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Winter flight/ streamlined struts

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craig.nelson(at)heraeus.c
Guest

Posted: Sat Feb 02, 2008 3:16 pm Post subject: Winter flight/ streamlined struts

<<DSCN1844.JPG>>   <<DSCN1849.JPG>>   <<DSCN1859.JPG>>   

<<DSCN1874.JPG>>   <<DSCN1875.JPG>>   <<DSCN1876.JPG>>  

I did a flight today about 90 miles with some friends a titan tornado

and a Swiss bull dog. Level flight,59 degrees 3000 ft, 5100 rpm, and 90

indicated, 90 ground speed on the gps  verified with the titan and bull

dog. There was some talk about streamlining struts a few weeks ago--- I

like the PVC ones as there are no bolts sticking out. I used masking

tape and plaster to make lost mold technique fairings at the wing end of

the airfoil  strut. The part made of s glass and epoxy resin fits snug

around the pvc faring I got from Kolb and slides up over the attach

point after the pin is in place, then Velcro holds the part secure to

the bottom of the wing. If there were bolts to contend with it would

make this part much more difficult I plan to make fairings for the base

of the strut where it meets the fuselage. It looks like I will have to

make a cowl flap. I had to block off 1/2 of the radiator and oil cooler

to get up to operating temps. After my cardboard cowl flap the oil temp

was around 190



Uncle Craig

MIII X 912 uls



Do not Archive

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Possums

Joined: 03 Nov 2007
Posts: 247

Posted: Sat Feb 02, 2008 3:59 pm Post subject: Winter flight/ streamlined struts

I know I picked up about 6mph just by streamlining the struts.

That is a lot of drag - a round tube that long as opposed to

a teardrop shaped strut. There is almost nothing better you can

do to a stock plane to lose drag that streamlining the lift struts.

Plus - I lost the weird vibration and worry of watching the

lift struts go thru their little "shake rattle & roll" routine out there.

I'm sure it didn't hurt anything, but I just didn't like it.

Jeremy could do the math for you. I just know that it works.

_________________
Possum

ElleryWeld(at)aol.com
Guest

Posted: Sat Feb 02, 2008 5:23 pm Post subject: Winter flight/ streamlined struts

Uncle Craig man you do make some great parts That sure  looks great  are you selling any of the wing strut farings ? if not you  should be selling to everyone on the list  including me.  

  

 Ellery in Maine 

 do not archive

  

  In a message dated 2/2/2008 6:17:12 P.M. Eastern Standard Time,  craig.nelson(at)heraeus.com writes:

  	  Quote: 	
		  <<DSCN1844.JPG>>      <<DSCN1849.JPG>>      <<DSCN1859.JPG>>      

<<DSCN1874.JPG>>      <<DSCN1875.JPG>>   <<DSCN1876.JPG>>     

I did a flight today about 90 miles with some friends a titan    tornado

and a Swiss bull dog. Level flight,59 degrees 3000 ft, 5100 rpm,    and 90

indicated, 90 ground speed on the gps  verified with the titan    and bull

dog. There was some talk about streamlining struts a few weeks    ago--- I

like the PVC ones as there are no bolts sticking out. I used    masking

tape and plaster to make lost mold technique fairings at the wing    end of

the airfoil  strut. The part made of s glass and epoxy resin    fits snug

around the pvc faring I got from Kolb and slides up over the    attach

point after the pin is in place, then Velcro holds the part secure    to

the bottom of the wing. If there were bolts to contend with it    would

make this part much more difficult I plan to make fairings for the    base

of the strut where it meets the fuselage. It looks like I will have    to

make a cowl flap. I had to block off 1/2 of the radiator and oil    cooler

to get up to operating temps. After my cardboard cowl flap the oil    temp

was around 190



Uncle Craig

MIII X 912 uls



Do not    Archive 	




Who's never won?  Biggest Grammy Award surprises of all time on AOL Music.

  [quote][b]

azfirestar

Joined: 08 Dec 2007
Posts: 25

Posted: Sat Feb 02, 2008 9:52 pm Post subject: Winter flight/ streamlined struts

It's good to hear that I'm not the only one with that vibration.  How did streamlining the struts get rid of the vibration - did you use the extruded aluminum struts?  If so, where is the best place to buy those for a Firestar II?  I am also considering using the PVC covers that Craig mentioned - would they help with the vibration?  Where is a good place to get those?

 

 Thanks much

 Dan G.

 503 F2

 Tucson

 

 possums wrote: [quote]I know I picked up about 6mph just by streamlining the struts.   

 That is a lot of drag - a round tube that long as opposed to   

 a teardrop shaped strut. There is almost nothing better you can   

 do to a stock plane to lose drag that streamlining the lift struts.   

 Plus - I lost the weird vibration and worry of watching the   

 lift struts go thru their little "shake rattle & roll" routine out there.   

 I'm sure it didn't hurt anything, but I just didn't like it.   

 Jeremy could do the math for you. I just know that it works.   

 [b]

_________________
Dan G.
503 Firestar II
Tucson AZ

planecrazzzy
Guest

Posted: Sun Feb 03, 2008 2:42 am Post subject: Re: Winter flight/ streamlined struts

Did the "Dog Sled" ever get into the air ???

.

.

Gotta Fly...

Mike & "Jaz" in MN

.

.

.

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craig.nelson(at)heraeus.c
Guest

Posted: Sun Feb 03, 2008 7:19 am Post subject: Winter flight/ streamlined struts

Thanks for asking yes! We plan to run the Iditarod this year! Have had

to keep the dogs in the deep freeze he! He! He! If there is enough

demand I would consider making molds and offering them to any one

interested. Again right now my trailer is my hanger and the plane is

folded and put in the trailer every time I fly.( I hate it but It's a

kolb and it is possible) The strut faring goes on real simply. Just put

it on the strut slide it down, put the wing together secure the pin.

Slide the faring up to the wing to cover the bolts streamlining the end

of the strut and Velcro on the underside of the wing and the top of the

faring hold it in place. Takes all of 2 seconds to put on. To tie the

plane down simply pull the faring down from the wing to expose the

mounting point for tie down rope or chain 

Uncle craig

Do not Archive



--

Possums

Joined: 03 Nov 2007
Posts: 247

Posted: Sun Feb 03, 2008 11:45 am Post subject: Winter flight/ streamlined struts

At 12:45 AM 2/3/2008, you wrote:



  How did streamlining the struts get rid of the vibration - did you 

use the extruded aluminum struts?

No - I just had some metal (T6061 I think) bent for me at a shop with 

an 8 foot brake.

Had them cut it to shape, then roll both edges a little to partially

go around the strut. After that - bend it in the break. I riveted it on

the struts and with the rolled edges, it fits pretty tight. Been on 

there for 10 years.

It stopped all the vibration and hardly weighs anything. But there 

are all kinds of

ways to do it. Many are more aerodynamic than mine, but most weigh a lot more.

I would think that they all would stop the vibration.

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_________________
Possum

azfirestar

Joined: 08 Dec 2007
Posts: 25

Posted: Mon Feb 04, 2008 9:18 pm Post subject: Winter flight/ streamlined struts

Thanks for the idea and especially the photos.  That's a very ingenious solution- light and simple, and looks like you get 90 percent of the benefit of a full airfoil.  That would be perfect for my purposes.  Seems like that would also be a slick way to streamline the aft end of the aileron torque tubes (like Jack Hart did on his Firefly), provided there is enough prop clearance.

 

 Dan G

 503 F2

 Tucson

 

 possums wrote:

 [quote]No - I just had some metal (T6061 I think) bent for me at a shop with an 8 foot brake.   

 Had them cut it to shape, then roll both edges a little to partially   

 go around the strut. After that - bend it in the break. I riveted it on   

 the struts and with the rolled edges, it fits pretty tight. Been on there for 10 years.   

 It stopped all the vibration and hardly weighs anything. But there are all kinds of   

 ways to do it. Many are more aerodynamic than mine, but most weigh a lot more.   

 I would think that they all would stop the vibration. [b]

_________________
Dan G.
503 Firestar II
Tucson AZ

Dennis.Kirby(at)kirtland.
Guest

Posted: Wed Feb 06, 2008 12:32 pm Post subject: Winter flight/ streamlined struts

Dan G wrote: << It's good to hear that I'm not the only one with that

vibration.  How did streamlining the struts get rid of the vibration >>



Dan, and other interested Kolbers -



Airflow downstream of any strut with circular cross section creates an

eddy current called a "Von Karmann street."  This flow phenomenon is an

eddy that curls back and forth in alternating directions, similar to

what you see in the stream of smoke rising from a cigarette.  You can

also see the Von Karmann street effect in rivers that meander along a

flat countryside - the water course appears to curl alternately from one

direction to the other.  



In airflow, these rapidly-oscillating eddy currents translate into a

vibration, and this is what we encounter with un-streamlined struts.



Dennis Kirby

Amazed to even remember this stuff since my Aero-101 courses 25 years

ago, in

Cedar Crest, NM

mdnanwelch7(at)hotmail.co
Guest

Posted: Wed Feb 06, 2008 1:00 pm Post subject: Winter flight/ streamlined struts

Hey Dennis,

  

   How's the rebuild going??  Taken any photos lately?  What's the timeframe to getting your plane back in the air?

  

 Mike Welch

 MkIII



 	  Quote: 	
		   Subject: Re: Winter flight/ streamlined struts 

 Date: Wed, 6 Feb 2008 13:27:17 -0700

 From: Dennis.Kirby(at)kirtland.af.mil

 To: kolb-list(at)matronics.com

 

 --> Kolb-List message posted by: "Kirby Dennis Contr MDA/AL" <Dennis.Kirby(at)kirtland.af.mil>

 

 

 

 

 Dan G wrote: << It's good to hear that I'm not the only one with that

 vibration. How did streamlining the struts get rid of the vibration >>

 

 Dan, and other interested Kolbers -

 

 Airflow downstream of any strut with circular cross section creates an

 eddy current called a "Von Karmann street." This flow phenomenon is an

 eddy that curls back and forth in alternating directions, similar to

 what you see in the stream of smoke rising from a cigarette. You can

 also see the Von Karmann street effect in rivers that meander along a

 flat countryside - the water course appears to curl alternately from one

 direction to the other. 

 

 In airflow, these rapidly-oscillating eddy currents translate into a

 vibration, and this is what we encounter with un-streamlined struts.

 

 Dennis Kirby

 Amazed to even remember this stuff since my Aero-101 courses 25 years

 ago, in

 Cedar Crest, NM

 

 

&gt======
	


 	  Quote: 	
		   

 

 


	


Helping your favorite cause is as easy as instant messaging. You IM, we give. Learn more.  [quote][b]

John Hauck

Joined: 09 Jan 2006
Posts: 4639
Location: Titus, Alabama (hauck's holler)

Posted: Wed Feb 06, 2008 1:15 pm Post subject: Winter flight/ streamlined struts

Before MV.

  

 john h

 mkIII

 [quote]      How's the rebuild going??     Taken any photos lately?  What's the timeframe to getting your plane back    in the air?

 

Mike Welch

 

[b]

_________________
John Hauck
MKIII/912ULS
hauck's holler
Titus, Alabama

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