X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fmailhost01.isp.att.net ([207.115.11.51] verified) by logan.com (CommuniGate Pro SMTP 5.2c1) with ESMTP id 2551262 for flyrotary@lancaironline.net; Sat, 01 Dec 2007 18:31:50 -0500 Received-SPF: none receiver=logan.com; client-ip=207.115.11.51; envelope-from=rusty@radrotary.com Received: from rad (adsl-065-006-194-009.sip.pns.bellsouth.net[65.6.194.9]) by isp.att.net (frfwmhc01) with SMTP id <20071201233112H0100n1tr0e>; Sat, 1 Dec 2007 23:31:12 +0000 X-Originating-IP: [65.6.194.9] From: "Russell Duffy" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Giving up on single rotor Date: Sat, 1 Dec 2007 17:31:12 -0600 Message-ID: <000001c83472$42d1f030$6c01a8c0@rad> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C8343F.F8378030" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6822 Importance: Normal Thread-Index: Acg0X3bQTrPB/B+sRTS4IbUHjAZ74wAD82RA In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C8343F.F8378030 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable What was the latest problem with the single development, was it the torsional reversals. The last I heard was you were going softer with the damper material - did that work out?=20 =20 Hi George, =20 The last straw was the new damper arrangement. Going from a 60 = durometer to a 50 durometer made some difference. I then hacked up one of the 60 durometer dampers so it would be softer, and have more flex. With that = one, I felt like the problem was gone. =20 =20 After some thought (staring it into submission), I figured out a way to = make a steel adapter to allow me to couple two 50 durometer dampers in = series, and still fit where it needed to go. After spending almost a week = working on it, and being very proud of what I was able to make on my home 3-in-1 machine, I finally gave it a try. Unfortunately, it wasn't good. =20 =20 This was a classic case of "if a little more is good, then a lot more = will be great". I ended up with a damper that was so soft, and had so much = play that it was like a rubber band. The result was almost as scary as that wacky peroxide rotorcraft video I posted. The engine almost tore my = test stand apart before I could shut it down, and I'm probably lucky it = didn't chop me to bits just for spite. I had the video running, but all I got = was "memory card error" when I tried to view it. =20 =20 While this damper didn't work out as planned, there are still other solutions I could try, and I'm sure it's possible to make this work. Unfortunately, I've already spent almost 3 years (time flies) messing = with this, and there's just no escaping the fact that it's going to be too = heavy to be a 912S replacement. Until someone manufactures a better 100 HP = rotary solution (two rotor I hope), that they are actually willing to sell for aircraft use, I'm afraid the 100 HP rotary isn't going to be much of an option. The 912S so desperately needs competition... =20 Rusty (UAVP) =20 ------=_NextPart_000_0001_01C8343F.F8378030 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message
What was the latest problem with the single development, was it the = torsional reversals. The last I heard was you were going softer with the = damper=20 material - did that work out? 
 
Hi=20 George,
 
The last=20 straw was the new damper arrangement.  Going from a 60 durometer to = a 50=20 durometer made some difference.  I then hacked up one of the 60 = durometer=20 dampers so it would be softer, and have more flex.  With that = one,=20 I felt like the problem was gone. 
 
After=20 some thought (staring it into submission), I figured out a way to = make a=20 steel adapter to allow me to couple two 50 durometer dampers in series, = and=20 still fit where it needed to go.  After spending almost a week = working on=20 it, and being very proud of what I was able to make on my home 3-in-1 = machine, I=20 finally gave it a try.  Unfortunately, it wasn't=20 good.  
 
This was a=20 classic case of "if a little more is good, then a lot more will be = great". =20 I ended up with a damper that was so soft, and had so much play that it = was like=20 a rubber band.  The result was almost as scary as that = wacky=20 peroxide rotorcraft video I posted.  The engine almost tore my = test=20 stand apart before I could shut it down, and I'm probably lucky it = didn't=20 chop me to bits just for spite.  I had the video running, but = all I=20 got was "memory card error" when I tried to view=20 it.  
 
While=20 this damper didn't work out as planned, there are still other = solutions I=20 could try, and I'm sure it's possible to make this work.  =20 Unfortunately, I've already spent almost 3 years (time flies) messing = with this,=20 and there's just no escaping the fact that it's going to be too heavy to = be a=20 912S replacement.  Until someone manufactures a better 100 HP = rotary=20 solution (two rotor I hope), that they are actually willing to sell = for=20 aircraft use, I'm afraid the 100 HP rotary isn't going to be much of an=20 option.  The 912S so desperately needs = competition...
 
Rusty=20 (UAVP)  
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