BUILDING THE LITTLE ZINGER I & II

Step 1. - Rib Template

Make rib template by printing is according to the proper dimension. Then cut it out and trace it on to a piece of balsa. Cut out a sand. To make sure that both side are equal, turn the paper template over and sand until both side are the same. Save the balsa template as your master template. You can make the template a little smaller to allow for the pen line.

Step 2.

Trace RibsTrace the ribs template on to a sheet of 1/16" or 3/32" balsa sheet. Try not to waste any balsa wood by staggering the rib close together.

Step 3. - Cut the Ribs

Carefully cut out all rubs using a Xacto Knife. For Zinger I, cut l4 ribs of equal size.
For Zinger II cut 16 ribs. Cut 4 additional ribs and make them 1/16" smaller in width. The 2 center ribs are glue together.

Step 4 Sand the Ribs

Stack all of the rib together and sand them so that all have the same uniform shape.

Step 6 - Spar Notch and Tail Edge

Notch Cut away a notch for the spar, use a Zona or Xacto Razor Saw. To make if easier, cut the notch together.

 Step 7 - Drill the Lead Out Hole

Stack all of the ribs and drill a three 1/2" hole trough all of the ribs. One for the front lead outs and two for the back.

Tip:

Step 8 Assembly the Wing

Draw the rib layout onto a piece of velom (drafting paper) or butcher paper. Tape this to a flat surface or building board.

Note: Zinger II has an extra rib on each side.

Step 9 Wing Jig

Make a wing jig from 1/4" scraps. This will insure a level leading and trailing edge.

Step 10

Lay the bottom spar first. Tack the ribs down on the spar with only 1 drop of wood glue (Elmers or Titebond). DO NOT over glue it at this point, until you are sure that every is straight.2. Pin the 1/4" leading edge into place, but DO NOT GLUE IT.

Step 11- Bell-crank Assembly

Make the Bell-crank mount from 1/16" or 3/32" plywood or hardwood scrap. Drill the hole for the bell-crank and install it according to the instructions diagram. Install lead-out assembly.  Make lead-out wires from scrap .015 or .018 cable or music wire.

I like to use a 2-56 bolt and blind nut to secure the bellcrank in place, rather that using the stock sheet screw setup.

Step 12 - Sheeting

Sheet the center 3 rib sections of the wing with 1/16" balsa. Install pushrod before sheeting and allow enough play for an exit hole on top of the wing.
 

The C.G. (Center of Gravity) should be about 15% behind the front L.E. (leading edge). This come out to about 3/4" back.

Therefore the center of your leadout should be about 1 - 1/2" hehind the L.E. Space the leadout wire about 1/2 apart.

Tip Weight: Glue 2 pennies to the aboard wing tip (assuming engine cylinder is upright)
Zinger II: Glue 1 penny to the aboard wing tip.

Step 13. - Designing the Fuselage

For the most part, fuselage shape does not effect the flying characteristic of your model. You can make the fuselage shape any design you desire at long as the engine and tail moments remain the same.

Step 14. - Cutting out the Fuselage

Cut the fuselage from a stock of 1/4" X 3 X 36" balsa sheet. Make sure that engine mount is perpendicular to the wings center line and that is stab cut out is also parallel to this line.

Use a triangle to draw a reference line from the engine mount. Use the rib template to cut out the wing hole.

Step 15.1. - Zinger II Engine Mount

Put your engine between the 2 piece of 3/16" X 1/4" hardwood. Measure the distance carefully between the block and transfer this to the fuselage.

Cut out the slot for the engine mount. Make sure that the width of the engine mount is 1/4". Recheck by inserting the mount into the fuselage and see if the engine fits before final gluing.

I recommend, Titebond Wood Glue or Polyurethane Glue for this process.

Step 16 - The Rudder

The same is true with the rudder design. Start with a piece of 3/32"X3"X 2" scrap sheet. Cut out any design you wish. Keep the wood grain vertical (up and down).

If you are make a wider rudder, a lot of design require that you make it in 2 pieces instead of 1. Note the grain on the "Shark Fin".

Step 17 - The Stabilizer & Elevator

Make the stabilizer and elevator from 3/32" balsa sheet.

Step 18 - Elevator Hinge

The 2 methods for make hinges are cloth or dental-floss.

Step 19 - Installing the Wing and Stab/Elevator

Step 20- Covering

Monocote or Ultracote film covering is the fastest way to get the wing covered.

Step 21- Painting

You can used any fuel proof paint although model airplane dope is the best. If you can not get dope, use Rustoleum brand paint will give you enough fuel proofing. Epoxy paint is very fuel proof but don't apply too heavy a coat. You should not use more that 2 coat on this model. One good coat should do it. If you want a smoother job on the fuselage and tail section, apply a few coat of clear dope and sand it smooth with 400 grit before spraying the final color coat. 

Step 22. - Control Horn & Pushrod

Install all hardware. Drill holes for the control horn first. Bolt on control horn with 1 washer on the bottom. 

Make a Z or J-bend and one end.  Make an adjustment Z-bend in the middle. Install the Control Horn and attach the pushrod to it. 

Step 23. - Install Brodak Engine Mount (Zinger I)

Install the Brodak 1/2A engine mount and do not over tighten the screws on the mount. 

Step 24 - Flying

This Zinger I model can be flown on 30' to 35' dacron string lines.

The Zinger II with Norvel engine should be flown with at least 40' to 45' by .008 steal cable for best performance.  I recommend a Cox 5 X 3 propeller for Cox engine and a APC 5.5 X 2.5 propeller for the Norvel .049.

Click on picture to see video