§36-05 thru -20 (R)

It's been a busy two days.  First, let's get the bad news out of the way.  (It has nothing to do with the plane, so, relax.) In order to be legally allowed to do my job I have to hold a set of "merit badges" such as BLS (CPR), ACLS, PALS, NRP and ATLS.  That last one, Advanced Trauma Life Support, is good for 4 years.  My current certificate expired on the 11th and I was informed that day that I was not allowed to work until I get it renewed.  I had received a warning, that I would be "locked out" of the schedule but I took that to mean that I could not be scheduled for any additional shifts.   I was never told that I had to stop working.   This has thrown a major monkey wrench into the ER's of two of my hospitals.  They are scrambling to find people to cover  4 shifts of 24 hrs each.  I've done what I can and will trade one shift to work at a hospital where I'm allowed a grace period to renew my ATLS.  Interestingly, I'm being told that the mandate is system wide, yet I'm allowed to work at Grady.  Go fig.   I renew on Saturday the 20th.

The good news is that I suddenly have an entire week off and I'm going to make good use of it!

As the title says, I got 16 pages done on the Right wing.  We're making progress.   Marking a page off in the book doesn't convey the prep work that goes into just assembling parts.   Most of yesterday morning & afternoon was spent clecoing all of the flap ribs onto the spars.  It went great, with only a few expected moments of head scratching ensuring that I was on track for L vs R.  Again, I would greatly appreciate Van's making explicit direction marks on their instructions and maybe a few comments to help orientation.  For example, on the flap spars a comment such as "The inboard side of the spar has two lightening holes between the 1st and 2nd rib.  The top webbing faces forward."     Anyway, after a false start or two I got both sets of ribs fully assembled. 

Ribs attached to the wrong spars

I looked at it and get ready to rivet.  Then I paused.  Then I pulled out the skins and laid them on the table and inserted the L rib subassembly into the L leading edge skin.  Everything slid together perfectly.  Happiness.  Just because I'm anal-retentive, I decided to cleco everything together so it would have some structural rigidity.  The ribs fit right in.  

Then I realized that the spar did not align with the skin.  I spent about an hour trying to figure out what had happened.  I never figured out how I spun myself into that circle, but eventually I got both spars into both skins and then reattached everything.   The left flap (assembled w/ clecos) went onto the shelf and I went to work on the right.

Left flap assembly, correctly oriented

Last night I finished up deburring and fluting all of the ribs and hardware attach points.  Today, I tackled bucking the larger rivets that are what hold this plane together.  All in all, I think I did a pretty good job, but I'm nowhere near being consistent.  Oddly, I think that I may be holding the bucking bar too tightly.   The physics isn't completely clear to me but it might be that if I hold too tight then a lot of the impulse goes into moving my fingers against muscle force and that dissipates energy into my hand.  Maybe by letting the bar absorb all of the impulse, more energy is reflected back into the rivet to cause it to set.   I'll think about it later.

Typical driven rivets.  Factory head (on top) has a "smiley" 

which is only a cosmetic defect.

The 3 shop heads are acceptable. 

At least 80-90 % of them look pretty close to the text book pictures.  A few are ugly but serviceable.  One is clearly a basket case, but drilling it out will cause more damage to the flange and actually weaken the final joint so it stay.  In case you're curious, it stays hidden because this all internal stuff that will never be seen again after I close it up.

I'm taking a lunch break and plan to write more later tonight.

Intermission

I'm have a lot of trouble finishing the ailerons.  The last step is deceptively simple -- insert the lead weights and install screws to hold them in place.  Unfortunately, there is no way to apply back pressure to the nut plates in which the screws thread, and without back pressure it is very difficult to get the threads to engage.  I've ruined the AN509-8R16 screws that came with the kit. I ordered new ones from Aircraft Spruce, but they use the new designation and I ordered the wrong sizes.  (yes, sizes--plural.  I want some screws that are a tad larger than called out to try a few tricks.).  I'll document the issue in more detail when I get it finished.

As is typical for me, when I have a problem or am facing a "don't screw this up!" task, I often take a break and do something else for a while.  I find that it lets me ruminate on the problem and reduces the risk of doing something out of frustration and making it worse.  This weekend is one such example, hence the title of today's posting.

Remember back in June 2013 when I built a toolbox as a practice kit?  (No, you don't.   But you can go read Metal has been bent; Rivets have been placed for reference.)  That tool box and a second one have been accumulating miscellaneous small tools for 13 years.  Van's isn't selling that practice kit any more, but I got a different practice kit that's a lot more fun.

Light Box

Light Box in the dark

This is a very simple, straight forward aluminum box with Van's logo cut out from the front.  It's internally illuminated by a strip of LEDs.  The point of the kit is to learn how to work with aluminum sheet metal and rivets.   As mentioned in the 2013 post, I really didn't want to use driven rivets.  To be honest, I have been slightly afraid of driving rivets all this time.  I have a borrowed a rivet gun from a hangar neighbor and bought some accessories including a totally cool tungsten bucking bar.  (It's really fun to feel its heft as it's about 20 % denser than steel!)  I finally bucked rivets to build the box and it really wasn't a big deal after all.  I feel much better about the fact that I will be driving rivets to assemble the main wing spars in a month or so.

I also painted it. (duh!) I made it another learning opportunity by using two different brands of primer before painting.  I have a clear preference for one of them, so I'm glad I did it.

The second part of the intermission involves the tool boxes mentioned above.   When I started building this month, I just had a bunch of tools moved from the hangar and thrown into a new tool chest.  They really weren't organized and just kind of thrown in at random.  I quickly ran out of space and yesterday I bought a second tool chest.   

Before:

two tables full of loose tools

After:

Two organized tool chests

Now that the light box is finished and the tools are properly organized, I'm going back to building.  I'll start on the flaps while I wait for the AN509-8R16's to arrive so I can finish the ailerons (eventually.)

§34-12, -13

Well, that took longer than I thought.  (So, what else is new?)

Page 12 is deceptively simple -- cleco & rivet the leading & trailing edges to the framework of the ailerons.  

Having said that, it is a relatively time intensive process with some 700 rivets that need to be set. I was (and still am) somewhat paranoid about the whole L vs R thing and went to the trouble of clecoing together not one, but both of the ailerons.   The leading edges are under a great deal of tension so I did a 100 % cleco as my test fit.   Both sets of skins looked great, but it was a lot of time and effort.  All of that was done with the skins still in blue plastic, so it all had to come off so I could pull the plastic and deburr all the edges, then get clecoed back together again.   My wife offered to help and learned a little bit about clecoing.  (She's OK with flying in planes in order to get somewhere, but isn't into aviation as such. The reason she offered to help is because she loves me 💘.)   Lesson:  pull the plastic and deburr parts before test fitting things together.  If they fit, you can go straight to riveting instead of backtracking all of those clecos. 

 

My wife, learning how to cleco.

 I put them both together again and started riveting.  I  got the trailing edge skins attached and had riveted the upper surfaces of the leading edges when this caught my eye:

Poorly aligned parts

What you are looking at is the hole in the leading edge skin but only part of the hole in the counter weight underneath it.  It doesn't take an aeronautical engineer to figure out that something is wrong and there's no way I'm going to be able to fit a screw in there.   What happened was that I got fooled by the initial test fitting of the counterbalance tubes and stopped thinking about orientations.  After the test fit (see previous post) I took them off to give them one more coat of primer and must have swapped them when I re-attached them.  I didn't think to double check their alignment before doing all of that riveting.

Today  I drilled out ~ 130 LP4-3 rivets.  I only messed up 3 or 4 of the flanges of the underlying ribs and that pleasantly surprised me.   I swapped the balance tubes and crossed my fingers when I put the skins back on and they aligned perfectly.   Finishing up the riveting gave me two nearly finished ailerons.

Left Aileron

Left Aileron (inverted)

Right Aileron

Page 13 was pretty straightforward and I'm not bothering to put in a picture.  I tried installed the lead weights inside the counterweight tubes and it's going to be tricky.  See the next post.

§34-05 thru -09 Right, §34-10, §34-11

I built up the Right Aileron framework yesterday, but didn't get a chance to document it until tonight.  As hoped, it went together about twice as fast as the Left.  I'm getting back into the rhythm of building and it's really a good feeling.   I've often appreciated the fact that my memories of building the RV-12 are positive, even accounting for the days of frustration and setbacks.   I love flying, I love building, but I'm not real fond of maintaining.  Oh, well.   That's why I'm building again.

I'm still getting to know how to use the pneumatic squeezer.  There were a few rivets that felt 'off' and the part twisted in my hand when the rivet set.  On inspection, I found that there was a gap between the two pieces that were being joined and there was a bit of a bulge of rivet material in between them.  I looked at it for a few minutes before realizing that it wasn't "close enough" and drilled out a few rivets, bent the ribs back towards their desired shape and squeezed again.    Better.

Today I primed the steel balance tubes and proceeded to figure out how to countersink steel.  The countersink tool that I have is an offset handle that you can rotate by hand.   I gave that a try and realized very quickly that I was "Going nowhere mighty fast".  (Scotty, Star Trek TOS).   It took about 30 min of prowling around my converted garage (aka "the shop") before I stumbled upon a solution.  The deburring tool had come with a 12" extension that I never used.  I cut off the end that accepted the counter sink tool and stuck that in the chuck of my hand drill and solved the problem. 

There are several comments in VAF regarding ensuring that the counterweight tubes are properly oriented.  I can't find any difference between them and they appear perfectly symmetrical.  Having said that, I was paranoid that I would mess something up so I decided to completely cleco the LE and TE skins to both ailerons before doing anything permanent. In the process I developed a migraine worth of confusion because the TE skins simply did not align.   I double checked my part numbers (e.g., the suffixes -001 and -002) but everything was correct, except that they didn't fit.  I eventually concluded that I had swapped the identity of the R and L parts in my mind and was actually assembling the wrong parts.   I swapped and everything fit together in typical Van's fashion.

Screwing in the bolts that hold the counterweights on was a challenge.   I truly wish that Mr Phillips had not made such an impression on the manufacturing industry.   Should I ever be asked to select fasteners, I will NEVER select a Phillips head screw.  They require significant axial loading in order to prevent the screw from stripping.  Hex, Robertson (square), Torx -- you name it -- any other screw design (well, not slotted) is better.

OK.  Enough bitching.  Next session will be a lot of preparation of the leading & trailing edges, then clecoeing everything together, then riveting.   That'll be a nice bit of progress!

Completed R frame, 

temporary LE skins, 

attached counterweights

 and trimmed tails.

The building has finally begun! (§34-05 thru -09, Left)

OK, so now we are officially started on actual construction.  It took about 3 hrs de-clecoing the Left aileron skeleton, deburring all of the edges and holes, reassembling and finally using rivets to hold things together.  

Behold -- the Left aileron skeleton

It took me three tries of remembering to ensure that all of the ribs were properly aligned before I started riveting.   The new squeezer is definitely different from using hand squeezers.   While it is easier to actually set the rivets pneumatically, it's a very heavy tool and puts a lot of stress on my thumb (which is not it as good shape as it was 15 years ago!)  I actually found that using it L handed was pretty workable,  I had to drill out my first rivet when I missed being on center with one and it was nice to realize that I remembered how to remove one.  Specifically, I used a #53 bit to make a pilot hole then a #40 to remove the bulk of the rivet and finally a pair of pliers to easily remove the remnants.    The pulled rivets went in without a problem and the old rivet puller showed no signs of age.

I won't have time to work on it today.  Tomorrow I am expecting it'll take me about half the time to assemble the R side.  Stay tuned.

Oh, BTW, today I'm supposed to get the delivery of the backordered and missing parts.  Fingers crossed!

The building has (almost) begun!

We were out of town for the week, playing grandpa & grandma with my daughter's family outside of New Orleans.   We got back late Friday night and Saturday I worked on one of Van's practice projects.  Specifically, there's a simple aluminum box with their logo cut out in front and illuminated from inside by a strip of LEDs.   I already built one and it was a good project to remind myself about how to cut, dimple, deburr, cleco and rivet things together.   The project comes with enough rivets to use either the default LP3-4 pop rivets or you can use a rivet gun.  I elected the latter as I have no significant experience driving rivets.  Alas, the rivet gun I borrowed today didn't work for some reason, so I shelved the rest of the practice project for now.  I will finish it using driven rivets whenever I get a functioning rivet gun.

Having put that on the shelf, I finally started working on the kit itself.  The instructions just say "here's the Left, you just mirror it in your head when you do the Right."  The user group has published a Wiki with errata & gotchas.  One of the first ones is that some of the parts are mis-labeled with respect to orientation.   Van's nomenclature leaves much to be desired.  As far as I've been able to deduce, parts that end with -001 are the first ones designed in CAD.  If a mirrored part is required, it gets a -002 suffix.  Note that these have nothing to do with the left or right of the airplane.

Armed with all of the trepidation that these factors engendered, I elected to do no cutting or bending or anything else that is not reversible.   Instead, I clecoed both of the aileron skeletons side by side.  Even so, there were several steps that are (IMHO) poorly illustrated in the KAI.   I'd love to see orientation vectors (up, fwd, outboard) next to many parts.   I did, in fact, cleco several things upside down or swapped inboard vs outboard.  I was very happy that I hadn't cut or drilled anything!

Right and Left aileron frameworks

When I return to the shop on Wednesday, I'll disassemble one framework, remove the plastic, deburr, etc, and start riveting.   I'll go back to my usual pattern of labeling each post with the pages of the KAI.   Talk next time!

Completely Unpacked Wings

Well, inventorying the small parts only took about an hour or so.   Van's has changed their method of packing small parts and are now using a collection of "tackle boxes" as they are called on VAF.  They are translucent plastic boxes with customizable inserts that are postioned to make ~25-30 little part bins.  Van's then printed a 'parts map' that physically overlays the bins for easy identification.  Think 'box of chocolates' from Valentine's Day with the candies labeled on the inside of the lid.    VAF had a few grumpy comments about parts that spilled over, but mine were just fine.

(I did forget to double check the length of the Cherry Max rivets that I received.  Some very early kits apparently had the wrong length of those parts.)

Tackle Boxes of Small Parts

Despite my reticence about throwing away good material, I just cut up the crate into <5' chunks and folded and tied all of the heavy duty cardboard into individual bundles and drug it all to the curb.   I hope it all got picked up today!  (My wife has not texted me anything to the contrary, so I'm hopeful.) The garage is now officially a workshop and ready for business!

Workshop (neé garage),

 generously donated by my loving wife.