Flap arms installed and wing tip fit-up

My second Monday night session at the shop was a productive one.  Three uninterrupted hours of build time and I got some good stuff done.

First up, I decided to go ahead and rivet the flap arms in place.  The three outboard arms follow the standard rivet head on thinnest material (in this case the ribs):

The inner-most flap arm sits inside the fuel tank bay.  In order to allow clearance for the fuel tank, the rivets are pulled with the head on the thick side of the joint here (the flap arm):

Rivet tails on flap side:

​Rivet heads on rib side:

Fuel tank bay is opposite - rivet heads on flap arm side of joint: 

All rivets double checked for correct pulled form.  Lots of strength here:

I decided it was time to start trimming up the wingtip and cut it out of the moulding material.

I tested the Dremel cutting wheel on waste edge first, it makes quick work of cutting out the wingtip from the form:

Here it is, rough cut out:

Careful use of the Dremel trims it down to the flat flange edges that will eventually tuck under the wing skin tips:

There are a couple of spots where the flange narrows around the point of the nose and at the trailing edge.  I was careful to leave lots of extra for fine trimming later:

I removed the skin stiffeners that were clecoed in place on the inside of the upper skin.  I can't believe how much drill debris (called swarf) that can fin it's way into the little spaces between parts.

A quick vacuum with the ShopVac and a soft brush attachment cleaned up most of it.

With things cleaned up, I slid the wing tip onto the end of the spar and rear channel.  I still need to make the support angles for each, but really happy how it's shaping up!

Neither the picture above or the one below capture how slanted the wing tip is.  The is on purpose and is for aerodynamic reasons (more on this in a future blog):

Finally tonight, I finished deburring the upper wing skin stiffeners, cleaned them and primed them.

They will go back on the upper skin once the wing is right-side-up.  For now, I'll leave them off until the upper skins are deburred, primed and not rolled up for storage.

Overall a good night.  Back on Wednesday for more.

​Thanks for reading :)