Buzzard Models OMICRON User manual

OMICRON
Our latest iteration of precision indoor pattern F3P style design! The omicron was born to approach a goal of advancing the state of
the art in terms of easily attainable performance. The Omicron provides a large fraction of the performance of the best F3P models,
for a small fraction of the effort and cost.
Please read and understand all steps to these instructions before beginning assembly. This plane is not a toy and is
potentially dangerous to operate. Children should not operate this aircraft without adult supervision. To start assembly,
gather the required electronic hardware and building supplies. You will need some foam-safe glues, and optional paint.
Look for the recommended electronic hardware at the end of these instructions and painting tips in that section.
1

Supplies and tools - We like the BSI Foam-Cure for all foam to foam joints. For basically everything else, we use the BSI Super Gold
Plus medium viscosity foam safe CA (cyanoacrylate) glue, with a BSI-301 extender tip. Between uses the extender tip can be closed
with a bit of masking tape. On these types of materials the CA really needs to be accelerated with the BSI Insta-set, or curing can
take some time. The Insta-set can be put into a small dropper bottle for precise application. To install the covering you will need to
buy a small can of 3M super 77 spray adhesive, don’t try other brands, I have not found anything else that is suitable. Mixing the
Super 77 1:10 with Naptha makes a brushable very thin contact cement suitable for covering repairs. Other than basic tools, you will
want a good pair of tweezers or three, a hobby knife with brand new blades, and a small electronics flush cutter such as a xuron
170-II to cut the carbon dust free. A good general purpose solvent like denatured alcohol will be needed to clean all of the carbon
and composite parts before gluing, and can be used to thin and clean up the Foam-Cure. I would also recommend cleaning all
depron faces with alcohol before painting, covering, and gluing.
2

Kit contents-
3

Assemble top and bottom fuselage - Glue the top and bottom fuselage halves together. This is best done over some waxed paper.
I like to use Foam-Cure for this, and the excess can be cleaned up with some denatured alcohol on a paper towel. Denatured
alcohol can also be used to thin the Foam-Cure as desired. Once the glue is mostly dry, you can trim out the interior scraps. A very
sharp #11 hobby knife works well for this. The carbon reinforcements will be installed much later.
4

Trim Parts - With a sharp hobby knife, remove the extra foam and tabs from all of the parts. Smooth any tabs that are visible when
done.
5

Hinge beveling - The hingelines are cut most of the way through, the material left forms a great hinge. However, you need to add a
little clearance to the opposite side (bottom) to ensure full defletion. Fold the hinges open over the sharp edge of a table or board
to support the foam, hinge side down. Using 120grit sanding paper, bevel the corners of the foam just enough to allow the hinges to
flex closed (the opposite direction) at least 45 degrees. Be careful that you do not sand though the hinge.
6

Picture of hinge flexed closed to 45 degrees - Flex the control surfaces up and down and verify free movement. Sand more
clearance as necessary to allow full movement. Do the rudder, elevator, and aileron hinges the same way.
7

Empennage assembly - Wipe all carbon rods down with a paper towel and denatured alcohol. Most carbon comes from the
factory with a residue. With the elevator and rudder hinges beveled and freely flexing, dry fit the carbon fiber reinforcements in their
slots, and conservatively apply a foam safe CA glue with an extender tip. Foam Cure or white craft glue may also be used. Dabb
any excess glue off with a paper towel before it dries. Working on wax paper prevents the parts from sticking to the table.
8

Wing assembly - Working on wax paper, glue the right and left wing halves together. Add the precut 1.2mm x 18” carbon mainspar,
and the 0.8mm x 10.6875” aileron trailing edge and 0.8mm x 3.5” aileron horn reinforcement. All carbon lengths given in these
instructions are approximate and for reference only. Measure, cut and dry fit all parts. The curved forward aileron reinforcements
are 0.5mm carbon. Dry fit the parts and then glue. CA glue can add a ton of weight to the airframe, use sparingly, you can always
add more later if it breaks. Make sure everything is flat as it dries. CA accelerant can be used. Do not apply glue where the aileron
horns will go yet.
9

Aileron Horn Installation - Dry fit the aileron horns before gluing with CA. Make sure the horn pushrod holes are directly above the
centerline of the hinge.
10

Painting- You can optionally paint now, after the covering is in place, or both as shown below. It is easier to do it now. Airbrushing is
the best way to paint, alcohol or india inks are ideal, basic acrylic paint thinned one-to-one with denatured alcohol works great
through an airbrush. Alternatively the craft acrylic paints can be thinned and brushed on conservatively. Paint can add a lot of
weight, so be careful. Good markers also work well. Make sure to test any paint for compatibility. Some great painting stands can
be made with scrap foam or cardboard, and some toothpicks and tape. All of the Omicrons you see in these pictures are painted
with acrylic craft paint thinned one to one with denatured alcohol through a basic airbrush.
11

Painting - This Rudder and elevator were painted before and after covering.
12

Wrinkle your mylar - This film is normally "wrinkled", unpackage your film, form into a ball with your fingers, repeatedly
compressing and releasing many times until a uniform "wrinkle" pattern is formed in the film. This provides a uniform surface finish
free of small wrinkles or other defects, helps prevent the film from resonating with airframe vibrations, and provides additional
visibility by reducing the transparency of this very clear film. More wrinkling is better than not enough. Layout the mylar covering on
a flat work surface, tape the edges down pulling it just taught enough to remove any large wrinkles. The mylar in this picture was
not wrinkled enough and the finish is not uniform. Be careful not to form bubbles that you pop when you are wrinkling.
13

Covering - The covering goes on one side only, make sure the hinge sides are down. So the covering goes on the top of the wing
and stabilizer, and on the RH side of the vertical fuselage and tail. Layout and space where your parts will fit before applying glue.
One part at a time, remove each from the covering film, and very lightly mist one side with 3M 77 spray adhesive. Stick the part
back down on the covering where it came from. Press evenly on the parts to ensure contact. Repeat that process until all of the
parts are glued down. I highly recommend finding a large cardboard box to place each part in while spraying the 3M 77 adhesive,
and I can’t emphasize enough to very lightly mist with the glue. Practice with some scrap depron parts before trying the real thing.
14

Trim the covering - With the parts still upside down, trim around their perimeters with a new sharp hobby knife blade over a
cutting mat.
15

Painting - Here is an example of a similar plane that was painted after covering with alcohol ink though an airbrush.
16

Optional Decal Installation - When the parts are still flat on the bench makes a great time to add decals, if you can resist gluing
the airplane together for a while. Please refer to the full decal instructions later in these instructions.
17

Assembly - Glue the middle fuselage in place. Install the two 0.8mm carbon longerons, they just float over the main wing spar.
18

Lower fuselage install - dry fit, and then glue with your glue of choice. Install the 0.8mm x 18.312” lower fuselage longeron. (it is not
shown in this picture)
19

Bracing - Install the ten angled 0.8mm fuselage braces, and right and left 0.8mm main spar brace. There should be small notches
at each end of these braces to guide the installation.
20