2 hrs. working on the rear seat belts.  As soon as I started working on it I wished I had done some of this before putting on the side skins...

This the recommended washer...  But, a bolt head would nearly pull through that, so...

.... another washer is in order.

The recommended bolt AN3-5A is too short.  The next size I had on hand was a -10A, and that worked perfectly.

In place.

One done...  3 more in the back to go...

The center ones are impossible to reach over the side skin, so in I went...  My first time working "inside" the plane. ;-)

 The buckle side in place.  I see the belt pushed up a bit against the rudder cable guide.  OK?  It's the guide, so I think it's OK, but I'll double check with the factory.

Glad I have knee pads to work inside.  Without = Ouch.

All 4 rear lap belt assemblies in place.

Onto the reel assembly..  Big bolt, which didn't come with a matching nut.  What size?  Another question for the factory.

Will do down there with the bolt going through that hole at the bottom.  Should be interesting to see how I'll tighten that nut since it will be under the reel assembly.. :-O

1.5 hrs. finishing up the right side skin and some cleaning up.  Next up will be the rear seat belts.

Some of my "exception" rivets needed to be done.  The "exceptions" were the holes that needed some attention before riveting (e.g. flange on other side was bent or misaligned, etc.)

Saw that new Sling 4 builder Pat bought this nifty rivetnut driver and I thought I MUST have that!  While I'm nearing the end, I still have lots of rivnuts to drive and this will make it much easier.  Wish I had this when I was driving the M6 rivnut a couple of weeks ago...

Two new Sling 4 builders to add!  Here are their blogs:

John Weiser

Pat Shine

2.5 hrs. on the right side skin and it's nearly complete.

Just a few holes remain to be done on the right side.

With a bit of weighing and multiplying I figure I've pulled about 1000 rivets over the last 2 weeks...

4 hrs. working on the right side center fuselage side skin.

One last thing I needed to finish on the left side was the seat belt anchor.  3 4.8mm rivets and an AN3-5 bolt.  It's not going anywhere.

On to the right side.  Made sure to put in the 3 rivets that are easier to do with the wing root plate off.

Lots-o-rivets...  Most done, with still a good number to go.  Top row needs to be reamed out to 4mm.

Half hour of more riveting.

All except one done (still need to do the bottom except as noted).  The one remaining has a channel that's bent a bit behind the hole, so I need to fix that before driving the rivet.  Some holes on the bottom (flat area in middle) will wait until the wing is attached.

3 holes enlarged to 4.8mm for the 4.8x15mm rivets.  One enlarged to accommodate an AN3-5 Bolt.

1.5 hrs finishing priming and riveting the wing root plates.

I finished up priming the wing root parts, but I also primed this area of the skin.  While the exterior skins will be professionally primed and painted (so I haven't primed the outside of skins), this area will be covered and mated with the wing root plates, so I primed it.  Looks messy brushed on...

...but, once it's dry it's fine (not that it matters).

The seat belt anchor gets attached here on the inside, so don't forget that.

Cleco'ed in place.

Since the seat belt anchor is thick you really can't use standard 4mm rivets for it because they're not long enough.  Those will be reamed out to 4.8mm, so I can use the 15mm long rivets.  Also, I saw other builders ream out the corner hole to accommodate a bolt for extra strength, so I'll do that too.  I've marked those holes, so I don't try to put a 4mm rivet in them.

Lots-o-rivets!  Most of the 4mm rivets are in.

A new Sling 4 builder alerted me to a new tool coming out that looks great.  It's a new electric, battery-powered rivet gun from Milwaukee (coming out next month).  Use this tool and you have absolutely no need for a compressor for building a Sling.  Big win!

3.5 hrs on side skins.

Don't forget the wing root parts (2 of them on each side) must go on before riveting the skins on.

There are a few rivets that are easier to do with the root parts off, like this one.

In place...  Though I realized that these parts were not primed, so it came off again...

I noticed several months ago that the holes in the gussets and spacers that go on the inside of the side skins are 4mm, while the skins are 3.2mm.  So, I reamed the holes out to 4mm.  As a matter of fact I reamed the whole row to 4mm so it looks consistent.

Holding the strips in place while I drilled/reamed.

Left side mostly done.

Bigger view.

Inside view showing all the gussets that have 4mm holes.

3.5 hrs. on the center side skins.

Printed out various installation and maintenance manuals.  Time to get organized!

In the binders and ready at hand.

I saw that some people had done this bend at the bottom of the center skins while off the plane, but I managed to get it to bend while on.  There are two bends to do, in the back of the center skin and in front of the spar.

Slowly bending it...  I used a wood block to apply pressure to get it to bend.

The front bend was harder.

This section was tough...  Kept working it though and it finally was bent.

Now that I knew where the bends were I decided to bend the right side skin while off the plane.  Much easier....

On it goes...

Ran out of cleco's before completing the right side.

Inside view.  Tomorrow I start riveting both sides on.

Man I've wanted to work on the plane.... But, it's been a bit nutty at work this week.  I'm a hardware design engineer at Intel and I've been debugging my design recently.  The pressure is on to get it working soon....  So, I've been working every night to get the bugs out.

This is a screen shot of a simulation of my design.  Time flows left to right and the horizontal lines are different signals in my design.  I have to stare at these simulations sometimes for hours until I figure out what's wrong...  Detective work.  Sometimes obvious and found in minutes, sometimes it's a needle in a haystack...

Hoping I can get some good hours in on the plane this weekend!

4 hrs. on installing the regulator rivnuts and left side center skin.

Installing these M6 rivnuts is a pain...  The device on the right is what I used to install them.  I couldn't imagine doing these with the side skins already on...

One of the mounting bushings in place.

Removed these for now since the parachute cables need to attach to these.

Older daughter putting in some cleco's on the left side center skin.  Thanks for the help! :-)

Mostly cleco'ed on with all spacers and gussets in place.