X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from qmta13.emeryville.ca.mail.comcast.net ([76.96.27.243] verified) by logan.com (CommuniGate Pro SMTP 5.4.5) with ESMTP id 5600662 for flyrotary@lancaironline.net; Thu, 14 Jun 2012 22:04:43 -0400 Received-SPF: pass receiver=logan.com; client-ip=76.96.27.243; envelope-from=hoursaway1@comcast.net Received: from omta04.emeryville.ca.mail.comcast.net ([76.96.30.35]) by qmta13.emeryville.ca.mail.comcast.net with comcast id NS181j0020lTkoCADS471x; Fri, 15 Jun 2012 02:04:07 +0000 Received: from sz0081.ev.mail.comcast.net ([76.96.26.137]) by omta04.emeryville.ca.mail.comcast.net with comcast id NS461j01m2xV6SL8QS46vv; Fri, 15 Jun 2012 02:04:06 +0000 Date: Fri, 15 Jun 2012 02:04:06 +0000 (UTC) From: hoursaway1@comcast.net To: Rotary motors in aircraft Message-ID: <524569474.136919.1339725846437.JavaMail.root@sz0081a.emeryville.ca.mail.comcast.net> In-Reply-To: Subject: Re: [FlyRotary] Re: IVO Prop controls MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_136918_1803044445.1339725846415" X-Originating-IP: [71.206.108.115] X-Mailer: Zimbra 6.0.13_GA_2944 (ZimbraWebClient - IE8 (Win)/6.0.13_GA_2944) ------=_Part_136918_1803044445.1339725846415 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable I=20 I have =C2=A0the set-up you disscribe with the constant speed controler, ha= ve not programed or set it up yet but it is mounted, we are useing manual c= ontrol for now.=C2=A0 David R. Cook=C2=A0 RV6A=C2=A0 Rotary.=20 ----- Original Message ----- From: ARGOLDMAN@aol.com=20 To: "Rotary motors in aircraft" =20 Sent: Thursday, June 14, 2012 1:39:01 PM=20 Subject: [FlyRotary] Re: IVO Prop controls=20 Ed,=20 =C2=A0=20 What a great idea, sorry it never made it to the general flying public.=20 =C2=A0=20 Ivo does, in fact have a C/S controller. Reading some posts, some are not h= appy with it and have removed it, much like some are unhappy with rotaries = and have removed them, despite the success others are having.=20 =C2=A0=20 The ivo controller has a simple hall effect transducer which reads a magnet= buried in one of the prop blades, or the spinner back plate, if a normal s= pinner is used (as opposed to the skull-cap that IVO sells).=20 =C2=A0=20 It does not use=C2=A0 the amp draw of the blade change mechanism at all, to= the best of my knowledge. The draw will disconnect if the physical limits = are hit in the case of an error. The controller, electronically is set for = max and min pitch via it's adjustments.=20 =C2=A0=20 Don't know about the circuitry or the programming-- haven't taken mine apar= t--yet. When engaged, and properly adjusted (several pots) the RPm is contr= olled by a knob, which obviously is a POT. there are switches (remotely mou= nted) to select manual pitch change or C/S.=20 =C2=A0=20 Rich=20 =C2=A0=20 In a message dated 6/14/2012 11:29:59 A.M. Central Daylight Time, eanderson= @carolina.rr.com writes:=20 Back a few years ago, there was a variable pitch prop hub designed by a gen= us of a mechanical engineer.=C2=A0 It had a pitch control mechanism similar= to the IVO adjustable pitch prop.=C2=A0 I designed a control circuit which= among other things monitored the current draw of the pitch motor.=C2=A0=20 =C2=A0=20 While the prop project was not completed (to the best of my knowledge),=C2= =A0I found it was =C2=A0possible by conducting some test measurements to co= rrelate the current draw curve to propeller pitch.=C2=A0 Now the missing pa= rt was - =C2=A0we never got to the point of installing and running the prop= using the controller.=C2=A0 Its highly likely that the current curve would= be different under air loads than not.=C2=A0 We did not use a meter but in= stead had the current turn on an LED (red) when the limit was hit.=C2=A0=20 =C2=A0=20 One of the things that I had planned to do was incorporate a manifold press= ure input (as well as prop rpm) to automatically adjust to prop pitch to ma= intain rpm under various loading.=C2=A0 The hardware to do so was completed= and the software - just never got tested.=20 =C2=A0=20 Just found some of the old code=20 =C2=A0=20 begin=C2=A0 //Main=20 =C2=A0=20 =C2=A0=C2=A0 RPM_Limit_Low :=3D 3000;=20 =C2=A0=C2=A0=C2=A0 RPM_Limit_High:=3D 7000;=20 =C2=A0=20 =C2=A0=C2=A0=C2=A0 RPM_TO :=3D 5800;=20 =C2=A0=C2=A0=C2=A0 RPM_CC :=3D 5600;=20 =C2=A0=C2=A0=C2=A0 RPM_CR :=3D 5200;=20 =C2=A0=C2=A0=C2=A0 RPM_DC :=3D 5500;=20 =C2=A0=C2=A0=C2=A0 //Put address of varible RPM_TO into Pointer variable=20 =C2=A0=C2=A0=C2=A0 PORTB.RB0 :=3D 1; //set to enter while loop in procedure= =20 While testbit(INTCON,RBIF) =3D 0 do=20 =C2=A0=20 I now recall that we actually had several target settings such as TO (Take = off), CC (Cruise Climb), CR (Cruise Range), and others for various flight r= egimes.=C2=A0 So you could choose TO, CC, CR or DC from a menu and the prop= was pitch was positioned/adjusted to maintain the rpm.=C2=A0 Manifold pres= sure was also a factor.=C2=A0 Also it had direction LEDs so you could selec= t to manuall/electrically increase or decrease pitch and a bunch of other t= hings I have now forgotten.=C2=A0 You could adjust those rpm values that be= st suited your particular aircraft/engine combination - the preset values w= ere intended to reduce the pilot work load.=20 =C2=A0=20 I was programming a PIC 18F450 chip to handle the control and sensor inputs= and provide a user interface on an LCD display with buttons.=20 =C2=A0=20 It would have been great had the prop project gone on to completion, but al= as despite the best efforts of a number of good folks it did not.=20 =C2=A0=20 Ed=20 =C2=A0=20 Edward L. Anderson=20 Anderson Electronic Enterprises LLC=20 305 Reefton Road=20 Weddington, NC 28104=20 http://www.andersonee.com=20 http://www.eicommander.com=20 =C2=A0=20 =C2=A0=20 =C2=A0=20 =C2=A0=20 From: Chad Robinson=20 Sent: Wednesday, June 13, 2012 5:52 PM=20 To: Rotary motors in aircraft=20 Subject: [FlyRotary] Re: IVO Prop controls=20 I think there's a miscommunication about how this device works. It's quite = simple: two commutator brushes on a fixed arm transfer current into the pro= p hub to engage the motor and twist the prop blades. Like most motors/actua= tors, you wire it such that positive voltage is applied to turn it one way,= negative turns it the other, and while not moving there is no voltage appl= ied. A simple (ON)-OFF-(ON) switch drives this.=20 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 th= at can operate properly inside the prop at full RPM would have been complic= ated/maybe unreliable? They'd also be a pain to adjust.=20 Anyway, the motor draws only a moderate amount of current in the middle of = its travel, and this increases as you approach the limits. Standard practic= e is to install a meter to indicate this draw and it tells you when you're = near the limit.=20 You could install a PTC instead of a breaker, but it's hardly an emergency.= It's not actually SOP to run it that far - in the times I've flown with Jo= hn I don't recall him ever doing it except perhaps once to show me what hap= pens. You don't "run it until it pops." You "run it until it's where you wa= nt it to be." So PTC or breaker, it doesn't really make that much of a diff= erence. Choose the safety device you prefer.=20 I don't understand the bit about the shorted switch. That's pretty rare, an= d the breaker would deal with it just fine. And I can't speak for anybody e= lse, but every car I've ever owned doesn't use a PTC to set the travel limi= t 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 Cozy.=20 Besides, what's the down side here? You short your switch and the breaker w= ill deal with it, and the prop will stop twisting. No matter WHICH device y= ou use, in this case you now have no way to move the prop because a short w= ould hold a PTC open and also keep tripping a breaker when you manually res= et 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 it's not at the opti= mal pitch. See if you can jiggle the switch to clear the short...=20 To each his own.=20 Regards,=20 Chad=20 On 6/13/12 5:15 PM, Lehanover@aol.com wrote:=20
Why in the world would IVO use a device that is designed to fail critical f= light gear in the case of improper control=20 manipulation when they don't have to? Isn't this the classical and proper a= pplication for a polyfuse? Polyfuses are=20 used in power windows for this exact reason. You're kids can pull on that s= witch all day without damaging the window=20 motor. I'm thinking of the case where a switch gets shorted (like my belt s= ander's switch is right now...the power cord=20 is serving as a temp fix until I get time), or someone accidentally leans s= omething against the switch.=20 Why does the motor draw current after the pitch has been changed?=20 =C2=A0=20 Lynn E. Hanover=C2=A0=20 No virus found in this message.=20 Checked by AVG - www.avg.com=20 Version: 2012.0.2180 / Virus Database: 2433/5068 - Release Date: 06/13/12= =20
------=_Part_136918_1803044445.1339725846415 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable <= div style=3D'font-family: Arial; font-size: 12pt; color: #000000'>I
I ha= ve the set-up you disscribe with the constant speed controler, have no= t programed or set it up yet but it is mounted, we are useing manual contro= l for now.  David R. Cook  RV6A  Rotary.
From: ARGOLDMAN@aol.com
To: "Rotary motors in aircraft" &l= t;flyrotary@lancaironline.net>
Sent: Thursday, June 14, 2012 1= :39:01 PM
Subject: [FlyRotary] Re: IVO Prop controls

Ed,
 
What a great idea, sorry it never made it to the general flying public= .
 
Ivo does, in fact have a C/S controller. Reading some posts, some are = not happy with it and have removed it, much like some are unhappy with rota= ries and have removed them, despite the success others are having.
 
The ivo controller has a simple hall effect transducer which reads a m= agnet buried in one of the prop blades, or the spinner back plate, if a nor= mal spinner is used (as opposed to the skull-cap that IVO sells).
 
It does not use  the amp draw of the blade change mechanism at al= l, to the best of my knowledge. The draw will disconnect if the physical li= mits are hit in the case of an error. The controller, electronically is set= for max and min pitch via it's adjustments.
 
Don't know about the circuitry or the programming-- haven't taken mine= apart--yet. When engaged, and properly adjusted (several pots) the RPm is = controlled by a knob, which obviously is a POT. there are switches (remotel= y mounted) to select manual pitch change or C/S.
 
Rich
 
In a message dated 6/14/2012 11:29:59 A.M. Central Daylight Time, eand= erson@carolina.rr.com writes:
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<= BR>
 
 
 
 

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 hardly an emer= gency. It's not actually SOP to run it that far - in the times I've flown w= ith John I don't recall him ever doing it except perhaps once to show me wh= at 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 understan= d the bit about the shorted switch. That's pretty rare, and the breaker wou= ld deal with it just fine. And I can't speak for anybody else, but every ca= r 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 Cozy.
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 re= set 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 it's not at the opt= imal pitch. See if you can jiggle the switch to clear the short...

T= o 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 - www.av= g.com
Version: 2012.0.2180 / Virus Database: 2433/5068 - Release Dat= e: 06/13/12

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