Aluminum extrusion spar web.

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TFF

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I worked in the steel business for a short while and buying these items is generally taken as a commodity trade. Price was pretty much per pound. You bought 40 of something, they were not stickered as $12 each. They balanced the number you wanted with weight it came out the mill with going price per pound. They would sell you one of something sometimes. Most times there was a minimum charge to make it worthwhile. These places really are expecting to sell a partial truck load. That’s really the original need for Aircraft Spruce and such. They bought enough to deal with the wholesaler. Most of these types of trades need you to show up with money to the sales office, then they know your not a tire kicker.
 

PiperCruisin

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Idaho
“I will also point out that the extruded spar in the Cherokee wing only goes out to level with the flap/ aileron join, after that a folded C channel spar is spliced on from there to the tip, straight on the 'hershy's', and tapered on the warriors (et al).”
Right. The extruded Cherokee spar has almost 1” thick solid upper cap. So using that heavy extrusion beyond the undercarriage would be very heavy. So one extrusion is of limited use on an ultralight wing or any cantilever wing since the load tapers drastically toward the tip. Extrusion is nice for strut braced.
However, I would say the thin web does not carry the heavy vertical compression. Rather, the vertical 1” tube mentioned is for compression.

(still unable to use the quote button on this newer iPad) ?
1637773919988.png
 

BBerson

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That doesn’t look like I recall, upper cap somewhere out on the wing near the undercarriage strut it looked 1” x1” (40 years ago?)
From the looks of that broke part, it should be 1”….
 

WonderousMountain

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One of my design portfolio calls for a rectangular Tube, with C Channel extrusion bolted to the top and bottom. Doesn't save much on weight, but the 3/16th single blind rivet lines seemed very clean and quick?
 

PiperCruisin

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That doesn’t look like I recall, upper cap somewhere out on the wing near the undercarriage strut it looked 1” x1” (40 years ago?)
From the looks of that broke part, it should be 1”….
I believe it is the lower spar cap in the photo. Not sure what grade of aluminum it is. I don't have dimensions for the upper.
 

cheapracer

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Sep 8, 2013
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Australian
Quote; The top picture is actually for the motor glider, why so many bolts in the center join of the very long wings.
Yeah, and some of us know how that went...
The wing didn't fail there, it failed at the root, see the picture, and Gary, who I spoke to about it, admits it was his own fault, he undersized the root gusset plate trying to save a bit of weight. .

Morgan crash.jpg

For those interested, they both walked away.
 
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