2 hrs. wiring the tip light and test fitting the aileron and flap.

In order to have the tip at the same angle as the other wing, some of the bottom holes ended up kind of close to the edge.  So, just to be sure it won't come lose I'm going to layer in some fiberglass (first time I'm doing that!).  So, I ordered some cloth and it's coming tomorrow.  Watched a bunch of YouTube videos on laying fiberglass and I think I've got it.

While I'm waiting for the fiberglass I decided to complete the tip light wiring.

This is called a "Western Union" or "lineman's" splice.  Well, close to that...  Note that I've already slipped on the heat-shrink tubing.

All soldered up!

And, using a heat gun, the heat-shrink tubing is wrapped tight.

Wiring pushed through the opening.

And the light is bolted in place!

Test fit of the aileron and flap.  Very close...  hmmm...  Maybe I can hand warp it a bit so I don't have to de-rivet the whole leading edge of the aileron?...  We'll see tomorrow.

Meanwhile...  The outer edge rivets rub up against the wing...  Does the aileron move this far down?...  Because if it does...

... it's a problem...  If it gets past the rivets it won't go back.  So, question to the factory or other Sling 4 builders/owners, does it angle this far??

NEXT TASKS:

1. Fiberglass along the bottom inside edge of the tip to reinforce it.
2. Composite wing tip riveted to wing.
3. Use epoxy filler to fill between the composite top and wing.
4. Issue or solution for my aileron tolerance problem?
5. Finish filling and sanding rivets.
6. Rivet the one on the left wing's step rib that needs special handling (waiting to hear back from the factory on what to do with that hole).
7. Finish one of the composite tips of the elevator.
8. Fill rivets of elevator.
9. START ON FUSELAGE!

3 hrs. testing out a sanding method for the rivets and installing the small wing skin and composite tip.

Made a thinner template for sanding the rivet heads.  It's thin and the rivet head fits through completely so it's easy to sand.  Tried sanding it with a buffing bit on my Dremel and that worked well except it wore down very quickly, so maybe I'll try hand sanding.  Seems like there is no "quick" way to fill rivets...

Got the part yesterday.  Deburred, cleaned and primed (inside only) it.

And it's on!

Took awhile to sand down the inside trailing edge of the tip to get it to fit, but it's in.  Making sure the tip is at the same angle as the other wing I marked the first hole to be drilled on the top and drilled that off the wing since the fiberglass gives too much to do that first hole.  After that one is cleco'ed on I did one on the bottom and then you can start working your way out one or two holes at a time: Drill through the holes into the fiberglass with a small bit, ream out to the right size, insert a cleco and then go to the next one or two holes.

Working out from the center...

And they're all done!

Tip off to clean up the inside of all the debris and deburr all the holes.  Next will be to pull the wiring through the tip and solder all the wires.  Then the tip is riveted on!

NEXT TASKS:

1. Composite wing tip riveted to wing and light installation.
2. Use epoxy filler to fill between the composite top and wing.
3. Test fit of aileron and flap, with likely adjustment of the aileron to line up the trailing edges.
4. Fill rivets - most done already...
5. Rivet the one on the left wing's step rib that needs special handling (waiting to hear back from the factory on what to do with that hole).
6. Finish one of the composite tips of the elevator.
7. Fill rivets of elevator.
8. START ON FUSELAGE!

1 hr more of tedious rivet filling...  All the top rivets are done (well, not the sanding part...).

I won't bore you with a picture of filled rivets, so here's a picture of my Stratux build.  Works like a charm!

And click here to see a great video of the Blue Angels (click the gear icon in the lower right of the video to change it to HD).  Watch how he grunts and bears down to counteract the g's he's pulling.  I'd guess he's pulling over 7 g's.

NEXT TASKS:

1. Composite wing tip riveted to wing and light installation (wing skin part coming on Monday).
2. Use epoxy filler to fill between the composite top and wing.
3. Test fit of aileron and flap, with likely adjustment of the aileron to line up the trailing edges.
4. Fill rivets - most done already...
5. Rivet the one on the left wing's step rib that needs special handling (waiting to hear back from the factory on what to do with that hole).
6. Finish one of the composite tips of the elevator.
7. Fill rivets of elevator.
8. START ON FUSELAGE!

I've pretty much decided to wait for the new Rotax 915iS, which is their fuel injection update to the turbocharged 914.  It will be available in the fall of 2017.  While I think I'll be ready for an engine before that, I think it's worth waiting a couple extra months for the 915.

Check it out here.

I see that it has dual redundant ECU's made by Rockwell Collins and that reminds me of this totally hilarious video made several years ago.  This bit has actually been around in various forms for many decades.  If you're an engineer you're going to love this!  Enjoy!  :-)

1 hr. filling rivets (as long as my back can take it hunched over the wing...).  Doing this while I await the arrival of the small wing skin (Monday).

Here's a video of me filling rivets to show you how I do it.

Still have the large (4mm) rivets to do and a bunch of the smaller 3.2mm rivets.  SO many rivets....

NEXT TASKS:

1. Wing tip assembly and light installation.
2. Test fit of aileron and flap, with likely adjustment of the aileron to line up the trailing edges.
3. Fill rivets - 2/3rd's done already...
4. Rivet the one on the left wing's step rib that needs special handling (waiting to hear back from the factory on what to do with that hole).
5. Finish one of the composite tips of the elevator.
6. Fill rivets of elevator.
7. START ON FUSELAGE!

1.5 hrs. filling rivets.  I tried the factory approach using my newly made masking tool and it works great!  Especially using epoxy filler instead of Bondo since it lasted for the entire time.  In an hour and a half I was able to do about half the rivets on the top and leading edge of the wing.  I'd say that's easily twice as efficient as my previous painter's tape approach.

I still have to sand them but I think that will be fast (I'll use the masking tool for that too).

NEXT TASKS:

1. Wing tip assembly and light installation.
2. Test fit of aileron and flap, with likely adjustment of the aileron to line up the trailing edges.
3. Fill rivets - Half done already.
4. Rivet the one on the left wing's step rib that needs special handling (waiting to hear back from the factory on what to do with that hole).
5. Finish one of the composite tips of the elevator.
6. Fill rivets of elevator.
7. START ON FUSELAGE!

.5 hrs. making a new tool for filling the rivets by the factory method.  I figure I'll do that while I'm waiting for the new wing skin to arrive.

Fits nice!  The one I made a long time ago had holes too big so the filler would leak around the rivet head.  This should work better.  I'll be using epoxy filler this time instead of the much more toxic (so I've heard) Bondo.  Another benefit of the epoxy is that I can make more since it will last much longer before hardening.

Bonus picture of Crosby being a bad boy!  He got hold of a roll of paper towels while we were out...

He loves shredding paper of any sort!