Wing ribs almost complete

Again the power of the quickbuild! However, the ribs had significantly more custom work than just what the plans call for - I wanted to run two conduits (power and signals) through the wing, plus pitot and AoA tubes.

To enlarge the pre-drilled wiring hole for a conduit, I followed Van's recommendation and enlarged them to the maximum of 3/4". I verified that I could get .81 conduit through the 3/4" holes using a scrap piece:

Checking that I can get the .81" conduit through a .75" hole.

To actually do the enlarging for the inboard ribs where both skins were already riveted, I used a 12" 3/8 drill extension (from Home Depot) and a unibit which had 3/4" as its largest size:

"The harpoon" - setup to enlarge rib holes

Deburring those holes was slightly annoying and required some contorting, but was doable.
Running the conduit through them, on the other side, was VERY annoying and time-consuming:

Conduit done on the right wing

Luckily, I recruited an intern (visiting friend) to do it for the other wing:


She looked happy on this picture - that's because then she hadn't yet realized how painful it'd be to run the conduit through the inboard section with the bottom skin already riveted on :) but she got it done anyway.

I chose to install the pitot tube one bay outboard of the aileron bellcrank (per previous post) and cut/bent/deburred/flared its tubes such that they'll go through the rib, angled such that they point towards the holes in the next rib:

Pitot and AoA tubes bent for passing through the rib.

In the process, I found that using a tube bender on these is a very bad idea - I tried to create a bend a little further down, and it created a kink, which made the tube break, forcing me to cut them a little shorter. Going back to the Garmin manual, I realized they were not 1/4", but rather 3/16", which explains it :/

Just in case, I protected that lightening hole so the tubes can't contact the ribs:

Grommet edging protecting the path of the pitot/AoA tubes

I drilled the second set of tube holes, for the AoA tube, using a combination of the extension shown above, long drill bits, a right-angle drill, and a snake drill (it was especially annoying to drill through the 3rd and 4th inboard ribs):

Pair of pitot/AoA holes next to the 

AoA tube holes through the ribs (not yet their full size)

Initial drilling the inboard AoA tube holes

Finally, I enlarged the holes to 3/8" (slowly, #40 -> #30 -> #21 -> #10 -> 1/4" -> 3/8") for the SB375-4 snap bushings and verified that the tubes run fine through those paths:

Pitot and AoA holes with snap bushings installed

Pitot and AoA holes just before the aileron bellcrank

Finally, I test-ran the tubes through the bushings and cut them to size (+slack):

Tubes running all the way to the pitot tube
Tubes reaching the pitot tube

I realized I don't have the proper snap-on tubing connectors for the root rib holes, so I'll need to order those.

For the second conduit, I didn't want to drill another large hole, so I used ClickBond right-angle cable tie mounts (CB4020V5N12-750):

ClickBond CB4020s for the second wing conduits
Wife examines the installed cable tie mounts

Row of installed cable tie mounts for the second conduit

For some reason, removing the Clickbond fixtures was really hard, and in fact some of the cable tie mounts came out when we pulled them and had to be re-installed.

Cable tie mounts with the fixtures removed

I ran the conduits and cut them to size (with a couple feet of slack) - it was amazingly easy compared to the first one, made me wish I had just done this for the other as well:

Second conduit running through the wing

The outer rib has no Clickbond for now - I'm leaving that for when the wingtip is installed, so I can figure out which side won't interfere with the wingtip itself. Also, if it goes on the inside, that'd interfere with riveting. Should be pretty easy to install it from the outside anyway.

Since the 2nd and 3rd inboard ribs have no Clickbond mounts (no good reason to, and it'd be quite painful to install in the tight space), I put grommet edging on those to prevent chaffing of the conduit:

Grommet edging on lightening holes that have no cable tie mount

I found the right position for the Garmin GAP-26 heatet pitot regulator, one rib inboard of the bellcrank:

Position for pitot heat controller

This position is close enough to the inspection hole but will minimize wingtip (NAV antenna/magnetometer) interference by keeping the high-current box further from the tip, and there's enough wire length to still reach the pitot tube. I match-drilled the box's holes into the ribs, then installed Clickbond CN614CR06P nutplates to hold it without interfering with the aileron pushrod:

Pitot heat controller in place

Clecos holding the pitot heat controller show that the nutplates won't interfere with the pushrod
Clickbond nutplates for attaching the pitot heat controller

Clickbond nutplates with the center shaft removed

When I test-ran the conduit, I also tried attaching the box and running the wire to the probe - the wire length is indeed good, and the run will be away from the pushrod:

Garmin pitot heat controller box with wires running to the pitot tube

Pitot heat wires arrrive at the pitot tube with good slack

In retrospect, given how much effort it was to get all of this through the inboard ribs, I probably should just have removed the inboard skin, done the work, then riveted it again - I still don't understand why Van's has to rivet that skin at the QB factory.

At this point, the only thing left related to the ribs is the root connectors (for both air and wires).

Time lapse:

Total wing ribs time: 13.2h
Total wing rib rivets: 0!!

Fuel tanks tested and attached

Before moving, we wanted to put the wing parts together, such as attaching the tanks back in place - for that, we had to leak-test them.

We used a product called Snoop (thanks once again VAF!).

Applying snoop to the rivet lines
Applying Snoop to the sealed baffle
We weren't finding any leaks and I kept wondering if we were doing it right, but then Snoop proved that it really works - there was a tiny bit of air leaking from the return line cap (which was temporary and thus not sealed), and it produced a lot of bubbles:

Bubbles from the fuel return cap (underneath it)

We're looking forward to those camping trips, sleeping under the airplane :)
We then attached the tanks and moved both wings onto the same wing stand:

Attaching the left fuel tank

Attaching the right fuel tank

Tanks attached
We then realized that there was some skin overlap between the tank and the other skins which was making them buckle:

Buckled skin which needs to be trimmed down to match the inboard skin

Buckled skin which needs to be trimmed down to match the leading edge skin
This was just a couple of days before moving, though, and we didn't have the time to fix it then. The only remaining step is to fix that, but it involves removing the tanks, filing down the skin edges, and then attaching them again.

Time lapse:

Total fuel tank time: 14.2h
Total fuel tank rivets: 30 

We're back (some bottom wing skin progress)

I've finally made some small progress on the bottom wing skins at the new house :) That said, I'll likely spend some time posting progress that happened before we moved that I hadn't had the time to upload yet.

The new workshop is set up, full with a new compressor:

New workshop
New compressor
I spent some time deburring the outboard bottom wing skins at the old place and started preparing the inboard nutplate holes - more than 6 months later, at the new place, I finally finished those and installed the nutplates:

Inboard nutplates installed
Dimpling the aftmost screw hole was a challenge, since the dimple die wouldn't fit there - I took a #8 screw dimple die and simply ground down the side until it fit:

Customized #8 dimple die which will fit to dimple the aftmost inboard nutplate screw hole

Small progress, but I'm back to work nonetheless.

Time lapse:

Total bottom wing skin time: 40h
Total bottom wing skin rivets: 430

We've moved!

We finally moved to the new house today.
I seriously considered the suggestion on VAF to move the airplane myself, but since we were hiring movers for a lot of other stuff anyway, we just had them take it. They did a pretty good job, and the only thing I had to ask them to do differently was to lay my flaps flat on the truck floor instead of on their trailing edges.
Garage all packed up and ready for moving!
Loading the wings onto the truck
Loading the tailcone
Goodbye, old workshop! You served me well, but I shall not miss you.
Unloading the (intact) wings
Moving the wings into the new garage
New workshop full of parts
A few of the smaller parts will still need to be taken by car (ailerons, vertical stabilizer, rudder, etc.), but all the large parts and a lot of the small stuff is already there.

Now on to putting the workshop together again to build on!

Fuel tank assembly complete

The tank comes mostly assembled, with a few finishing items not yet done.

The first task was to remove the tanks, which was easy but time-consuming (lots of screws and bolts):
Tank removed from the right wing
riveting the bearing:
Bearing riveted to right tank
I installed the skin nutplates, including those that are only called for much later in section 44 (didn't find a reason not to):
Nutplates riveted to right tank
I bent and cut the fuel sender arms, only to find that I, like others, had screwed up and cut it too short without realizing the arm is supposed to go through the sender. Ordered new arms, re-did it - correctly this time:
Fuel sender arms after bending

Fuel senders, VA-261 pickups, drain and other hardware for the tank
I read up a little more on the fuel system and realized that, if I decide to use a FADEC, I may need a fuel return line. Much easier to do it before installing the tank, so I did some careful planning - some people from VAF pointed out that it can't be too far aft or it'll get in the way of the wing attachment. I got two more VA-141 brackets for this, and used a 3/8" NPT tap to make sure I could screw VA-261s in from the other side. I then used those to drill the holes on the side of the tank, next to the vent line:
Holes drilled for fuel return line bracket on left tank
We did the drilling with a vacuum cleaner extension (piece of conduit taped to the tip of the vacuum) strategically placed to catch aluminum bits, which greatly minimized the mess inside the tank, but we still had to later move that extension around to clean up all the bits that flew around the tank.

When I drilled the left one, I realized I, too, had made a small mistake - notice the J-channel from the tank's structure shows through the hole - the hole was too close to it, so I had to shave off the corner of the J-channel to ensure the VA-261 would still fit.

On the second tank, I drilled the hole a bit further to the side, and instead trimmed the bracket itself to fit, this time hitting no obstacles inside:
Holes for fuel return line bracket
Trimmed VA-141 bracket for fuel return line
Finally, I installed the senders, return bracket, pickup, and drain, using tank sealant and thread-locking sealant. For the fuel return brackets, I used CR3212-4-2 rivets:
Fuel return bracket, fuel level sender and fuel pickup installed on left tank

Fuel return bracket, fuel level sender, fuel pickup and drain installed on left tank

Right fuel tank with all plugs and brackets installed
We then installed the Newton fuel caps - even in the garage, the Van's caps were annoying enough to open and close to make me want to replace them:

Cleaning the excess sealant from the fuel cap bracket the best we could

Newton fuel cap installed (needs some cleanup afterwards)
Last but not least, someone at VAF called my attention to the fact that I hadn't left a ring terminal around one of the fuel sender screws, so after the sealant cured I checked the ground continuity between the fuel sender plate and the skin, and it seems to be conducting just fine.

Among the next steps are leak-checking the tanks and reattaching them to the wing spars.

Time lapse:

Total fuel tank time: 12.1h
Total fuel tank rivets: 30

Popular posts