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Collin
General
Gender: Male
Location: McMinnville. Oregon
Registered: Oct 2006
Status: Offline
Posts: 711
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Posted Thursday, February 19, 2009 @ 01:20 PM
Hello,
Tail wheel drag has been covered. Here is a idea I have.
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Jorgen
Captain
Gender: Male
Location: Lund, Sweden
Registered: Apr 2007
Status: Offline
Posts: 833
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Posted Thursday, February 19, 2009 @ 03:42 PM
Hi Collin,
that´s really neat and probably would work. I´ve been toying ideas on how to fair the whole fork and the wheel, but it´s a kind of complicated shape and needs to be flexible. If a fairing is too flexible it could flap around and possibly increase drag not to mention the risk of obstructing steering. Your suggestion is more in adherence with the "KISS"-principle (Keep It Simple, Stupid!) which I´ve found to be a valid general rule for many different applications....
Take 5(b) just 4 fun/ Jörgen
P.S. I like the rubber turbulence generators on your sturdy tail wheel too D.S.
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Collin
General
Gender: Male
Location: McMinnville. Oregon
Registered: Oct 2006
Status: Offline
Posts: 711
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Posted Thursday, February 19, 2009 @ 04:57 PM
The tail wheel I stole from a wheel chair.
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Jorgen
Captain
Gender: Male
Location: Lund, Sweden
Registered: Apr 2007
Status: Offline
Posts: 833
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Posted Tuesday, March 10, 2009 @ 06:16 PM
Alright Collin,
keep e´m flying as they say about vintage aircraft. However, if that forces disabled peolpe to crawl it could be considered taking it a bit too far though- I hope no one was in the chair when you stole the wheel...
But seriously, are you going for plastic or aluminium on your fairing? And also, since I with contentment note that we are now fellow RF 4+5b nuts, how about fairing that rear tractor tire on the R 5b?
Take 5(b) just 4 fun/ Jörgen
[Edit by Jorgen on Tuesday, March 10, 2009 @ 06:21 PM]
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Collin
General
Gender: Male
Location: McMinnville. Oregon
Registered: Oct 2006
Status: Offline
Posts: 711
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Posted Wednesday, March 11, 2009 @ 02:16 PM
Hi Jordan,
When I get the RF5B home I will look into a tail wheel fairing. It is still on the east coast. I am going to make the fairing with .020" aluminum.
Collin
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Collin
General
Gender: Male
Location: McMinnville. Oregon
Registered: Oct 2006
Status: Offline
Posts: 711
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Posted Friday, March 20, 2009 @ 08:20 PM
Hello,
Hear is my finished fairing. I will put it on tonight.
Has any herd from Bob? Has not been on the forum for over a month.
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cooperman
Staff Sergeant
Gender: Unspecified
Location:
Registered: Oct 2007
Status: Offline
Posts: 43
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Posted Friday, March 20, 2009 @ 08:22 PM
I will see him at Seighford tomorrow - any messages Collin?
Rgds
Paul
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Sam M.
First Sergeant
Gender: Male
Location: Santa Paula, CA
Registered: Jul 2008
Status: Offline
Posts: 228
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Posted Saturday, March 21, 2009 @ 10:18 PM
speaking of Bob, I need to send off his carb, Anyone know his address?
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Jorgen
Captain
Gender: Male
Location: Lund, Sweden
Registered: Apr 2007
Status: Offline
Posts: 833
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Posted Sunday, March 22, 2009 @ 07:11 AM
They seek him here, they seek him there,
the Fourniéres seek him everywhere.
Is he down under? Where is his job?
That damn, elusive FournierBob!
Take 5(b) just 4 fun/ Jörgen
[Edit by Jorgen on Sunday, March 22, 2009 @ 11:58 AM]
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Bob Grimstead
Captain
Gender: Male
Location: Perth, Western Australia or West Sussex, England
Registered: Dec 2006
Status: Offline
Posts: 2027
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Posted Monday, March 23, 2009 @ 09:22 AM
Hi Guys,
Thank you all for your concern.
Fournierbob is of course Fournicating!
Summer is coming (slowly) to the Northern Hemispherre, so Matt Hill and I are getting our red one ready for the display season.
So far, this has mostly involved fixing some wiring problems and flying aeros, but now we get on to the serious stuff.
Sorry I haven't been in contact, but I have no e-mail access in Britain except that I can access this forum from the Staffordshire Gliding Club office when there is nobody else there.
Back in full contact soon.
Yours, Bob
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Collin
General
Gender: Male
Location: McMinnville. Oregon
Registered: Oct 2006
Status: Offline
Posts: 711
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Posted Friday, April 17, 2009 @ 01:26 PM
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Markku
Master Sergeant
Gender: Male
Location: Kouvola, Finland, EFWB
Registered: Oct 2006
Status: Offline
Posts: 167
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Posted Saturday, April 18, 2009 @ 03:22 AM
Hi Collin
Did you notice any diffference in cruise speed with that modification
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Collin
General
Gender: Male
Location: McMinnville. Oregon
Registered: Oct 2006
Status: Offline
Posts: 711
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Posted Monday, April 20, 2009 @ 01:48 PM
Hello,
I like to think it helped. Maybe 2 mph?
Collin
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Bob Grimstead
Captain
Gender: Male
Location: Perth, Western Australia or West Sussex, England
Registered: Dec 2006
Status: Offline
Posts: 2027
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Posted Tuesday, April 21, 2009 @ 10:01 PM
Hi Guys,
That fairing looks very neat, and as with all Collin's work, it is a really nice job.
But I am sure you will all remember from the aerodynamics you know that it is the 'afterbody drag' that is worst.
If we could devise a fairing for the rear of that wheel etc, it should considerably reduce its drag.
That's why the fairings on the rear face of the outriggers work so well. It would be nice to have small ones on the front of the outriggers, but that's nothing like as important as having them on the back.
You might also be aware that only one of the fast glass manufacturers ever offered a tailwheel fairing (Glasair) because by the time the slipstream has gone all the way to the back of the airplane the boundary layer is pretty thick and much of the tailwheel is probably in slow-moving turbulent air, where a fairing will not have a huge amount of effect.
I've concentrated on keeping the tailwheel leg tied up as close as possible to the fuselage, and I use a really small wheel to minimise drag. (It was also useful for improved prop ground clearance when I was running with the longer RF5 propeller).
Nevertheless, well done Collin, it is great to see every attempt at weight and drag reduction.
I've been re-shaping my rather 'clunky' under-belly skids for the same reason, but I dont think either that or the recessed antenna (or the outrigger fairings) actually had any measurable effect. Makes me feel good though!
Yours, Bob
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Bob Grimstead
Captain
Gender: Male
Location: Perth, Western Australia or West Sussex, England
Registered: Dec 2006
Status: Offline
Posts: 2027
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Posted Thursday, October 29, 2009 @ 08:53 AM
Hi Guys,
This all started when I found my Australian Fournier's tailwheel was dangling down, and I tied it up with locking wire to reduce the drag.
Then, when we bought the English one, the tailwheel on that was held up by a small spring (which keeps snapping).
Now we're rebuilding one that last flew in 1972, we've discovered that Rene had a neat solution all along.
Some of you probably already know this, but some may not.
If your tailwheel pivot has the original rubber-filled ('Metalastic') bush, you will see it has two notches (See Collin's first photo above) which fit into two pips on the inside of the tailwheel arm. If this is adjusted correctly, the rubber's torsion keeps your tailwheel arm up.
If somebody has repalced that bush with the wrong one, you get this problem, and this has clearly happened with both HDO (Australia) and WGN (England).
Matthew has sourced bushes of the correct dimensions, and we've cut the notches, so now we should not have that problem any more.
I'll try to get photos for you.
Yours, Bob
[Edit by Bob Grimstead on Thursday, October 29, 2009 @ 08:54 AM]
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Bob Grimstead
Captain
Gender: Male
Location: Perth, Western Australia or West Sussex, England
Registered: Dec 2006
Status: Offline
Posts: 2027
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Posted Friday, November 20, 2009 @ 08:41 AM
Okay Guys,
Here are a couple of photos of the correct, original tailwheel pivot bush.
Using this correct bush prevents the tailwheel from dangling.
Yours, Bob
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