Monthly Archives: June 2011

Vertical Stabilizer Skin

I have attached the vertical stabilizer skin with clecos and drilled most of the holes to the final size.  I also attached the piano hinge for the rudder.  I need to disassemble and deburr, but should be ready to rivet it soon.

I noticed a laser cut part on the rear spar with edges that looked like they weren’t totally deburred.  It seemed like it would probably be fine–I couldn’t really catch my fingernail in any of the bumps, but I knew it would bother me.  I ended up drilling out the stainless steel rivets.  This was a huge chore with my HSS (high speed steel) bits.  Apparently I need to get some cobalt bits as they are good on stainless steel.  I don’t have enough rivets to finish the job and will need to order more of that type from Sonex.  Notice the empty holes.

First rivets

I decided to pull my first rivets.  I hand riveted the forward and rear tail spar and most of one elevator.

Here is the horizontal stabilizer from another angle.

Caroline was sympathetic about how much work pulling the rivets by hand was, so she let me get an air compressor!

The Harbor Freight air hydraulic riveter made quick work of the elevators and both are now almost complete.  I read the instruction manual for the riveter and was led to believe I needed to disassemble it and add oil.  Then the rivet gun didn’t work at all.   After searching the internet it seemed everyone who disregarded the instructions had no problem with the gun, but those who added oil had the same problem as me. Notice how the reviews on the Harbor Freight website are unusually hight–9 ratings for an average of 5/5 stars.  I bet these people didn’t disassemble it to add oil, or they just knew what they were doing :-)

While searching the internet for help, I found this amusing piece of advice about not adding oil.  Since this is a “hydraulic” riveter and not simply a pneumatic one, it is clear that oil is actually required in the riveter.  The trick is making sure you add it in the right place and not too much or too little or it won’t work correctly.  I now believe it comes ready to run right out of the box.

After spending 3 hours messing around and totally disassembling it, I realized I had added too much oil and was able to determine the correct amount.  I expect it to last the entire project now that I figured it out.  I operate it at ~45 psi and it is fantastic.  By tuning the pressure I can have the stem break off in one or two trigger pulls.  I prefer two.

Here I am demonstrating to Caroline how much harder the hand riveter is.  From the look on my face, it looks like I am right in the middle of the final stem-breaking squeeze.

Here are both of the mostly-completed elevators.

Aluminum Sheet Order

I thought it would be fun to try scratch building the fuselage.  Since I have already made all the aluminum angle components, I am thinking I might be able to have something beginning to resemble an airplane without too much effort.  We’ll see how well this idea holds.

Wicks seemed to have good prices on aluminum sheet, but said shipping for 5 sheets of 4’x12′ would be around $100.  I found a local company L. Miller & Son, Inc. with similar prices but no shipping charge.  I did end need to pay around $50 in taxes, but I would have needed to pay that on the other order anyway (Alabama wants you to provide proof you paid sales tax on the airplane).

I was concerned about getting 4’x12′ sheets to fit in the back of the van.  Everyone including myself seemed skeptical that they would roll, but they rolled easily and I used a ratcheting strap to keep them that way.  This is what 3 sheets of 4’x12′ .025″ and 2 sheets of .032″ look like rolled up in the back of a van.  It’s not nearly as impressive as it would be unrolled.

This would not work without the “Eagle Scouts” bumper sticker.

Left Elevator and Hinge

After figuring out a workable method on the right elevator I thought I’d show some pictures of my method on the left one.  First I cut reasonably close to the line with my bandsaw.  Then I trim up to the line with these offset Wiss snips.

I cut the corners with my Dremel tool.

I do the holes for the ribs using my handy rivet spacing tool.  There is a warning specifically saying not to drill through those holes (use it as a layout tool instead), but I have totally disregarded the warning.  Hopefully whatever bad outcome I receive by disregarding the warning is offset by all the time I save.

I also attached the hinge to the right elevator.  This needs to be positioned such that it will line up with the rest of the horizontal stabilizer when it is riveted together.  My yard stick seemed to be just the right thickness to use as a spacer and get everything lined up.

Horizontal Stabilizer and Right Elevator

I hear it is important to have photos in the builder’s log of myself building the airplane, so Caroline volunteered to come down and take some pictures.  I drew an outline of the horizontal stabilizer on my workbench and here I am precisely positioning the forward spar.

While we are at it, here is the vertical stabilizer.

I am still trying to decide what to do about corrosion protection, so I have been too chicken to start riveting.  I decided to start working on the elevators–I have been worried about how to cut the control surfaces with the tight bends.  I ended up cutting within an inch or so of the line with the bandsaw since it is difficult to see how close to the line I am on the bottom side.  Then I used offset Wiss snips to cut close to the line.  The Andy snips seemed to big for this job except on some of the long cuts.  I used my Dremel tool with an abrasive disk to cut through the bends.  Then I used the  scotch brite wheel to shape right to the line.

I started drilling pilot holes in my first piano hinge.