X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [66.219.56.248] (HELO qnsi-xch.qnsi.net) by logan.com (CommuniGate Pro SMTP 5.2.0) with ESMTP id 2717951 for flyrotary@lancaironline.net; Wed, 06 Feb 2008 13:30:57 -0500 Received-SPF: none receiver=logan.com; client-ip=66.219.56.248; envelope-from=bhughes@qnsi.net Return-Receipt-To: "Bobby J. Hughes" Subject: RE: [FlyRotary] Re: 20B rotors / Renesis sensor wiring change MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C868EE.60CF9582" Date: Wed, 6 Feb 2008 12:30:40 -0600 Message-ID: Disposition-Notification-To: "Bobby J. Hughes" Content-class: urn:content-classes:message X-MimeOLE: Produced By Microsoft Exchange V6.5.6944.0 X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [FlyRotary] Re: 20B rotors / Renesis sensor wiring change Thread-Index: Achowwnoz7ec3ZDyQBKWYkkdZnkqcwAKISkQ From: "Bobby J. Hughes" To: "Rotary motors in aircraft" This is a multi-part message in MIME format. ------_=_NextPart_001_01C868EE.60CF9582 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable =20 Mark, Tracy, =20 Remember we put a 22K ohm resister and zener in the CAS circuit to drop the voltage and allow for higher rpms. My notes say 8.1V peak to peak at 6300 rpms with this arrangement. The higher the resister value the higher the rpms you could run. If I remember correctly changing the CAS bracket to aluminum (possibly changed gap ) allow you to go to 7500 rpm+. We never did look at the signal after you changed the CAS bracket. =20 Bobby ________________________________ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Tracy Crook Sent: Wednesday, February 06, 2008 7:19 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: 20B rotors / Renesis sensor wiring change Your's must be spot on Mark. I finally got mine well centered and it worked fine but it was a pain to get it there. Took me an hour and several tries before I got it close enough to run at WOT. =20 While this does work, I'm not happy with how touchy this Renesis sensor and trigger wheel is when used with the EC2. The EC2 was designed for the RX-7 sensor since that was what was available at the time. I think a change is needed for the RX-8 sensor in order to be Plug n' Play like I want it to be. My first experiment in that direction was to put a simple voltage clamp across the sensor (in addition to the 1000 ohm resistor I mentioned before) and this seemed to work well. I'm still testing this to make sure it covers all the bases. =20 Now that I can run consistently at full throttle, 20B testing continues. Since the wings (and fuel tanks) are not on the RV-8 yet, I'm feeding the engine from a small gas can. It is amazing how fast a 20B at maximum power will empty a 2 1/2 gallon can! =20 =20 Tracy On Feb 5, 2008 2:27 PM, Mark Steitle wrote: Tracy, =20 I had wondered if a slight off-center of the trigger wheel could cause problems. So, I tried my best to get it dead on. To answer your question, I left the trigger wheel alone and just changed the sensor mount. I'll check the runout again just to be sure it is within spec. Since I can see up to 7500 rpm on initial takeoff run, I doubt that the trigger wheel is off center by any significant amount.=20 =20 Mark =20 (Locally I'm known as the flying chainsaw.) =20 On 2/5/08, Tracy Crook wrote:=20 OK Mark. Also take note of my last message on centering the trigger wheel. Nearly drove me nuts figuring that one out last week. Yours must have centered up OK when you installing it. BTW, did you happen to remove and re-install the trigger wheel when you changed CAS mounts? That could have accounted for the different results. =20 Tracy=20 =09 =20 On Feb 4, 2008 8:12 AM, Mark Steitle wrote: =09 =09 Tracy,=20 I'm reluctant to change anything now that its running like it should. My engine always starts right up with very little priming. Since I still have the 4130 bracket, I may reinstall it along with the 1k ohm resistor and see how it runs. I'll let you know if it helps or hurts. =20 =09 =20 Mark =09 =20 On 2/3/08, Tracy Crook wrote:=20 I did the 9.7 CR rotors in mine but have never done a front to back comparison with the stock 9.0s. It does run strong with the 9.7s though! =20 BTW, all builders using the Renesis Crank sensors take note: =20 I had a lot of trouble starting my 20B with Renesis CAS installed. Just yesterday I found out why. The Renesis CAS is a much higher impedance sensor than the RX-7 CAS and this makes it much more sensitive to noise pickup, especially when the starter is running. It needs a load resistor across it to avoid this problem. Install a 1000 ohm (1/4 or 1/2 watt is fine) across the leads of the sensor either at the sensor or near the EC2. =20 =20 After installing one on mine it went from very difficult to instant starting.=20 =20 I'm not sure why I have not seen this problem on my RV-4 with Renesis engine but one other Renesis user has seen the problem and the resistor fixed it immediately. =20 Mark S., you should definitely do this on your 20B / Renesis setup as well. I am starting to suspect that this is why your earlier steel mount (for CAS) did not work. A very small difference in how the CAS is mounted affects the noise characteristics a lot. Either mount would probably have worked fine with the resistor installed. =20 =20 Future EC2s for Renesis engines will have this installed internally. =20 Tracy =20 =20 =20 On Feb 3, 2008 4:44 PM, bob.kaufmann wrote: =09 Gang =09 I have a 20B that I have taken the turbos off and will be using it in an aircraft, a RV-10. A friend of mine said that I should use the 9.7 compression rotors instead of the turbo rotors. What say you all? =09 I have pulled the engine off to powder coat the engine mount and if I'm going to switch rotors, now is the time before I hang the engine again. I have the flat plate on milling machine so I could make plates for the 20B if people wanted. I think I would be competitive. I would like to do them in groups of ten if people are interested. =09 Bob K Finished except all the parts aren't together yet. =09 =09 -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html =09 =20 ------_=_NextPart_001_01C868EE.60CF9582 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable
 
Mark, Tracy,
 
Remember we put a 22K ohm resister and zener in the CAS = circuit to=20 drop the voltage and allow for higher rpms. My notes say 8.1V peak = to peak=20 at 6300 rpms with this arrangement. The higher the resister value the = higher the=20 rpms you could run.  If I remember correctly changing the CAS = bracket to=20 aluminum (possibly changed gap ) allow you to go to 7500 rpm+. We never = did look=20 at the signal after you changed the CAS bracket.=20
&nbs= p;
Bobby

From: Rotary motors in aircraft=20 [mailto:flyrotary@lancaironline.net] On Behalf Of Tracy=20 Crook
Sent: Wednesday, February 06, 2008 7:19 AM
To: = Rotary=20 motors in aircraft
Subject: [FlyRotary] Re: 20B rotors / = Renesis=20 sensor wiring change

Your's must be spot on Mark.  I finally got mine well centered = and it=20 worked fine but it was a pain to get it there.  Took me an hour and = several=20 tries before I got it close enough to run at WOT.
 
  While this does work, I'm not happy with how = touchy this=20 Renesis sensor and trigger wheel is when used with the EC2.  The = EC2 was=20 designed for the RX-7 sensor since that was what was available at = the time.=20  I think a change is needed for the RX-8 sensor in order to be Plug = n' Play=20 like I want it to be.

My first experiment in that direction was to put a=20 simple voltage clamp across the sensor (in addition to the 1000 ohm = resistor I mentioned before) and this seemed to work well.  I'm = still=20 testing this to make sure it covers all the bases.
 
Now that I can run consistently at full throttle, 20B testing=20 continues.  Since the wings (and fuel tanks) are not on the RV-8 = yet, I'm=20 feeding the engine from a small gas can.    It is amazing = how=20 fast a 20B at maximum power will empty a 2 1/2 gallon = can! =20
 
Tracy
On Feb 5, 2008 2:27 PM, Mark Steitle <msteitle@gmail.com> wrote:
Tracy,
 
I had wondered if a slight off-center of the trigger wheel could = cause=20 problems.  So, I tried my best to get it dead on.  To answer = your=20 question, I left the trigger wheel alone and just changed the = sensor=20 mount.  I'll check the runout again just to be sure it = is=20 within spec.  Since I can see up to 7500 rpm on = initial=20 takeoff run, I doubt that the trigger wheel is off center by any=20 significant amount. 
 
Mark   
(Locally I'm known as the flying=20 chainsaw.)
 
On 2/5/08, Tracy=20 Crook <tracy@rotaryaviation.com> wrote:=20
OK Mark.  Also take note of my last message on centering = the=20 trigger wheel.  Nearly drove me nuts figuring that one out last = week.  Yours must have centered up OK when you installing = it. =20 BTW, did you happen to remove and re-install the trigger wheel when = you=20 changed CAS mounts?   That could have accounted for the = different=20 results.
 
Tracy 

 
On Feb 4, 2008 8:12 AM, Mark Steitle = <msteitle@gmail.com>=20 wrote:
Tracy,
I'm reluctant to change anything now that its running like it = should.  My engine always starts right up with very little=20 priming.  Since I still have the 4130 bracket, I may = reinstall it=20 along with the 1k ohm resistor and see how it runs.  I'll let = you=20 know if it helps or hurts. 
 
Mark

 
On 2/3/08, Tracy=20 Crook <tracy@rotaryaviation.com> wrote:=20
I did the 9.7 CR rotors in mine but have never done a front = to back=20 comparison with the stock 9.0s.  It does run strong with = the 9.7s=20 though!
 
BTW, all builders using the Renesis Crank sensors take = note:
 
I had a lot of trouble starting my 20B with Renesis CAS=20 installed.  Just yesterday I found out why.  The = Renesis CAS=20 is a much higher impedance sensor than the RX-7 CAS and this = makes it=20 much more sensitive to noise pickup, especially when the starter = is=20 running.  It needs a load resistor across it to avoid = this=20 problem.  Install a 1000 ohm (1/4  or 1/2 watt is = fine)  across the leads of the sensor either at the sensor = or=20 near the EC2. 
 
After installing one on mine it went from very difficult to = instant=20 starting. 
 
I'm not sure why I have not seen this problem on my RV-4 = with=20 Renesis engine but one other Renesis user has seen the problem = and the=20 resistor fixed it immediately.
 
Mark S., you should definitely do this on your 20B / = Renesis setup=20 as well.  I am starting to suspect that this is why your = earlier=20 steel mount (for CAS) did not work.  A very small = difference in how=20 the CAS is mounted affects the noise characteristics a = lot.  Either=20 mount would probably have worked fine with the resistor=20 installed.  
 
Future EC2s for Renesis engines will have this installed=20 internally.
 
Tracy
 
 


 
On Feb 3, 2008 4:44 PM, bob.kaufmann = <bob.kaufmann@cox.net> wrote:
Gang

I=20 have a 20B that I have taken the turbos off and will be using = it in=20 an
aircraft, a RV-10.  A friend of mine said that I = should use=20 the 9.7
compression rotors instead of the turbo rotors. =  What=20 say you all?

I have pulled the engine off to powder = coat the=20 engine mount and if I'm
going to switch rotors, now is the = time=20 before I hang the engine again.  I
have the flat plate = on=20 milling machine so I could make plates for the 20B = if
people=20 wanted.  I think I would be competitive.  I would = like to do=20 them in
groups of ten if people are interested.

Bob=20 K
Finished except all the parts aren't together = yet.


--
Homepage:  http://www.flyrotary.com/
Archive and = UnSub:=20   http://mail.lancaironline.net:81/lists/flyrotary/List.htm= l


&nbs= p;


<= /BLOCKQUOTE>

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