Engine and engine mount:
Once the bulk of the fuse construction was finished, I decided that
now was the time to install the engine firewall. Installing the engine was
pretty straight forward. The only thing that threw me off, was the
incidences built into the fuse. In aerobatic type airplanes, the general
rule is 0 degrees to the thrust line, although in this kit, the engine is
set with 1 degree of down thrust. I figured that if it's built that way,
then I will follow it, fly it, and if I don't agree, I will modify it later.
The fuse is built in such a way, that the actually firewall is tied into
the whole shell. All you need to do is mark a pre-fitted 1/4" aircraft ply
firewall, then epoxy it in. (I also used a little fiberglass
tape inside the fuse to insure a strong bond)
the firewall was set, the next step was to make standoff's for the
engine. I used hardwood dowel, and made 1" standoff's which
pushed the engine forward enough to clear the front of the cowl.
Now that the motor was mounted, I decided to finish off the other small
things related to the motor. I made a small plate out of 1/8" light ply to
mount the ignition module on to. I will just Velcro the ignition pack in.
The throttle servo is just mounted in a simple mount, with a plastic push
rod, and the ignition switch is just mounted to a small plate on the side
of the fuse. As far as mounting the cowl, I just drilled some holes all
around, then glued in small pieces of wood with 4-40 blind-nuts. I then
used some 4-40 button head screws to hold hold the cowl on. I'm trying to keep things
simple and light in this plane.
Here are a few pics of the exhaust set up. I originally had in mind to set
up a tuned pipe system, but after thinking about it, I started to realize
that all the effort of making tunnels, support shelves, etc, would just be
a lot of work (and weight) For what I feel to be "not really worth it". I
called my friend Jim Bisson from Bisson Custom Muffler, and he made up a
set of cans to my specification. I have run cans similar to these in the
past, and in all instances I found them to perform very well.
I also decided that the cowl opening was a little large and that cooling
might be a problem for this motor. So I installed some baffling in the
cowl to direct the air flow over the cooling fins of the motor. All that I
used was some 1/32 ply.
Stabs and Wings:
Now that most of the major sections of the fuse are complete, I've
decided to finish off the stabs and wings. Again, the stabs and
wings come pre-sheeted, so what is remaining is to cut out your control
surface, glue in the leading/trailing edges. Hinge, and bevel your hinge
line. Cut out and install servos, push rods, etc.
As you can see in the pictures, I decided to double bevel the leading
and trailing edges in order to achieve 3-D type throws. As far as hinging
is concerned, I'm using plain CA hinges. Now I know there are many out
there that will disagree with that, especially in a plane this size, but
I've done it many times before of planes this size (even bigger), with no
problems. I've also installed a
servo box in the stab. ZN line doesn't cut a servo hole for you in
the stabs, and I'm
assuming they leave it so that if you decide to install your servo in the
fuse, you can. I on the other hand decided to install the servos in the
stab, hence cutting and installing a servo box.
Here is a picture of the hinging process.
Once the servo is installed, I hook up all the linkages to the servo arms.
As you can see by the picture, I'm using metal servo arms from Air Wild
Hobbies, as well as Nelson Hobbies control horns (formerly Rocket City)
This form of hook up is very common on giant scale airplanes, and works
rather well. The process is simple, in that you hook up a ball link to the
servo arm. Followed by a 4-40 threaded rod. I then make sure that my
geometry is correct, and that the arm will be 90 degrees to the hinge
Once I mark that, I then use a piece of brass tube, sharpen the end of it,
and slowly cut a hole through the Aileron/stab. Once that is cut, the next
step is to epoxy a piece of wooden dowel through the hole you just made,
drill and tap the dowel to accept an 8-32 screw, and voila....You have a
control horn! (special note: For those of you not sure, the screw is
screwed into from the top of the control surface, and then counter sunk as
to keep it neat for covering and finishing.)
Here are a few pics of the completed stab hook up, with all the linkages.
Here are a few pics of the aileron setup as well. This is similar to the
stabs, the only difference being that I'm using two servos per surface,
which does take a little tinkering to line up, but once they are lined up
will work in unison. The idea here is to use a Y harness to link the two
servos to one channel, and have them working together.
As far as the rudder hook up is concerned, I decided to install the
servo's in the back of the fuse. I was going to install the servo's in the
fuse and use a pull pull system of some sort, but figured that It would be
more positive to have the servos in the tail. By having the servo's in the
tail, I'm now creating more of a push pull system. As you can see in the
pictures the installation is fairly easy. I just cut out holes in the
fuse, reinforced the holes with some 1/8 light ply frames on the inside,
and installed push rods. Again I'm using Nelson Hobbies connectors (Rocket
City) and a solid push rod on either side. (note: The push rod in the
pictures are 4-40 steel rods, although I plan to use carbon fiber push
rods from Central Hobbies. I'm just waiting for them to arrive and will
install them once I get them)
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