B24 Manual

If you have not worked with foam before, it is strongly recommended that you read the How To section first.
Do not discard any foam pieces that came with the kit, until after the construction is finished.

The Wowplanes B17 is a builder's kit. We assume that the builder has at least an intermediate skill level in building RC flying models and has built kits and ARFs before in balsa, if not in foam. The objective of this manual is to illustrate the features and construction techniques that are unique to this model.

It is not the intent of this manual to show the basics such as installation of motors, radio, servos, linkages, etc. which are common to all models.

Wowplanes kits lend themselves to finishing the model in multiple ways. The model may be left as bare foam and painted with foam safe paint, or covered with low temperature heat shrink covering, or fiber glassed and painted, or sheeted with balsa and painted, etc.

Before you start building it is recommended that you decide what option you plan to pursue. Depending on the finishing option, you may have to alter the sequence of construction outlined below. e.g. if you plan to sheet the model with balsa, it would be easier to build and sheet the individual sub-assemblies before assembling the whole plane.

Contents
1.0 The Fuselage
2.0 The Wing
3.0 Attach the Wing and Fuselage
4.0 The Tail
5.0 Attach the Tail and Fuselage.
6.0 Install the Plastic
7.0 Motor wiring
8.0 Finishing ideas
9.0 Center of gravity.

1.0 The Fuselage

  • Glue the seams that run along the underside of the two fuselage halves.
  • Glue a 1/8" x 1" plywood in the slot on the side of the fuselage.
  • Insert 1/16" balsa in the wire cuts between the plywood cutouts and the top of the wing cutout.
  • Cut a foam piece shown and glue it to the plywood.
  • Sheet the wing saddle with 1/32" balsa, but DO NOT sheet the leading side as yet.

 

  • The inner core of the front fuselage comes in 3 slices.
  • Glue the upper slice in place to form the cockpit floor and the top of the nose cone.
  • Discard the middle slice.
  • Cut the bottom slice equal to the length of the battery and glue it in place to form the floor where the battery will sit.

 

  • Position the canopy in place and mark the front edge.
  • Position the nose plastic bubble in place and mark the outline.
  • Sand the nose cone sloping it forward from the canopy line all the way around the fuselage to look like the picture below.
  • Position the tail gunner plastic in place, mark the outline and sand the foam to conform.



 

 

 

 

 

 

 

 

  • Sand a fish belly as shown in the picture below.

1.1 Battery Hatch

The battery is hidden behind the nose bubble, which is held in place with 4 small magnets. This method avoids hatch lines and hinges and is completely concealed.

  • Epoxy glue two magnets. One at the top of the nose and the other diametrically opposite at the bottom of the nose.

  • Place wax paper over the magnets and hold it in place with two other magnets.

 

  • Cut a 1/8" sheet larger than the dimensions of the nose.

  • Apply epoxy glue to the exposed side of the outer magnets and glue the balsa sheet to them.

  • Trim and sand the balsa to conform to the outline and slope of the nose.

  • This is the balsa former that will be glued inside the nose bubble.

 

  • Paint the front side of the balsa sheet with the color you like.

  • Slide the plastic nose bubble into place and check for fit. When satisfied, use 30 minute epoxy to glue it to the balsa edge.

  • When cured, twist the nose bubble and it will come off.

1.2 Battery Cooling

  • Make a small hole in the nose plastic bubble for air intake.

  • Make 3 slits in the balsa former just in front of where the battery is located.

  • Make a slanted air exit hole under the tail cone.

2.0 The Wing

2.1 Nacelles

  • Lay the nacelles side by site with their rear ends in line. Note that the outboard nacelles are shorter than the inboard ones.
  • Mark and cut off where shown.
  • Trim and sand the rear ends of the nacelles to look as shown. The front ends should not require any trimming or sanding.

   

  • Use the nacelles as templates to trace and cut the firewalls from 1/8" plywood.
  • Cut a slot as shown and dig out some foam to make compartments for the ESCs.

 

2.2 Main Wing

  • Trim and round the tips.
  • Cap the aileron cut outs with 1/16" balsa. Extend the liner on the servo side all the way into the servo cutout.
  • Insert a HS55 servo in the servo cutout until flush with wing bottom. Insert the servo plug from the top and glue in place. Slice off the excess servo plug with a sharp blade.

  • Make two spars from 1/8" x 24" stock plywood according to the dimensions shown on the picture above.
  • Pour a liberal amount of 30 minute epoxy in the spar channel and glue them in place.
  • Glue the wing sections together with 30 minute epoxy, with the mid section resting on a flat surface and each tip raised by 2 3/8".

Make a wiring harness and use the channel provided to route the wires. The channel can be capped with a strip of scrap foam.

2.3 AILERONS

  • Sheet the top and bottom sides of the ailerons with 1/32" balsa using M77 spray glue and trim.
  • Do not sheet the ends as yet.
  • Sand a 15 degree angle on the hinge face as shown in picture.
  • Cap the hinge face with 1/16" balsa.
  • Fit ailerons to the aileron cutouts in the wing leaving a 1/16" gap at each end.
  • Sheet the aileron ends with 1/32" balsa.
  • Do not attach the ailerons as yet, it will be done during final assembly.

2.3 FIXED MAIN UNDERCARRIAGE

  • Cut two U/C mounts from 1/4" x 1 1/2" x 3" plywood.
  • Drill a 1/8" hole along the center line, 1/2" from the shorter side closest to the fuselage.
  • Attached the U/C wire with straps, and bend then in to compensate for the dihedral angle of the wing.

 

The wing is done.

3.0 Attach the wing and fuselage

  • The wing cover has 3 parts. Glue the inner core inside the outer cover.
  • Cut a 1/8" x 1" piece of plywood. Insert it in the slot and glue in place.
  • Sheet the trailing face of the cover with 1/32" balsa.

 

  • Place the wing in the saddle.
  • Make the distance X=X and make alignment marks.
  • Glue the wing cover over the wing.
  • Bore a 1/2" hole all the way to the plywood insert, along the center line and 3/4" in from the trailing face.

 

  • Cut two pieces of 1/16" plywood to the profile of the leading face using it as a template.
  • Tape the two pieces together and drill two 3/16 holes as shown.
  • Cut 3/16" dia dowels 1 1/2" long each and shapen one end like a pencil.
  • Glue the dowels to one of the pieces allowing them to protrude 1/4" on one side.

 
 

  • Pierce the foam with the sharp ends of the dowels, align the plywood and glue in place. Use the second plywood piece to keep the dowels straight.
  • When dry, insert a sheet of wax paper between the plywood pieces and push the second piece flush. Tape the dowel ends with masking tape.
  • Set the wing back in the saddle, using the alignment marks that you had made. Make X=X again and glue the front plywood to the fuselage face using 30 minute epoxy.
  • Allow to dry.
  • Drill a hole for a 6-32 size screw, vertically in the plywood at the trailing side, all the way through to the plywood insert in the fuselage.
  • Remove the wing and install a blind nut in the fuselage plywood insert.

 

 
 

4.0 The Tail

  • Round the edges of the vertical stabilizers.

  • Insert a 1/8" plywood spar in the channel provided in the stabilizer and glue it in place.

  • Cap the elevator cutouts with 1/16" balsa.

  • Sheet the elevators with 1/32" balsa.

  • Sand the hinge face at 15 degrees and cap with 1/16" balsa.

  • The elevators are driven separately by a Y control rod configuration.

 

The tail is done.

5.0 Attach the tail and fuselage

5.1 Horizontal Stabilizer

  • Dry fit the horizontal stabilizer in place and make the dimensions Y=Y

  • Sight from the rear of the model to see if the elevator is level with the wings.

  • When satisfied, glue it back in place.

   

5.2 Vertical Stabilizer

  • Slide the vertical stabilizers onto the ends of the horizontal stabilizer.
  • Use triangulation to square the vertical stabilizer to the horizontal stabilizer. Make X=X.
  • Rudder is optional and if desired can be cut, and a HS55 servo imbedded in the fixed portion.

6.0 Install the Plastic

Use the pictures below to locate and install the plastic.

  

7.0 Motor Wiring

8.0 Finishing ideas

Wowplane models can be finished in a variety of ways. Please click here to go to the Final Finish section.

  

9.0 Center of gravity

  • The Center of Gravity is located 2 3/4" back from the leading edge of the wing measured at the root where the wing enters the fuselage.
  • The model should be balanced at this point after all the equipment and finish has been applied. This must be the final step. Use the battery location to achieve the balance.

HAPPY LANDINGS !!