Yanking and banking soon possible
If you have
good health, consider yourself lucky. I have had some health challenges of late
and am far behind schedule, but enough about me.
We have
ailerons and engines. Before the doom and gloom set in, and after my last post
I made a set of ailerons and they are quite handsome, if I do say so myself.
The construction method is somewhat similar to the wing ribs, foam rib cores
with sheetmetal capstrips. A 1.5” tube is the spar and a ½” tube for the
trailing edge with sheet metal to make a pointy edge. I designed the ailerons
on Solidworks and had a full size template printed out. I glued this to a
hollow core door to build on, just like my RC modeling days. I made rib
locators out of blocks of 2 x 4 and glued them in place. This holds all parts
in location and all that is necessary is to drill the rivet holes and pop them
in place. The ailerons are very strong in torsion, more so than I expected, without using triangular gussets like on the Lazair. In
the pictures the trailing edge sheetmetal is only sitting in place, it is not
permanently fastened yet. You can see the end caps, which also are not
finished, they need trimming and riveting. A unique aspect of these ailerons is
they are symmetric so both LH and RH ailerons can be built on the same jig. To move
from one side or the other all you do is install the control horns (not
pictured) on the top or bottom of the spar tube to get the alignment to match
the aileron control rod, which will exit the top of the wing on the Mark IV.
This
symmetric construction required a different pivot setup than the original
Lazair. If you will notice the pivot is in the center of the spar tube, via a
bushing and stud setup. You will also notice a “pillow block” type bearing on
the stud. This gives an illustration of how the aileron pivots. A bearing is
installed on the inboard (#6) rib and the outboard tip rib. The inboard stud
will float in the bearing. That is it is free to slide inboard/outboard because
the stud is considerably longer than need be and will actually penetrate into
the inboard rib about an inch, a hole in the rib allows for this by design. The
outboard rib will constrain the aileron as it will have a bolt as a stud and
will capture the aileron inboard/outboard motion. This end is covered by the
wingtip and will not be seen except during maintenance. To install the aileron
you will slide the inboard stud into the bearing at an angle until the aileron
will fit in the aileron gap of the wing. Lift the aileron into place and align
the outboard bearing. Install the bolt and safety. Install the wingtip, connect
the aileron control rod, repeat for the other side.
Engines, The
Heartbeat of the Bird
I think I
posted some time ago that I had intentions of using Hirth F-36 engines on this
first Mark IV prototype. However fortune has smiled on me and I have been able
to acquire two brand new, in the box, Evolution 7 cylinder 260cc four stroke
engines. They are sitting in my closet right now and every now and again I have
to open the door to look at the boxes and smile. These engines are an
incredible work of art in metal. Check out the website and youtube video links
below:
I expect to
be the first ultralight with twin radial engines. Maybe a world record? Probably
not but really cool never the less. I am making a test stand to break these
engines in. I plan to post videos of them running as soon as possible.
Propellers
are a beast of another color and have proven to be more troublesome than you
might think. I could certainly get propellers for these engines from the RC
world, but I think they look out of place on the Lazair, too thin. The problem of what pitch to use is also problematic. I don’t want to
buy a dozen props to figure out which pitch is right, that’s expensive research.
I really wanted a ground adjustable prop and in particular a three bladed
adjustable prop. After many years of research there was only one choice, Solo
Props.
So right now Solo is building two sets of 32”
3-blade adjustable props. Should be ready in the next month or so. They look just like Hamilton-Standard props off a DC-3.
More next time,
Gene
