).
Last I heard, Egg was supplying his engines with the SDS EFI system
(instead of the Subaru ECU - I believe for the reasons mentioned
above). This system has a VERY good history in aircraft and many
happy customers. Ross Farnum is active on a number of aircraft
lists, very knowledgeable, very helpful, and "eating his own dog
food" (flying behind his own product).
Hth,
Jon Finley
N413JF - Q2 - Subaru EJ-22
http://www.finleyweb.net/Q2Subaru.aspx
DO NOT ARCHIVE
--
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
klehman(at)albedo.net
Guest
|
| Posted: Mon Jun 29, 2009 3:12 pm Post subject: Electric dependent Engine - Pucker Factor? |
|
|
As reliable as ecu's are, solid state electronics and wiring often don't
give much warning before failing. So I opted for Z-14 with a second
independent engine control system running off the second electrical
system. At 300 hours I too have never needed it. It is handy for
troubleshooting as well as pucker minimization.
In the past, a manual backup valve to feed fuel into the intake manifold
was mentioned. Another thought would be a switch (and diodes) to
ground all the injectors low side. On an installation with separate
backup ignition, positive voltage supply to the injectors, and positive
fuel pump control, that will keep the engine running as long as the
throttle is kept at near a cruise setting or higher, even after a total
EFI system electronic failure. Certainly simpler, if less elegant in
operation, than my second ecu system. A robust exhaust system would be
in order and of course the challenge of implementing it without reducing
primary system reliability.
Ken
Gordon Smith wrote:
| Quote: | I have been following the posts on this list for a year or so and
âLectric Bobâs writings for maybe 10 years. This has led to my
understanding of failure tolerant design, so that if any part fails (as
any part can and will) you go to planâBâ with out needing to raise a
sweat. Not considered as possible failures in this case are such things
as prop bolts, wing struts, connecting rods and the like.
|
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
