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Aircraft Spruce Streamlined Tubing
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kmccune

Joined: 22 Sep 2007
Posts: 577
Location: Wisconsin, USA

Posted: Sun Dec 23, 2007 6:24 am Post subject: Aircraft Spruce Streamlined Tubing

Has anyone tried the "Streamlined Tubing" from aircraft Spruce for the wing struts? A little stream lining and no fairing to deal with.



Kevin

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Dorothy McCune

John75142

Joined: 05 Dec 2007
Posts: 56
Location: Kaufman, TX

Posted: Sun Dec 23, 2007 9:43 am Post subject: Aircraft Spruce Streamlined Tubing

I was thinking of using myself but it is a little pricey.



Another 701 builder told me he thought there was a tremendous amount of drag 

created in the struts and anything to help would be a benefit. But I think 

there over $100 for like 6 ft.

---

_________________
John Short

dredmoody(at)cox.net
Guest

Posted: Sun Dec 23, 2007 11:56 am Post subject: Aircraft Spruce Streamlined Tubing

They look good and they are tremendously strong but  they don't do a lot for streamlining other than in terms of appearance. I have  them on an Excalibur ultralight and the plane still acts like a sheet of plywood  turned flat to the wind.

  

 Dred

 [quote]   ---

kmccune

Joined: 22 Sep 2007
Posts: 577
Location: Wisconsin, USA

Posted: Sun Dec 23, 2007 3:46 pm Post subject: Re: Aircraft Spruce Streamlined Tubing

Wow so the 701 must be a double sheet of plywood  

I didn't check the price.I think the ratio is like 3:1 length to width for fairings so they are a little short.But they have to be better then round tube. 

Kevin

planecrazydld(at)yahoo.co
Guest

Posted: Sun Dec 23, 2007 4:41 pm Post subject: Aircraft Spruce Streamlined Tubing

I can't remember where I saw it but one of the ultralight sites sells PVC streamline fairings that slip over the structural tube. The only downside - besides the weight - is that you can no longer see the structural tube for visual inspection without removing the fairing.



You could also make a single ply glass/epoxy 3:1 teardrop fairing that would overlap and tape in place so that it could be easily removed for periodic inspection.



John Short <creativesigns(at)embarqmail.com> wrote:[quote] --> Zenith-List message posted by: "John Short" 



I was thinking of using myself but it is a little pricey.



Another 701 builder told me he thought there was a tremendous amount of drag 

created in the struts and anything to help would be a benefit. But I think 

there over $100 for like 6       Be a better friend, newshound, and  [quote][b]

kmccune

Joined: 22 Sep 2007
Posts: 577
Location: Wisconsin, USA

Posted: Mon Dec 24, 2007 4:02 am Post subject: Re: Aircraft Spruce Streamlined Tubing

Fairings are easy to make out of Al,  but I like the idea of not having fairings. They just seem fragile, funny really, when you consider that I'm build a plane out of big pieces of shim stock. The PVC ones would be more durable I suppose.



Kevin

psm(at)ATT.NET
Guest

Posted: Mon Dec 24, 2007 4:19 am Post subject: Aircraft Spruce Streamlined Tubing

Hi Kevin,



I'm afraid PVC is not a suitable material for use in airplanes.  I 

did a little digging on this question for use in air ducts in the 

cabin.  I found it is not recommended for use at temperatures above 

70 degrees Celsius.  That sounds pretty hot, but is easily reached 

when parked in the sun.



Paul

XL fuselage

do not archive

At 04:02 AM 12/24/2007, you wrote:



 	  Quote: 	
		  Fairings are easy to make out of Al,  but I like the idea of not 

having fairings. They just seem fragile, funny really, when you 

consider that I'm build a plane out of big pieces of shim stock. The 

PVC ones would be more durable I suppose.



Kevin

kmccune

Joined: 22 Sep 2007
Posts: 577
Location: Wisconsin, USA

Posted: Mon Dec 24, 2007 5:12 am Post subject: Re: Aircraft Spruce Streamlined Tubing

2 inch Schedule 40 PVC (standard in the states) is rated for 280PSI at 73F

this is a working pressure and not a bursting pressure. The actual burst pressure is some absurdly high number.  True these values go down as temp goes up, but  even at 120F they are not going to droop and melt off of your struts. I wouldn't use them in any plumbing on an airplane, but for struts fairings I wouldn't give it a second thought.

Kevin

rsteele(at)rjsit.com
Guest

Posted: Mon Dec 24, 2007 6:55 am Post subject: Aircraft Spruce Streamlined Tubing

This is probably not a factor because the wing provides shade, but  

PVC pipe will deteriorate in sunlight (UV).  It becomes brittle and  

will turn into PVC shards with little prompting.  Still, I don't  

think I'd use it on an tied down plane in Arizona.



Ron

On Dec 24, 2007, at 8:12 AM, kmccune wrote:



 	  Quote: 	
		   



 2 inch Schedule 40 PVC (standard in the states) is rated for 280PSI  

 at 73F

 this is a working pressure and not a bursting pressure. The actual  

 burst pressure is some absurdly high number.  True these values go  

 down as temp goes up, but  even at 120F they are not going to droop  

 and melt off of your struts. I wouldn't use them in any plumbing on  

 an airplane, but for struts fairings I wouldn't give it a second  

 thought.

 Kevin



 --------

 Kevin





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=153978#153978

John Bolding

Joined: 23 May 2006
Posts: 281

Posted: Mon Dec 24, 2007 7:50 am Post subject: Aircraft Spruce Streamlined Tubing

GUYS,  you paint the fairings to match the plane, use a UV resistant primer, 

LOTS of them out there for a LONG time, plastic and fabric airplanes don't 

become shards. When I cut the fabric off my Pacer (recovered 32 yrs ago) it 

still passed the punch tests. If you DON'T protect it however, fabric looses 

half it's strength in 6 months.



 The simple fix is to do what the fellows on the Great Aggie Expedition to 

the sun in '88 did.  When asked how they were gonna keep from becoming toast 

due to the intense temperatures they laughed in unison at the question and 

announced proudly they were going after dark when it was a lot cooler.



Merry Christmas everybody!!



LO&SLO   John Bolding



 	  Quote: 	
		   



 This is probably not a factor because the wing provides shade, but  PVC 

 pipe will deteriorate in sunlight (UV).  It becomes brittle and  will turn 

 into PVC shards with little prompting.  Still, I don't  think I'd use it 

 on an tied down plane in Arizona.



 Ron

lrm(at)skyhawg.com
Guest

Posted: Mon Dec 24, 2007 8:14 am Post subject: Aircraft Spruce Streamlined Tubing

Here ya go, http://www.ultralightnews.ca/streamlinedfairings/1.html,  

 That is the way I will go on my new one, Larry www.skyhawg.com

  

 ---

kmccune

Joined: 22 Sep 2007
Posts: 577
Location: Wisconsin, USA

Posted: Mon Dec 24, 2007 10:50 am Post subject: Re: Aircraft Spruce Streamlined Tubing

I'm not too worried about the heat in NW Wisconsin.



Kevin

kmccune

Joined: 22 Sep 2007
Posts: 577
Location: Wisconsin, USA

Posted: Mon Dec 24, 2007 1:13 pm Post subject: Re: Aircraft Spruce Streamlined Tubing

Cut and paste from my email (Kevin) for Christopher Desmond



 

I am a occasional list reader and I saw your question about using streamlined struts (I haven't yet figured out how to post, so if you wish, you can cut and paste this to the list, it is a good question and I haven't seen these issues discussed previously).  

 

I fly a 701 with streamlined struts.  The struts are made of extruded, anodized, 6061-T6.    I do not think extruded struts offer any considerable aerodynamic performance advantage over the steel tubes with fairings, but . . .   these struts are really very nice aesthetically (especially when up close).  I am currently building an 801 and I am installing similar extruded aluminum struts on it as well.   NOTE:  The 801 will obviously need bigger, beefier, stronger struts than a 701.  

 

Changing over to the, more refined, extruded aluminum strut is not a simple undertaking.  Here are just a few considerations:

 

First and foremost is SAFETY, you must ensure that the strut material and extrusion design is approved by an engineer so they are structurally adequate.  My advice here is to contact Mark Townsend at Can-Zac Aviation Ltd.  Can-Zac has recently done some development in this area.

 

Once you have extruded struts that you know are adequate from a safety standpoint, the biggest challenge is to engineer and then create the attachment pieces that will anchor both ends of the struts to the underside of the wing and to the fuselage respectively.  To solve this problem, you will most likely need the help of a talented machinist who is willing to do some creative work.  One of the machining challenges here is to establish (and then cut) the proper angles for the mounting-slot in the attachment pieces.  You will find some difficult compound angles and depending on accuracy of the airplane's construction, the angles may differ side to side. 

 

Next there is the issue of the jury-struts.  All of the same design/engineering/machining considerations, noted above, also apply to the jury-struts.  Remember that you will need a compression block inside the hollow extruded main strut so an attachment eye-bolt for the jury-struts can be tightened without compressing and deforming the walls of the main struts.

 

I estimate that this one refinement added at least a month to the build time and several thousand dollars to the cost of my 701 and a bit more to my 801.  

 

You can see the struts on my CH701 on my website:  www.STOL-Adventures.com

 

I have just produced a DVD of my backcountry flying adventures featuring my 701.  There are some close-up shots of the streamlined 701 struts in the video.

 

I hope these comments are helpful.

 

Kind regards,

Christopher Desmond

kmccune

Joined: 22 Sep 2007
Posts: 577
Location: Wisconsin, USA

Posted: Mon Dec 24, 2007 1:25 pm Post subject: Re: Aircraft Spruce Streamlined Tubing

Christopher,



The struts in question are 4130 chrome-moly. I just like the idea of having the shape and no fairings. I don't think that they are even as low drag as a fairing. I just don't like the look of fairings. I have not gotten to the the point were these decisions need to be made. I  will consider structural integrity carefully, when the time comes.





Kevin

planecrazydld(at)yahoo.co
Guest

Posted: Mon Dec 24, 2007 8:21 pm Post subject: Aircraft Spruce Streamlined Tubing

Gentlemen;



Please be advise that Wicks has a limited amount of DRAWN 6061T6 streamline tube in 4 or 5 sizes. This could be considerably lighter than the Carlson strut extrusion depending on size. Length is also not limited like the Carlson parts. Also the drawn tube does not have the "pad" on the inside making flat an parallel mounting interface - you will have to create something to affect the same result.



A Merry and Blessed Christmas to all!



kmccune <kmccune(at)somtel.net> wrote:[quote] --> Zenith-List message posted by: "kmccune" 



Cut and paste from my email (Kevin) for Christopher Desmond



 

I am a occasional list reader and I saw your question about using streamlined struts (I haven't yet figured out how to post, so if you wish, you can cut and paste this to the list, it is a good  question and I haven't seen these issues discussed previously).  

 

I fly a 701 with streamlined struts.  The struts are made of extruded, anodized, 6061-T6.    I do not think extruded struts offer any considerable aerodynamic performance advantage over the steel tubes with fairings, but . . .   these struts are really very nice aesthetically (especially when up close).  I am currently building an 801 and I am installing similar extruded aluminum struts on it as well.   NOTE:  The 801 will obviously need bigger, beefier, stronger struts than a 701.  

 

Changing over to the, more refined, extruded aluminum strut is not a simple undertaking.  Here are just a few considerations:

 

First and foremost is SAFETY, you must ensure that the strut material and extrusion design is approved by an engineer so they are structurally adequate.  My advice here is to contact Mark Townsend at Can-Zac Aviation Ltd.  Can-Zac has recently done some development in this  area.

 

Once you have extruded struts that you know are adequate from a safety standpoint, the biggest challenge is to engineer and then create the attachment pieces that will anchor both ends of the struts to the underside of the wing and to the fuselage respectively.  To solve this problem, you will most likely need the help of a talented machinist who is willing to do some creative work.  One of the machining challenges here is to establish (and then cut) the proper angles for the mounting-slot in the attachment pieces.  You will find some difficult compound angles and depending on accuracy of the airplane's construction, the angles may differ side to side. 

 

Next there is the issue of the jury-struts.  All of the same design/engineering/machining considerations, noted above, also apply to the jury-struts.  Remember that you will need a compression block inside the hollow extruded main strut so an attachment eye-bolt for the jury-struts can be tightened      [quote][b]

kmccune

Joined: 22 Sep 2007
Posts: 577
Location: Wisconsin, USA

Posted: Tue Dec 25, 2007 5:09 pm Post subject: Re: Aircraft Spruce Streamlined Tubing

I don't understand "pad" and flat on parallel"



Kevin



Quote:

"Also the drawn tube does not have the "pad" on the inside making flat an parallel mounting interface - you will have to create something to affect the same result."

planecrazydld(at)yahoo.co
Guest

Posted: Tue Dec 25, 2007 5:47 pm Post subject: Aircraft Spruce Streamlined Tubing

Hi Kevin;



The extruded strut forms from Carlson are teardrop shaped on the outside but in the area of maximum section thickness there are flats on the inside that are parallel to each other so that when you clamp on a block or whatever there is maximum surface contact. In those areas the wall gets thicker because the outside is curving and the inside walls are flat and parallel.



The drawn tube is just like circular drawn tube except that the section is similar to streamline steel strut tubing (very nearly constant wall thickness). When you make the attachments for the end fittings they need to be shaped like the inside of the drawn tubing or some consideration given to stability of the joint.



Hoe that is clearer - I may not speak the same english!



kmccune <kmccune(at)somtel.net> wrote:[quote] --> Zenith-List message posted    [quote][b]

kmccune

Joined: 22 Sep 2007
Posts: 577
Location: Wisconsin, USA

Posted: Tue Dec 25, 2007 6:57 pm Post subject: Re: Aircraft Spruce Streamlined Tubing

So... you need to make a plug to fit inside, to bolt to the wing?



Kevin

planecrazydld(at)yahoo.co
Guest

Posted: Wed Dec 26, 2007 1:37 am Post subject: Aircraft Spruce Streamlined Tubing

Be a better friend, newshound, and [quote][b]

kmccune

Joined: 22 Sep 2007
Posts: 577
Location: Wisconsin, USA

Posted: Wed Dec 26, 2007 4:44 am Post subject: Re: Aircraft Spruce Streamlined Tubing

[quote="planecrazydld(at)yahoo.co"]Be a better friend, newshound, and   	  Quote: 	
		  [b] 	


What does this mean?



Kevin

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