Finished Deburring the Wing Ribs!

I finally finished deburring all of the remaining leading edge and fuel tank ribs for both wings.  This incredibly tedious job was made much quicker by the use of some small abrasive wheels that had been recommended on VAF.  I had seen these months ago but never got around to buying any until last week.  They enabled me to cut down the time to finish deburring a rib from close to an hour to more like 10 minutes.  Unbelievable!

I primarily used the 3M wheels for finishing and polishing and the Brite Rite wheels for roughing work.  I only used about 3 Brite Rite wheels (they are very durable, but remove a lot of material) and about 10 3M wheels.

It is such a relief to be done with this part of the build!  When I have to deburr ribs in the fuselage, I will definitely be using this technique.  It should work for all kinds of other parts as well.  I’m going to order lots more of these wheels.

 

LW Top Skin Dimpling

Today I deburred the top wing skin parts and dimpled the appropriate parts per plans page 16-2 Step 6.  Test reassembled and everything fits pretty nicely.  I had set up the DRDT-2 dimpler a while back for prior work and it was still set up well.  It didn’t need any adjustment, and the dimples came out looking crisp and flat.

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Left Wing Top Skin Work

Today I finished Page 16-2 Steps 1-4 for the left wing.  Countersinking the wing walk area went more smoothly than I expected.  Afterward, I prepared for dimpling the top skin holes by removing the blue vinyl from the top surfaces of the W-1003 and W-1002 skins.

Time Lapse Videos:

 

Countersinking Large Screw Holes

Countersinking large screw holes for nutplates in thin sections of sheet is no fun.  The countersink bit tends to wander and make a hash of the hole.  I thought about how to minimize chatter and keep the bit centered for a few minutes and came up with this:

First, I cut a piece of wood to fit a small area along the line where the nutplates are.   In this case, the nutplates will eventually hold the wing root fairing on the left wing.  I clamped the piece of wood in place and drilled #40 holes in the wood to correspond with the nutplate rivet holes.  Then I clecoed a nutplate through the top of the skin into the wood.

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Then I used the nutplate as a drill guide to drill a #30 hole in the wood below, centered on the screw hole in the nutplate.

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Next, I used my 90 degree drill and a #30 piloted countersink bit to carefully make the appropriate countersink (in this case, to accept a sheet above dimpled for a #8 screw.

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Finished product is a well centered countersink with minimal chatter.  I used pine wood here but in the future I will use oak or another hardwood because the pine is so soft, and allows a bit of movement to the countersink pilot.

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Page 14-5 Errata

I noted when riveting the outer ribs to the left wing spar that Page 14-5, Figure 2 calls out for the two ribs inboard of the most outboard rib, “AN470AD4-5, 4 PLACES.”  There are eight holes to be riveted here.

I believe this is an error on the part of Van’s, and it appears others have found the same error.  The thought is that it was introduced after the design of the RV-14 was finalized.  Here is a relevant VAF thread on the subject.

Outboard Aileron Brackets

Finished deburring and test fitting outboard aileron brackets yesterday.   Need to final drill and machine countersink.

Left and right outboard aileron bearing brackets
Left and right outboard aileron bearing brackets

 

Also etched and alodined the left wing flap brackets and torque tube bracket assembly parts.  Priming to commence when I have enough parts to justify a batch.

Alodined left wing parts 2016-10-16
Alodined left wing parts 2016-10-16