Pitot tube mount, §31-11, -32

 Vans stepped up to the plate and FedEx'ed a part to me to replace an incorrect one.  It was just a few minutes to mount the brackets to the plate and then clecoed (but not riveted) into the leading edge of the wing.

Pitot Tube mounting bracket

I really want to dive in a work fast to finish things as quickly as possible, but the rumor mill on Van's Air Force suggests that that may not be a good idea.   It sounds like the next kit (fuselage) won't be offered for sale until January and deliveries are not expected until March or April.   Going slow, that means I can put on the left skins in November, right skins in December, cove skins & attachments in January, and work on the tail feathers during February & March.   Ugh.

To make matters even more interesting, the rumor is that not only will the fuselage kit be offered in January, but also the Finish Kit and Firewall Forward Kit,   I have no idea about how that would work, nor why would Vans do that instead of offering the kits in sequence. I think that I'd rather have the fuselage kit sooner and be content for the finish and FWF kits later.

Finally, we have to try to predict the future with respect to Lycoming's delivery of an engine.  It's not unreasonable to think it might be two years from deposit, so I may end up ordering that sometime soon, too.  Oh, by the way, there's a $1000 discount if the propeller is ordered from Hartzell at the same time as the engine.   This is going to cost a fair amount of cash up front that I'll be paying interest on,  Oh, well.  No one feels sorry for anyone who owns an airplane.  Or two,  Or three, 

it looks like a porcupine!

 §31-20, -21, -23 Left

I was able to get not only an afternoon to work on the plane, but also get the help of my friend Edwin.  Yesterday we attached the nose skins to the skeleton.   We completed the vast majority of the work of page 22 as well, but couldn't mark the page as finished since it needs the pitot tube mount that is en route from Van's.  That'll be 10 min to do, so expect to see that page marked off on the next post.

The leading edge skins have a much larger radius of curvature than the nose ribs themselves.  The instructions have a very bad pun describing the situation:  "the skins are in-tension-ally open". Groan.  We followed the recommended sequence of attaching the clecos until the skins were tangent enough that I could continue on my own.  Despite buying a lot of clecos this summer I'm about 150 shy of the recommended practice of 100 % cleco coverage!  I do have 100 % coverage on the curved parts of the ribs that are under tension.  I have 33 % coverage on the top spar where the skin is nice & flush so I think that will be just fine.

I'm really happy that I've reached this stage.  It's looking like a wing!  I anticipate getting a few hours of work done on Sunday.  Stay tuned.

Leading & Upper skins in place

Behold, The Porcupine!

Major progress! (with minor setbacks)

 It's been over a week since I published, so let me bring y'all up to date. 

Progress

§29-08 R, -10 R, -12 L & R, -14 L & R, -16 L & R —  completion of the nose ribs

The tie-wrap clips finally arrived and I was able to finally finish the Left wing and do the entire Right wing in about an hour.  Recall that I had problems with getting the rivets to properly set.  There was a suggestion to use a small washer to reinforce the thin metal of the rib, but that didn't work.  That was my only spare, so I went with a more fool proof method of using #6 nuts, washers & bolts.  These had the advantage of being removable.  Later, when I was running the wiring harnesses, I realized that the tie wrap clips on the outside 2 ribs are attached at the rear of the lightening hole and not the front.  Had I riveted them in, I wouldn't have been able to correct my overside.  Anyway, §29 is done.

§30-05, -06, - 07,  -08, -09  Left & Right — Wiring harness

This chapter is the placement of the wiring harness.   It was very straightforward and took about an hour or two.  As mentioned, I needed to reposition 4 of the clips, but no other complications.  

Left wiring harness

§31-05, -06, -07, -08, -09, -10    — Wing skin preparation

I've been really looking forward to putting on the skins since they are what transforms a collection of spars & delicate ribs into a structurally sound and clearly recognizable wing.  These pages were all about prepping the skins.  Nothing conceptually difficult, but lots of labor.  Each page represents two skins that needed to have the plastic removed, edges deburred, some edges 'broken', and nut plates riveted on.  Pretend that there's another page for the single skin that didn't have nut plates to be added, so it doesn't even have a page to represent it.

me, marking a part number on a 

part as I remove the plastic film

§31-15, -16 -17 L & R    — Clecoing top skins into place

The top skins got placed before the bottom skins since the wings were already right side up and I didn't have anybody to help me flip them.  The stiffeners went in easily and the skins attached without a hitch.  I put a cleco at every intersection of a rib and a stiffener. Those are essentially the load points in flight and the clecos will be able to support the wing when inverted to work on the bottom.   Unfortunately, I forgot to take a picture of my handy work.

§31-18, -19 L & R    — Light Bracket

Man, by this time I was flyin'!   Translation:  I was working so fast that I got sloppy.   On each side is a simple bracket (same on both sides) and a truncated nose rib.  I missed the fact that the bracket is symmetric L vs R, but isn't symmetric Up vs Down.  I also missed the fact that the -002 rib is called out on the L wing because typically the L side gets the -001 variants of parts.   Anyway, those got assembled and riveted in without double checking.   The next day I looked at one of them and realized that there was no way that a skin was going to go over and get fastened properly.  By this time my son-in-law, Dennis, had come over to help so he got a lesson in drilling out rivets and backtracking your work to see where you screwed up.  He helped install the rebuilt brackets and then we were able to flip the wing onto its back.

light mounting brackets

Lighting bracket in place on the R wing

Obstacles

Pitot tube mounting bracket.

I thought I had a W-00039-001 and a W-00039-002 (mirror image parts), but discovered that I have two of the -001 variants.  I've written to Vans to get a replacement, but the web store shows 30-60 day backorder.  Luckily, it's something that can be installed at any time in the future.  In fact, I might not use this one as it sounds like Dynon has a different mounting system.

Rib interference

When I placed the left lower mid skin on the assembly, I noticed that there was rib that was obstructing the opening through which the wing strut would attach.  I verified that things wouldn't fit and decided to just shut down the shop because I was tired and had been working hard and fast.  I know from personal experience that if I kept going to find my own fix for the problem, I'd likely make something much worse or fail to realize that there was a reversible error in previous work.

Rib underneath the slot in wing skin

Luckily, I was able to find a simple explanation & fix.  Per the RV-15 Wiki, there was a design flaw in the rib in question and it was made with the same tabs as the rest of the ribs, but the tab shouldn't be present in this location.  I presume they modified the part after I got mine.  Vans says to just cut the offending material out as they won't send a replacement.  They advise that you do that before you install it.  Oh, well.   

That's it for today and probably for the week. It's a busy work schedule and I doubt I'll have time to get into the shop for the rest of the week.

§29-17 R, §31-06 L. problems w/ tie clips

 Well, it was the usual "2 steps forward, 1 step back" kind of day.  I received a shipment from Van's, but it only had the LP4-4 rivets that I had ordered, but not the replacement tie wrap clips for the ones that I had ruined the other week.  I sent off a note to Vans asking for an explanation and/or a shipment.

I was able to attach the 3 remaining R nose ribs with the new rivets without any problem.  On the other hand, when I went to attach some clips to the remaining L ribs that needed them I had 4 consecutive failures.   For some reason, the tips (shop heads) of the rivets just aren't getting a good grip on the rib and they pull right through and then expand inside the plastic clip.  I tried using the hand puller, and both low and high pressure on the hydraulic puller but it just isn't working.   I then tried squeezing some 470AD4-7 rivets, but the rib is curved where the rivet goes and I couldn't get it to squeeze squarely.

2 of today's 5 ruined clips

I think I know what's going on.  Rivet holes gets punched at the factory using a tool and matching die.  These wear over time so there is a subtle drift in the dimensions of the resulting hole.  In this particular case the hole in question is punched into a spot that is then stamped into a curved shape (to provide strength around the lightening hole).  I suspect that I have a batch of ribs that were punched slightly larger than typical and then the stamping procedure stretched them just enough that the rivets don't get a good bite as the are pulled and expanded.

I posted my plight to VAF and 2 other builders reported similar instances.  One gentleman used an idea that I was already thinking about -- using nuts & bolts.  I'll also use some lock tight to secure the nuts.   I'll get some at the local hardware store and finish up putting the clips on the left wing wait for the missing clips to do the right.

Going back to prepping the wing skins, I finished unwrapping, deburring, edge breaking and installation of the nut plates to the lower outboard wing skins.

nut plates held with clecos, 

prior to squeezing flush rivets.

Started prep work on wing skins

 Steve & I bucked 6 rivets holding one of the nose ribs.  That officially completes page §29-11 R.  Still waiting on the missing rivets to finish off the entire section, but I'm sure they'll arrive eventually.   By the way, I didn't show you a 'big picture' of the current organization of the workshop.   Here you go!  On the right are both of the wing assemblies.  They are 'backwards' from this point of view with the Left wing on the right, and vice versa. From here, you can't see the clecos that are still in place.   The work tables are now freely accessible and ready to be used in prep work.

workshop with cleared tables

I finished §31-05; prepping the bottom middle skins.  (The inner skins are pre-assembled as part of the fuel tanks).  On paper, this was very simple—attach a dozen nut plates to the access holes.  In reality, it took about an hour to do each skin.   Firstly, there's an awful lot of surface area which means that there's a lot of the protective blue plastic that must be pulled off.  For small parts, it's easy.  For these guys, I was actually getting painful finger tips from pulling and then peeling off the adhesive.   Life got a bit better when I borrowed my wife's hair dryer and heated up the surface as I went.

Secondly, there's a lot of linear edge that needs to be deburred.  The pieces are too large to hold and run by the scotch bright wheel on my bench grinder.  They are way too big to use the tiny Dremel wheels.  I had to drive to the Aviation Division of Roush Hardware and pick up a scotch bright wheel that I then put in a hand drill and could finally deburr the edges with something like efficiency.

Thirdly, some of the edges need to be "broken".  When two pieces of sheet metal are riveted together, the top piece can have a tendency to have its edge bend upward slightly due to the compression of the nearby rivets.   To counter this, the appropriate edge is 'broken' with a downward flare before being assembled.  I happen to have an outstanding custom built tool for this purpose.   It's a pair of vice grips with the jaws replaced by steel rollers, one of which has a nice tapered flare.  I just roll it along the correct edge and it produces a clean, uniform break.

[I will take some pictures of the broken edge and tool  and edit this post to include them the next time I update this blog.]

right lower middle wing skin 

resting on top of the right wing assembly

§29-09, -13 & -15 Right. most of the R nose ribs

Still making progress.  I prepped all of the nose ribs and riveted 11 of the 15 total.   I also did 80 % of another page, but I can't mark it complete until Steve comes over tomorrow to help me buck a set of rivets that are impossible to do by yourself.   After that, I'm at a work stoppage for both wings with respect to completing section 29 until I get a shipment from Vans.   I placed the order last Sunday and got crickets for 4 days.  Yesterday I sent a nice note asking "when?" and explained that I could either wait or change gears and tackle something else.  They promised that I would be a priority on Monday.  We shall see.

both wings with all ribs attached (but not riveted)

Tomorrow, I plan on doing the prep work for installing the skins as per section 31.   Putting in the wiring harnesses from section 30 can absolutely wait until the skins are actually attached and they shouldn't take more than an hour. (Hah!  Where have I heard that before!)  Hopefully the wayward parts will arrive by the time I finish prepping the skins and I won't have lost too much time.  If not, I'll set the wings aside and start on the tail feathers.

Yesterday I caught up on reading the forum and came across a bit of intelligence that Vans is not expected to take orders for the next kit until November and shipments won't be until after New Year.   That means that I will almost certainly be done with both wings and the tail feathers before I get another shipment.  While frustrating, it is also somewhat calming in that I no longer have that nagging feeling that I should be spending all of my free time in the shop.

To that end, my darling wife gets off work in 5 min.  She's going to change and put on make up and we're going out on the town on a Saturday night!  

§27 R, $28 R, §29-5—7 R -- Main spar attached, push rods installed

 Another really productive day.  It wasn't all roses, but it was very productive and enjoyable.   Bottom line—the two wings are essentially at an equal state of assembly! 

For the record:  §27-05, -06, §27-08, -09, -10, §28-13, -18, -19, -20, §29-05, -06, -07

Section 27 was started the day before yesterday (I played hooky yesterday and went flying.  More about that below) and really is just riveting the flap mixer to the rear spar/tank.  This is where the famously expensive Cherry Max rivets are used.  These puppies can be used in lieu of driving AD470's in almost all locations, but Van's cheerfully lets you ensure you find the correct length and you must source them yourself.  Apparently there was a fire at the factory that made them and now they sell for ~$2 a pop! Ouch!   As much as I'm tempted in a few places, I'll pass for those prices.

I jumped ahead (§29) and attached the front spar to the tank and clecoed it to all of the loose ribs that would otherwise be hanging in the breeze.  This gives the assembly a significant increase in rigidity and makes me feel better about picking it up and moving it, etc.   Prepping the front spar involved riveting an extension to it using a doubler.  Those were all driven 470 rivets and, because access was easy, it was actually fun.

Front Spar clecoed in place

Section 28 involved finishing up the push rod that I had to set aside a few months ago when I spilled some loctite onto a bearing and decided I didn't want to use it.   When I went to find the replacement, I spent 5 panicky minutes searching before I realized that the smart place to have put it was in the parts bin supplied by Vans.  Yep, there it was.   The rest of that chapter was taking the previously manufactured bell cranks and figuring out which way was which and getting them installed.  Rather than last time, when I wished for a trained capuchin monkey, I discovered I could attach a push rod to a bell crank out in the open, then insert the bell crank through an access hole and into position. Much easier!

top view of the R outboard (aileron) mixer

Looking inboard, under the fuel tank top skin, 

at the inboard aileron  pushrod 

At this point, I could sort out the D-cell nose ribs and cleco them to the front, but I can only attach 11 of the 15 as I am waiting on LP4-4 rivets from Vans.  I'm also waiting on the plastic clips for attaching the wiring harness.   Essentially, the wings are at the same place and both stuck.

Steve Brown will return on Sunday to help me drive the awkward rivets for one of the nose ribs, and I'll attach what I can.  I have enough saw horses and work stands that I can actually move both wing skeletons off of the work bench.  That will give me room to start prep work on the skins so that when the errant parts arrive from Vans I can get right to work installing the skins.  That's going to be 2 or 3 days of long, tedious but FUN work!

(I played hooky yesterday because the weather was just too good to pass up.  I managed to get out to Marysville and fly the Citabria in moderate winds from about 45° off the runway.  I'm nowhere near feeling comfortable landing that plane and it was a good workout.  Surprisingly, I made 4 very good landings on the grass.  My technique wasn't really 'full stall' nor 'tailwheel'.  I was too busy not loosing control to think about classifying them.  I flew the Cirrus and did a set of engine verification procedures.  For the curious, they are called "GAMI spread determination" and "LOP mag checks."  Both went well.  Finally, I took up the RV-12 just to say I flew all 3 aircraft for which I am current.  I didn't fly the CAF PT-26 because (1) I'm not current, and (2) it has a bad mag and is grounded.)