Eagler's Nest

General Category => Off Topics and General Interest => Topic started by: grdev on July 11, 2014, 08:49:23 AM

Title: XL folding wing
Post by: grdev on July 11, 2014, 08:49:23 AM
After several years of asking, I finally got permission to use our local airport, MO84. It is owned by the city, but leased to Doe Run Mining CO. Doe Run does not allow any hangers or tie downs for any length of time. for now I'm just happy I can use the airstrip, as the next closest one is an hours drive away.
Now that brings me to the question of folding wings for the XL. I saw Léonard's cabin Eagle with folding wings, but I think that would put the XL well out of the 103 range. Most folding wings I have saw have both struts coming from station two, much like a Cub struts. Is there any reason this can not be done on an Eagle? It would make the removing of the struts unnecessary. I think the wings folded would be over 8" wide, but I would only be using city streets from my home to the airport,t and it is well within walking distance, so federal Highway rules dealing with width would not apply here. Any Ideas?
Title: Re: XL folding wing
Post by: rockiedog2 on July 11, 2014, 06:18:38 PM
It is a MAJOR change
Title: Re: XL folding wing
Post by: grdev on July 14, 2014, 07:35:53 AM
With a wing cord of well over 4' I don't see anyway of folding the wings and being legal on the highways. Seems to me you would have to turn the wings vertical to comply with DOT widths. Also  you simply cant attach a hinge on the rear spar, it would have to be able to telescope outwards so when the wings were folded the trailing edges would be parallel to one another

I have a 4x4 utility trailer with raised sides I can build a 3/4" floor  6' wide .Then put two side walls up, one on each side that fold down 90 degrees with wing brackets/cradles to set the wings in, and then build the rotating wing stand Steve has in the old Eagle file section.

Building a folding wing doesn't seem to be a good option on the XL. You would still have to remove the struts, or at least one set, so I don't see the folding wing option a good one for me.
Title: Re: XL folding wing
Post by: Murray Randall on July 16, 2014, 03:17:19 AM
I wanted to V the wing struts to attach at station 2 thinking that would feed a bunch of loads into one cluster.  V the struts like the Cub rather than parallel like all Eagles.  Contrary to my intuition the stresses computed by a finite element stress analysis were significantly higher using the V geometry than parallel.  I quit the V analysis when it was pretty obvious that I was going to add weight with the V rather than reduce weight as I had expected.  Like Joe said thats a major change and it didn't look good from my perspective.     Murray
Title: Re: XL folding wing
Post by: grdev on July 16, 2014, 12:01:44 PM
A lot of light planes have the V. An old time builder told me that the V is much stronger than the parallel  struts. That is what my Wagabond has, and the center section is beefed up as compared to the rest of the fuselage.  I don't have any thoughts on that one way or the other , as I'm totally ignorant on the stress points or how to calculate stress at a given point on the structure. . .I did play around a little bit with a cardboard wing I fabricated, and soon realized a folding wing wasn't a simple change. One solution I would consider though is to build a wing similar to the Backyard Flyer, that rotates, one end over the tail, the other over the engine. I don't know if that is possible with wood spars like the Eagles have.  Any way you go about it your going to have to assemble /dissemble something each trip you make to the airstrip, but a rotating wing would solve storage  and handling problems as it is already partially  mounted. Wonder if there are any plans out there for a 30' spar?
Title: Re: XL folding wing
Post by: rockiedog2 on July 16, 2014, 02:05:20 PM
>>>wing similar to the Backyard Flyer, that rotates, one end over the tail, the other over the engine.

I think you will find that the weight will go thru the roof
Title: Re: XL folding wing
Post by: grdev on July 16, 2014, 02:46:54 PM
I will check, but I believe the Back Yard Flier meets 103
Title: Re: XL folding wing
Post by: grdev on July 16, 2014, 02:51:32 PM
Yep, the backyard flyer is  UL 103 cert. Doesn't look like it has struts.
Title: Re: XL folding wing
Post by: Vince Carucci on September 04, 2014, 01:51:11 PM
I've recently purchased the LE plans, so in the next few years you may see posts about T-53 flying into a tree. Any how, I have the same problem as many of you do - MUST HAUL AIRCRAFT TO AIRFIELD. So I'm looking to fold wings that are not fold-able. The challenge is... how to make folding wings without fundamentally changing the Leonard's design; how to add features without exceeding 103 rules; how to safely secure them during transportation; how to minimize connecting/disconnecting flight control rigging? I have some early thoughts:

Have a central wing box which will also serve as a new location for the fuel tank (will require changing fuselage ceiling, OUCH)
Have a pivoting hing at the rear spars connecting wings to wing box.
Have pivoting hinges on the rear struts (remove the forward strut before stowing).
A multipurpose "cart" would be needed to support both the tail section and the folded wings (could make ground handling easier).

It may be that I've only articulated the known problems rather than suggesting any real solutions, but I'm going to think about it for a while.
Title: Re: XL folding wing
Post by: Steve on September 04, 2014, 02:15:30 PM
I've recently purchased the LE plans, so in the next few years you may see posts about T-53 flying into a tree. Any how, I have the same problem as many of you do - MUST HAUL AIRCRAFT TO AIRFIELD. So I'm looking to fold wings that are not fold-able. The challenge is... how to make folding wings without fundamentally changing the Leonard's design; how to add features without exceeding 103 rules; how to safely secure them during transportation; how to minimize connecting/disconnecting flight control rigging? I have some early thoughts:

Have a central wing box which will also serve as a new location for the fuel tank (will require changing fuselage ceiling, OUCH)
Have a pivoting hing at the rear spars connecting wings to wing box.
Have pivoting hinges on the rear struts (remove the forward strut before stowing).
A multipurpose "cart" would be needed to support both the tail section and the folded wings (could make ground handling easier).

It may be that I've only articulated the known problems rather than suggesting any real solutions, but I'm going to think about it for a while.

 The fold can be done with another wing internals design and has been done that way on Bodacious in the yahoo group photo archive... The wing structure has been copied from the Kitfox Lite by Belite and others...
Title: Re: XL folding wing
Post by: Sam Buchanan on September 04, 2014, 09:06:55 PM
It is possible to redesign the plane for folding wings, but you almost certainly will not be able to meet the Part 103 weight limit. The XL has precious little fat that can be trimmed off.....

No harm in exploring all options, however. Best wishes for a most enjoyable project!
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