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Help: Spar Bending Tool

PhatRV

Well Known Member
Hello all,

I need to smooth out the ski jump on the upper rear spar of my RV8. I tried to order the spar bending tool from Vans but the tool was checked out by another builder for the last 3 months. I don't think the tool will be returned to Vans any time soon.

Does anyone have the homemade spar bending tool I borrow? I'll pay for the shipping cost.

If you created a similar tool before, can you post a picture of it?

Thank you,

The tool should looks something like this.
 

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That's a shame someone would bogart the tool like that. I used it for my wings and it worked great. It's perfectly suited for the task. I hope whoever has it sees this and returns it.

I know this isn't much help but hoping it gets returned soon.
 
Spar bender

I built one for myself.
not very hard. a couple pieces of 2 1/2" wide 11" long of 1/4" steel
a couple bolts a little felt and little grinding
Oh ya you need a piece of wood to wedge into the back for the tightener. Now it's up to your imagination to get it to work
Art
 

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From F1 world:

Two piece of 1x4 hardwood bolted together and gapped at ~032. Shape the ends to usable radii and recess for shop heads as required.

Whatever you use, go slowly and in increments and all will be fine.
 
Multigrips

I used a pair of 400mm multigrips (and a piece of aluminium bar taped to the skin, for protection).
 

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Had a similar problem on my F1 wings. No need for a special tool. I took a hand squeezer with a deep throat and squeezed on every rivet lightly while tweaking the spar along the length.
 
Thanks to all the replies. I have to call Vans again for the status of the tool. It may end up that I have to build a tool for the job.
 
Curious about this. Is this tool required per the plane? Or is it an ad hoc to achieve a desired effect?
 
Curious about this. Is this tool required per the plane? Or is it an ad hoc to achieve a desired effect?

A byproduct of all the dimples and riveting on the rear spar often causes a “ski jump at the back of the wing. This is a way to fix it.
 
Probably zero effect on the flying quality, maybe 1/4 knots less comparing to the flush version.
 
The history of the ski jump, as explained to me;

Back around 2007-ish there was a run of parts where the top flange of the aft wing spar was under-bent, resulting in the ski-jump. Vans developed the loaner tool as a response to this.

I found this out after I bought a set of almost finished wings to start my rv7 project from that time frame and saw a noticeable joggle in the upper skin trailing edge where it transitions from the aileron area where supporting structure makes it lay flat and the flap well where it's free to just do it's own thing.

I asked Vans to be put on the list for the loaner tool at that time.


That was over 2 years ago, and still no joy.

See my build log entry March 8, 2020 for my homemade tool and results.
 
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