X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from m12.lax.untd.com ([64.136.30.75] verified) by logan.com (CommuniGate Pro SMTP 5.1.9) with SMTP id 2085442 for flyrotary@lancaironline.net; Tue, 05 Jun 2007 12:49:09 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.136.30.75; envelope-from=alwick@juno.com Received: from m12.lax.untd.com (localhost [127.0.0.1]) by m12.lax.untd.com with SMTP id AABDGME83A54SF72 for (sender ); Tue, 5 Jun 2007 09:48:25 -0700 (PDT) X-UNTD-OriginStamp: L941HVjjYzDhN3itp//mkIU6d5N6EctfoqycFQ7wOj5GZAlMVBbkIw== Received: (from alwick@juno.com) by m12.lax.untd.com (jqueuemail) id MPG3MKNV; Tue, 05 Jun 2007 09:47:56 PDT To: flyrotary@lancaironline.net Date: Tue, 5 Jun 2007 09:47:17 -0700 Subject: Re: [FlyRotary] Re: Single rotor video Message-ID: <20070605.094724.3280.2.alwick@juno.com> X-Mailer: Juno 5.0.49 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary=--__JNP_000_4bb1.693b.37f4 X-Juno-Line-Breaks: 8-6,9-10,15-16,22-23,25-26,30-35,37,39-43,45-51,56-57,59-64,66,68-69,70-32767 From: al p wick X-ContentStamp: 18:9:120993790 X-MAIL-INFO:0cbcbca89df5d15cad18dca8dddcd908853dcddce1bd1d419de1cd3de171e1b975f19981bc58a8eda8359d7cd98cd87c5cf548f139a528b5915968153cf1d9f8894d1c611c2501715d1c X-UNTD-Peer-Info: 127.0.0.1|localhost|m12.lax.untd.com|alwick@juno.com 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. ----__JNP_000_4bb1.693b.37f4 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit 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 Cozy IV powered by Turbo Subaru 3.0R with variable valve lift and cam timing. Artificial intelligence in cockpit, N9032U 240+ hours from Portland, Oregon Glass panel design, Subaru install, Prop construct, Risk assessment info: http://www.maddyhome.com/canardpages/pages/alwick/index.html On Tue, 5 Jun 2007 09:17:07 -0500 "Russell Duffy" writes: What a great video. I ran it in slow motion. Hi Al, I never thought about running this in slow motion, but holy crap!!! For the dialup folks, here are a couple frames from the video, when the engine was probably around 2500 rpm. These are sequential frames, so only a 30th of a second apart. Take a look at the blade flex, but then note the position of the engine from rotational torque. It's undeniable that this is a torque reversal issue. Before I change dampers, I may make another video at more controlled rpms, and with the camera zoomed in on the engine/prop more. Rusty (creating a monster) -al wick Cozy IV powered by Turbo Subaru 3.0R with variable valve lift and cam timing. Artificial intelligence in cockpit, N9032U 240+ hours from Portland, Oregon Glass panel design, Subaru install, Prop construct, Risk assessment info: http://www.maddyhome.com/canardpages/pages/alwick/index.html ----__JNP_000_4bb1.693b.37f4 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: quoted-printable Message
Your video has really inspired me. One of the keys to problem solving = is it=20 to convert your impressions to numbers. You've just invented the "Duffy = prop=20 analysis method".
 
Measure the distance from you hangar door to your prop. Put mark on=20 pavement, say at 20 ft. Put another mark at 30 ft. That's where your camera= =20 goes. Now, video your engine as well as others at those same locations.=20 Calibrate your system by measuring the distance between the pleats on your= =20 hangar door.
 
Now go home, sit on the couch, get a beer. Fire up your videos. Find = the=20 worst deflection by using slow motion. Measure how far prop tip is from the= =20 hangar door pleat in background. So it's going to be around 1/4" on your = video=20 screen. We can convert that mathematically to actual tip deflection at prop= !=20 You've now measured deflection of 4 different aircraft and haven't lost a=20 finger.
 
Then you just test your various ideas, trying to beat the best = measurements=20 you could find.
 
You could also use the video to measure prop diameter. Just in case = one of=20 the planes has different diameter. That would also prove how accurate this= =20 method is. I expect it would be unexpectedly accurate and meaningful.
 
Write up your test. This would be great one for Contact.
 

-al wick
Cozy IV powered by Turbo Subaru 3.0R with variable = valve=20 lift and cam timing.
Artificial intelligence in cockpit, N9032U 240+ = hours=20 from Portland, Oregon
Glass panel design, Subaru install, Prop construct= ,=20 Risk assessment info:
http:= //www.maddyhome.com/canardpages/pages/alwick/index.html
 
On Tue, 5 Jun 2007 09:17:07 -0500 "Russell Duffy" <rusty@radrotary.com> writes:
<= FONT=20 face=3DTahoma size=3D2>
What a great video. I ran it in slow motion.  
 
= Hi=20 Al,
 
= I never=20 thought about running this in slow motion, but=20 holy crap!!!  
 
= For the=20 dialup folks, here are a couple frames from the video, when the engine = was=20 probably around 2500 rpm.  These are sequential frames, so only a = 30th of=20 a second apart.  Take a look at the blade flex, but then note=20 the position of the engine from rotational torque.  It's = undeniable=20 that this is a torque reversal=20 issue.    
 
= Before I=20 change dampers, I may make another video at more controlled rpms, and = with the=20 camera zoomed in on the engine/prop more. 
 
= Rusty=20 (creating a monster)
 

-al wick
Cozy IV powered by Turbo = Subaru=20 3.0R with variable valve lift and cam timing.
Artificial intelligence = in=20 cockpit, N9032U 240+ hours from Portland, Oregon
Glass panel design, = Subaru=20 install, Prop construct, Risk assessment=20 info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html
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