F-22_Construction_Guide--Scratchbuild.pdf

Construction Guide for the F/A-22 Raptor Park Jet

By Steve Shumate

Page 1

Building Tips

This model can be built using the following types of adhesives:

· Epoxy (with or without microballons)

· Odorless cyanoacrylate (CA) with accelerator

· UHU Creativ for Styrofoam (or UHU POR)

· 3M 77 spray adhesive

· Hot glue gun

· ProBond (or Gorilla Glue)

To minimize weight, try to use as little epoxy as possible on this model,

saving it for only critical joints such as wing spars and motor mounts. You

can also mix microballons into the epoxy to reduce weight considerably and

help it fill gaps better. The majority of construction should use a lightweight

and quick-drying adhesive such as foam-safe CA, UHU Creativ, or 3M 77. I

personally use 3M 77 and UHU Creativ (both pictured at left) for the majority

of construction since they are strong and dry very quickly.

3M Satin tape is called out many times in these instructions since it works so

well for hinges, leading edge protection, and general strengthening. Make

sure to get 3M Satin tape (sometimes called 3M Gift tape), which is sold in

the purple container. The common 3M Scotch tape sold in the green

container doesn’t work nearly as well, nor does common packing tape.

Begin construction by cutting out all of the paper parts templates with

scissors, trimming them to within approximately 1/8” of the lines. Then test fit

all of the templates onto the foam sheet, trying to minimize wasted foam as

much as possible. Once you’re satisfied with the arrangement, remove each

template individually and spray the back of the template LIGHTLY with 3M 77

spray adhesive. Then replace the template onto the same spot on the foam

sheet. Repeat for every template.

After all the templates are tacked onto the foam, cut out all the pieces by

cutting on the lines with a SHARP hobby knife. To help keep track of the

parts, keep the paper templates on each piece until you’re ready to use it.

Page 2

1. Begin assembly with the forward fuselage. Start by carefully cutting the

beveled edges on all of the forward fuselage pieces as shown on the

plans. Draw a reference line on each part that’s inset from the edge the

distance indicated on the plans (note you can trace the lines from an

identical part onto the opposite part). Then cut the bevel with a sharp

hobby knife. You can use a straightedge for the straight segments, but the

curved segments will need to be cut by hand. It’s best to practice with

some scrap foam first to get the hang of it before cutting the actual parts.

Be sure to make mirror-image left- and right-side pieces!

The beveled parts should look like the photo at lower left when done

(upper forward fuselage side shown).

Page 3

2. Next form the curvatures in the lower forward fuselage sides. Use a heat

gun to gently heat and soften the foam and then bend them to the shapes

shown. The curves required are a bit complex—there should be one

gradual curve over the entire piece to form the taper of the fuselage (as

seen from the top), and a quick twist at the aft end to match the angled

fuselage sides to the vertical fuselage centerline support. Study these

photos and the photos in the following pages to guide you. The curves

don’t have to be exact since the bulkheads will help form the fuselage as

well once it’s assembled.

Again be sure to make mirror-image left- and right-side pieces.

Page 4

3. Glue the bottom half of the three fuselage bulkheads (the ones with the

notch on top) to one of the lower forward fuselage sides at the locations

shown on the plans, making sure they are perpendicular. Then set the

fuselage sides upright and flat on the workbench, apply glue to the edges

of the bulkheads, and then glue the two fuselage sides together.

After the glue has dried, glue together the aft ends of the fuselage sides as

shown, ensuring they are perfectly vertical. You may need to heat-form

the foam a bit more to get things to align just right.

4. Next build the wing. Cut a slot to fit the carbon wing spar and use 30

minute epoxy to spar into place. Mixing some microballons into the epoxy

is recommended to reduce weight and help the glue fill gaps better (you

can also use ProBond). Place wax paper and some heavy books on top of

the wing to hold it perfectly flat as the glue cures.

After the glue has cured, sand the leading edge of the wing to a well-

rounded shape, as well as the wing tips. Apply a strip of 3M Satin tape

around the leading edge for smoothness and improved durability.

Cut the flaperons free from the wing.

Page 5

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