Wing Cradle

Now that the leading edges are on I can't lay them flat any more, so I built the wing cradle.  I reused some huge 2x6s that were part of our old ceiling, recycled 2x4s, and the casters were in a shop drawer that was Carrie's grandpa's.  They look 50 years old.

I'm duplicating instructions from Mouser here because he abandoned his build and I want them saved for posterity.  Full credit to Mouser for these, although I think he credits them to someone else also.



When you go to the lumber store, you need:

• 2x 10' 2x6
• 3x 10' 2x4
• 1 8' 2x4
• Carpet 16"x8'
• Casters

Here's how you cut the 2x4s:






The carpet should be 16" by at least 8'.

TIP: Don't try to staple the carpet to the wood before putting the wings in.  I did and it was a little crooked and the carpet side hung too low.  I measured just 1.8 degrees of downslope, but it looks like a lot more.

Instead, staple the middle of the carpet to the middle support.  Put your wing in there, and with another person holding the outboard edge, get it level.  Then pull the carpet tight and fasten.  I should have done it that way the first time .

Wing Leading Edges

The outboard wing leading edge assemblies are done and permanantly riveted to the main wing spars.  These would have been a really simple chapter if it weren't for my "quick-build" fuel tanks.  I bought my tanks from someone who had flown them hundreds of hours.  He built 4 new ones for an extreme extended range mission.  More on that in a bit...

Here's my handy tool for marking the centerline of J-channel.  Notice the notch just big enough to rest the fine tip sharpie into.




As usual the rib deburring takes a long time.  Then things initially go together pretty quickly.
 


Now back to the splice strip.

The problem with not having the uncut tank skins is that there is a "splice strip" attached to the tank skins which you normally cut off and attach to the leading edge.  This has nutplates in it lined up perfectly so that the fuel tank can be screwed to it also.  This bonds the outboard leading edge and tanks together so they are lined up properly and rigid with respect to each other.  Vans does not make that part alone, they would have to send me a whole tank skin or have me pay for a tank skin and cut that little piece off for me.  No thanks!  Not having the splice strip meant I had to fabricate my own.

I acquired a chunk of leading edge skin from the same RV-10 flyer and cut them to the right shape.  Attached them as tight as I could to the leading edge and match-drilled.



Then I put the whole leading edge on the wing spar with a bunch of clecos.  Then put the tanks on.  Using a fine tip sharpie the tank screw holes were traced onto the splice strip.

 

Getting the drill bit perfectly in the center even with my drill press wasn't easy.  Pre-punching the hole helps.  Here is the finished splice strip half riveted on.  The tanks aren't on yet, so hopefully soon I'll know if this worked.


Primed and ready to rivet.



Riveting these was no big deal, except for the front 3 or 4 which I maybe could have done by myself but instead summonsed a helper.  On the easy ones I did get some help from my mini builders:
 

I let him sign it.  Hopefully both these guys will enjoy flying it someday.





 

Before attaching to the main spar I wanted to fill the hole used for the stall warning vane.  I'll have an AoA sensor so no need for it.  I used a glob of proseal for now, hoping that will make a good backer to put in some filler later to sand out and make smooth.
 


Riveting these on the main spars was mostly easy, especially the bottom skin.  However the top skin required help.  I've seen where people online come up with contraptions to help them do it themself, to me it wasn't worth it.  So much easier grabbing a friend for 20 minutes.  I also got help with the most inboard rib to spar rivets.  They are big AD470-4 rivets and required a double-offset set.  With two people they came out perfect.

Here is the wing mounted to a bench with the outboard end hanging WAY over so you can rivet these things on.
 

Wing Skins

These skins were a pretty big job.  I guess I'd say the size of the ouboard skins and the sheer number of holes is what makes it time consuming.  I could manage moving around the big outboard skins myself, but going slow and thinking things out was a requirement.

First thing is edge debur all the skins, doublers and J-channel.  Then put the wing walk doublers on.  These add strength right next to the wing root to make an area of the wings you can walk on to get on/off the plane.

 Be careful to orient the doublers correctly.  I saw a guy online who had interference between the J-channel and the wing walk doubler because the doubler was flipped the wrong way top-to-bottom.

On one of the wings I ended up grinding a tiny amount from the ribs where it was interfering with the J-channel also.

The instructions give you an optional step "for aesthetics" to sand down the joint between the inboard and outboard skins into a taper.  I gave it a shot with some 80 grit and an electric sander.

I put the edge of the skin on the edge of a 2x4 and sanded in full even strokes.  I tried to put more pressure on the end of the skin so it would taper.  I don't think I ended up taking off much, maybe 25% of the total thickness, but that was ok with me.  If you really wanted to make that seam even, you'd probably need even more coarse sandpaper.

Commence assembly then match drilling.  Oil that air drill up, its going to get some use!

Priming these big suckers is actually not that much work compared to the ribs.  Just big flat surfaces.  Scratch 'em up, shoot 'em green.

I always wait to dimple until after the skins are primed.  The akzo epoxy is bulletproof so it sticks even during dimpling.  Also, preparing the skins for priming with scotchbrite pads is much harder when there are dimples in the skin.  It tears up the pads really fast.

It was difficult to get these monster skins dimpled myself, but between moving the tables around and some physical gymnastics, I made it happen.

Last you rivet.  There are like 2000 of these suckers to shoot, and it took Dad and I about 14 hours over three days.

You do these in a different order than usual.  Start in the middle of the skins, and rivet outwards.  The double row that joins the inboard and outboard skins is last.

I did get a new tool to help us back rivet these skins.  I know my buddy Mike J used a straight extended back rivet set to get his done.  I presume he just nudged the bottom of the rib over to get a straight shot at the shop end of the top-side rivets.  I tried out the double-offset set from Cleavland.  It was pricy, like $50, but I think it worked really good and allowed me back-rivet quite a few more than would be doable with a straight set.

The thing you MUST do with this bar though is crank the air pressure.  On my 3X gun I had it at 60 lbs to get the job done.  I would hold the end near the rivet with one hand to keep it from spinning while running the trigger with the other hand.  

 
Done.  What a marathon!
 

Unfortunately I found out in the course of this chapter that a small number of folks I thought were close to me consider my project a joke.  So be it I guess, to each his own.  Doesn't phase me though, I know that this plane is going to be awesome and its going to haul my kids and me to some awesome adventures and memories.  Maybe I even like people betting against me, its motivating as hell.  So onto the leading edges I go!

Wing Rear Spars

I'm way late getting this section published.  Wanted to get a picture of the kids with them and kept forgetting, oh well.

There are two parts here that are a little tricky.  Getting the holes created in the rear spar doublers and incorporating the Service Bulletin into the build.

For the holes in the rear spar, I first tried drilling large holes then filing out the remainder.  Pretty sure this is how the instructions tell you to do it.

That seemed to be more work than it was worth.  So instead i drilled the perimeter with smaller holes.

 

Same result, just easier to do.  Once the middle was cut out, I used a half-round bastard file I've had laying around forever.

 

 Oh and here's a BEEFY stiffener that is warped from the factory from the cutting process.  I stuck in in the vice, put tension on it and whacked it a bunch with a soft-faced hammer to get it straight.

 

The service bulletin has been out for quite a while by now, but the instructions still say to do it the old way.  They just give you some parts and a set of instructions for fixing an already assembled wing.  Its fairly straightforward, but does require a bit of thinking.  The new aileron hinge design is SUPER strong.  Here's what it looks like when complete.

 

Next up, wing skins!