Tailcone first assembly

Tailcone first assembly is just about finished.  I've really slowed down this summer because of the massive home remodel that is happening concurrently.  Hope to have that mostly out of my life in the next few months.

All of the long thin pieces here are stiffeners.  There is a pile of them.  You put them in their slots, put the skin on, then match drill from the skin to the stiffeners.  There's a hole every 1.25" or so.  So yes this is a TON of drilling.



Here you can see the stiffeners have been drilled on the bottom skins, the side skin stiffeners have about 1 in every 10 holes.  I do this to get the position of the stiffener correct.  Then you can mostly just go nuts, only worrying about drilling straight.



Here's a nasty little lesson learned.  I have a big assortment of cheap drill bits I got from Menards.  Plans called for initially drilling the longerons holes to 3/32, not the usual #40 bit.  3/32 is a tiny bit smaller.  The reason is because the top skins end up overlapping these holes, so you final drill them later on.
Anyway I used one of those cheapie bits, and paid for it.  The tip of the bit broke off just as it was breaking thru to the back side of the longeron.  Took some messin', but I got it out.  No more cheap shitty bits!



Little buddy practicing writing his name while Dad works on the aft end.



I thought I had a good pile of clecos.  By the time you put the top skins on, its not enough, guaranteed!



My building partner



First assembly mostly complete.




I've taken a small departure to prepare for some things I want to mount in the tailcone.  One is an oxygen bottle, other is the ADAHRS tray.

ADAHRS stands for Air Data Attitude Heading Reference System.  Its a sensitive little box that senses how fast your going, altitude, heading, pitch, roll and yaw.  They are not to the caliber of the Inertial Reference Units we put in the big jets, but still pretty darn accurate.  And for flying in clouds, they are critical to safety.  They have to be mounted away from ferrous metals because they have a compass.  So the top of the tailcone is a good place.

Another RV-10 builder Justin has some awesome plans for a shelf you put in the top of the cone.  Saved me a lot of time.  I had all the material laying around from scraps EXCEPT for the angle aluminum.  Had one chunk of .063 3/4 x 3/4 , but it was only long enough for one side.  Luckily my buddy Mike had a 4" piece to spare.







One last thing.  I had to buy a 12" long #12 drill to get two of the aft deck to longeron holes.  Wasn't in any of the tool lists I've seen.

Tailcone Start

This is the last assembly of the tail kit.  Construction usually takes around 100 hours going by what I see others have done online.  I'm heavily loaded on our house remodel too, so I expect this one to take a while.

The next kit is the wings, and they take 6-8 weeks from order to arrival so I'll be placing that order hopefully this summer yet.

At first, most of what you do is prepare the bulkheads, stiffeners, and longerons.  Its quite a bit of bandsaw work, drilling, sanding and deburring.  You have to mark a line down the length of all the J-channel stiffeners.  There's a lot of them so I made a little template to hold the marker as I slide it down.



The longeron bending was a little scary at first, but I picked it up quick.  You put some stiff pieces of angle aluminum in a vice and whack it with a hammer to get a slight bend, about 2 degrees.  I went nice and slow and got a bend that was just right on both.



Then you put the bottom tailcone skin upside down on some saw horses and start putting the bulkheads on the skin.  I don't have tall sawhorses so I improvised with some 2x6s fastened to the benches.


A small GOTCHA here.  I put the bottom skin on my "saw horses" in the wrong direction here.  This has the left side open to the outside, the plans ask for access to the right side first.  It won't matter if you are on real sawhorses or just keep it in mind when labeling parts L/R.

Elevators Finished

I didn't do a good job of keeping this up to date because along with the plane, we've started a massive remodel of our house.  Its pretty much mandatory when you build a plane.  You have to either move 3 times or remodel, is what other builders tell me.

Insides primed all nice:





This is the hole where the trim cable passes through



For the trim tabs, you cut out some foam ribs.  You'd be surprised how rigid this stuff is.



Bending the edges of the trim tabs is pretty tricky.  I'd grade mine average at best.  Went with a trick I found online where you take a flat piece of bar steel and sharpen the end to fit up into the trim tab bend.  Clamp it all down to the bench and bend with the hammer.  It didn't slip, but it didn't get the most crisp edge either.






I did have one GOTCHA.  I riveted the trim tab horns on first, then tried to rivet the bottom skin to the spar.  Nope, won't work.  The tab covers the last rivet hole just enough to make it impossible to set properly.



And done.  My buddy Mike says the elevators are "tricky".  I'd have to agree.

Elevators I

Before even starting these I made an ass outta myself.  Looked at these parts and thought, "why the hell did Van's send me used crap?  The had scuff marks, ugly bends, already dimpled, no blue plastic.



Wrote them an email asking for new not used parts, and got this friendly reply:

Most empennage ribs have strait bends so we can use 2024-T3 (hard) aluminum with blue vinyl. But if rib has compound curves, we must use 2024-T0 (soft) aluminum. If it’s (soft) aluminum it must go through a heat treating process after we press the part. We can’t use the blue vinyl with 2024-T0 (soft) aluminum because it will clog up the punch press and it won’t survive the heat from heat treating. When we punch parts without the blue vinyl It will have some small scratches in the part, so we use scotch bright pad to clean it up. The slight bend in the side of the part number E-903 is intentional to accommodate the overlap of the skins. You will see this on page 9-2 and 9-9 of the plans.

So ok... I'll carry on, hat in hand.

This is basically what you get after finishing the first page.  Counterweight ribs assembled and ribs cut out and cleco'd together.



The four skins are identical between left/right but unique top to bottom.  You have to bend some tabs, and the direction they bend determines which side they fit on.  Took my time with that, I could see it would be easy to mess up.

Horizontal Stabalizer

The HStab is finished after 87.3 hours.  This is where you start to grasp just how many freakin' rivets are in this plane.  The HStab itself is 11, maybe 12' wide and has close to 1000 holes.

The local EAA tech counceler Tom Olson stopped by to do a final inspection on this piece.  I had been reading some forums online where they showed some super poor examples of riveting in aircraft that were flying.  They hadn't crashed which speaks to the design of this plane, but they wouldn't have withstood the 6g design limits either.  So that scared me into thinking I need an experienced eye looking at my work before I moved on.  Tom had all good things to say, and even wondered if I had done metal work before.  We had a long conversation about his days working in my department 35 years ago.


Here's the front spar, doubler and attachment brackets on.



You use some of the longest rivets in the kit on these parts.



I'm slowly working the kids up to the point where they can make a meaninful contribution.  Here's Sawyer doing an excellent job of deburring a rib flange (aka flossing the teeth)



And some not-so-constructive playing toy swords with some stiffeners:



I let Sawyer come "help" me one day after his nap, he spent 45 minutes making a rough draft of the aircraft's paint design.



Here is first assembly/match drilling.  There's only clecos in half the holes.



The ribs after disassembly, ready for priming.  Just scrubbing these down in preparation for priming took the better part of an hour.



Dimpling the skins.  I really like my setup with just having the dimple die a little above table height to allow for the carpet.  Only thing I may change is to back it up a bit as its difficult to get some edge holes dimpled when the piece has to mostly hang off the front of the workbench.



Sawyer came in after a nap one afternoon and watched Ice Age.



Then helped me dimple, except he whacked the handle one time when he wasn't supposed to and made the first boo-boo on my skins.  Its not bad, and its on the bottom of the HStab so nobody will know.



Assembly starts with attaching ribs and the stiffeners to the rear spar.



Darn fine rivets if I may say so myself.  Sure love that pneumatic squeezer.



Dad helped for a few days when I was on vacation.



The finished product.  Whew that was a big one!

Rudder Finished

The rudder trailing edge was set with proseal and cured for a couple weeks while I fought with a nasty stomach bug.  It was ugly.

To rivet it, I bought a chunk of 2x2x1/8" angle iron, and match drilled every other hole in the trailing edge of the rudder.  My inspiration came from Tim Olson's instructions.  Put a rivet in every other hole, taped them then cleco'd all the open holes to the angle iron.  After it was done I wish I would have left 5-6 holes without rivets because then you could use them to hold down the rudder in a few spots once you flip it and do the rest of the rivets.





To actually drive the rivets, start with the backrivet set and start it, then finish off with the mushroom set.  I don't think mine turned out that great, but don't have anything to compare to.  The trailing edge however is super straight and that's the important part.



I did the last two steps out of order because I didn't have a pipe for rolling the leading edge laying around.  Here I bent the leading ledge and fitted the counterweight.  Its a heavy chunk of metal (maybe lead).  Feels like it nearly doubles the weight of the whole rudder.

First you crease the skins where they fold over the counterweight, then use a couple wood blocks and a soft hammer to actually make the crease.



In the process I found the first use for my super beefy DOTCO angle drill.  Doubt it was 100% necessary but did make it easier.




The leading edge counterweight installed.  The instructions give you an option last step of putting another rivet in the middle to snug down any "pillowed" metal.  Mine exhibited this a bit, so I did it.




Last was rolling the leading edge.  I bought both a 3/4" and 1" PVC Schedule 40 pipe for this, ended up using the 3/4" for all of it.  It was a little bit of a bear because the curve changes over the length of the rudder.



Once you get it rolled somewhat close, cleco it, match drill, and pop rivet.



Done!  This one took 38.3 hours.  I sure love knocking these big pieces out.  Now onto the big honkin Horizontal Stabilizer!