Empennage kit unpacked & inventoried

 Lots of grunt work involved in unpacking Van's kits!  The other night I unpacked and inventoried the major items and was very happy that none were missing.  It took a little bit of creative engineering to find places to store everything in the garage / shop, but it's all on shelves or standing behind other shelves.  I will need some help taking down parts of the empennage kit to get to the R wing spar, but that's a solvable problem for another day.

Today I inventoried the "small stuff".   The shipping company didn't pay attention to the "UP" arrows on the crate and it was actually on its side on the first day they tried to deliver it.   As expected, a few of the small parts shifted in their parts bin and were in the wrong bins.   it only took about 30 min to sort everything out and I can't complain too much more than I already have.    

EMP Bin #1 -- lots of 'small stuff' !

I'm about $6 short in parts that weren't in the kit.  I'm not even going to 'claim' them, I just put them into my cart for my next purchase.

Cutting up the crate for disposal was by far the most difficult part of the process.

Cut up crate parts & a pile of sawdust

3rd time was not the charm 😤

 Well, I had high hopes.   As my flight partner, Ed, often comments: "Hope is not a strategy."   Despite pre-smearing the adhesive on the mating surfaces, both tanks continue to leak.   The good news is that both are leaking in exactly the same place -- the electrical connection at the top right of the fuel senders.

Bubbles, Bubbles, everywhere! 😩

Since both tanks leak at the same place, and that place is where there are 3 stacked components, I clearly need to up my game in that location.  On Tuesday, I will pull off the fuel senders and the inboard access ports (again; for the 3rd time).  On Thursday, I will make another valiant effort to get these damn things on and air tight!

This time (next time?  Anyway, on Thursday) I'm going to repeat the technique of pre-smearing sealant on both of the mating faces.  I will then insert the screw for alignment.  I will place the first star washer on the screw and coat it with sealant until it is completely 'submerged' in the goo.  Then goes the electrical lug which will again be 'submerged'. and finally the 2nd star washer and its immersion.    Finally, I will place an absurdly large bead of sealant on one of the faces and finally install it.  Hopefully, that will be the final time.  

§22-08 thru -11 Inboard Aileron Bracket Assy Right

 Somewhere along the way, I lost a W-15015A-001 and couldn't finish the remaining aileron bracket.  The part was reordered and arrived last week.  It was pretty straightforward to press the bearing into the bracket and then rivet together the rest of the pieces.   The finished subassembly went back onto the shelf to await its installation on the right wing.

I also received a bearing that I had ruined and was planning on finishing the push rod that was affected, but doing so requires access to the front of a spar for measurement.   Steve & I put the R spar up in storage in a place that isn't convenient or safe for a single person to remove it, and the L spar now has nose ribs attached.  No big deal (except for my OCD).   It's a 5 min job and I can do it when I get access to the spar again.

Cool Picture

This is a pretty cool picture.  I just like the effect of staring down the perfectly aligned holes in the ribs after they are attached to their spar.  Check out December 5, 2013 for a similar shot of the RV-12 wing being built.

Empennage kit delivered

 Van's shipped my empennage kit (vertical & horizontal stabilizers, rudder & elevator) on the 5th.   It arrived in Columbus last Monday and I made an appointment for its delivery on Weds 12th.  When it showed up the driver spent about 10 min in the back of his panel truck, then came over to tell me he couldn't deliver it because it needed a fork lift and he didn't have one.   That's exactly what happened on May 9th when the first crates of the wing arrived!   That day, I enlisted my neighbor & his friend and the 4 of us manhandled the crates to the ground.  This time, I stood my ground and insisted that they re-deliver it.  Then I looked at the crate:

You'll notice something odd about this arrangement.  See the arrow?  Typically, that means "this side up", but the crate is on its side, not right side up.   

Yesterday, they arrived with a flat bed and attached parasite forklift. 

He got the crate off the truck and into my driveway and I pulled it into the garage. 

There was some minor damage to the wood and the paperwork is partially outside of the box.  I signed the e-receipt stating 'accepted with damage noted and not inspected'.  The driver/delivery guy was totally cool with that.  I'll file a claim with them if there are any damaged pieces when I get around to inventorying it next Thursday.

3rd time might be the charm ?

 Well, here's to hoping that I am capable of learning.  Specifically, this is the 3rd time I've sealed the fuel level senders & inboard access plate.   I have learned one thing -- I neither like nor am skilled with working with Proseal.  (BTW, Proseal is a brand name and I'm using generic products but will continue to abuse the name because I'm lazy.)

I'm pretty sure the access plates are not an issue because they are horizontal and straightforward.  The fuel senders are oriented vertically, so gravity is not my friend.  They also have a wrinkle in the installation:  one screw is fitted with an internal tooth washer, an electrical spade and a second internal tooth washer.  This stack-up is designed to have the angled teeth of the washers cut through the layer of sealant and ensure a good electrical connection from the tank itself to the electrical spade that will later be used to measure the fuel level.

On the previous installations, I had a lot of trouble holding the spade such that it didn't fall into the goop and I ended up making & breaking the connection of the sender's plate and the tank.  I suspect that didn't help the smooth, careful and uniform distribution of the sealant.

Rubber band as 3rd hand

I used a small rubber band to hold tension on the spade connector and trusted that the 'top' washer wouldn't go anywhere if I treated the arrangement with any delicacy.   In this photo, the connector is on backwards and would have dug into the side of the tank, but I installed it correctly after this dry run.

Sealant under electrical hardware

I smeared a small dab of sealant under the location of the hardware, then inserted everything and held it with the rubber band.

Smeared Sealant prior to installation

I then applied a bead around both the tank and the sender and smeared the beads into a relatively uniform bed.   Finally, I used one of my favorite tricks of inserting awls through two of the holes in the mounting plate and then into the corresponding holes in the tank and sliding the fuel gauge sender along the awls and into position.  I had a screwdriver at the ready to manipulate the screw (that was holding still because it was held by the rubber band) into its nut plate, then quickly inserted another screw into its nut plate. With two screws to hold orientation, the awls came out and the remaining screws were started, then evenly tightened.

Mounted Fuel Level Sender

As you can see in the final picture, there's a nice bead of sealant oozing out around the entire circumference.   It's a little thin at 12:30, but there is visible sealant. :)    BTW, I did both tanks at the same time, but only published pictures of one side.

I think the next time I'll have time to do a leak check is next Thursday, the 20th.   Fingers crossed!

§29-11 L, Nose Ribs to fuel tank

 Recall from a recent post that the Wiki community mentioned that getting the 6th rib attached requires two people because of the skins that are already attached to the tank making it impossible to hold the bucking bar and the rivet gun at the same time.  Steve B is a fellow RV builder and also an A&P.  In fact, he is the lender of the rivet gun I'm using to do this build.   He came over yesterday and used the gun while I assumed a very awkward position and held the W bucking bar.  Steve also noted that the FAA likes to see pictures of the builder and not just of the work done, so he offered to snap this:

Getting my head into the game!

Here's the photo of the rivets in question.  Even with the highlight, they're hard to see.  Imagine how hard it was to hold the bucking bar.   While I was in position, I had Steve hand me the go/no-go gauge and I discovered the top rivet needed a few more hits to meet spec and all the others were good.  I was really pleased! 

AN470AD4-12 shop heads

This completes page 29-11.

Busy & Productive Day!

Yesterday was a busy & productive day.  I got a descent amount of sleep after I got home at 8:30 AM.   In addition to the RV-15 stuff shown below, I also cleaned up the kitchen, trimmed all of the grass around the house where the lawn robot can't reach and installed the wall mount for a monitor in my wife's dance room.

• Got help & installed 6th nose rib
• resealed the tanks (again)
• received the empennage kit
• completed Right inboard aileron bracket

Rather than cramming all of that into one post, I'll make a separate post for each item.  Keep reading!

§29-06 thru -09 Left

Page 6 calls for making the spar even longer.  There is a doubler plate that connects a ~2 foot Spar Extension to the outboard edge.  I clecoed that up a few days ago and was very pleased with myself when 6 clecos went together nicely.  On Sunday I played Grandpa and gave Layne (an 8 year old) his 2nd lesson in riveting.  He did a good job of wearing ear & eye protective gear, too.   I shot my first 470AD4-6 rivet, but couldn't get the next one to insert.  Upon closer inspection I discovered that the doubler is not symmetric about the longitudinal axis and I had in fact installed it upside down.

Layne got another lesson; how to drill out a rivet.  It didn't take too long and I happened to have some spare 4-6's from the RV-12 kit so I won't be short at the end.

Wing Spar (gold) & Extension (silver)

I'm not able to re-seal the tanks (3rd time!) until I get some parts from Van's.  Specifically, I ordered replacement screws since the Phillips heads are getting stripped from so many insertion/removal cycles.  That left me with either the option of waiting around and wasting another day or starting another major component.   If there's a leak on the forward edge of the tank, I'm going to be very pissed at Past Me!

Attaching the main spar to the forward edge of the tank was very easy -- just my favorite LP4-3 blind rivets.   Attaching the inboard D-rib was pretty easy even with the ridiculously long 470AD4-12 rivets that were conveniently accessible from the root side of the wing. The next four D-ribs were another piece of cake as they, too, just attach with LP4-3's.    

On page 11, I came to a complete halt on the 6th rib.   To quote from the Wiki page: 6th rib from root: rivet gun + long-armed bucker through the lightning hole required. Plan for a helper or an unconventional body position.  That is an understatement.  I think even with a helper, it's going to be a bear.   I'm waiting for a confirmation that Steve B (he who lent me the rivet gun) will be able to swing by and give me a hand on Friday the 14th to finish that rib.   

The remaining 9 or so ribs will be attached with driven 470AD4-4's, which are not my favorite but will be easy to access.

inboard D-rib

§28-18 thru -21 Left Pushrod installation

 It's been a while since I last updated this.   Work is sucking up so much of my time, but that's how I keep up the cash flow to pay for this insane hobby.    Last week I finished up the pushrod installation on the Left wing.  It was fairly straightforward and kind of interesting to see how the system will work.  Basically, there is a pushrod extending from the root of the wing that will eventually connect to something inside the fuselage.  When that rod is moved outboard, it actuates a bell crank that moves the outer pushrod inboard.  This, in turn, pulls the small pushrod forward which will cause the aileron to deflect upward, thus banking the plane to the left.  It is left as an exercise for the reader to fill in the blanks regarding motion in the opposite directions.

Large pushrod at wing root.

Small pushrod at aileron attach point

Really getting a good look at the aileron pushrod system has done nothing to allay my concerns about how the flaps are going to be activated.  I identified a bracket that will hold a pulley for flap cables and can sort of visualize where something might fit in the inboard mixer box, but for the life of me I can't see how it's going to be retained in there since there are no nut plates or anything.   I'm guessing that there will be two cables in opposition connected to bell crank and one end of the bell crank will have yet another pushrod.  Why those components weren't included in the wing kit so they could be installed before buttoning up the skins is something that baffles me.   Regardless, I will trust the process and will complete the wing skins as directed by the instructions.

Finally, I have to report that the damn tanks are still leaking. It's a much slower leak now, and it's in the same place on both tanks -- at the ground lug that is behind the fuel sender plate.   I also learned that the soap bubble trick only works on really slow leaks and it did a great job of letting me see where the air was escaping.   On an academic note, there is a phenomenon known as Starling's Law that is really important in cardiology. Basically, the amount of stretch that you get out of a given pressure is highly dependent upon the radius (size) of the thing being stretched.   When you pump up the balloon with the hand pump, the balloon gets sort of inflated and does nothing for several pumps, then abruptly grows quite large without any further pumping.   Human hearts tend to do the same thing when they fail due to fighting high blood pressure for a long time.  It was really cool to see it in action rather than just imagining it as an academic factoid.

Today (well, yesterday) I spent two hours removing & cleaning the fuel sender units and the inboard access plates of both wings.  Man, I hate working with Proseal!   I'm going to use all new screws and lock washers for this 3rd attempt at sealing the tanks.   I've done some cruising through VAF and found several techniques that I will try to integrate into this next attempt.   Fingers crossed.

Finally, the tail kit is en route and should arrive some time this week.

§ 28 -6 thru 13 -- push rods

 Van's is famous for the smoothness of the control feel of their airplanes.  I think one of the contributing factors is that they use bearings and pushrods whenever possible when designing their flight control linkages.  I had already assembled the rotational bearings in bell cranks.  This post documents building the push rods that attach to them.

I also like a really nice technique they employed for establishing the exact length of the push rods.  When you build one, you can turn the stem of the spherical bearing to move the length in or out by 1/48" at a time.  When I built the RV-12, I remember trying to very precise about my measurement.  In the RV-15, they have you assemble the push rod and then use temporary bolts to insert into holes provided in the main spar.  In other words, the main spar has a jig built in to it.   Very easy to twist the bearings to get a perfect fit -- no tape measure required!

I used blue locktite as a safety feature for the jam nuts and ruined one of the spherical bearings when the locktite dripped on the bearing itself.  Although it felt like it was still moving freely in its race, I expect that it will not remain in good condition for very long.  I tossed it in the junk bucket and ordered another one ($26!) from Van's.

Aileron Push Rods

Push rods, prior to riveting and installation of bearings

I started the final assembly of this chapter where the bellcranks get installed in the mixer and the pushrods get attached to the bellcranks.   Even without the skins on the wing, it's definitely challenging!   I'd like to have a trained capuchin monkey w/ tiny hands to help out.    I am absolutely dreading / afraid of trying to install the flap control mechanism after the wing is closed up!

§27 L; IB Mixer - Rear Spar

 This was also a pretty straightforward chapter.  The Inboard Mixer was nestled into the space just next to the tank and directly in front of the spar attachment area.  The holes that were left open for the rear spar attachment were then used to rivet the mixer to the spar.  Here's where the infamous Cherry Max Rivets got used -- all 39 of them.  These are pull rivets ("pop rivets", although that's actually another brand name) but they are stronger than the typical LP3-4's used nearly everywhere else in the plane.   The book says to be sure to pull exactly in line with the stem, but that's not possible with a few of the rivets because there is a flange immediately in the way.  I bent the flanges as much as I could and did the best job possible.

IB Mixer, as viewed from the front of the wing assembly

For some reason, they decided to have the flap tracks installed in this chapter rather than give them their own chapter.   The flap tracks are interesting; they are jet black and I'm not sure if they're aluminum or something else.  I am getting better at riveting.  There were two rivets that couldn't be bucked with my titanium bar.  I used a flat plate of steel and got creative.  Worked great!

 

Flap Tracks

§26 L; Rear Spar - Tank

 I got a lot accomplished in the last week, but one thing I didn't have time to do was document it.  I typically have slow times between patients at night, but not recently.  Sorry for the delay.   I'll publish several updates in a row so i don't overwhelm you with a really long post.

Attaching the rear spar to the tank assembly wasn't too bad.  It was literally a one pager that consisted of bucking 33 rivets. The only challenging part was ensuring that I only riveted the holes called out in the KAI, as many holes were left open for the next chapter.

I'm starting to get a feel for when a bucked rivet will look good or look like a mess.  I think the key technique is to maintain pretty firm pressure with the rivet gun, but not much pressure on the bucking bar.  Time will tell.

Again, no picture as it really doesn't look any different.