Mid Fuse Ribs and Bottom Skin

This section was pretty cool.  The fuse starts getting its shape.  However, this must be the section where they really start slacking on the plans.  There are a number of gotchas in this one, and they can really screw you up later on so pay attention!

You start by creating some nice thick pieces that will be used to attach seat belts too.  Important stuff.  Then the big ribs start going on the spars and bulkheads you put together last chapter.

Here is the next bulkhead aft and the ribs you attach to it.

 

Then the thing gets big real fast and you need to stand it up on end.  I did make sure to measure this beast and make sure I can get it out to the garage.  The end is in sight for my time building downstairs in peace, quiet and warmth during the winter.

Here's the whole beast with the two bottom skins on.

**GOTCHA SECTION**
When putting on the skins I realized something.  For some of the outboard ribs it tells you to cleco them to the bottom skin and flute to match the curve.  For others it just says "flute the flanges...".  In these cases you need to make sure you put it against the bottom skin and flute to match, even though it doesn't say so.  Here I'm pointing to the ones I'm talking about, the F-1018-L/R outboard ribs.

On 26-3 Step 7, it says to dimple the screw holes in the inboard side of the intercostals that correspond to the flush nutplates.  There are 3 screw holes here, and each of them get a different type of nutplate.  The top one is a K1000-08.  This kind does not have the "divot" to accept a dimple.  I of course dimpled all 3 and the top one doesn't sit right.

What you need to do here is dimple the #40 holes for that top nutplate, but don't dimple that top screw hole.  The piece that goes over it is the F-1015C-L/R Mid Cabin Deck.  Its hole that corresponds to the top screw hole of the intercostal is machine countersunk.  There's also an inspection panel that slides in between those two pieces, so you don't want that countersunk or it'll be very hard to get in/out during annual.

Dimpled with the nutplate sitting wonky:

The piece that fits over this hole:

And the big gotcha's.  I'll just shamelessly copy from Mike J's blog because I can't say it better than him:

In summary, here's what I believe really should happen during Section 26-5, somewhere between steps 1-6:

• For the F-1015A-L/R ribs, dimple all of the #40 holes in the web of the piece, excluding the forward-most row that tucks behind the F-1004D bulkhead. Leave the #30 holes alone (careful, they crisscross!)
• Dimple the flanges of the F-1015B-L/R Intercostals to match the dimples you made in the previous step.
• When completing Step 6 on 26-5, the dimple callouts for the #40 holes in the F-1018-L/R are correct; however you should *also* dimple the three aft-most #30 holes that can be seen on the right side of the photo above. Are those holes not there yet? You'll want to fetch the fuse side skins and cleco this rib into place, and match-drill those #30 holes, then deburr and dimple the rib. Trust me, way easier to do now than when everything's all riveted together. As a final clarification on the #30 holes, none should be dimpled EXCEPT for these three. Refer to callouts on Page 29-15 Figure 1.

One thing I saw online but luckily did it correctly myself was putting the slightly bent forward flange of the F-1018 ribs inboard of the F-1005C vertical support channels.  Also applies to the F-1015A ribs whose forward flange goes on the inboard side. I saw cases were people accidentally riveted it in with that flange on the outboard side and it was a mess to clean up.  Remember you need to create a flat face which the side skins will mount to. 

Don't get scared when you see some extra parts that you primed laying there once riveting is complete.  At the beginning you cut apart the spacers to make F-1015E and F-1015F spacers.  You only use the "15E" ones in this chapter.  The "15F" ones go on the otherside of the intercostals but not until chapter 29 (Fuse Side Skins).

Yet ANOTHER gotcha.  This is the stuff that frustrates you.  On 26-6, step 9 has you dimple 2 holes on the Fuse BulkHead Assembly (F-1034A) that are shared with Rear Seat Rib Assemblies.  Problem is, those ribs have already been riveted on by step 6.  Total lazyness in planmaking.  To fix this, just do step 9 after step 5.  I'm just going to countersink them for a dimple.  They are unique from the others in that row because the rest get covered by a hinge:

So eventually you start dimpling and riveting this monster.  There are 978 holes in those bottom skins.  Woof!

  

The last two steps of this chapter are confusing too.  Which bottom holes in the bulkheads do you countersink, and which do you dimple?  The plans are clear on the big forward-most bulkhead (you couldn't dimple that monster after all).  But the rear two it never mentions anything about countersinking, but says to not dimple holes that correspond to rib tabs.  

After putting it together via plans you are forced into one solution - countersink the Rear Spar Bulkhead and Fuse Bulkhead holes that have a rib tab under them, and dimple everything else.

If I had to do it again, I could have dimpled everything (except the Aft Center Section Bulkhead).  You would just need to dimple all the rib bottoms and the Rear Spar/Fuse Bulkhead bottom holes before riveting them on.  Stated more simply, everything that gets riveted to the bottom skin gets dimpled unless its the Aft Center Section Bulkhead or touches the Aft Center Section Bulkhead.

When you dimple the bottom stiffeners, one end is squared off and one is cut back at an angle.  The angled side goes on the Aft Center Section Bulkhead, so don't dimple that hole.  Dimple the rest though.  Don't forget to dimple the upper flanges of these stiffeners too (#30 holes).  I forgot even though the plans were clear and had to buy a new squeezer to fix it.  DUMB.

Finally you finish.  Yeesh this chapter is kind of a doosey!

Flaps

Flaps are done!  It might be just me, but these seemed to take a long time for how simple their construction was. They are big (probably 8' each), so there was just a lot of time spent to get through all that deburring and drilling.  The day dad and I spent priming was a big one too, about a 9 hour job.

Now that the wings are mostly done, I'm sure glad I did both wings at the same time.  I couldn't imagine being at this point then having to go do it all over again.  There was definitely some economy of scale advantage to getting both knocked out at the same time.  I didn't always keep both wings in step-by-step lock though, only doing what made the most sense at the time.  For example during the leading edges, I only had enough room for 1 on the bench.  So I would get a long ways ahead on one and then catch up on the other just to save me from moving them around a lot.

The flaps were pretty easy.  No stainless pipe to deal with like the ailerons.  Lots of blind rivets.  For the trailing edge I used my trusty old door and angle iron.  Even though the flap overhung the iron by over a foot on each side, it still ended up arrow straight.

The first thing you do is create the big flap hinge brackets.  Its a little confusing as to how they go together L/R wise when you start on the Left wing, but in the end you figure out they are pretty much the same no matter what wing they are on.

The instructions have you put the bolt and associated hardware into the brackets to forcefully line them up before drilling.  I've read where others paid the price for not doing this, so I obliged.  Getting those washes in between the brackets can be a bear.  Luckily my mom gave me these left over surgical forecepts over 20 years ago.  I still have them because they are handy as heck.

Priming was a big job, because I scuff everything with scotchbrite first.  These little ribs just kill you, luckily Dad shared the pain with me.

I'm pretty sure these are the biggest rivets I've used so far.  AD470 4-10. They go through the middle flap brackets which are a big "sandwich" which consist of 6 pieces, the middle two being really fat.

My buddy John (RV-14 builder) borrowed me this trailing edge jig.  You put the extruded trailing edge piece in there and it makes it flat so you can countersink it with a drill press.  Here I'm holding it to the drill press table with a couple of clamped boards.  WHY did I not have this for the empenage?  What a no-brainer, this thing was awesome.  If your reading this and are still working on the tail, just buy it.

Here's the internal structure all riveted up.  I had to use the double offset set to get some of those rivets.  With that epoxy primer on this stuff, assemblies like this should not see the light of day for 100+ years.

Leading edge skins going on.

 

 Top skins

 

The plans have you back-rivet the two aft-most rivets in the top skin.  DONT DO THAT - its super easy to screw up.  The squeezer works perfect for this job, and its way easier.

The leading edge skins and the bottom skin is all blind-riveted.  These are the rivet tails from just 1 flap!

Fuselage Arrival

The Fuselage has arrived!  Van's called me about 9 weeks after ordering saying they have a windshield with a chip in the corner that shouldn't matter.  I didn't like it so told them I'd wait for a new one.  About 2 weeks later the crate showed up.

Here is my list of modifications.  I have the ControlApproach pedals so that was most of the change.  The hinge pieces are for the wingtip attach mod.  People suggested to put the Oil Cooler Mount on now as the firewall is much more accessable.  I'll be using the Andair fuel valve to be compatable with EFI return-style fuel systems.
I did forget to remove the brake master cylinders (already have Grove ones on the rudder pedals) and the flap actuator (there is a nicer one made by PH Aviation).  Will be returning those back to Vans.

Items to add:

6x: AN822-4D ELBOW 90DEG TUBE-PIPE

1x: VA-186 OIL COOLER MNT RV-10

2x AN257-P4X6'

2x AN257-P3X6'

Items to remove:

2x  TG-1010 L&R RV-10 Heat boxes

1x: BAG 487-1 FUEL VALVE RV-10 ONLY
2x: F-1052 RUDDER PEDAL SET
4x: F-1052B BRAKE SIDE PLATE
2x: F-1052C BRAKE PDL.DBLER.PLATE
1x: WD-1006-L-PC RUDDER PEDAL
1x: WD-1006-R-PC RUDDER PEDAL
1x: F-6115 CENTER BEARING BUSHING
1x: F-8105 BRAKE HOSE 20" 8/10
1x: PT-062x1/4x15' HI PRES BRAKE HOSE
1x: BAG 1377-1 BRASS FITTINGS/INSERT

This sucker is LARGE.  I had to put this in my upper garage as the other one has just a 8' door and it was raining outside.

They stuffed a longeron in the box and it popped open the back panel.  No big damage from that though.

 

Here's the big fiberglass canopy top.  Lots of work to get this bad boy installed.  The cardboard box has most of the metal in it, while the skins are below sandwiched in between layers of the white foam.

There was a bent skin though.  Of course it was the biggest skin in the whole shipment, F-1076.  I told Vans.  Sterling called me and said to put it on my back rivet plate and hammer it down.  Its not structural, and there are two rows of rivets there to "suck" it down.  Plus since its on the bottom nobody will see it.  I'm good with that as long as it doesn't crack.

Flaps get primed tonight, so they are almost done.  Excited to start phase 3!

Ailerons

Section 21 is complete.  Now that I've done enough of these primary flight surfaces, they are getting fairly routine.  The things about this section that make it unique are:

• That goddamn stainless counterweight pipe
• The weird dimple die you use one the end ribs

 About that counterweight ... they want the aileron balanced fore/aft so in the short forward part there is a real heavy stainless steel pipe that acts as a weight.  You have to assemble a few pieces of that forward section, then mark holes on the pipe to drill.  The first set of holes then gets lined up to rib holes, so that you can then mark another set of rib holes.  This second set is real hard to get to, the plans have you wedging a long drill bit in between rib flanges to make the mark.

I thought I had a better idea - cut off a sharpie and use that since the long bit wouldn't be square to the hole anyway:

The problem I had after this was that I made a pretty accurate mark of the hole, but drilling into this stainless with my drill bits just wasn't working for crap.  Tried some boelube and a new bit, NOPE.  Finially went to Theisens and got their best quality 3/32 Dewalt bit and had much better success.  Ended up with 2 sets of holes in each pipe before I got pretty close.  The once nice thing about a pipe is that if you screw up the hole in it, just turn it and start over.

Once I got those holes as good as I could, I could still see a degree or two of twist in the assembly.  I measured it by finding two spots on my bench with the exact same reading on my digital angle finder.  See that little area under the rib?  The other side is flat.

To fix that, i just did some milling of the rib flange holes.  That allowed some wiggle room on where the pipe mounts to the ribs.  I'm not worried about any structural issues, that pipe is still wrapped very tightly by the forward skin and bolted to the ribs.  Here's what the end of the assembly looks like.

 

The dimple die I was talking about is for the end ribs.  Not that big of a deal.  Oh also be really careful which sides of the little brackets you countersink.  It would be easy to mess them up.  I thought I did for a few minutes, only to realize I had actually done it correctly.

Oh and making these skin stiffeners was a total "shut your brain off" kind of task.  Each one required final-drilling holes, laying out lines, and 3 cuts on the band saw.  Seemed like it took forever, but oddly enough I almost enjoyed it.  I'm a sick individual, folks.

Here is the trailing edge.  This was wierd to me - the extruded trailing edge wedge stick just a TINY bit past the skin, maybe 1/32 or so.  Don't remember that from any of the other surfaces.

There were quite a few pop rivets to do.  I discovered something I wish I had thought of before - using chunks of extruded trailing edge to build up the area around a pop rivet so you can get to it.  This allowed me to use my awesome $20 Harbor Freight puller on all the aileron pop rivets.

Here the top skins are going on.  You Clamp a board on to the trailing edge so you don't lock in a wavy shape to the skin.

Some of the rivets on the ends were buggers.  Had to use the double offset for the ones between brackets.  This guy got some real careful hits, no room for a full mushroom set in that little corner.

This pop rivet stem broke in the wrong place.  I emailed Vans and they said if its set, just cut it off and grind down.  So thats what I did.

Waa-laa - done!  Probably had 50 hours in these.