X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [12.10.147.52] (HELO utmcmail.utmc.com) by logan.com (CommuniGate Pro SMTP 5.1.9) with ESMTP id 2085532 for flyrotary@lancaironline.net; Tue, 05 Jun 2007 13:22:51 -0400 Received-SPF: none receiver=logan.com; client-ip=12.10.147.52; envelope-from=Grant.Schemmel@Aeroflex.com Received: from pony.utmc.utc.com ([172.24.100.19] RDNS failed) by utmcmail.utmc.com with Microsoft SMTPSVC(6.0.3790.211); Tue, 5 Jun 2007 11:18:30 -0600 Received: by pony.utmc.utc.com with Internet Mail Service (5.5.2655.55) id ; Tue, 5 Jun 2007 11:20:57 -0600 Message-ID: From: "Schemmel, Grant" To: 'Rotary motors in aircraft' Subject: RE: [FlyRotary] Re: Single rotor video Date: Tue, 5 Jun 2007 11:20:56 -0600 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2655.55) Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C7A795.86FEBF5A" Return-Path: Grant.Schemmel@Aeroflex.com X-OriginalArrivalTime: 05 Jun 2007 17:18:30.0009 (UTC) FILETIME=[89601690:01C7A795] This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. ------_=_NextPart_001_01C7A795.86FEBF5A Content-Type: text/plain _____ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of al p wick Sent: Tuesday, June 05, 2007 10:47 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Single rotor video Your video has really inspired me. One of the keys to problem solving is it to convert your impressions to numbers. You've just invented the "Duffy prop analysis method". Measure the distance from you hangar door to your prop. Put mark on pavement, say at 20 ft. Put another mark at 30 ft. That's where your camera goes. Now, video your engine as well as others at those same locations. Calibrate your system by measuring the distance between the pleats on your hangar door. Now go home, sit on the couch, get a beer. Fire up your videos. Find the worst deflection by using slow motion. Measure how far prop tip is from the hangar door pleat in background. So it's going to be around 1/4" on your video screen. We can convert that mathematically to actual tip deflection at prop! You've now measured deflection of 4 different aircraft and haven't lost a finger. Then you just test your various ideas, trying to beat the best measurements you could find. You could also use the video to measure prop diameter. Just in case one of the planes has different diameter. That would also prove how accurate this method is. I expect it would be unexpectedly accurate and meaningful. Write up your test. This would be great one for Contact. -al wick If you want to use an off-the-shelf method, there is a company that makes software that will measure anything if a reference square is in the picture. See http://www.iphotomeasure.com/index.asp Have not used it myself, but it looked interesting. Grant Schemmel ------_=_NextPart_001_01C7A795.86FEBF5A Content-Type: text/html Message
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of al p wick
Sent: Tuesday, June 05, 2007 10:47 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Single rotor video

Your video has really inspired me. One of the keys to problem solving is it to convert your impressions to numbers. You've just invented the "Duffy prop analysis method".
 
Measure the distance from you hangar door to your prop. Put mark on pavement, say at 20 ft. Put another mark at 30 ft. That's where your camera goes. Now, video your engine as well as others at those same locations. Calibrate your system by measuring the distance between the pleats on your hangar door.
 
Now go home, sit on the couch, get a beer. Fire up your videos. Find the worst deflection by using slow motion. Measure how far prop tip is from the hangar door pleat in background. So it's going to be around 1/4" on your video screen. We can convert that mathematically to actual tip deflection at prop! You've now measured deflection of 4 different aircraft and haven't lost a finger.
 
Then you just test your various ideas, trying to beat the best measurements you could find.
 
You could also use the video to measure prop diameter. Just in case one of the planes has different diameter. That would also prove how accurate this method is. I expect it would be unexpectedly accurate and meaningful.
 
Write up your test. This would be great one for Contact.
 

-al wick
 
If you want to use an off-the-shelf method, there is a company that makes software that will measure anything if a reference square is in the picture.  See http://www.iphotomeasure.com/index.asp
 
Have not used it myself, but it looked interesting.
 
Grant Schemmel 
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