Wills Wing Carbon Fiber Wing Spar Testing

[@emotodude]

Smart use of the metal door! This is exactly the kind of practical testing I appreciate in your products!

[@johnborton4522]

Reviewing the comments I've again decided that no good deed goes unpunished. Kudos to the WW team for the meticulously designed, manufactured and tested aircraft.

[@someguydino6770]

Legend has it that Bob Will's grand daddy gave him that yard stick right before he passed away.

[@Telios733]

That's decent deflection and pressure. Pretty cool.

[@GlideLA]

When you guys aren't looking I load a pumpkin on my specially-fitted Talon cross spar and 'borrow' your testing jig as a trebuchet. So far I've gotten a 6-pounder to cross Batavia Street.

[@FLYWillsWing]

Haha, that would be awesome!

[@bake162]

Great stuff…. makes me wonder why K4098 failed at such a low load

[@ginobataiote8964]

I liked it, but i´m a layman on the subject and i always wach videos of Wolfgang Siess, i´m curious to see how it is manufactured or at least mounted a delta wing, this one has the reputation of being one of best in the world, hug.

[@tomthompson7400]

did it return to the starting point though ,,, you didnt take any notice of that or was that just '' off camera '' ??

[@ww2fly]

There is no permanent deformation or reduction in strength from the testing. Failures are always catastrophic

[@tomthompson7400]

@@ww2fly if you dont measure it , before and after you cant actually say that .. you can guess at it , but if thats good enough for you , for the sake of a two min difference , strikes me as a bit silly .. but then again , what would i know .. Former composites engineer Sorts Aircraft Division.

[@ww2fly]

Tommy, I specialized in composites for grad studies in aeronautical engineering, and we’ve now tested about 3000 spars, so yeah I can tell that it returns to 0 consistently after testing. Why not question why no one else even tests their spars?

[@tomthompson7400]

@@ww2fly no , actually you cant ,,, you think it does ,, if its not measured you cant quantify your findings ,,, Thats all I have to say , you do what you think is best.

[@nikosjasonfakaro5311]

Impressive . Carbon Fiber is incredible. Do you have any fail ? ( I would stand behind the steel door also ... that cable under tension like that would cut you in two if you get caught in the bight. )

[@ww2fly]

yes, some fail--that's why we test them to 100% of the strength required for airworthiness compliance. Composites are extremely process sensitive and you cannot verify their structural integrity by inspection.

[@nikosjasonfakaro5311]

Great job - thank you Steve and Wills Wing !

[@SteelDoesMyWill]

I hope that twill fiber pattern I saw on the spar is just for appearance on the last outside lamination... Are you making these on a CNC linear winder with uni-tow or outsourcing them?

[@joefaust777]

Do you wrap raw materials and cure the spars in your own factory?

[@FLYWillsWing]

No, they are made by one of our Carbon Fiber part suppliers

[@zopilotegalaz1128]

Aluminum tube wrapped with carbon fiber?

[@FLYWillsWing]

No the tube is made entirely out of carbon fiber. (with a couple of aluminum inner sleeves just for hole reinforcement.

[@brianphillips7235]

do you do retesting of spars on used spars?

[@ww2fly]

we can retest WW spars

[@joefaust777]

Does the testing input fractures?

[@FLYWillsWing]

If it does the spar is rejected which happens a few times a year.

[@joefaust777]

Possible micro fractures implaced in the region of the spar near the ground fixture by the stress test might not cause catastrophic failure for spar rejection, but it would be interesting to know well just what might be the micro fracturing caused perhaps by the testing.

[@woayerrrr]

Noticed the one on the log that failed at 160 lbs...

[@ww2fly]

Spar testing does not create fractures, and any spar that passes the load test can be re-tested to that load indefinitely. Fiber fractures of any significance are audible and usually precipitate and catastrophic failure

[@ajruncuban1158]

Something tels me you shouldnt be standing that close to a spar under load test :)

[@FLYWillsWing]

You're right but we take some precautions. There is a cable inside the spar and the operator always stands behind the blast door

[@ParagliderCollapse]

I notice Gary stays sheltered behind the door in case that baby explodes. Not sure if I'm reassured that they're tested or concerned that they're abused, lol. It's kinda like finding out if your wife is a suitable partner by having her "tested" by a pro football team.

[@ww2fly]

The spar is not weakened by the testing and could be retested to that load indefinately. The design load is about 50% higher than the test load, and the test load is 100% of load required for airworthiness compliance

[@ThermalCowboy]

Heavy duty!

[@1967250s]

You really should have a cage around the spar and cable! If it lets go somewhere, the spar could launch in the opposite direction, and the cable could easily whip over or around the door. Please do this.

[@ww2fly]

We have a safety cable inside the spar after many years of using the 'blast door' as protection

[@paulfinck259]

B