X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.120] verified) by logan.com (CommuniGate Pro SMTP 5.4c3j) with ESMTP id 4987940 for flyrotary@lancaironline.net; Wed, 18 May 2011 18:25:07 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.120; envelope-from=eanderson@carolina.rr.com Return-Path: X-Authority-Analysis: v=1.1 cv=u/nQQYiWxKD5h3SdfpQA5Ows1ULG5UjBZwfBisUcMrs= c=1 sm=0 a=v3Lj2-D6UPAA:10 a=rPkcCx1H5rrOSfN0dPC7kw==:17 a=FSvEHmYknDEAMVFUw_8A:9 a=eZFcQDtm2xx51n5eH78A:7 a=wPNLvfGTeEIA:10 a=ayC55rCoAAAA:8 a=Ia-xEzejAAAA:8 a=4PR2P7QzAAAA:8 a=mcvq2mTw-VnC9gkg2GkA:9 a=4X-ELceA7X_8VnL_NEIA:7 a=EzXvWhQp4_cA:10 a=djSSOgbfo6cA:10 a=rPkcCx1H5rrOSfN0dPC7kw==:117 X-Cloudmark-Score: 0 X-Originating-IP: 174.110.167.5 Received: from [174.110.167.5] ([174.110.167.5:63608] helo=EdPC) by cdptpa-oedge04.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTP id BE/74-28813-E1744DD4; Wed, 18 May 2011 22:24:30 +0000 Message-ID: From: "Ed Anderson" To: "Rotary motors in aircraft" References: In-Reply-To: Subject: Re: [FlyRotary] Re: Reliably starting Date: Wed, 18 May 2011 18:24:23 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0012_01CC1588.CFACDDD0" X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 14.0.8117.416 X-MimeOLE: Produced By Microsoft MimeOLE V14.0.8117.416 This is a multi-part message in MIME format. ------=_NextPart_000_0012_01CC1588.CFACDDD0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Regarding the old PC with serial port - can you not get a USB-Serial = (Rs232) dongle from your local Radio Shack - that is what I had to do = because I also need the D sub 9 type connector. One thing my precepitions is that your are starting to get close to = violating the old Keep it Simple Stupid principle. The more = components, the more redundancy, the more things that could go wrong = with the systems and there perhaps unintended interaction. Not saying = there should not be any redundancy - that is why I fly with the EC = after my HALTECH system went belly up (fortunately on the ground). But, = you gotta know where to draw the line. Another factor is that unless these systems are automatic, you will = find your time (and attention span) somewhat limited when things start = to go wrong (don't ask me how I know). But, thinking out the failure modes before you fly is certainly a good = thing to do. Ed From: Ernest Christley=20 Sent: Wednesday, May 18, 2011 6:02 PM To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: Reliably starting On 05/18/2011 05:21 PM, josrph berki wrote:=20 Ernest, Will you be running Megasquirt for flight or is it a gound development = tool? Do you have any words of wisdom for someone contemplating = Megasquirt? I would really like to see an electronic analog injection / = ignition system developed. Software that controls the engine scares me. = Thanks for any help. Analog injection/ignition systems scare me. Well...not really. All = software systems are analog underneath. I will be flying with the MegaSquirt, but I can throw it a lot further = than I trust it. But, that is ok. The goal is do design the system so = that it fails gracefully. The MS gives an incredible amount of = flexibility and configuration control. It is REALLY nice to have. So I = take the benefits, but have backup(s). =20 If the MS quits on me for some reason one day, I have a 3/16" line = plumbed to the throttle body with a needle valve sitting next to me in = the cockpit. I've already verified that on the ground, with gas barely = covering the bottom of the tank, I get flow to the throttle body. I'd = probably never be able to get the engine started with this setup using = the starter, but with the wind still spinning the prop I will be able to = slowly open the valve till I can maintain altitude. Then I can make for = the longest runway I can find. That's good for fuel, but what about spark? I'm having the MegaSquirt = control EDIS ignition control modules. The EDIS handles all the VR = pickup, dwell and other such details. These things have proven to be = very solid performers during a decade of use. All MS is doing is = getting a tach signal from the EDIS, and sending back a signal to = control advance. Two wire interface. If the EDIS looses communication = with the MS, it falls back to its limp-home mode which is 10*BTDC. I = shifted the VR so that I actually get 25*. But, that just shifts the = critical failure from the MS to the EDIS. I don't have it wired up yet, = but eventually I will have two EDIS modules running, one on Leading and = one on Trailing. The second will have its own power source, driven by = the distributor shaft. =20 Sure, power will degraded if all I have is the trailing plugs and I'm = dumping fuel into the throttle body instead of a proper spray, but it = isn't meant to be a normal mode of operation. It is meant to get me = past the crash site. I don't have to be scared of the software, because = I'm not hanging my life on it. The only other advice I have is buy one of the MS3s. They have a USB = interface, and can datalog directly to a flash card. I'm stuck with an = MS2 for now. Because of that, I have to use a 15yr old laptop, because = it is the only one I have that has a serial port. ------=_NextPart_000_0012_01CC1588.CFACDDD0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Regarding the old PC with serial port - can you = not get a=20 USB-Serial (Rs232) dongle from your local Radio Shack - that is what I = had to do=20 because I also need the D sub 9 type connector.
 
One thing my precepitions  is that = your are=20 starting to get close to violating  the old Keep it Simple Stupid=20 principle.  The more components, the more redundancy, the more = things that=20 could go wrong with the systems and there perhaps unintended = interaction. =20 Not saying there should not be any redundancy - that is why I fly with = the=20 EC  after my HALTECH system went belly up (fortunately on the=20 ground).  But, you gotta know where to draw the line.
 
  Another factor is that unless these = systems are=20 automatic, you will find your time (and attention span) somewhat limited = when=20 things start to go wrong (don't ask me how I know).
 
But, thinking out the failure modes before you = fly is=20 certainly a good thing to do.
 
 
 
Ed

From: Ernest Christley
Sent: Wednesday, May 18, 2011 6:02 PM
Subject: [FlyRotary] Re: Reliably starting

On 05/18/2011 05:21 PM, josrph berki wrote:=20
Ernest,
 
Will you be running Megasquirt for = flight or is=20 it a gound development tool?  Do you have any words of wisdom for = someone=20 contemplating Megasquirt?  I would really like to see an = electronic=20 analog injection / ignition system developed.  Software that = controls the=20 engine scares me.  Thanks for any=20 help.


Analog injection/ignition systems = scare=20 me.  Well...not really.  All software systems are analog=20 underneath.

I will be flying with the MegaSquirt, but I can throw = it a=20 lot further than I trust it.  But, that is ok.  The goal is do = design=20 the system so that it fails gracefully.  The MS gives an incredible = amount=20 of flexibility and configuration control.  It is REALLY nice to = have. =20 So I take the benefits, but have backup(s). 

If the MS = quits on me=20 for some reason one day, I have a 3/16" line plumbed to the throttle = body with a=20 needle valve sitting next to me in the cockpit.  I've already = verified that=20 on the ground, with gas barely covering the bottom of the tank, I get = flow to=20 the throttle body.  I'd probably never be able to get the engine = started=20 with this setup using the starter, but with the wind still spinning the = prop I=20 will be able to slowly open the valve till I can maintain = altitude.  Then I=20 can make for the longest runway I can find.

That's good for fuel, = but=20 what about spark?  I'm having the MegaSquirt control EDIS ignition = control=20 modules.  The EDIS handles  all the VR pickup, dwell and other = such=20 details.  These things have proven to be very solid performers = during a=20 decade of use.  All MS is doing is getting a tach signal from the = EDIS, and=20 sending back a signal to control advance.  Two wire = interface.  If the=20 EDIS looses communication with the MS, it falls back to its limp-home = mode which=20 is 10*BTDC.  I shifted the VR so that I actually get 25*.  = But, that=20 just shifts the critical failure from the MS to the EDIS.  I don't = have it=20 wired up yet, but eventually I will have two EDIS modules running, one = on=20 Leading and one on Trailing.  The second will have its own power = source,=20 driven by the distributor shaft. 

Sure, power will degraded = if all=20 I have is the trailing plugs and I'm dumping fuel into the throttle body = instead=20 of a proper spray, but it isn't meant to be a normal mode of = operation.  It=20 is meant to get me past the crash site.  I don't have to be scared = of the=20 software, because I'm not hanging my life on it.

The only other = advice I=20 have is buy one of the MS3s.  They have a USB interface, and can = datalog=20 directly to a flash card.  I'm stuck with an MS2 for now.  = Because of=20 that, I have to use a 15yr old laptop, because it is the only one I have = that=20 has a serial port.
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