X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from nm5-vm0.bullet.mail.ne1.yahoo.com ([98.138.90.251] verified) by logan.com (CommuniGate Pro SMTP 5.4.5) with SMTP id 5602750 for flyrotary@lancaironline.net; Fri, 15 Jun 2012 21:55:52 -0400 Received-SPF: none receiver=logan.com; client-ip=98.138.90.251; envelope-from=kjohnsondds@yahoo.com Received: from [98.138.90.56] by nm5.bullet.mail.ne1.yahoo.com with NNFMP; 16 Jun 2012 01:55:17 -0000 Received: from [98.138.87.8] by tm9.bullet.mail.ne1.yahoo.com with NNFMP; 16 Jun 2012 01:55:17 -0000 Received: from [127.0.0.1] by omp1008.mail.ne1.yahoo.com with NNFMP; 16 Jun 2012 01:55:17 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 431127.87152.bm@omp1008.mail.ne1.yahoo.com Received: (qmail 99123 invoked by uid 60001); 16 Jun 2012 01:55:17 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s1024; t=1339811717; bh=5BzzApsbQhEW227TqW5xTERCaX1mk0Oxf/XTKZxeJqg=; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=E7ZsDus221BSelXPACnLFO2ph/tI88m2s1PcvzT1kH2Kp8QEmiDQdOONQjY11YWh/sfYmnZSaThG8jvAV3oh8mkZHubYqyuV03ZJRWFCpqvf9BkGUOIgkxxNM9ii4bQ/ERs7t/O8qhRYm+/7YSy99JBOIhtt9h+l55QTjOLQnmw= DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=xXRa3NaVpl7S4UbXAKWSDtQ9aFTa99AUZNzlZYQgk1LefmVqityttP3tsepRPvNSB7wLVe/ved4LMSAbID7Oikdk0cfCKlkPreHSperqZMWwZeJ9tTJp5VKJ1f9PHXIPdlpSHZHGFMMbgDsWA73uCkSM+CuhiEeXvT1ymv/S0do=; X-YMail-OSG: 5elDryEVM1mUPJ0EIAuNRVrQiD5GiYVTXR3Kc1jP.dozxvD x1phFvy4S1KEAIisWUNbOb6R8ApX6m48t0PloIFUeyTWL0GEZDK09u26ZV2Q 4hKUua7m.m4xKEHNGC175dE9V64PdpUqkffembQQO2uLUrkqUYYKAS7xek2i JERSpPaX.qqQlCJOqMmjTZYwISKRi4dVZyax_FcL7uNvFpiY.j6Fqwn5lEH. Ml7tbINIFHz7LZU_A9zepqxiOmY5exUua79p5m1zHCRM3blLNXNomsBpuuh8 9Vff1ln7xh1Xuazvz.eVoLCGcdVvT_6ma.FHE7qdZLLgFT6oVPVHa9WqDZFT I7oACahKm35qwkuaPlafbsvgUbYYq1YzL8y6AY58ZH4vSmRwNA_NrR5TuwBv YReCqdTeA.o7KZGxK690i8QVsw444TqV5uoM_C9iA344u4ZbP3s8CcFwoz08 P1Rkjr3MINMvw.CJQ1.b8jHj7ww9PM1_29jg7DyiiUl0RdZOb8wquYXwYayY fG8C0bz8593VxafKkWCKL4hLJXR.lTBtEJEVdnsVpmmODrSTii83GVIX28G. HTMpUJESAlqX6ahPC.zwYqDINYjrGoj5qpIz301iG9ldd87ygPezJj5Tf72w tJ1rhPJg- Received: from [66.168.8.63] by web120302.mail.ne1.yahoo.com via HTTP; Fri, 15 Jun 2012 18:55:17 PDT X-Mailer: YahooMailWebService/0.8.118.349524 References: Message-ID: <1339811717.98289.YahooMailNeo@web120302.mail.ne1.yahoo.com> Date: Fri, 15 Jun 2012 18:55:17 -0700 (PDT) From: Kenneth Johnson Reply-To: Kenneth Johnson Subject: Re: [FlyRotary] Re: IVO Prop controls To: Rotary motors in aircraft In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-874068440-431219037-1339811717=:98289" ---874068440-431219037-1339811717=:98289 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Hi All,=0AIn June of 2010 AeroElectric began a discussion on a simple wirin= g system to turn off the ivo prop motor when current progressly increases a= s the motor reaches the end of its run.=A0 This might be an alternative to = the amp meter.=A0 Ken Johnson=A0=0A=0AFrom: Ed Anderson =0ATo: Rotary motors in aircraft =0AS= ent: Thursday, June 14, 2012 11:29 AM=0ASubject: [FlyRotary] Re: IVO Prop c= ontrols=0A=0A=0ABack a few years ago, there was a variable pitch prop hub d= esigned by a genus of a mechanical engineer.=A0 It had a pitch control mech= anism similar to the IVO adjustable pitch prop.=A0 I designed a control cir= cuit which among other things monitored the current draw of the pitch motor= .=A0 =0A=A0=0AWhile the prop project was not completed (to the best of my k= nowledge),=A0I found it was =A0possible by conducting some test measurement= s to correlate the current draw curve to propeller pitch.=A0 Now the missin= g part was - =A0we never got to the point of installing and running the pro= p using the controller.=A0 Its highly likely that the current curve would b= e different under air loads than not.=A0 We did not use a meter but instead= had the current turn on an LED (red) when the limit was hit.=A0 =0A=A0=0AO= ne of the things that I had planned to do was incorporate a manifold pressu= re input (as well as prop rpm) to automatically adjust to prop pitch to mai= ntain rpm under various loading.=A0 The hardware to do so was completed and= the software - just never got tested.=0A=A0=0AJust found some of the old c= ode=0A=A0=0Abegin=A0 //Main=0A=0A=A0=A0 RPM_Limit_Low :=3D 3000;=0A=A0=A0= =A0 RPM_Limit_High:=3D 7000;=0A=0A=A0=A0=A0 RPM_TO :=3D 5800;=0A=A0=A0=A0 R= PM_CC :=3D 5600;=0A=A0=A0=A0 RPM_CR :=3D 5200;=0A=A0=A0=A0 RPM_DC :=3D 5500= ;=0A=A0=A0=A0 //Put address of varible RPM_TO into Pointer variable=0A=A0= =A0=A0 PORTB.RB0 :=3D 1; //set to enter while loop in procedure=0AWhile tes= tbit(INTCON,RBIF) =3D 0 do=0A=0A=A0=0AI now recall that we actually had sev= eral target settings such as TO (Take off), CC (Cruise Climb), CR (Cruise R= ange), and others for various flight regimes.=A0 So you could choose TO, CC= , CR or DC from a menu and the prop was pitch was positioned/adjusted to ma= intain the rpm.=A0 Manifold pressure was also a factor.=A0 Also it had dire= ction LEDs so you could select to manuall/electrically increase or decrease= pitch and a bunch of other things I have now forgotten.=A0 You could adjus= t those rpm values that best suited your particular aircraft/engine combina= tion - the preset values were intended to reduce the pilot work load.=0A=A0= =0AI was programming a PIC 18F450 chip to handle the control and sensor inp= uts and provide a user interface on an LCD display with buttons.=0A=A0=0AIt= would have been great had the prop project gone on to completion, but alas= despite the best efforts of a number of good folks it did not.=0A=A0=0AEd= =0A=A0=0AEdward L. Anderson=0AAnderson Electronic Enterprises LLC=0A305 Ree= fton Road=0AWeddington, NC 28104=0Ahttp://www.andersonee.com=0Ahttp://www.e= icommander.com=0A=0A=A0=0A=A0=0A=A0=0A=A0=0A=0A=0AFrom: Chad Robinson =0ASe= nt: Wednesday, June 13, 2012 5:52 PM=0ATo: Rotary motors in aircraft =0ASub= ject: [FlyRotary] Re: IVO Prop controls=0AI think there's a miscommunicatio= n about how this device works. It's quite simple: two commutator brushes on= a fixed arm transfer current into the prop hub to engage the motor and twi= st the prop blades. Like most motors/actuators, you wire it such that posit= ive voltage is applied to turn it one way, negative turns it the other, and= while not moving there is no voltage applied. A simple (ON)-OFF-(ON) switc= h drives this.=0A=0AThere are only two brushes so there's no way to transfe= r an at-limit signal, and although I'm just guessing here, a reliable pair = of limit switches that can operate properly inside the prop at full RPM wou= ld have been complicated/maybe unreliable? They'd also be a pain to adjust.= =0A=0AAnyway, the motor draws only a moderate amount of current in the midd= le of its travel, and this increases as you approach the limits. Standard p= ractice is to install a meter to indicate this draw and it tells you when y= ou're near the limit.=0A=0AYou could install a PTC instead of a breaker, bu= t it's hardly an emergency. It's not actually SOP to run it that far - in t= he times I've flown with John I don't recall him ever doing it except perha= ps once to show me what happens. You don't "run it until it pops." You "run= it until it's where you want it to be." So PTC or breaker, it doesn't real= ly make that much of a difference. Choose the safety device you prefer.=0A= =0AI don't understand the bit about the shorted switch. That's pretty rare,= and the breaker would deal with it just fine. And I can't speak for anybod= y else, but every car I've ever owned doesn't use a PTC to set the travel l= imit on the window, it uses a limit switch on the actuator. I recall having= to adjust mine one time in a Subaru, just like the nose gear travel switch= es in a Cozy.=0A=0ABesides, what's the down side here? You short your switc= h and the breaker will deal with it, and the prop will stop twisting. No ma= tter WHICH device you use, in this case you now have no way to move the pro= p because a short would hold a PTC open and also keep tripping a breaker wh= en you manually reset that. Both devices have the same failure mode if it's= the switch that's the problem. But you still have a working prop even if i= t's not at the optimal pitch. See if you can jiggle the switch to clear the= short...=0A=0ATo each his own.=0A=0ARegards,=0AChad=0A=0AOn 6/13/12 5:15 P= M, Lehanover@aol.com wrote: =0AWhy in the world would IVO use a device that= is designed to fail critical flight gear in the case of improper control= =0A>manipulation when they don't have to? Isn't this the classical and prop= er application for a polyfuse? Polyfuses are=0A>used in power windows for t= his exact reason. You're kids can pull on that switch all day without damag= ing the window=0A>motor. I'm thinking of the case where a switch gets short= ed (like my belt sander's switch is right now...the power cord=0A>is servin= g as a temp fix until I get time), or someone accidentally leans something = against the switch.=0A>=0A>Why does the motor draw current after the pitch = has been changed?=0A>=0A>Lynn E. Hanover=A0=0A=0ANo virus found in this mes= sage.=0AChecked by AVG - http://www.avg.com/=0AVersion: 2012.0.2180 / Virus= Database: 2433/5068 - Release Date: 06/13/12 ---874068440-431219037-1339811717=:98289 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Hi All,
In June of 2010 Aero= Electric began a discussion on a simple wiring system to turn off the ivo p= rop motor when current progressly increases as the motor reaches the end of= its run.  This might be an alternative to the amp meter.  Ken Jo= hnson 

From:= Ed Anderson <eanderson@carolina.rr.com>
To: Rotary motors in aircraft <flyrota= ry@lancaironline.net>
Sent: Thursday, June 14, 2012 11:29 AM
Subject: [FlyRotary] Re: IVO Prop controls

Back a few years ago, there was a variable pitch pr= op hub designed by a genus of a mechanical engineer.  It had a pitch c= ontrol mechanism similar to the IVO adjustable pitch prop.  I designed= a control circuit which among other things monitored the current draw of t= he pitch motor. 
 
While the prop project was not completed (to the be= st of my knowledge), I found it was  possible by conducting some = test measurements to correlate the current draw curve to propeller pitch.&n= bsp; Now the missing part was -  we never got to the point of installi= ng and running the prop using the controller.  Its highly likely that = the current curve would be different under air loads than not.  We did= not use a meter but instead had the current turn on an LED (red) when the = limit was hit. 
 
One of the things that I had planned to do was inco= rporate a manifold pressure input (as well as prop rpm) to automatically ad= just to prop pitch to maintain rpm under various loading.  The hardwar= e to do so was completed and the software - just never got tested.
 
Just found some of the old code
 
begin  //Main
 
   RPM_Limit_Low :=3D 3000;
 &nbs= p;  RPM_Limit_High:=3D 7000;
 
    RPM_TO :=3D 5800;
  = ;  RPM_CC :=3D 5600;
    RPM_CR :=3D 5200;
 =    RPM_DC :=3D 5500;
    //Put address of varib= le RPM_TO into Pointer variable
    PORTB.RB0 :=3D 1; //s= et to enter while loop in procedure
While testbit(INTCON,RBIF) =3D 0 do<= BR>
 
I now recall that we actually had several target se= ttings such as TO (Take off), CC (Cruise Climb), CR (Cruise Range), and oth= ers for various flight regimes.  So you could choose TO, CC, CR or DC = from a menu and the prop was pitch was positioned/adjusted to maintain the = rpm.  Manifold pressure was also a factor.  Also it had direction= LEDs so you could select to manuall/electrically increase or decrease pitc= h and a bunch of other things I have now forgotten.  You could adjust = those rpm values that best suited your particular aircraft/engine combinati= on - the preset values were intended to reduce the pilot work load.<= /DIV>
 
I was programming a PIC 18F450 chip to handle the c= ontrol and sensor inputs and provide a user interface on an LCD display wit= h buttons.
 
It would have been great had the prop project gone = on to completion, but alas despite the best efforts of a number of good fol= ks it did not.
 
Ed
 
Edward L. Anderson
Anderson Electronic Enterpris= es LLC
305 Reefton Road
Weddington, NC 28104
http://www.andersonee= .com
http://www.eicommander.com
 
 
 
 

Sent: Wednesday, June 13, 2012 5:52 PM
Subject: [FlyRotary] Re: IVO Prop controls

I think there's a miscommunication about how this device wor= ks. It's quite simple: two commutator brushes on a fixed arm transfer curre= nt into the prop hub to engage the motor and twist the prop blades. Like mo= st motors/actuators, you wire it such that positive voltage is applied to t= urn it one way, negative turns it the other, and while not moving there is = no voltage applied. A simple (ON)-OFF-(ON) switch drives this.

There= are only two brushes so there's no way to transfer an at-limit signal, and= although I'm just guessing here, a reliable pair of limit switches that ca= n operate properly inside the prop at full RPM would have been complicated/= maybe unreliable? They'd also be a pain to adjust.

Anyway, the motor= draws only a moderate amount of current in the middle of its travel, and t= his increases as you approach the limits. Standard practice is to install a= meter to indicate this draw and it tells you when you're near the limit.

You could install a PTC instead of a breaker, but it's hardl= y an emergency. It's not actually SOP to run it that far - in the times I'v= e flown with John I don't recall him ever doing it except perhaps once to s= how me what happens. You don't "run it until it pops." You "run it until it= 's where you want it to be." So PTC or breaker, it doesn't really make that= much of a difference. Choose the safety device you prefer.

I don't = understand the bit about the shorted switch. That's pretty rare, and the br= eaker would deal with it just fine. And I can't speak for anybody else, but= every car I've ever owned doesn't use a PTC to set the travel limit on the= window, it uses a limit switch on the actuator. I recall having to adjust = mine one time in a Subaru, just like the nose gear travel switches in a Coz= y.

Besides, what's the down side here? You short your switch and the= breaker will deal with it, and the prop will stop twisting. No matter WHICH device you use, in this case you now have no way to move the = prop because a short would hold a PTC open and also keep tripping a breaker= when you manually reset that. Both devices have the same failure mode if i= t's the switch that's the problem. But you still have a working prop even i= f it's not at the optimal pitch. See if you can jiggle the switch to clear = the short...

To each his own.

Regards,
Chad

On 6/13= /12 5:15 PM, Lehanover@aol.com wrote:=20
Why in the world would IVO use a device that is designe= d to fail critical flight gear in the case of improper control
manipulat= ion when they don't have to? Isn't this the classical and proper applicatio= n for a polyfuse? Polyfuses are
used in power windows for this exact rea= son. You're kids can pull on that switch all day without damaging the windo= w
motor. I'm thinking of the case where a switch gets shorted (like my b= elt sander's switch is right now...the power cord
is serving as a temp f= ix until I get time), or someone accidentally leans something against the s= witch.
Why does the motor draw current after the pitch has been changed?
 
Lynn E. Hanover 

No virus found in this message.
Checked by AVG - http://www.avg.co= m/
Version: 2012.0.2180 / Virus Database: 2433/5068 - Release Date: = 06/13/12


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