Eagler's Nest

Airframes => Single Seaters => XL => Topic started by: flyover1974 on July 11, 2017, 04:02:00 PM

Title: Wing strut teardrop shape tube
Post by: flyover1974 on July 11, 2017, 04:02:00 PM

Hello XL builders,

please can someone measure for me the size of the drop shape aluminum  wing strut tube?
Here in europe there are different sizes in diameter and i really have no idea which one to buy...

Thanks Hermann

Title: Re: Wing strut teardrop shape tube
Post by: Dan_ on July 11, 2017, 05:59:18 PM

Hit this page... http://www.carlsonaircraft.com/struts.html (http://www.carlsonaircraft.com/struts.html)

Title: Re: Wing strut teardrop shape tube
Post by: flyover1974 on July 12, 2017, 03:12:28 PM

Thank you Dan,

but there are 2 sizes. Is the small one strong enough?
On the italian store (aircraftspruce reseller) there are 4 different sizes...
See here:
http://www.speedcomfly.com/sito-ecommerce/index.php?main_page=index&cPath=8_9

Title: Re: Wing strut teardrop shape tube
Post by: Tom XL-7 on July 12, 2017, 05:25:21 PM

Hermann
 The Xl can use a round tube.
 1.25 inches - 0.058 inches That is the strength you need to match or exceed.
There is an advantage with the streamline strut even in our slow aircraft.
 I believe the small one will do. It is by the way over twice as heavy as the round tube.
I will use round tube and fair it and will hopefully come in lighter.
 The extrusions from your catalog are totally different.
 The have a round and a streamlined cover all in one.
The Carlson strut has the exterior shape only
you need one that exceeds the strength of the round tube
I don't know what sizes  are available to you
The direct conversion is 31.75mm by 1.4732mm wall thickness
Or you can use a round tube and fair it.
Tom XL-7

Title: Re: Wing strut teardrop shape tube
Post by: Tom H on July 13, 2017, 08:05:28 AM

LEU Treehugger is being rebuilt.  In the process, streamlined struts (not the large size, but one size down) were purchased from Carlson and installed.  They look good, but we compared the weight with the original round alum tubing, and found them to be almost three times heavier.  Seems the alum tubing struts were about 2 - 3 lbs, and the streamline struts were around 7 - 8 lbs each.  Jury struts were installed, but the strut from forward spar to aft spar was left off (saved a few ounces?).

I know the Carlson struts will have lower drag compared to round, but, at the speeds this airplane flies, I don't see a pay-off.  I think keeping weight down is the way to go.  If  this was my decision alone, I would go with round tubing and use some light-weight technique to streamline them.  I'm not a primary player in the rebuild, so my vote did not count for too much!!!

Title: Re: Wing strut teardrop shape tube
Post by: Dan_ on July 13, 2017, 10:28:01 AM

Blue foam technique attached below:

Title: Re: Wing strut teardrop shape tube
Post by: Dan_ on July 13, 2017, 11:20:42 AM

Another approach:

http://www.uflyit.com/streamline_fairings.htm (http://www.uflyit.com/streamline_fairings.htm)