X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 73 [XX] (57%) BODY: contains text similar to "low payment" (29%) URL: contains host with port number (14%) HEADERS: mail has MS Outlook properties but missing "Outlook" in "X-Mailer" Headers Return-Path: Received: from bay0-omc1-s40.bay0.hotmail.com ([65.54.246.112] verified) by logan.com (CommuniGate Pro SMTP 5.1.7) with ESMTP id 1917667 for flyrotary@lancaironline.net; Mon, 12 Mar 2007 21:22:19 -0400 Received-SPF: pass receiver=logan.com; client-ip=65.54.246.112; envelope-from=lors01@msn.com Received: from hotmail.com ([65.54.250.88]) by bay0-omc1-s40.bay0.hotmail.com with Microsoft SMTPSVC(6.0.3790.2668); Mon, 12 Mar 2007 18:18:30 -0700 Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Mon, 12 Mar 2007 18:18:30 -0700 Message-ID: Received: from 4.174.5.187 by BAY115-DAV16.phx.gbl with DAV; Tue, 13 Mar 2007 01:18:28 +0000 X-Originating-IP: [4.174.5.187] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] MOV fail closed? / Injector flow rate mystery solved Date: Mon, 12 Mar 2007 21:18:22 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0016_01C764EB.F6F59410" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: MSN 9 X-MIMEOLE: Produced By MSN MimeOLE V9.50.0034.2000 Seal-Send-Time: Mon, 12 Mar 2007 21:18:22 -0400 X-OriginalArrivalTime: 13 Mar 2007 01:18:30.0417 (UTC) FILETIME=[82A4D810:01C7650D] Return-Path: lors01@msn.com This is a multi-part message in MIME format. ------=_NextPart_000_0016_01C764EB.F6F59410 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Yes, MOVs can fail closed (most likely in fact) but the nice thing about = the method I am using is that if the MOV does short, the EC2 goes back = to working exactly like it does before the MOV (IF that is what I end up = with) was added. The effect of this failure in-flight would be that the = mixture would go rich but not enough to cause the engine to stop. = Corrective action would be to reach over and adjust the manual mixture = control. Today's testing was interesting in several ways. I was flight testing = the simplest possible fix (a resistive snubber) and after takeoff it = seemed like the engine was quieter. Enough so that the XM radio music = in my headset seemed louder and clearer. I know that I didn't just bump = up the XM volume accidentally because doing so requires purposefully = bringing up the display and audio menu on the Garmin in order to adjust = it. The power was as good or better than ever (~100 more rpm on = climbout than usual) so a weak engine did not explain it. I started = looking at other data and soon forgot about it and wrote it off to human = perception error. After putting the Renesis through it's paces and letting the DL1 log the = engine data (what a great tool!) I landed and started my post flight = inspection routine. Then my neighbor at the south end of the runway = came over and asked me what I changed to make the engine quieter! = Hmmm... As usual, I had made more than one change to the EC2. Besides the = snubber, I had updated the ignition advance curve in view of some recent = findings but this was a very minor change and I do not see how that = could account for a change in engine exhaust sound. I haven't looked at = the DL1 data yet so maybe there will be a clue there. Or maybe me & the = neighbor are going deaf from rotary noise. The resistive snubber worked fine, the engine ran fine but the EM2 fuel = flow sucked. With the longer injector pulses required with the snubber = installed, the EM2 did not have enough range to calibrate the fuel flow = properly. Adjusted as far as it would go, it read about 30% high at = economy cruise power setting. Simple program change to correct it but = one more 'gotcha' that I had not counted on. How come nothing is ever = simple? Tracy ----- Original Message -----=20 From: Ed Anderson=20 To: Rotary motors in aircraft=20 Sent: Monday, March 12, 2007 8:31 PM Subject: [FlyRotary] MOV fail closed? was A solution? was : The = truth??? / Injector flow rate mystery solved Hey, Joe Get better and worry only about getting that project done . You and everyone is certainly welcome to state their viewpoint on = this list - don't know of anyone banned as yet. While all viewpoints = are subject to debate and counter arguments - that's the value of this = list.=20 More than one viewpoint gets presented and no one arbitrarily decides = when there has been sufficient discussion - but us guys on the list. = When we get tired of it - no one is going to comment further and you end = up debating with yourself. But, that's about the extent of anyone = getting "banned".=20 So never hesitate to throw in your 0.02, it may be the one that saves = somebody's butt - I was not aware that a MOV could fail closed - I = thought once the magic smoke went that it did no more conducting (or = anything else) but opened up. =20 Ed ----- Original Message -----=20 From: Joe Ewen=20 To: Rotary motors in aircraft=20 Sent: Monday, March 12, 2007 5:12 PM Subject: [FlyRotary] Re: A solution? was : The truth??? / Injector = flow rate mystery solved My original thoughts regarding a dropping resistor were the result = of being bored while lying in bed with a 102 degree fever, otherwise I = would have likely been working on my airplane. In the end, I believe = Tracy is likely the best person to devise the ultimate solution. But in = fairness to Tracy, he seems to be a rather busy person juggling his = manufacturing, airplane building, technical support, and product = development may not leave much time to work on this particular issue. = So I threw my 2 cents into the ring. My first though was an RC circuit, = but thought it may not be a reasonable solution due to its Time/Decay = rates. Last point I would like to make is anyone considering using a MOV = "Please read the following info:"=20 = http://www.iaei.org/subscriber/magazine/04_b/04_b_brown.htm Like any solid state device an MOV is subject to degradation = (quickly if the power through it is greater than its heat dissipation = capacity). Further, unlike many other solid state devices that fail in = the off state when they loose their internal smoke - a MOV can fail in = the ON state. Sincerely, Joe (Hoping I have not offended anyone, or be banned from FlyRotary = like so many others have been from the other list.) ----- Original Message -----=20 From: marv@lancair.net=20 To: Rotary motors in aircraft=20 Sent: Sunday, March 11, 2007 2:30 PM Subject: [FlyRotary] Re: A solution? was : The truth??? / Injector = flow rate mystery solved What about MOV's? Typical transient response time measured in = nanoseconds... =20 "Steven Boese" > wrote: Ed and Joe, The diode in the EC2 allows the current from the collapse of the injector magnetic field to flow to the positive supply rail = (~14V); it doesn't oppose this. A resistor allowing this current to flow = would also result in a close delay since the current flowing is what = maintains the magnetic field during this delay. What is needed is a way to decrease the rate of voltage rise just after the EC2 pulse ends so arcing in the A/B selection relay is suppressed. After the relay contacts open enough that an arc is no longer possible (which = shouldn't take long) an open circuit condition now would allow the injector = to close quickly. The arcing may or may not be a problem any given = tim Ed =20 -- Homepage: http://www.flyrotary.com/ Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html ------=_NextPart_000_0016_01C764EB.F6F59410 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Yes, MOVs can fail closed (most likely in fact) but the nice thing = about=20 the method I am using is that if the MOV does short, the EC2 goes = back to=20 working exactly like it does before the MOV (IF that is what I end up = with) was=20 added.  The effect of this failure in-flight would be that the = mixture=20 would go rich but not enough to cause the engine to stop.  = Corrective=20 action would be to reach over and adjust the manual mixture = control.
 
Today's testing was interesting in several ways.  I was flight = testing=20 the simplest possible fix (a resistive snubber) and after takeoff it = seemed like=20 the engine was quieter.  Enough so that the XM radio music in my = headset=20 seemed louder and clearer.  I know that I didn't just bump up the = XM volume=20 accidentally because doing so requires purposefully bringing up the = display and=20 audio menu on the Garmin in order to adjust it.   The power = was as=20 good or better than ever (~100 more rpm on climbout than usual) so a = weak engine=20 did not explain it.  I started looking at other data = and=20 soon forgot about it and wrote it off to human perception = error.
 
After putting the Renesis through it's paces and letting = the DL1=20 log the engine data (what a great tool!) I landed and started my = post=20 flight inspection routine.  Then my neighbor at the south end = of the=20 runway came over and asked me what I changed to make the engine=20 quieter!  Hmmm...
 
As usual, I had made more than one change to the EC2.  Besides = the=20 snubber, I had updated the ignition advance curve in view of some recent = findings but this was a very minor change and I do not see how that = could=20 account for a change in engine exhaust sound.  I = haven't looked=20 at the DL1 data yet so maybe there will be a clue there.  Or = maybe me=20 & the neighbor are going deaf from rotary noise.
 
The resistive snubber worked fine, the engine ran fine but the = EM2=20 fuel flow sucked.  With the longer injector pulses required with = the=20 snubber installed, the EM2 did not have enough range to calibrate the = fuel flow=20 properly.  Adjusted as far as it would go, it read about 30% high = at=20 economy cruise power setting.  Simple program change = to correct it but=20 one more 'gotcha' that I had not counted on.  How come nothing is = ever=20 simple?
 
Tracy
----- Original Message -----
From: Ed Anderson
To: Rotary motors in = aircraft
Sent: Monday, March 12, 2007 = 8:31=20 PM
Subject: [FlyRotary] MOV fail = closed? was=20 A solution? was : The truth??? / Injector flow rate mystery = solved

Hey, Joe
 
Get better and worry only about getting that = project=20 done
 
. You and  everyone is = certainly welcome=20 to state their  viewpoint on this list - don't know of anyone = banned as=20 yet.  While all viewpoints are subject to debate and counter = arguments -=20 that's the value of this list. 
 
 More than one viewpoint gets presented = and no one=20 arbitrarily decides when there has been sufficient discussion - but us = guys on=20 the list.  When we get tired of it - no one is going to comment = further=20 and you end up debating with yourself.  But, that's about the = extent of=20 anyone getting "banned". 
 
 So never hesitate to throw in your 0.02, = it may be=20 the one that saves somebody's butt - I was not aware that a MOV could = fail=20 closed - I thought once the magic smoke went that it did no more = conducting=20 (or anything else) but opened up. 
 
Ed
----- Original Message -----
From:=20 Joe=20 Ewen
To: Rotary motors in = aircraft=20
Sent: Monday, March 12, 2007 = 5:12=20 PM
Subject: [FlyRotary] Re: A = solution?=20 was : The truth??? / Injector flow rate mystery solved

My original thoughts regarding a = dropping=20 resistor were the result of being bored while lying in bed with = a 102=20 degree fever, otherwise I would have likely been working on my=20 airplane.  In the end, I believe Tracy is likely the best = person to=20 devise the ultimate solution.  But in fairness to Tracy, he = seems to be=20 a rather busy person juggling his manufacturing, airplane building,=20 technical support, and product development may not leave much time = to work=20 on this particular issue.  So I threw my 2 cents into the = ring. =20 My first though was an RC circuit, but thought it may not be a = reasonable=20 solution due to its Time/Decay rates.
 
Last point I would like to make is = anyone=20 considering using a MOV "Please read the=20 following info:" 
http= ://www.iaei.org/subscriber/magazine/04_b/04_b_brown.htm
 
Like any solid state device an MOV = is subject=20 to degradation (quickly if the power through it is greater than its = heat=20 dissipation capacity).  Further, unlike many other solid state = devices=20 that fail in the off state when they loose their internal smoke = -  a=20 MOV can fail in the ON state.
 
Sincerely,
Joe (Hoping I have not offended = anyone, or be=20 banned from FlyRotary like so many others have been from the other=20 list.)
 
----- Original Message ----- =
From:=20 marv@lancair.net
To: Rotary motors in = aircraft=20
Sent: Sunday, March 11, = 2007 2:30=20 PM
Subject: [FlyRotary] Re: A = solution?=20 was : The truth??? / Injector flow rate mystery solved

What about = MOV's? =20 Typical transient response time measured in=20 nanoseconds...

   <Marv>  =20




"Steven Boese" <sboese@uwyo.edu> = wrote:

Ed and=20 Joe,

The diode in the EC2 allows the current from the = collapse of=20 the
injector magnetic field to flow to the positive supply rail = (~14V);=20 it
doesn't oppose this. A resistor allowing this current to = flow=20 would
also result in a close delay since the current flowing is = what=20 maintains
the magnetic field during this delay. What is needed = is a way=20 to
decrease the rate of voltage rise just after the EC2 pulse = ends=20 so
arcing in the A/B selection relay is suppressed. After the=20 relay
contacts open enough that an arc is no longer possible = (which=20 shouldn't
take long) an open circuit condition now would allow = the=20 injector to
close quickly. The arcing may or may not be a = problem any=20 given tim Ed
 

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