Rear spar WOES

[Area 51%]

Took delivery of my kits about a year ago. I assembled the rear spars and put them into storage till a couple of days ago when the wing structures required their installation.

Much to my dismay, the supplied spars are on the order of 1.7mm (.067in) narrower, flange-to-flange, than listed in the drawings. What that translates to is a really crappy transition from the rib flange to the spar flange. I'm no engineer, but it seems to me the wing skin needs to be able to rest flat against the flanges to give the hinges a solid base on which to attach.

If that wasn't enough, the angles of the left-hand spar flanges are inverted with the 11degree bend on the bottom and the 7 degree bend on the top. The right-hand spar has the correct angles, but is also undersized.

Any other recent kit deliveries experiencing these issues?

Tech has been informed.

Frustration Factor 9.0 here @Area 51% .

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[Murray Parr]

That's disappointing.
Did you flute all the ribs and get the flanges to 90 degrees? A bit under bent could make a difference. I have a recollection that my B model wasn't a perfect fit but close and it isn't noticeable. What has Sonex recommended to improve this?

[Area 51%]

The ribs were all properly "massaged". Being my second Waiex, I'm no stranger to the phenomenon that Sonex protractors end at 85deg and pick back up at 100deg.

I believe what's at fault is the undersized spar. Didn't have a problem with my first set of wings, but now the spars have gone through another evolution that doesn't seem to be for the better. 3.7in is the print dimension.

I've ordered a section of the Z01-02 spar channel that was used in early kits to build your own spars and is still available. We'll see if it measures up. If so, I plan to order enough to replace the factory units.

[flyguy0609]

Did you request an RMA ? (Return Material Authorization) I'm going to check my rear spars for this. Sonex is pretty good about manufacturing problems. My kit was orphaned before I rescued it. I sent my main spars to Sonex for assembly. Once there, they discovered that one of my spar caps was manufactured to the incorrect (short) length. Sonex replaced it at no cost, even though the kit was 20 years old.

If you don't ask, they can't say yes.

[Area 51%]

They have already acknowledged the LH spar with the incorrect angles will be replaced.
A 20 year old kit will probably have proper dimensions on the spar. My 2015 spars were spot on. The recent incarnation of rear spars are missing the flap drive tube hole that's required on the Legacy but not the B. The undersize probably started there.

I can't find anywhere on the page that says a .065in gap between the skin and rear spar is acceptable.

[Area 51%]

Not sure if Sonex agrees with my assessment of their rear spars, but they did supply the needed blank spar channel and splice plates to manufacture replacements.
I couldn't be happier with the results. The task set me back a bit, but worth every minute.
I now have a much clearer picture of what a scratch-builder must go through. I'm talking a 60 pixel picture and not a 1000.
Thanks to Sonex for their support on this matter.

Onward then upward.