Section 9 - Elevators (wired trim tab motor; rolled left leading edge; fabricated counterbalances)

The elevators have (finally) been completed! The pictures and tasks below are from several days during the past ~week.

5 wires emanate from the trim tab motor, and need to be stripped, crimped into male micro-fit Molex pins, and then inserted into the black Molex housing shown below. Easy enough task? Not without the right tools.  First, I ordered a crimper that another blogger recommended - it is cheap, and really not great quality; however, for these 5 crimps, it should (and did) work fine. Then I tried to strip the 5 wires with my trusty old (emphasis on OLD - 35 years at least) wire strippers that my dad passed down to me. No dice - they were too dull to do the job on these fine 26AWG wires.  Next, I ordered a Chinese knock-off automatic wire stripper ... which is STILL in the mail, on the slow-boat from China.  Since I wanted to complete the elevators this week, I ordered a very high quality wire stripper (Ideal Stripmaster; 16-26AWG) that came the next day, and made quick work of stripping those 5 wires.  That's it - no more crappy tools!

A word about micro-fit Molex connectors:  Several folks on the VAF forums have made a big deal out of these connectors, but they are actually quite easy (if your eyesight is good - they are tiny). Strip about 1/8" of the wire; insert the metal pin into the crimper, making sure that the back end is flush with the crimper; insert the wire such that only about 1/16" of the insulation sticks into the pin - i.e. just enough so the first band crimps the insulation and the second band crimps the wire; and, then crimp firmly (but not too hard); finally, tug the wire to make sure the connection is secure.  Next, note that the pin's cross-section is a "U" and also note that inside each hole of the 6-pin molex housing has a little tab on one side.  That tab slides between the "U" of the metal pin.  You may or may not hear a click when it fully inserts; pull to make sure the pin seated in the black housing, and that's it!  It only goes in one way.  Others have just tried rotating it 90deg when it doesn't work ... but why guess? Take a look inside the housing to locate the little tabs, and then orient your pins to match.

Section 9 - Elevators (riveted right trailing edge; rolled/riveted right leading edge)

After letting the 6 right trailing edge foam ribs cure for 3 days following adhering with proseal, I double-blind riveted the 51 rivets in the trailing edge, riveted the remaining rivets in the tip rib and inboard rib, and then rolled and riveted the leading edge of the right elevator. Just as with the rudder, rolling the leading edge is an exercise in patience - two-thirds with a 1" PVC pipe duct-taped to the entire length (see section 5.9), and then the rest of the way slowly massaging it by hand.  The two skins must overlap to reduce/eliminate stress on the rivets; once they do overlap, blind-riveting them together was a snap ... and a great sense of accomplishment.

Straight, right trailing edge (top view, machined rivet heads):

Section 9 - Elevators (proseal foam ribs to elevators and tabs; rivet trailing edge; trim tab motor)

Productive week in the workshop - prosealed all foam ribs to the trailing skins of each elevator and trim tab; used VHB tape to attach all trailing edge wedges (3); squeeze-riveted the trailing edge of the left elevator and trim tab; pop-riveted the closeout tabs for the left elevator and trim tab; and, started working on the trim tab motor. I had to stop since my very old wire strippers were inadequate, and my new ones are on the slow boat from China.  Damn, I should have bought those from Cleaveland Aircraft Tool - they would be here by now. That's what I get for trying to save $4.

Proseal is a mess; and this particular formulation hardens quickly, so you have to work fast ... thus no pics of the foam ribs slathered in the dark grayish goo.  Left elevator is shown here.  Note that for all trailing edges, I modified the process only slightly - attach VHB tape to both sides of the trailing edge wedge, let cure for about an hour, stick to the lower skin, proseal the foam ribs in place, close the skins, and remove the VHB protective backing and stick wedge to upper skin (instructions has you doing this after proseal curing).  Worked well, and it was easier to remove the tape's backing.

Section 9 - Elevators (riveting skins to spars, and other misc. riveting)

This will be a long entry, because of a very productive Friday night and all-day Saturday ... most of it spent riveting many pieces together.  A "special bucking bar," used only for the RV-14 and RV-10 elevator to attach the bottom of the left elevator skin and top of the right elevator skin to their corresponding rear spar with AN426AD3-3.5 rivets, was used today ... and likely will never be used again for this build.  I wish I had taken pictures of bucking those rivets, but I spent so much of my mental energy trying not to F it up - one has to position the elevators on a shim (I used cardboard), and the edge of the elevator is then placed about 3" inward of the edge of the table.  The foot-long bucking bar uses the edge of the table as a fulcrum, and thus you press down on the back end of the bar, bucking upward into the rear spar under the skin.  Counterpressure pushing from the flat rivet set will set the rivet.  Anyway, here are the pics from the last two days:

Midway through riveting the trim tab motor housing doubler:

Section 9 - Elevators (riveting two skins to rear spars and ribs)

Slow yet steady progress on the elevators this week.  During the last few days, I riveted the left and right spars to 12 rib halves (not shown; the other half goes on the respective skins in a subsequent step) and 3 shear clips (2 for left elevator, 1 for right elevator). Shown below are the first steps to attach the skins to the rear spars and rib halves.

Clecoed then riveted top left skin to left rear spar and front part of trim tab hinge:

Section 9 - Elevators (riveting items to front spars)

I had a very productive Sunday, consisting mostly of riveting.  Specifically, I riveted the tip ribs to each other and then to the front spar; hinge reinforcement plates, nutplates and root ribs to the front spar; counterbalance skins to tip ribs; and, elevator horns to the root ribs and front spar.  Also installed a bushing for what I assume will serve as a conduit for wires that lead to the trim tab motor.

Section 9 - Elevators (riveting trim tab spar and horn; scuffing elevators for foam ribs)

The beginning of this week didn't have much to report - just riveting the trim tab spar and horns to the trim tab, as well as scuffing all 4 skins of the elevators and 2 rear spars to accept the prosealed foam ribs.  I hope to accomplish more this weekend, when I have a little more time (busy week at work and with after-school kid activities).

Riveting of trim tab spar and horns:

Section 9 - Elevators (trim tab; priming)

Today's task was to fabricate the trim tab to the point where I have to Proseal the foam ribs to the skins/spar ... but I'll actually hold, so I can do that part when I glue the foam ribs to the left elevator (i.e. don't waste the Proseal).  I was almost to the point of riveting the trim tab horns, until I realized I wanted/needed to prime them prior to installation.  So I ended up priming all the other parts that either were non alclad, or that I scuffed so much during fabrication that the alonized coating had worn off.

Most of the trim tab parts (there's not a lot to it) - not shown are one foam rib, the small trim tab horns, and the aft hinge:

Section 9 - Elevators (deburring, match-drilling, and a bunch of other tasks)

A lot of small, but (seemingly) important tasks happened since the last update, including bending close-out tabs on left skins, cutting right rear spar, drilling the 5/8" and 3/8" holes in left spar, clecoing (and then unclecoing) ribs and skins, match-drilling #30 and #40 holes as requires, and lots and lots of deburring of edges and all holes.  Oy.  Did I mention deburring?  Finally, I dimpled the ribs, spars, trim motor access doubler, shear clip, etc., fashioned the trim tab horns and pushrod, countersunk the trailing edges and rear spars, and riveted nutplates. All this and more took about 21 hrs. I didn't take too many pictures of all these steps, but here are a few:

A couple holes needed this little bad boy (90deg angle drill attachment from Cleaveland Aircraft Tools):

Section 9 - Elevators (initial prep; ribs; foam ribs; clecoing main structures)

Gathered all of the parts necessary for this section, which will build the elevators.  It seems that building the elevators will be as involved as the three sections that preceded it combined, so I'm sure this section will take me quite a bit of time.  Below are the smaller parts; not shown are the elevator skins, trim tab skins, lead weights, elevator horns, various hardware, and trim tab motor.