THE ASTRO-HOG STORY
The Astro-Hog is one of modeling's classic designs. It's appearance on the scene in 1957 changed the course of radio control aerobatics. Up till that time, R/C pattern flying consisted mainly of clumsy looking maneuvers performed by over-stable, high wing, free-flight style models that were primarily steered by rudder alone. The Astro-Hog was the first successful low-wing aileron-controlled R/C model, designed by Fred Dunn of California. Its flight performance was revolutionary - smooth, graceful, controlled maneuvers were now possible! The Berkeley Model Company quickly came out with a kit of the Astro-Hog, and it became a common sight at flying fields everywhere. Astro-Hogs made a clean sweep of 1st, 2nd. 3rd, and 4th place at the 1958 National Championships.

Model Airplane News magazine, in its April 1958 issue, proclaimed: "An airplane to top anything so far in multi R/C. Out of this world maneuverability!" (A report of that MAN article is included in this kit.)

The Astro-Hog kit production came to a premature end in 1961 when the Berkeley Company went out of business. Though it had only been on the market for 3 years, the Astro-Hog had established itself as a legend against which new designs would be measured.

The flight characteristics that made the Astro-Hog so popular back then are still perfect for today's flier. A thick semi-symmetrical airfoil, large wing area, and light wing loading give it perfect stability plus great maneuverability. It will perform any maneuver in the book, yet flies slow enough to let you enjoy it. The Astro-Hog makes an ideal first low-wing trainer for learning pilots, or it can be the ultimate fun machine for experienced fliers.

.

THE RETURN OF THE ASTRO-HOG

Sig Mfg. Co. now owns the old Berkeley kit line. This modern version of the Astro-Hog, is a faithful copy of the original with these improvements.
  1. Simplified construction - The inner structure of the model has been redesigned to make it quicker and easier to build.
  2. The wing dihedral has been reduced from the original 8" under each wing panel to 6" per panel (12" total).
  3. Strip ailerons are provided instead of the original "barndoor" style. Strip ailerons have dominated model design since the days of the Astro-Hog because they are much easier to build and install; have no slop or play in their movement; and they will roll a model just as well as the barndoor style. No materials are supplied in this kit for making barndoor ailerons.
  4. Bolt-on wing mounting is provided instead of the original rubber band wing mounting. No materials are supplied for making the old rubber band mounting.
  5. The stabliizer is now permanently mounted on top of the fuselage sides, instead of the original rubber band mounting onto the bottom. No materials are supplied for making the old style mounting.
  6. Tricycle landing gear has been incorporated into the redesigned Astro-Hog as standard equipment, to provide trouble-free ground handling by pilots of all skill levels. The materials and standard construction sequence in this kit are for building the trike gear installation. (*see note below).

These changes from the original design make it easier than ever to build and fly an Astro-Hog. Nothing has changed that alters the airplane's legendary flight characteristics. The materials supplied in this kit are for building this modern Sig version of the Astro-Hog as shown on the kit box label. The "Optional Taildragger Conversion" is the only modification of the kit we endorse.


FRED DUNN with his original Astro-Hog

Optional Taildragger Conversion
There may be some of you, especially veteran fliers, who will want to convert your Astro-Hog back to the original taildragger landing gear for aesthetic reasons. On plate 2 of the full-size plans, you will find all the patterns necessary to convert back to the taildragger version. Also in section 15 there are instructions on making the installation. Decide now whether you want to make this modification and plan accordingly.

COMPLETE KIT PARTS LIST
Die-Cut Balsa Sheets
2Sheet No.1 W1, W4, FSD, S1 6Sheet No.2 W2, W4 2Sheet No.3 W3, W4, W5A 2Sheet No.4 W5, W6, W1A, W1B
2Sheet No.5 TB-1, TB-2, TB-3, TB-4, TB-5, TB-6 1Sheet No.6 F5A, F1C, F3, F4
Printed Balsa Sheets
1Sheet No.7 Right Fuselage Side 1Sheet No.8 Left Fuselage Side 1Sheet No.9 FN-1, FN-2, FN-3 1Sheet No.10 S-2
1Sheet No.11 Cowl Side Doublers, Wing Filler Blocks, Tail Fairing Blocks
Sheet Balsa
63/32x4x36 Fuse Top Sheeting, Wing L.E. Sheeting 53/32x3x36 Sheeting for Stab & Wing Center-Sections, Fuse Bottom 43/32x1-1/4x30 Wing T.E. Sheeting
Block Balsa
11/2x4-3/16x6 Nose Bottom Block 15/8x3-3/16x4-1/2 Cowl Bottom Block 13/4x1x3-3/16 Cowl Top Filler Block 23/4x2-1/2x2 Wing Fairing
Stick Balsa
33/16x5/16x36 Stab Ribs 53/32x3/16x36 Capstrips 21/8x9/16x36 Leading Edges 23/16x3/4x36 Leading Edge Cap
53/16x3/16x36 Top Stringers, Bottom Middle Stringer 23/16x3/8x30 Stab Spars 61/4x1/4x36 Corner Stringers, Uprights & Tip Braces 61/4x1/2x30 Cross Braces, Main Spars & Spar Doublers
21/4x5/8x30 Trailing Edges 35/16x5/16x30 Stab T.E. & Pushrods 11/2x1/2x18 Triangular Stock for Fuselage 13/4x3/4x6 Triangular Stock Wing Bolt Support
11x1x6 Triangular Stock for Cowl
Special Shaped Balsa
11/4x3x10-1/2 Tapered Stock for Rubber 21/4x3x13-1/2 Tapered Stock for Elevators 21/2x1-1/2x36 Shaped Aileron Stock

.

Hardwoods
11/4 Dia. x6-1/2 Dowel Elevator Joiner, Wing 23/4x3/4x1-1/2 Basswood Wing Bolt Blocks 23/8x3/4x6-1/4 Basswood L.G. Blocks 23/8x3/4x3/4 Maple L.G. Anchor Blocks
15/16x5/16x36 Sprice L.E., Stab L.E. Doubler
Music Wire
15/32 Dia. Coiled Nose Gear 25/32 Dia. Formed Main Gear 2Formed Left & Right Aileron Torque Rods 11/16 Dia.x12 Straight Wire for Pushrod Ends
Plastic
1.015 Clear for Windshield 1ABS Molded Headrest
Hardware
20Molded Poly Hinges 21/4x20 Nylon Wing Bolts 2Nylon Control Horns; elevator, rudder 12#2x3/8 Sheet Metal Screws; control horns (4) L.G. straps (8)
15/32 Nylon Nose Gear Bearing 15/32 Nylon Steering Arm 16-32x1/4 Set Screw; for steering arm 44-40x3/8 Mounting Bolts; for nose gear bearing
44-40 Blind Nuts; for nose gear bearing 2Aluminum Engine Mounts 86-32x3/4 Mounting Bolts; engine mounts (4), engine (4) 46-32 Blind Nuts; engine mounts
4Nylon L.G. Retaining Straps 2Nylon Aileron Connectors 42-56x10 Threaded Rods; ailerons (2), rudder (1), elevator (1) 5Nylon R/C Links; ailerons (2), rudder (1), elevator (1), throttle (1)
12-56 Threaded Coupler; for throttle pushrod 1Pushrod Connector Assembly
Miscellaneous
1Plan Plate 1 1Plan Plate 2 1Instruction Book 12x24 Fiberglass Tap; for wing center section
11/8 od x32 Nylon Tubing; throttle and nose gear pushrods 11/16x32 Steel Cable; throttle and nose gear pushrods

Die-Cut Plywood

RADIO EQUIPMENT REQUIREMENTS

For best results, we recommend that you install 4-channel radio equipment in your Astro-Hog to operate the ailerons, elevator, rudder and engine throttle. The Astro-Hog's fuselage is spacious enough that any common brand of radio equipment with standard size servos and battery pack can be used.

.

ENGINES AND MUFFLERS

The Astro-Hog can be flown with a wide range of glow engines, either the 2-stroke or 4-stroke type. Because of its light wing loading (about 20oz/sq.ft. - similar to a "Cub" type trainer), a lot of high reving power is not needed. The Astro-Hog was designed to fly at slower airspeeds than today's typical pattern models.

In a 2-stroke cycle glow engine, we recommend .45 - .60 cu. in. displacement. A good .45 or .50 is adequate if the model is kept light, preferably 7 pounds or slightly less. If you fly off a grass field, live at high altitude, or just prefer a little reserve power, a .60 size engine would be a better choice. A non-schneurle .60 (like the venerable Webra ,61 Blackhead, Veco or K&B .61 Enya .60 III etc.) makes and ideal powerplant for the Astro-Hog in most cases.

A .60 size 4-stroke cycle glow engine is also a very popular choice for the Astro-Hog. Typically, 4-stroke engines are quieter and more economical on fuel than an equivalent size 2-stroke. They develop their power at a lower rpm. Their realistic sound and performance blend perfectly with the Astro-Hog's flying style. Since 4-strokes don't produce quite as much power as the same 2-stroke, we do not recommend .40 - .50 size 4-strokes.
There is no one type of muffler that is best suited to the Astro-Hog. It all depends on the particular engine that you've elected to use. You will have to figure out your own muffler installation. However, since the Astro-Hog cowling is large and wide open, you will find that almost any normal muffler will work.

GLUES

There are so many different glues available today for model construction that it can be confusing for the newcomer. To simplify matters, most glues can be classified as one of four basic types:
  • Easy to use water-base wood glues such as Sig Bond (yellow) and Sig Super-Weld (white).
  • Super strong two-part epoxy glues such as Sig Kwik-Set (5 minute cure) and Sig Epoxy (3 hour cure).
  • Traditional solvent-base model cements such as Sig-Ment.
  • Fast cyanoacrylate "super" glues such as Zap, Hot Stuff, Jet etc.
Each of these types has different characteristics and advantages. Often times, the choice of which type to use is strictly a matter of personal preference based on your experience with a previous model. If you are new to the hoby and not sure what type to use, we recommend that you try Sig-Bond glue for the majority of the general Astro-Hog framework construction. It is a great all-purpose alphatic glue that is easy to use . You should also have on hand some epoxy glue, either slow dry or 5-minute, for areas subject to unusual strain or involving metal pieces. Some of the steps in these instructions call out the type of glue to use for that particular assembly. In other areas you can use your own judgement as to which type is best suited to the purpose and to your building schedule.

CAUTION:
Some people have experienced allergic reactions when exposied to epoxy or cyanoacylate glues. This is very rare. However, it is always important that such glues, and also paints, thinners, and solvents, be used with adequate ventilation to carry fumes away.

There are also a couple of places ahead in these instructions where it calls for "model putty" or "wood filler". We recommend Sig Epoxolite Putty, regular household spackling compound (DAP, Red Devil etc.) or automotive body putty (Bondo, etc.) for these instances.

NOTES BEFORE BEGINNING CONSTRUCTION

Any reference to right or left refers to your right or left as if you were seated in the cockpit.

To build good flying models, you need a good straight building board. Crooked models don't fly well! The building board can be a table, a workbench, a reject "door core" from the lumber yard, or whatever - as long as it is perfectly flat and untwisted. Cover the top surface of the building board with a piece of celotex-type wall board or foam board, into which pins can be easily pushed. Don't hesitate to use plenty of pins during assembly to hold drying parts in the correct position.

When pinning and gluing parts directly over the full-size plans, cover the plan with wax paper or plastic kitchen wrap to prevent gluing the parts to the plans.

.

Don't use a ball point pen for making marks on the model during construction. If not sanded off, these ink marks will show through the model's final finish. Use a pencil instead of a pen.

Balsa die-cut parts have identification numbers printed on them. The plywood die-cut parts do not. Use the diagrams in the "COMPLETE KIT PARTS LIST" above to mark the i.d. numbers on the corresponding plywood parts.

Leave all the die-cut parts in the sheets until needed in construction. Remove pieces from the sheets carefully. If difficulty is encountered, do not force the part from the sheet. Use a modeling knife to cut it free. A jig saw works best for cutting out the printed balsa parts. If a jig saw is not available, a sharp modeling knife and a straightedge can be used. Cut just outside the printed lines, leaving all of the line on the part. When fitting the piece into the structure, use a sanding block to bring the edges to an exact fit.

All of the other kit parts can be identified by the "COMPLETE KIT PARTS LIST". Sort the different sizes of sticks and sheets into individual piles to avoid confusion during building. Cut all long pieces of balsa first, followed by medium lengths, before cutting up any full length strips into short pieces.

Any model parts mentioned in these instructions, but not furnished with the kit, are marked by and asterisk (*).

SANDING BLOCKS

An assortment of different size sanding blocks are indispensable tools for model construction. A good general purpose block can be made by wrapping a full 9"x11" sheet of sandpaper around a piece of hardwood or plywood. Use three screws along one edge to hold the overlapping ends of the sadnpaper. Put 80 grit paper on the block during general construction. Switch to 220 grit paper for final finish sanding just before covering,

Another handy block can be made by gluing sandpaper onto a 24" or 36" long piece of aluminum channel stock. Most hardwood stores carry a rack of aluminum in various sizes and shapes. This long block is very useful for sanding leading and trailing edges accurately.

Finally, glue sandpaper onto different sizes of scrap plywood sticks and round hardwood dowels. These are handy for working in tight places and for careful shaping where a big block is too hard to control.



1. BASIC WING PANEL CONSTRUCTION

a.

Six pieces of 1/4"x1/2"x30" balsa are supplied for making all the top and bottom wing spars. Cut two of the 30" pieces into four 11-7/16" long spar doublers. Glue one spar doubler onto the end of each remaining 30" main spar. Pin them down straight and flat until dry.


b.

Glue the W2A ply doublers onto the W2 balsa wing ribs. Make three with the doubler on the right side of the rib and three with the doubler on the left. Align carefully and let dry!
CAUTION: Be sure to properly identify the front end of each W2A before gluing them to the ribs.

.

c. Notice the notches for the grooved landing gear blocks have been pre-cut into the W2A ply doublers but not in the W2 balsa ribs. There are two sets of notches. Those in back of the main spar are for the standard trike gear installation, and those in front of the spar are for the optional taildragger installation. Cut open the balsa ribs to match the notches in the ply doublers for your choice of landing gear.




d.

Glue the die-cut balsa riblets W5A onto the ends of the W5 ribs. Make one right and one left. Let dry.


NOTE: The Astro-Hog wing consists of two separate panels - a right wing panel and a left wing panel. Each panel is first constructed by itself, entirely separate from the other, before they can be joined together later. Beginning with the next step e) the instructions are describing the assembly of one wing panel at a time.



e.

Pin one of the wing panel plans to the building board and cover it with wax paper. Pin the 1/4"x1/2"x30" bottom spar assembly in place on the plan. Slant the pins rearward so that they can be easily removed later.

f.

Glue and pin balsa wing ribs W2, W3, W4, and W5 in place along the bottom spar. Use a small triangle or other 90 deg. object to make sure the ribs are vertical.

g.


h.

Glue the 1/4"x1/2"x30" top spar assembly in place. The end of the spar doubler should fit snug against W3.

A Dihedral Angle Guage is pictured right. Cut it out carefully and glue it to a piece of cardboard or scrap balsa. Then glue the W1 center rib in place, using the guage to tilt the rib towards the wing tip.

NOTE: This same Dihedral Angle Guage is to be used for tilting the W1 rib in both wing panels. The angle of the guage is 6 deg., half of the total dihedral amount (12 deg.) of the finished wing.

i.

Glue in the die-cut balsa pieces W1A and W1B. When dry, use a sandpaper file to make sure they are not sticking above the tops of the ribs W1 and W2.



j.

Glue the 1/8"x9/16"x36" balsa leading edge onto the fronts of the ribs. Notice that the leading edge must extend on past rib W5 into the wingtip area - don't cut it off too short!

.

k. Glue in place the 3/32"x1-1/4"x30" balsa trailing edge top sheeting. The rear edge of the sheet should be flush with the ends of the ribs. If your sheet is bowed a little, any slight overhang past the ends of the ribs will be sanded of later.

l.

Glue the die-cut balsa wingtip parts TB-1, TB-2, TB-3, TB-4, TB-5, and TB-6 on top and bottom of the die-cut lite-ply wingtip bow. Pin flat until dry.

m.

Glue the laminated wingtip bow in place on the end of the wing panel. The outer edge of the tip bow should be blocked up 1/2" off the building board. The inner two ends of the bow should be centered directly over the datum line of rib W5 (datum line is from the leading edge to the trailing edge centers. See cross-section.).




n.

Glue balsa rib W6 in place.

Let the entire wing panel dry thoroughly!

2. COMPLETING THE WING PANEL

a.

Unpin the wing panel from the board and cut off the jig tabs at the back of each rib. Cut from the front towards the die-cut slit at the back. Then use a sanding block to lightly touch up the ribs until they are all even.

b.

Glue on the 3/32"x1-1/4"x30" balsa trailing edge bottom sheeting. When dry sand sheets flush with the end of the ribs.

c.

Glue on the 1/4"x5/8"x30" balsa trailing edge piece.

d.

Trim and sand the 1/8"x9/16" balsa leading edge flush with the top and bottom of the ribs.

e.

Cut the 1/2" balsa wing filler block from the printed balsa sheet No.11. Glue it in place between ribs W1 and W2, behind the leading edge. When dry, carve and sand the top and bottom of the block flush with the ribs.




f.

Use the pattern to the right to cut the top and bottom front wingtip braces from 1/4" sq. balsa stock. Soak both braces in a bowl of water for 2-3 minutes to make them bendable, and then glue both in place at the same time. Glue and pin the square ends first, flush against the wing panel main spars. When those ends are secure, squeeze both angled ends together onto the tip bow and glue them securely. Also glue at rub W6.

.

g. Bevel the top and bottom balsa edges of the wingtip where the 3/32" leading edge sheeting will attach. Blend the bevel into the 1/4" sq. tip brace at the back and the shape of the leading edge at the front. Sand all the way down to the edge of the light-ply center at the tip bow.

h.

Glue on the 3/32"x4"x36" balsa top and bottom leading edge sheeting. Attach both sheets to the main spars, leading edge, and all the main wing ribs W1 through W5. Do not try to bend the ends of the sheets over W6 and the wingtip bow yet,

i.

Wet the ends of the top and bottom leading edge sheets with water to make them easier to bend over the wingtips. Let the water dry in a couple of minutes, then glue and pin the sheets securely to the wing tip structure. When dry, trim the excess sheeting off flush with the leading edge and the tip bow.




j.

Glue the 3/8"x3/4"x3/4" anchor block onto the grooved landing gear block. Note the anchor block should be offset 3/16" from the end. Drill a 5/32" dia. hole straight through the grooved block and the anchor block - see wing plan for exact location of the hole.

k.

Glue the grooved landing gear block assembly into the rib notches. It should stick out 3/32" so as to be flush with the balsa sheeting when it is added.







l.

Plank the bottom of the wing panel, from rib W1 out to rib W3, with 3/32" sheet balsa. Cut pieces to fit from the 3/32"x3"x36" balsa stock provided, and then glue the pieces in place.

m.

Plank the top of the wing panel, from rib W1 out to the last W2 rib, with 3/32"x3" sheet balsa in the same manner as you just did the bottom.

n.

Cut to length and glue all of the 3/32"x3/16" balsa capstrips for the top and bottom of the wing ribs. NOTE: Do not cpastrip rib W6.

o.

Cut and install the 1/4" sq. top and bottom rear wingtip braces. Make these braces out of separate straight sections of wood, with a break at rib W6. Do not try to make them in one piece and bow them in place as you did the front tip braces.


p.


q.


Glue the 3/16"x3/4"x36" leading edge cap. When dry, carve and sand the leading edge cap to finished airfoil contour.

Carve and sand the 1/4"x5/8" balsa trailing edge piece (installed earlier, step 2c) flush with the trailing edge sheeting.

.

r. Carve and sand the wingtip to final shape - except for the area near the end of rib W5 which must be blended into the aileron after it is attached.

s.

Carefully block sand the entire wing panel until all joints are smooth and even. Use a large sanding block to avoid sanding down any one area too much.




Now go back to step 1e and repeat the process up to this point to build the opposite wing panel.

3. JOINING THE WING PANELS

a.

Carefully block sand the center end of both wing panels until the sheeting, spars, leading edge and trailing edge are all flush with the pre-angled center rib W1. Use a large sanding block and sand slowly to keep the ends of the panels straight and true.


b.

Check the fit of the wing panels to each other by blocking them up together as shown below. When the center ribs are tightly together on the building board, each wingtip should be approximately 3-1/8" above the board. The 3-1/8" measurement is from the bottom of rib W5 to the board. The pre-angled W1 center ribs should automatically put the tips close to the correct measurement.


If your tips measure anywhere from 3" to 3-1/4" and the center ribs are fitting together nice and snug - that's close enough - don't try to alter the angle of the center ribs to get the tips exactly 3-1/8".

Being 1/8" off at the tips only changes the actual total dihedral angle 1/4", and that won't harm the model's flying characteristics at all.

It's more important to have the center ribs perfectly snug to each other, without any gaps, than it is to get the dihedral exactly 3-1/8". If you do have gaps between the center ribs, resand with the large sanding block until the fit is good.

c.

Cut a 3/32" wide slot in the W1 center rib of each wing panel to accept the die-cut plywood dihedral brace. The slot should be the full height of the rib, right at the front of the main spars. Use a good sharp modelling knife for making this cut to avoid splintering the rib.



d.

Trial fit the wing panels together again without glue, this time with the dihedral brace in place to make sure it doesn't interfere with the snug fit of the center ribs. Alter the slots if necessary.

.

e. Glue the right and left wing panels together, including the dihedral brace, with slow drying epoxy glue. First work glue into the slots with a dowel or wire to insure that the dihedral brace will get securely glued to the main wing spars inside. Then smear a coat of glue on both center ribs so that the joint between the wing panels will be completely filled. Finally, coat the dihedral brace with glue and slide the parts together. Carefully line up the leading and trailing edges so there is no twist between the panels. Pin securely and wipe off any excess glue that has oozed out of the joint. Block up the wing assembly as you did for checking the dihedral angle, double check the final alignment, and then let dry.

f.

A pocket has been built into the center of the wing where the aileron servo will be mounted. The pocket is the space between pieces W1A, W1B, and the back of the spars. Carefully remove the 3/32" top wing sheeting flush with the sides of these pieces. Then use a small saw to remove the section of center ribs W1 that runs through the middle of the pocket. Do not cut into or remove any of the 3/32" bottom wing sheeting.


g.

Cut both pieces of shaped balsa aileron stock to the length shown on the plans for the ailerons - 26-5/16" long. Save the cutoff ends of aileron stock for later use.

h.

Draw a hinge center-line down the middle of the leading edge of both ailerons. Draw a corresponding hinge center-line along the middle of the wing trailing edge.

i.

At one end of each aileron, mark the location for the aileron torque rod installation. Slot and drill the aileron leading edge to receive the torque rod wire and then epoxy them in. Don't get any glue on the brass bearings!







j.

With a sanding block, curve the trailing edge of each aileron at the tip until it matches the plan.

k.

Finish sanding the the ailerons to final shape with 220 grit sandpaper. It's not necessary to change the actual shape of the aileron much, just round off the corners of the leading and trailing edges and make the entire aileron smooth. Don't sand off the hinge center-line.

l.

Cut the molded plastic hinges loose from their connecting spruce and pre-fix each one at the center by bending it back and forth several times. Cut slots in the aileron leading edge and the wing trailing edge to receive the hinges. Use 5 hinges per aileron as shown on the plan.


m.
Do Not Glue The Hinges In Yet!

Dry fit the ailerons onto the wing without any glue on the hinges. Check the movement of the aileron up and down. If there is any binding or misalignment, alter the hinge slots if necessary to correct. Keep in mind that the gap between the aileron and the wing should be kept as narrow as possible (about 1/32" to 1/16" maximum). The aileron should be able to travel about 1/2" up and 1/2" down. If you need a bigger gap than that to get much movement, you may have to round the leading edge of the aileron a little more.

An X-Acto #11 knife blade or a Goldberg or Du-Bro hinge slotting "fork" are the handiest tools to use for cutting the initial hinge slots. Then clean out the slots by working an X-Acto #15 saw blade in and out of the slot repeatedly until just enough wood has been removed to allow the hinge to slide easily. NOTES ON MAKING HINGE SLOTS

.

n. Epoxy the hinges in permanently. Working with one aileron at a time, fill all 5 hinge slots in the aileron with slow drying epoxy glue. Insert the hinges halfway into the slots. Wipe off any excess glue that oozes out of the slot. Set aside and epoxy five hinges into the slots in the other aileron. Let both ailerons dry completely!
Repeat the process to glue the other end of the hinges into the slots in the wing trailing edge. Make sure to wipe off all excess glue in the hinge gap. Let dry.

o.

Epoxy the torque rod bearings to the trailing edge of the wing. The brass tube bearings might not actually touch the back of the wing depending upon how wide your hinge gap is. Do not force the bearing against the trailing edge when gluing! Let it adopt whatever natural position it takes from the lineup of the aileron and surrounding it with glue, allowing the glue to fill any gap. Be careful not to get any glue on the wires.

COVERING NOTE:
If you are going to cover your Astro-Hog with an iron-on pre-colored covering material (like Monokote, etc.), it is best to cover the ailerons and wing trailing edge at this time before proceeding to the next step.


p.

Glue the 1/16" die-cut plywood wing bolt supports in place on the bottom of the wing. They should extend approximately 1-9/16" past the wing to line up with the trailing edge of the ailerons.
From the rear view, the ply bolt supports should line up just under the bottom surface of the ailerons when the ailerons are held in neutral position.



q.

Cut two pieces of leftover aileron stock to fill in the area between the ailerons. Notch the front of the pieces to fit over the torque rods. Glue in place, being careful not to get any glue on the torque rods where it could bind them up.

r.

Fill in the gaps between the aileron stock and the wing trailing edge with scrap balsa. When dry, sand the filled in area to final wing contour.

s.

Pin the ailerons in neutral position and finish shaping the wing tips at the back of rib W5. Make the tips blend smoothly into the ailerons.



t.

Cut strips of 2" fiberglass tape to reinforce the wing center joint. Cut 3 pieces for the top of the wing and 1 piece for the bottom.

To Apply the Fiberglass Tape
  1. Coat the wing center with slow drying epoxy glue.
  2. Lay the tape on top of the glue.
  3. Holding one end of the tape so it won't slip, "squeegee" the glue through the tape with a small paddle of scrap balsa. Scrape over the tape several times with the squeegee paddle to smooth the tape and remove excess glue.
  4. When dry, sand lightly to remove any rough spots. Try not to sand into the fiberglass tape itself.