||Cutting the stabilizer spar doublers...
Believe it or not, I had to try several methods before I could efficiently cut those 1220mm bands of 0.040" 6061-T6. I tried with
aluminum snips. It was difficult and the result was really not nice.
Then, I tried a couple of other methods (different saws)... did not work
well. Then, I tried with this saw with a 150 teeth plywood blade.
It worked well!
The setup displayed on the left includes a piece of wood that is clamped
over the aluminum sheet (to serve as a guide for the saw). I also
put two bands of duck tape over the sheet to avoid scratches.
||What is this extra piece?
When drilling the stabilizer attachment to the spar, the spar assembly
moved... resulting in an elongated hole in the spar doubler. I corrected
this by making a doubler that fits over the existing spar doubler.
This new piece covers three holes, as it can be seen in the picture.
||Completed spar assemblies!
These are the stabilizer front and rear spars. Quite nice hey?
At the time I am writing these lines, I have the 6 middle ribs attached
to the front spar. I starts to look like an airplane part.
||The stabilizer skeleton!
It's funny... one of my neighbor came by that evening and thought it
was a full wing! In fact, another neighbor thought the same thing
about my rudder. It is true that this assembly is about 7.5
foot wide... nearly the same as a wing.
||Does it fit?
I am looking at how the skin will fit on the assembly (considering
that a piano hinge has to be inserted in there).
||My 8 foot hydraulic press!
This is the setup I used to bend my stabilizer skin. What we
do not see on the picture is the 2X4 suspended from the ceiling.
To make the bend, I put the skin over the 2X4 assembly (center line
between the 2 2X4) and I position a 3/4" (take note here!!!) plumbing steel
pipe over the skin. To make is stable, I duct taped the pipe on the
skin. Then, I put my "T" assembly (the 2X8 with 2X4 mounted at the
center) over the pipe and the hydraulic jack between the two vertical 2X4s.
I then compress the skin until it is seated between the 2X4 in the jig.
We really need to be two people to do this... the whole thing is pretty
unstable when we start operating the jack. It did fall one time on my skin,
leaving permanent damage.
The first time I did this was with a 1/2" pipe... this is too small!
The radius was too small to fit on the end ribs (1/2" was the correct radius
for the rudder nose skin).
||I wanted this picture...
That is self explanatory... as you can see (by the straps), I nearly
forgot to take the shot.
One important comment here. When you strap the assembly on the
work table, do not just do what is in the assembly manual! I ended
up with a skin not correctly positioned on the end ribs and as a result,
my rivet line on top of the front spar is not correctly located (but it
is acceptable). The correct way would be to strap the assembly with
a 2X4 on the rear spar in addition to strapping the assembly on the work
table. This is to make sure the skin follows the contour of the end
||Bottom riveted and top clecoed
Notice that the skin is oversize. Since I don't work with pre-cut
and pre-drilled skins, it is pretty hard to forecast how everything will
fit. For example, in this particular case, I did not make my bend
exactly on the line. So, there was a difference of about 20mm between
planned and actual bend position on the skin. This is OK since I
made the whole thing several inches oversize both on the bottom and top
sides of the skins (on the picture, bottom skin has been cut to correct
size after clecoing).
||Bending the elevator skin
I was pretty nervous about this step; especially after a correspondent told me he failed when he tried. Before actually putting the skin
in the bending brake, I practiced three times on scrap 0.016". When
I was satisfied with the result, I then made the real thing.
Surprise! It is fine the first shot! I can tell you I was
Note that I strongly believe that a 8 foot bending brake is required...
if anyone reading this knows of another method, please tell me. I
will share this right here.
||Bending the skin, part "deux"
The trailing edge bend was not complete when coming out of the bending
brake (it is able to bend only to about 110 degrees). To complete
the bend, I inserted a 1/4" masonite in the skin and I pressed the top
flange with a 2X4. The result was still not satisfactory. I
took a friend to help me press the skin again, this time without the masonite.
On the right side, we can see one of my practice run with the skin bending.
||Is this nice? NOT!
I was so happy at this stage... I even attached the elevator to the
stabilizer to see the effect. This changed rapidly when I opened
the elevator to deburr the holes and prime... I found that I scratched
the front flange at every 40mm rivet location when drilling the piano hinge
rivet line :( Another important tip here: NEVER
inspect, open, look at any work you have done at midnight just before going
to bed! (obviously, I did not say "to sleep" here). The next morning,
I called Zenith Aircraft and spoke with Roger who told me to redo the whole
elevator. It took me about 11 hours to get back to this point.
||Cutting new rib blanks
My morale was not at its best, but I took my courage with both hands
and cut new rib blanks out of my beautiful elevator skin.
||Priming inside the skin? Not difficult at all!
I read in someone else log that it is difficult to prime the inside of
the skin... well, anticipating the difficulty, I decided to prime it before
completing the bend of the top flange.
||The cutout for the rudder
A friend showed me how he cuts aluminum with a knife. Quite
easy and makes straight cuts. Thanks Angelo!
||A great moment...
I like gadgets... and this trim servo is considered one. After
installing the servo and tab, I made a testing unit with the switch and
indicator. I used a dive light battery (12v 14ah). It worked
||Another look at the trim tab assembly
This is after I made the inspection plate (not shown) and primed it.
I developed new skills while installing the fairings... I learned to
apply fiberglass. At first, I installed the fairings just ensuring
that the back portion was quite square with the stabilizer. I found
that the elevator was almost touching the fairing on one side. After
showing this to André Létourneau, he told me to patch the
holes, lay a stripe of fiberglass inside and redril the fairing in the
proper position. This was quite easily done and the result is very
good. I took the opportunity to correct some imperfections in the