X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 2 [X] Return-Path: Received: from smtprh02.spirittelecom.com ([165.166.0.78] verified) by logan.com (CommuniGate Pro SMTP 5.1.7) with ESMTPS id 1913408 for flyrotary@lancaironline.net; Sat, 10 Mar 2007 11:38:36 -0500 Received-SPF: pass receiver=logan.com; client-ip=165.166.0.78; envelope-from=jewen@comporium.net X-Report-Abuse-To: abuse@spirittelecom.com X-DKIM: Sendmail DKIM Filter v0.5.2 smtprh02.spirittelecom.com l2AGbkmn023429 DKIM-Signature: a=rsa-sha1; c=relaxed/simple; d=comporium.net; s=spiritmail; t=1173544668; bh=2trBirTtt7l8Y2o+3FLNwN4+wtU=; h=Message-ID:From:To: References:Subject:Date:MIME-Version:Content-Type:X-Priority: X-MSMail-Priority:X-Mailer:X-MIMEOLE:X-Virus-Scanned: X-Virus-Status; b=Y9V7qoQwJIUW6BC5To9O9sAYF7Q/rohhvXlaiKeul/wKVRmoC CmuSQDtT55fO5ygsojxpg5QZLybYUHdBHOP4w== Received: from Engineer1 (208-104-87-198.lnhe.2wcm.comporium.net [208.104.87.198] (may be forged)) by smtprh02.spirittelecom.com (8.13.6/8.13.1) with SMTP id l2AGbkmn023429 for ; Sat, 10 Mar 2007 16:37:47 GMT Message-ID: <004101c76332$6e29b450$6e05a8c0@cooleygroup.local> From: "Joe Ewen" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: The truth??? / Injector flow rate mystery solved Date: Sat, 10 Mar 2007 11:37:44 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_003E_01C76308.852D86B0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3028 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 X-Virus-Scanned: ClamAV 0.88/2799/Sat Mar 10 15:36:39 2007 on smtprh02.spirittelecom.com X-Virus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_003E_01C76308.852D86B0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MessageEd, It has been my experience, in industrial control, environment that there = are several sources of latency (delay time) on and off delay time of the = IO circuitry, clock speed of the IO controller, on and off delay times = for the controlled device, mechanical delays etc. When a machine = operator presses a control button, expecting a action to occur such as = starting a motor conveyor, a stacked latency of 5 or even 100 mS is not = perceivable. But trying to put a patterned glue line on a web moving 5 = to 10 feet per second, requires accounting for the IO delay time, = pneumatic solenoid delay, air line charging time, glue head mechanical = delay, glue reaction (like a dripping faucet, the glue will form a = droplet before becoming a stream.) =20 When I have been up against applications like the latter, I have found a = curve fitting program that has worked very well. In the example cited, = I have run a rudimentary control algorithm and collected the resultant = data. Dump the data into the curve fitting program, and the program = will crunch the data and make recommendations for the closest formula as = well as the required formula constants. This has worked very well for = some difficult applications. IMO a great way to work your fuel flow situation might be to install a = flow sensor. Run your engine at various RPMs recording EC2 indications = and actual fuel flow sensor readings. Dump the data into a curve = fitting program and viola. One of the best fitting programs I have = found is called XLFit (VBA add on to Excel). The program cost is $725, = but it has a 30 day fully functioning trial. =20 If you would like to try an approach such as this, I could provide IO = for capturing fuel flow sensor data, curve fitting program, as well as = coming up to give you a hand (since I am less than an hour's drive from = your location.) =20 Joe (If I stop rambling, I might actually be able to turn on the = battery masters and fire up the CPU this week end.) ----- Original Message -----=20 From: Ed Anderson=20 To: Rotary motors in aircraft=20 Sent: Friday, March 09, 2007 8:30 PM Subject: [FlyRotary] Re: The truth??? / Injector flow rate mystery = solved Ah, the old induced current caused by the collapsing magnetic field = of the injector has no place to go (quickly at least) due to the diode. = That would indeed tend to prolong the closing - hummm up to 5 msec - now = the duration - that is surprising. =20 That's at least part (if not all) of the reason why I always had to = add a "fudge factor" increase over the number I calculated for the = specified flow rate. The injectors were staying on a bit longer and = therefore flowing more fuel than the specified flow rate would indicate. = OK! so now I know why I had to have a fudge factor - I feel better and = will finally be able to sleep {:>) Thanks for the additional information, Tracy. It will keep the rumors = to a minimum {:>) Ed ----- Original Message -----=20 From: Tracy Crook=20 To: Rotary motors in aircraft=20 Sent: Friday, March 09, 2007 5:20 PM Subject: [FlyRotary] Re: The truth??? / Injector flow rate mystery = solved Still refining the exact numbers but here is the basic cause. The diode clamp on the injector drivers (in EC2) serves 3 purposes. = It limits the inductive flyback voltage to protect the driver = transistor. It recovers some of the energy used to open the injector = thus reducing the current consumption of the system. It eliminates = arcing at the A/B injector switching relay that can cause noise problems = with the processor chips. Unknown to me until recently, it also significantly increases the = closing time of the injector after the driver pulse ends. I thought the = delay would be negligible. The actual delay depends on several factors = but may be as much as 5 ms (!) Ed will know what a big deal this is. = The factors that go into this and how much it is magnified by the diode = clamp is still under investigation. The good news is that there is a very simple fix. (Note, Do NOT go = out and remove the diode clamps! That isn't the fix! Tracy ----- Original Message -----=20 From: Ed Anderson=20 To: Rotary motors in aircraft=20 Sent: Friday, March 09, 2007 7:13 AM Subject: [FlyRotary] Re: The truth??? / Injector flow rate mystery = solved I certainly don't know, Rusty. Like I said the only thing that = Tracy and I could conclude was that Mazda was under-rating their = injectors - I wondered whether it might have something to do with the = way an engine is taxed in Japan. In any case, Tracy is clearly ignoring our pleas for more = information - poor guy is undoubtedly working furiously getting orders = completed before Sun & Fun. But, he really shouldn't tease like that = {:>) Yes, I understand what you mean about measured flow rates - I = suspect there is something subtle about this matter. Perhaps the = current profile used to open the injectors plays some role in this as = Tracy indicated he was working on a Fix. Perhaps a two stage or = progressive flow rate profile - opens and provides normal flow for = typical automobile usage but, when wide open (like ours are at cruise) = perhaps the flow rate is more. Who knows - Tracy Crook that's who. Ed ----- Original Message -----=20 From: Russell Duffy=20 To: Rotary motors in aircraft=20 Sent: Friday, March 09, 2007 12:19 AM Subject: [FlyRotary] Re: The truth??? / Injector flow rate = mystery solved Tracy and I have been discussing this injector flow rate anomaly = for years - =20 For some reason, I was certain that the Mazda injectors flowed = more than they were rated for, but after sifting through some old logs, = that's not true for all Mazda injectors. I sent 4 slightly used 550's = to RC Engineering, and they tested them at 547, 549, 551, and 551. If = that ain't 550, I don't know what is :-) =20 I guess I'm baffled now. Does Mazda operate them at 5 volts or = something, rather than 12V? That would slow down the response time. =20 Hey the HKS is a good little engine in my opinion - not as good = as a light weight rotary (which we don't have yet - Richard! get a move = on {:>)), but it'll get you flying again.=20 Thanks for the comments. It can't hurt much to try it, because = I've already got people who want to buy it if it doesn't work out. = Still, it's as much trouble to install as the rotary, so it really comes = down to a weight issue, and perhaps whether I'll ever get my redrive = from Autoflight... =20 Rusty ------=_NextPart_000_003E_01C76308.852D86B0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
Ed,
It has been my experience, in industrial = control,=20 environment that there are several sources of latency (delay time) on = and off=20 delay time of the IO circuitry, clock speed of the IO controller, on and = off=20 delay times for the controlled device, mechanical delays etc.  When = a=20 machine operator presses a control button, expecting a action to occur = such as=20 starting a motor conveyor, a stacked latency of 5 or even 100 mS is not=20 perceivable.  But trying to put a patterned glue line on a web = moving=20 5 to 10 feet per second, requires accounting for the IO delay time, = pneumatic=20 solenoid delay, air line charging time, glue head mechanical delay, glue = reaction (like a dripping faucet, the glue will form a droplet before = becoming a=20 stream.) 
 
When I have been up against applications like = the latter,=20 I have found a curve fitting program that has worked very = well.  In=20 the example cited, I have run a rudimentary control algorithm and = collected the=20 resultant data.  Dump the data into the curve fitting program, and = the=20 program will crunch the data and make recommendations for the closest = formula as=20 well as the required formula constants.  This has worked very well = for some=20 difficult applications.
 
IMO a great way to work your fuel flow situation = might be=20 to install a flow sensor.  Run your engine at various = RPMs recording=20 EC2 indications and actual fuel flow sensor readings.  Dump the = data into a=20 curve fitting program and viola.  One of the best fitting  = programs I=20 have found is called XLFit (VBA add on to Excel).  The program = cost is=20 $725, but it has a 30 day fully functioning trial. 
 
If you would like to try an approach such as = this, I could=20 provide IO for capturing fuel flow sensor data, curve fitting program, = as well=20 as coming up to give you a hand (since I am less than an hour's drive = from your=20 location.) 
 
Joe  (If I stop rambling, I might actually = be able to=20 turn on the battery masters and fire up the CPU this week = end.)
 
 
 
----- Original Message -----
From:=20 Ed=20 Anderson
Sent: Friday, March 09, 2007 = 8:30=20 PM
Subject: [FlyRotary] Re: The = truth??? /=20 Injector flow rate mystery solved

Ah, the old induced current caused =  by the=20 collapsing magnetic field of the injector has no place to go (quickly = at=20 least) due to the diode.  That would indeed tend to prolong the = closing -=20 hummm up to 5 msec - now the duration -  that=20 is surprising. 
 
That's at least part (if not all) of = the reason=20 why I always had to add a "fudge factor" increase over the number I = calculated=20 for the specified flow rate.  The injectors were staying on a bit = longer=20 and therefore flowing more fuel than the specified flow rate would=20 indicate.  OK! so now I know why I had to have a fudge factor - I = feel=20 better and will finally be able to sleep {:>)
 
Thanks for the additional = information,=20 Tracy.  It will keep the rumors to a minimum {:>)
 
Ed
----- Original Message -----
From:=20 Tracy = Crook
To: Rotary motors in = aircraft=20
Sent: Friday, March 09, 2007 = 5:20=20 PM
Subject: [FlyRotary] Re: The = truth??? /=20 Injector flow rate mystery solved

Still refining the exact numbers but here is the basic = cause.
 
The diode clamp on the injector drivers (in EC2) serves 3=20 purposes.  It limits the inductive flyback voltage to protect = the=20 driver transistor.  It recovers some of the energy used to open = the=20 injector thus reducing the current consumption of the system.  = It=20 eliminates arcing at the A/B injector switching relay that can cause = noise=20 problems with the processor chips.
 
Unknown to me until recently, it also significantly increases = the=20 closing time of the injector after the driver pulse ends.  I = thought=20 the delay would be negligible.  The actual delay depends on = several=20 factors but may be as much as 5 ms (!)  Ed will know what a big = deal=20 this is.  The factors that go into this and how much it is = magnified by=20 the diode clamp is still under investigation.
 
The good news is that there is a very simple fix.  (Note, = Do NOT=20 go out and remove the diode clamps! That isn't the fix!
 
Tracy
----- Original Message ----- =
From: Ed Anderson
To: Rotary motors in = aircraft=20
Sent: Friday, March 09, = 2007 7:13=20 AM
Subject: [FlyRotary] Re: = The truth???=20 / Injector flow rate mystery solved

I certainly don't know, = Rusty.  Like I=20 said the only thing that Tracy and I could conclude was that Mazda = was=20 under-rating their  injectors - I wondered whether it might = have=20 something to do with the way an engine is taxed in = Japan.
 
In any case, Tracy is clearly = ignoring our=20 pleas for more information - poor guy is undoubtedly working = furiously=20 getting orders completed before Sun & Fun.  But, he = really=20 shouldn't tease like that {:>)
 
Yes, I understand what you mean = about=20 measured flow rates - I suspect there is something subtle about = this=20 matter.  Perhaps the current profile used to open the = injectors plays=20 some role in this as Tracy indicated he was working on a = Fix. =20 Perhaps a two stage or progressive flow rate profile - opens and = provides=20 normal flow for typical automobile usage but, when wide open (like = ours=20 are at cruise) perhaps the flow rate is more.  Who knows - = Tracy=20 Crook that's who.
 
Ed
----- Original Message ----- =
From:=20 Russell Duffy
To: Rotary motors in = aircraft=20
Sent: Friday, March 09, = 2007 12:19=20 AM
Subject: [FlyRotary] Re: = The=20 truth??? / Injector flow rate mystery solved

Tracy and I have been = discussing this=20 injector flow rate anomaly for years -  
 
For some reason, I was certain that = the Mazda=20 injectors flowed more than they were rated for, but after = sifting=20 through some old logs, that's not true for all Mazda=20 injectors.   I sent 4 slightly used 550's to=20 RC Engineering, and they tested them at 547, 549, 551, and=20 551.  If that ain't 550, I don't know what is=20 :-)  
 
I guess I'm baffled now.  Does = Mazda=20 operate them at 5 volts or something, rather than 12V?  = That would=20 slow down the response=20 time.   
 
 
Hey the HKS is a good = little engine=20 in my opinion - not as good as a light weight rotary (which we = don't=20 have yet - Richard! get a move on {:>)), but it'll get = you =20 flying again. 
 
Thanks for the comments.  It can't = hurt much to=20 try it, because I've already got people who want to buy it if it = doesn't=20 work out.  Still, it's as much trouble to install as the = rotary, so=20 it really comes down to a weight issue, and perhaps whether I'll = ever=20 get my redrive from=20 Autoflight...  
 
Rusty
 
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