X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [24.25.9.100] (HELO ms-smtp-01-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 5.0.7f) with ESMTP id 950628 for flyrotary@lancaironline.net; Mon, 23 Jan 2006 13:45:15 -0500 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.100; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-025-165.carolina.res.rr.com [24.74.25.165]) by ms-smtp-01-eri0.southeast.rr.com (8.13.4/8.13.4) with SMTP id k0NIiR6p001618 for ; Mon, 23 Jan 2006 13:44:29 -0500 (EST) Message-ID: <001101c6204d$0b0d00d0$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Prop controller RPM and Motor Limits - Automatic props Date: Mon, 23 Jan 2006 13:44:29 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000E_01C62023.21DC55B0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_000E_01C62023.21DC55B0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MessageOk, that tracks, Thomas. I also use the injector PW to calculate = and display power based on fuel burn rate.=20 My controller design was a simply one to emulate a constant speed prop - = not trying for optimum pitch/speed/distance advanced features. =20 Having seen my good Friend, Tracy Crook, go from happy hobbyist to hard = working business Entrepreneur - not certain I am eager to follow {:>). = The technical challenge is fun, but once you get past that all sorts of = things rear their ugly head - like production, consumer handling Ugh!, = liability, keeping records for tax purposes, etc., etc., Now Tracy had Laura who runs their business like a Navy Captain aboard a = boomer, so that at least frees him from many (how about MOST, Laura? = {:>)). Just don't think my spouse would be as willing to do that = (almost) thankless job {:>). Struck a deal to have the old hangar haul away next week. I have a new = one selected but not ordered, going to be a bit different (and better). = Mean while don't plan on getting started until after the trip to Texas = in Mid Feb to attend Bill Eslicks Flyin at Pecan Plantation airpart near = Dallas. Ed A =20 ----- Original Message -----=20 From: rijakits=20 To: Rotary motors in aircraft=20 Sent: Monday, January 23, 2006 11:31 AM Subject: [FlyRotary] Re: Prop controller RPM and Motor Limits - = Automatic props Hi Ed, thanks for the details! So far I get it, but Mark seems also to measure "performance" = (injector-pulse width), so I guess there would be a "best performance"- = mode. However to really be able to program max-performance one would = also need some kind of airspeed indication. Did anyone ever check on the Atomatic AVIA props? They work hydraulically, but seem to be selfcontained - a little ring = wit vanes in front of the prop, adjusts the blade pitch according to = speed and rpm. No idea about price and suitability.... ED, get back on the project!! Only 10% to go!! The market has space = for some competition!! Besides you need something to do! How is the new hangar goin'? Thomas J. ----- Original Message -----=20 From: Ed Anderson=20 To: Rotary motors in aircraft=20 Sent: Monday, January 23, 2006 10:45 AM Subject: [FlyRotary] Prop controller RPM and Motor Limits was Re: = Injector pulseing ? Tracy ? Hi Thomas, There at two design considerations that need attention when = designing a controller for an electric pitch prop. One is determining = prop rpm and the second is to determine when the pitch motor has reached = its limits of travel. Prop RPM? When I decided to design an electric prop automatic pitch = controller, I ran into the same design considerations. You need = engine/prop rpm from some source. I decided to use an IR sensor reading = a tape on the prop (to read its rpm directly) since I did not know what = rpm sources might exist on different automobile engine conversions as = well as different gear ratios which would ,of course, affect = relationship between engine and prop speed. However, there are many ways to approach that need. I currently = derive RPM form my EFI Monitor from measuring the interval between = injections (once per e shaft rev). I suspect that Mark is taking a = similar approach to get rpm for his controller. My controller was designed to maintain a certain prop rpm by sensing = the prop rpm and automatically varying the pitch to maintain that rpm = within a small window (to prevent rpm hunting). So if Power was = increased the prop would automatically increase pitch to absorb the = power and keep the rpm within the window and vice versa when power was = reduced. I also had three "pre-programmed" rpms for Take off, Climb and = Cruise that you could set by the push of a button. You could also = manual establish your target rpm. I had the design 90% completed when the prop project went away so = never finished it. Pitch Motor Limits? I think the second problem, as you mentioned, is determining the = pitch motor travel limits to which I do not believe rpm is a crucial = factor. You could install limit switches with the risk of added = complexity and weight or you can devise a method to determine and warn = when the limits are approached.=20 I used a current sensing circuit (which you could adjust for = different current levels) to light an LED. The more current the motor = drew the brighter the LED glowed. So when the motor approached its = stall limit and current increased dramatically over the running current, = the LED would start to glow and the further you ran the motor to the = limit the brighter it would glow. The operator must take the corrective = action - although I already had a design in the conceptual stage to = reverse the motor when the current exceeded a set amount. Then I = decided that I did not want some computer making that decision {:>) Hope this might clarify some of the discussion Ed ----- Original Message -----=20 From: rijakits=20 To: Rotary motors in aircraft=20 Sent: Monday, January 23, 2006 9:46 AM Subject: [FlyRotary] Re: Injector pulseing ? Tracy ? Question. Why does he ( Mark B.) need the injector pulses? Unless he wants to have an automatic-best-performance feature, a = simple rpm reading from the crank will do fine. a) Electronics will increase pitch when power is increased to = maintain rpm in C/S mode. b) Pilot will change pitch in a variable pitch mode. AFAIU the problem is to find the exact endpoints of pitch travel. = How does knowing the injector pulse width help with that? It will tell him how much power is produced in combination with an = rpm input, but does he also measure airspeed? Not bitching, just trying to get the idea!! Thomas J. From: Russell Duffy=20 To: Rotary motors in aircraft=20 Sent: Monday, January 23, 2006 8:55 AM Subject: [FlyRotary] Re: Injector pulseing ? Tracy ? And how would Mark Burton's constant speed controller react if the EC2 was switched = to injector disable mode. Depending on how it was wired, it might suddenly = sense zero power or 2X power. Just thinking out loud. Good point Dean. If he only senses pulses to one injector, then = it would have to be the primary, which is always active, unless you turn = it off via the disable switch. He may not realize we have the ability = to do that, so it would be worth telling him about it. =20 Cheers, Rusty=20 ------=_NextPart_000_000E_01C62023.21DC55B0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
Ok, that tracks, Thomas.  I also use the = injector PW=20 to calculate and display power based on fuel burn = rate. 
 
My controller design was a simply one to emulate = a=20 constant speed prop - not trying for optimum = pitch/speed/distance advanced=20 features.  
 
Having seen my good Friend, Tracy Crook, go from = happy=20 hobbyist to hard working business Entrepreneur - not certain I am = eager to=20 follow {:>).  The technical challenge is fun, but once you = get past=20 that all sorts of things rear their ugly head - like production, = consumer=20 handling Ugh!, liability, keeping records for tax purposes, etc.,=20 etc.,
 
Now Tracy had Laura who runs their business like = a Navy=20 Captain aboard a boomer, so that at least frees him from many (how = about=20 MOST, Laura? {:>)).  Just don't think my spouse would be as = willing=20 to do that (almost) thankless job {:>).
 
Struck a deal to have the old hangar haul away = next=20 week.   I have a new one selected but not ordered, going to be = a bit=20 different (and better).  Mean while don't plan on getting=20 started until after the trip to Texas in Mid Feb to attend = Bill=20 Eslicks Flyin at Pecan Plantation airpart near Dallas.
 
Ed A 
----- Original Message -----
From:=20 rijakits
Sent: Monday, January 23, 2006 = 11:31=20 AM
Subject: [FlyRotary] Re: Prop = controller=20 RPM and Motor Limits - Automatic props

Hi Ed,
 
thanks for the details!
So far I get it, but Mark seems also to = measure=20 "performance" (injector-pulse width), so I guess there would be a = "best=20 performance"- mode. However to really be able to program = max-performance one=20 would also need some kind of airspeed indication.
 
Did anyone ever check on the Atomatic AVIA=20 props?
They work hydraulically, but seem to be = selfcontained -=20 a little ring wit vanes in front of the prop, adjusts the blade pitch=20 according to speed and rpm. No idea about price and=20 suitability....
 
ED, get back on the project!! Only 10% to go!! = The=20 market has space for some competition!!
Besides you need something to do! How is the = new hangar=20 goin'?
 
Thomas J.
----- Original Message -----
From:=20 Ed Anderson
To: Rotary motors in = aircraft=20
Sent: Monday, January 23, = 2006 10:45=20 AM
Subject: [FlyRotary] Prop = controller=20 RPM and Motor Limits was Re: Injector pulseing ? Tracy ?

Hi Thomas,
 
There at two design considerations that need = attention=20 when designing a controller for an electric pitch prop.  One is = determining prop rpm and the second is to determine when the pitch = motor has=20 reached its limits of travel.
 
Prop RPM?
 
When I decided to design an electric prop = automatic=20 pitch controller, I ran into the same design considerations.  = You need=20 engine/prop rpm from some source.  I decided to use an IR = sensor=20 reading a tape on the prop (to read its rpm directly) since I did = not know=20 what rpm sources might exist on different automobile engine = conversions as=20 well as different gear ratios which would ,of course, affect = relationship=20 between engine and prop speed.
 
However, there are many ways to approach = that=20 need.  I currently derive RPM form my EFI Monitor from = measuring the=20 interval between injections (once per e shaft rev).  I suspect = that=20 Mark is taking a similar approach to get rpm for his=20 controller.
 
My controller was designed to maintain a = certain prop=20 rpm by sensing the prop rpm and automatically varying the pitch to = maintain=20 that rpm within a small window (to prevent rpm hunting).  So if = Power=20 was increased the prop would automatically increase pitch to absorb = the=20 power and keep the rpm within the window and vice versa when power = was=20 reduced.
 
I also had three "pre-programmed" rpms for = Take off,=20 Climb and Cruise that you could set by the push of a button.  = You could=20 also manual establish your target rpm.
 
I had the design 90% completed when the prop = project=20 went away so never finished it.
 
Pitch Motor Limits?
 
I think the second problem, as you = mentioned, is=20 determining the pitch motor travel limits to which I do not believe = rpm is a=20 crucial factor.  You could install limit switches with the risk = of=20 added complexity  and weight or you can devise a method to = determine=20 and warn when the limits are approached. 
 
 I used a current sensing circuit = (which you=20 could adjust for different current levels) to light an LED.  = The more=20 current the motor drew  the brighter the LED glowed.  So = when the=20 motor approached its stall limit and current increased dramatically = over the=20 running current, the LED would start to glow and the further you ran = the=20 motor to the limit the brighter it would glow.  The operator = must take=20 the corrective action - although I already had a design in the = conceptual=20 stage to reverse the motor when the current exceeded a set = amount. =20 Then I decided that I did not want some computer making that = decision=20 {:>)
 
Hope this might clarify some of the=20 discussion
 
 
Ed
----- Original Message ----- =
From:=20 rijakits
To: Rotary motors in = aircraft=20
Sent: Monday, January 23, = 2006 9:46=20 AM
Subject: [FlyRotary] Re: = Injector=20 pulseing ? Tracy ?

Question.
 
Why does he ( Mark B.) need the injector=20 pulses?
Unless he wants to have an=20 automatic-best-performance feature, a simple rpm reading from the = crank=20 will do fine.
a) Electronics will increase pitch when = power is=20 increased to maintain rpm in C/S mode.
b) Pilot will change pitch in a variable = pitch=20 mode.
 
AFAIU the problem is to find the exact = endpoints of=20 pitch travel. How does knowing the injector pulse width help with=20 that?
It will tell him how much power is = produced in=20 combination with an rpm input, but does he also measure=20 airspeed?
 
Not bitching, just trying to get the=20 idea!!
 
Thomas J.
 
 
To: Rotary motors in = aircraft=20
Sent: Monday, January 23, = 2006 8:55=20 AM
Subject: [FlyRotary] Re: = Injector=20 pulseing ? Tracy ?

And how would Mark
Burton's constant speed = controller=20 react if the EC2 was switched to injector
disable mode.  = Depending on how it was wired, it might suddenly sense = zero
power or=20 2X power.  Just thinking out loud.

Good point=20 Dean.  If he only senses pulses to one injector, then it = would have=20 to be the primary, which is always active, unless you turn it = off via=20 the disable switch.  He may not realize we have the = ability to=20 do that, so it would be worth telling him about it. =20
 
Cheers,
Rusty=20
 
 
=


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