Chapter 25 – Finishing Elevators

Chapter 25 – Finishing Elevators

8 October 2015 – After I applied the third coat on each side, I started work on the Left elevator to get it ready for finishing.  I double checked the width of the elevator and ended up sanding the trailing edge to get it to a uniform width along the whole length of the elevator.  The outboard width of the elevator was 4.578″ inches wide while the inboard was 4.624″ wide.  After some very minor sanding, focusing on the inner 2/3rds of the elevator, I got the very inboard edge right at 4.6″.  With just a tad bit more sanding, while ensuring my TE was straight, I ended up with the inboard edge at right about 4.597″ …. less than 20 thou along that span is golden for me.  Any more sanding was just asking for a “chasing of the numbers” with the result being an elevator that’s too narrow.

I then started sanding then entire front nose area & top of the elevator.  Since I got the elevator foam cores from Feather Light, and since Feather Light uses the original Roncz elevator templates, a decent amount of foam along the razor-thin top front edge of the “C” shaped cutout (where the elevator tube is embedded) was broken off or torn away when I micro’d the foam to the elevator tube.  I think this is fairly common since using the original template results in that “C” channel just being ever so slightly too narrow for the elevator tube to fit into.  In other words, besides either cutting them myself and slightly modifying the channel before hot-wiring the foam, or using Steve’s Eureka CNC elevator cores, the bottom line is that minor carnage on each leading edge of the “C” channel was bound to ensue as the elevator foam is micro’d to the elevator tube.

Why am detailing all of this?  Because after glassing the elevator skins, there remains a very slight depression (trough, if you will) along the length of my elevator right at the top junction between elevator tube and foam core.  In the picture below, it is the line that is even with the top of the elevator hinge slot, and again, runs the full length of the elevator along the “nose”.  Also note in the pic below that the area to the left of the elevator hinge slot is sanded while the area to the right is not.

Prepping elevator for finishing

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10 October 2015 –  I finished sanding the slight span-wise trough in the right-side elevator in preparation for applying micro along the trough on each elevator.

Elevators sanded

Below is a pic of the applied micro in those troughs.  Once the micro is sanded, the elevators will be ready to mounted to the canard.

Fixing my "dented" elevators

I waited about 2-1/2 hours and then sanded the micro in the trough while it was in it’s “green” stage.  Unfortunately, it was only at the very beginning of the “green” stage and was still a bit more gooey than rubbery.  But, since it was late, I sacrificed the already well-used piece of 36-grit sandpaper on my sanding board to plow through the gooeyness and knock down the ridges and lumps on the elevator rounded leading edge.

Elevators sanded while "Green"

The next step is to sand smooth the micro I just added to the elevators.  After that’s complete I’ll be working on mounting the elevators onto the canard.

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12 October 2015 –  I started off today by hitting the cured micro on the elevators with my 36-grit sanding board.  After I got the edges somewhat feathered out & the ridges removed, I switched to a piece of 36-grit sandpaper that I simply wrapped around the curve of the front part of the elevators.  I then finished up with a few quick passes of 80 grit.  Below is a pic showing the comparison of the sanded elevator (top) to the other one still needing sanding.  Below that is a shot of both elevators’ sanded top leading edge micro strips.

Elevator front edge micro finish

Sanded elevator front edge micro

After sanding the front sides of the elevators, I checked the TE of the Right elevator.  Actually, I was checking the width from front to back along the entire span of the elevator just like I had done with the Left elevator.  Each end of the elevator was a tad thicker at just over 4.6″ wide, while the center of the elevator was 4.583″ wide.  I sanded the elevator on the edge of my long aluminum straight board that has 80 grit sandpaper tacked to it ( I bought this in Germany, and yes, still thinking it’s awesome!).  After a few minutes of some very careful sanding, I had the ends narrowed to 4.589″ on one end and 4.587″ on the other.  I figured that I would stop while I was close and not muck it up by going too far.  Now both my elevator widths are confirmed in specs.

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27 January 2016 — Since I took a fair amount of time in rebuilding the elevators, I decided to hold off on the finishing of the elevators at this time.  I do strongly feel that getting the parts finished as they’re completed is a good way to go, but since I’m most likely heading back to school in early February to take the Commercial Rating ground school and flight instruction, I want to focus on getting the main gear and associated components installed as a completed milestone before I start back spending a fair amount of time flying.

•••

Recent Posts

Project Update

Hey Guys,

I wanted to touch on something that while I was in the military was attributed to Gen. Petraeus, who stated, “Perfect is the enemy of good enough.”  I know a lot of people in the homebuilding world would groan at that statement, but the simple fact is that focusing on perfection, or the perfect solution, on every task is simply a huge time bust.  Burt definitely did not ascribe to this methodology, because choices simply have to be made for efficiency…. especially if we are to finish these airplanes in a decent, timely fashion.

To be clear, I’m not talking about being unsafe, or a lack quality, I’m talking about doing all the myriad of little extra tasks just for the sake of making the plane “better.”  Having run large organizations in the military, I can tell you often the amount of time and energy getting from, say, 93% to 98% can be way too big of a chunk of the overall effort.  If we’re honest, that 93% mark would be more than sufficient in meeting the mission, yet our drive for excellence and recognition pushes us to spend way too much time on the added 5%. In the end it gains us nothing but Kudos and Brownie points, but very little true value added. 

My point in all this is I’m attempting to make decisions based heavily in efficiency, more so than on perfection or “quality”, which is almost always in the realm of cosmetic areas vs. actual operational, functional or safety-related areas. 

Ok… I’m about 2 months back on the build.  I’m close to finishing up the major canopy tasks that will then free me up to really start focusing more just on the nose, which I have been dabbling with somewhat regarding the nose hatch hinges.

As far as shop tooling capabilities, over the past few weeks I’ve been using both my 3D printer and plasma cutting table regularly, both seeming to be working fine now. And yes, I am still slowly reassembling the milling machine to convert it to CNC.

As I get towards the end of really finalizing the nose tasks, I’ll start transitioning to the strake build (Chapter 21).   Again, the final big airframe assembly will be the winglet/rudder install (Chapter 20).  

 

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