X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml Date: Fri, 04 Dec 2009 16:28:30 -0500 Message-ID: X-Original-Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.121] verified) by logan.com (CommuniGate Pro SMTP 5.3c3) with ESMTP id 4002886 for lml@lancaironline.net; Fri, 04 Dec 2009 15:15:05 -0500 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.121; envelope-from=dfs155@roadrunner.com Received: from dan ([76.178.186.181]) by cdptpa-omta02.mail.rr.com with SMTP id <20091204201429445.MHML14763@cdptpa-omta02.mail.rr.com> for ; Fri, 4 Dec 2009 20:14:29 +0000 X-Original-Message-ID: <6885767BA0EF417CACD6A4B1A3321AC9@dan> From: "Dan Schaefer" X-Original-To: "Lancair list" Subject: Ivoprop X-Original-Date: Fri, 4 Dec 2009 12:14:27 -0800 MIME-Version: 1.0 Content-Type: text/plain; format="flowed"; charset="windows-1252"; reply-type="original" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5843 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 Michel: I tried Ivoprop's two and three bladed prop on my 235 back in about '94 - 5 before giving up and going to an MT electric CS prop. On the Ivoprop, the blades are individually bolted to a hub assembly, sandwiched between a base and cover-plate, so that the two mounting bolts for each blade are in shear. At the root of the blades, metallic "tell-tales" bridge across the junction of one blade to the next that are meant to break if there is any relative motion between blades (meaning that a blade is moving back and forth in the rotational plane relative to the hub) - not a good thing and a pain in the rear to inspect since the spinner has to be removed to see the tell-tales. On the Lycoming O-235-N2C in my early LNC-2, I could never even get around the pattern without breaking one or more of the tell-tales. I was located in LA at the time so called Ivo to see what he thought. He came to my hangar and decided that the three blade prop might correct the problem and that hub cover plate needed to be more agressively knurled to provide more purchase on the blade roots. None of this worked and in the end, Ivo took the prop back and I bought the MT. Perhaps it was related to just the rotational dynamics of the O-235 in my airplane (or maybe not - I'll never know) and would work fine on a O-320). In any case, if you decide to try one, be sure to get a committment from Ivo to take the prop back if this, or other, difficulties arise. Regards, Dan Schaefer Early LNC-2, N235SP -- I am using the free version of SPAMfighter. We are a community of 6 million users fighting spam. SPAMfighter has removed 639 of my spam emails to date. Get the free SPAMfighter here: http://www.spamfighter.com/len The Professional version does not have this message