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Wingtip Installation

J

JDA_BTR

Well Known Member
I know that the consensus is to install the wing tips after final rigging. But.....

Is it true that all rigging of the ailerons, flaps and wing tips starts with jigging the aileron to the design position lined up per the plans? I have mine in that position with the W-730 jig holding all solidly. It was super easy to do the RV14 tips in the wing stand because the flap set the aileron and thus the tip alignment. It worked out great.

??--> How much error is likely to be introduced if I fit the tips in the wing stands with the aileron in the design neutral position?
 
JDA_BTR said:
SNIP

??--> How much error is likely to be introduced if I fit the tips in the wing stands with the aileron in the design neutral position?
Click to expand...

For some just enough to ruin their day. I suggest you wait.

Get the flaps perfect (flush against the bottom of the fuselage), then check your ailerons using the W-730 tool against the flap trailing edge. Remember to verify aileron height and compare left and right wings. Look for any twist in the flaps and aileron. The W-730 tool is a great way to get the ailerons close, but some may find it not perfect.

Once the ailerons are perfect, fit the wingtip.

Carl
 
How is the twist in a flap or aileron fixed at that point? Some small amount is in tolerance can’t remember but it wasn’t a tiny number last I Charlie’s.
 
I’ve been itching to do the same since my fuse is on lcp lockdown. But I’m holding off to get it just as perfect as I can once wings are on. I’ve heard people do it on the stands with success. But I’ve chosen to hold off, for now.
Post what you do and how it turns out.

Don’t mean step all over the op.
Thanks for info Mike. I think it helps us all.
 
Rigging wingtips

I'm sure my airplane is going to fall out of the sky because mine were rigged in the cradle.
I used both the jiggy thingy that bolts to the bellcrank and a hone brew jig made from 1/8" strip of aluminum. The ailerons were aligned to the centerline tooling holes in the wing ribs and locked to the bellcrank jig.
Jig was centerlined, drilled for the rib tooling holes then bolted in place. Details on my blog. Too much to write.
Actually a pretty cool way to install them.
They are also hinge mounted. In fact I just put them back on today. Solo. Hold it, slip in the hinge pins.
 
The Van's instructions say it doesn't matter where you do the tip installation, but suggest leaving it until later to avoid hangar rash. Quote:

"The tips may be installed with the wing lying down on a table or with a wing positioned in a cradle style storage fixture."

For me, it was actually easier with the wing nose-down in a cradle, since the tip tends to hang in about the right position and I could work along top and bottom surfaces in parallel to avoid warping.

The important thing is to align the ailerons with the tip rib tooling holes before starting on the tips, as shown on DWG 12A. I made a jig roughly as Van's suggested, then installed and aligned my ailerons with the wings in the cradle. I took care that the line joining inboard and outboard pivot points was parallel to the aft spar. After the alignment was complete, including spanwise positioning, adjusted the pushrod length using a variation on the W-730 fixture to lock the aileron in place..
 

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Dan, what is the significance of aligning the line between the aileron attach points to the aft spar? I have a prepunched kit and it all fit together as intended. I don’t know what I would do if it wasn’t already close enough. I judge that it likely is within spec looking at it without measuring.
 
On my 14 I did them in the stand, and used hinges. I incorporated an Archer VOR antenna in the hinge line in the tip to ground it properly. Works great and was so easy without having to crawl under a wing.

But the 8 I appreciate opinions seems it is either way. I had to set the aileron at neutral to drill and fit the flaps. That looks to have turned out great. The acceptable gap in plans is 3/16 inch and my long ruler from aileron to flap is just about perfect. I notice the flap is a little different between the 8’and the 14. The Fowler flap on the 14 resting against the rear spar set the aileron and thus tip alignment. The 8 flap in neutral doesn’t rest on the spar. Close but not on it.
 
JDA_BTR said:
Dan, what is the significance of aligning the line between the aileron attach points to the aft spar? I have a prepunched kit and it all fit together as intended. I don’t know what I would do if it wasn’t already close enough. I judge that it likely is within spec looking at it without measuring.
Click to expand...

If it all fits together well, there is no binding, and the gaps on top and bottom surfaces between wing and aileron are constant along the length, then there is no problem.

Some minor misalignments of the hinge bracket components with each other and with the wings can affect the control forces, the freeplay, the zero position, and possibly the rolling moments generated.

On one of mine I had a problem when I riveted the W-414-L bracket assembly together and noticed the bearing became stiff. Measured everything and found the outer race was not quite sitting square in the housing. Drilled it apart and cleaned some excess primer out of the housing, re-seated the bearing race carefully, and re-riveted with no further problems. It was probably only about 0.020" off, but that was enough to make a noticeable difference to the forces.
 
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