SPAD  Saturday Night Midget

The Saturday  Night Midget is a low cost, quick building entry into .15 sized A-class combat.  Due to the weight of the plastics used in construction, this planes thrives on a  good strong engine and micro radio gear. Using 2 mil
Coroplast®  for the wing, and Canadian 2 3/8" O.D. gutterpipe is a MUST. THIS IS NOT A BEGINNER'S AIRPLANE. It's  pitch sensitivity and roll rate are high, but any experienced combat pilot will  enjoy the SNM's performance. The prototype is equipped with a Magnum® .15 XL, 3  Hitec® HS-81 metal geared servos, and a 600 ma. battery, and weighs in at 2  pounds 4 ounces. The prototype is plenty competitive, but we're sure that with  lighter equipment, and a little "nipping" at our design by the experienced  builders, a SNM weighing under 2 pounds is easily possible!  We DO NOT recommend  this plane be built by an inexperienced builder/pilot, the use of larger  diameter gutterpipe, 4 mil coroplast wing, or the use of standard sized radio  equipment. Although it may fly, it could be a disappointing  experience.

Please note  that none of our dimensions, materials, or techniques are set in stone! We know  that what is presented here works, but if you have different or better ideas,  TRY THEM! EXPERIMENT! Have fun! That's what this is all
about!

Fuselage:

1) Starting  with a 24" piece of gutter pipe, measure, mark, and cut out the radio access  hole, and rear fuselage cut out. Radio access hole starts 5 1/2" from front of  fuselage, and is 1/2" x 5". A Dremel® with a cutting wheel works best for this.  Save the scrap pieces! They are used to make other PVC parts! There is NO down  or right thrust on the SNM.  If you are using full size radio gear (not  recommended) - see the note below, if you are using micro gear, proceed to step  2.

NOTE:  If you are planning on using  full size radio gear, we highly recommend installing all of the radio gear,  engine and fuel tank in the fuselage first (before drilling the wing hold down  dowel holes).  Then take the wing and
tape it to the fuselage -  sliding it fore and aft as necessary - until the correct CG position is  achieved.  Mark the fuselage where the leading and trailing edges are on the  fuselage.  Then mark and drill for the dowel holes -
keeping them  1/2" in front of the leading edge mark and a 1/2" aft of the trailing edge mark  you made earlier.  If you build the SNM per plans, and you use full size gear,  you will have a tail heavy airplane that you may not be able to balance  correctly!

2) Drill for,  and install the 4" long x 3/16" dia. wing hold down dowels. Install forward  dowel 3 1/2" from front of fuselage, and space them 9" apart. Fuel proof the  hold down dowels with CA.

NOTE: Install the wing hold down dowels  as close to the upper fuselage gutter pipe radius as possible to assure proper  fuel tank clearance!

3)  With the  rear fuselage cut out scrap, fabricate three 3/4" x 3/4" x 1/2" base control  horns, four 1/2" x 1/2" x 3/4" long tail mounting "L" brackets, and two small  aileron servo mounting pieces (size will be determined by the servo you  use).

4)  The  firewall is fabricated from 1/2" plywood cut to the inside diameter of the  gutter pipe, and is mounted flush with the forward edge of the fuselage with  four small self tapping screws. Servo screws work great for  this.

5)  Drill a  small hole in the rear left side lip of the fuselage for combat streamer  attachment!

Tail:

1)  Cut the  horizontal stab/elevator, and vertical stabilizer from 4 MIL Coroplast® as shown  on the drawing, with the corrugations running in the direction shown in the  drawing.

2) Hinge the  elevator by cutting away the bottom side of the hinge line  corrugation.

NOTE: Flame all plastic parts with a  butane or propane torch before gluing! Medium CA is used for Tail attachment. USE SEVERAL SMALL  DROPS - TOO MUCH GLUE MAY NOT  WORK! USING TOO MUCH GLUE IS THE BIGGEST MISTAKE HERE!  Also make sure there is no parts movement after initial contact!  Please practice "flaming" the Coroplast® on a piece of scrap. The idea is to  pass the flame across the area to be glued slow enough to burn the manufacturing  oils out of the plastic, but quick enough so the plastic doesn't melt! It only  takes seconds, and there is very little "visual" evidence of the oil burning. If  the lighting is good in your shop, you may see the oil "shock wave" just in  front of the flame, and the plastic may turn a slightly darker color for several  seconds.

3)  Attach  the tail "L" brackets to the vertical stab, using  medium CA. Exact location of  these "L" brackets is not critical.

4)  Glue the  Horizontal Stab/Elevator to the fuselage as shown on the drawing, making sure it  is mounted squarely.

5)  Now  things get CRITICAL! Glue your Vertical stab/"L" bracket assembly to the  horizontal stab, making sure it does not interfere with the elevator hinge.   This assembly MUST be centered and perfectly straight when glued in  place!

Wing:

1) The wing  is fabricated from a 38" x 17" piece of 2 MIL Coroplast®, with the corrugations  running chordwise

2) The  ailerons are fabricated from 4 MIL Coroplast® with the corrugations running  spanwise. Hinge as shown in the drawing. A 4" x 1/2" piece of 4 MIL scrap is  used as a filler between the ailerons.

3) Mark the  wing leading edge fold line, and spar glue line. Using a straight edge and small  blunt tipped object, score the inner radius of the leading edge fold line, flip  over, and bend over the edge of a table.

NOTE: Flame all plastic parts with a  butane or propane torch before gluing!  Medium CA is used for all wing  construction. USE SMALL  DROPS EVERY 1/8" INCH OR  SO.  A BEAD OF GLUE MAY NOT WORK! USING TOO MUCH GLUE IS THE BIGGEST MISTAKE  HERE!

4)  The spar  is a standard 36" wooden yardstick CUT DOWN TO 7/8" IN HEIGHT. Glue the spar to  the bottom wing. There will be 1" of wing overhang past the spar at each wing  tip.

5) Separate  the TOP wing into two halves, by cutting TO THE LEADING EDGE FOLD LINE ONLY.  This is to facilitate folding and gluing the wing, one side at a time...which we  have found to be much easier! Test bend the
wing top  panels over the spar. Here is where things can get tricky, and it's nice to have  5 hands or a helper! The bottom wing panel should remain as flat as possible  (the LE will naturally raise slightly), and the top panel trailing edges must be  marked and trimmed flush with the bottom panel trailing edge. Once accomplished,  unfold the wing, and glue the ailerons (and 4" scrap coroplast filler piece  between them) to the bottom wing panel.

6) Fold and  glue the top panels to the spar and trailing edge. A wood 2 x 4 works great for  holding the trailing edge down!  Kraut has found that holding the leading edge  down with a piece of angle iron while gluing also works  great!

NOTE: By nature, the leading edge of  your finished wing may be slightly raised, and your lower wing may be slightly  undercambered towards the rear, giving you a natural eppler type airfoil. This  is perfectly acceptable, and is what gives this airplane such great  performance!

7)  Cut a 4"  wide 2 MIL wing center wrap and glue to the top of the wing. Insert a 4" piece  of coat hanger into the end flutes of the center wrap, for rubber-band crush  protection. Small scrap pieces of yardstick will also  work if you think the coat hanger is too  heavy!

Engine and  Fuel Tank:

1) The fuel  tank is wrapped in foam for a snug fit, and the engine and engine mount are  mounted conventionally. Make sure the throttle pushrod housing doesn't chafe  directly on the fuel tank (we've learned this one the  hard way!). We have also learned that mounting the engine  at 45° (muffler down) not only helps keep goop off your plane, but helps fuel  draw during high G maneuvers!

Radio  Installation:

NOTE: Your engine and gas tank should  already be mounted at this point.  USE YOUR RADIO EQUIPMENT PLACEMENT TO ACHIEVE  PROPER CG. Your SNM MUST balance level to slightly nose heavy at the wing spar. A tail heavy condition is not acceptable, and is VERY  unsafe!

1) Glue the  elevator and aileron control horns in place. Be sure to take into account the  pushrod angles on the ailerons. FLAMING OF THE HORNS  AND CONTROL SURFACES PRIOR TO GLUING IS VERY  IMPORTANT!!!

2) Cut a hole  in the wing just aft of the spar for a snug aileron servo fit.  Flame and glue  the two PVC aileron servo mounts to the wing. Cut a small hole in the bottom of  the wing for the servo lead. Drill for, and mount the aileron servo using servo  screws.

3) Mount the  elevator servo by cutting a hole in the rear fuselage to accept the servo, and  secure using servo screws. We have found that drilling a hole, and then using a  small dremel stone works great for this. Exact fore/aft placement of  the elevator servo can be used to achieve proper CG. Note: Before cutting the  elevator servo hole, MAKE SURE YOUR SERVO LEAD WILL  REACH YOUR RECEIVER!

4) Secure the  throttle servo to the inside of the fuselage using two sided foam mounting tape.  For extra security, you may wish to drill a hole on each side of the servo in  the fuselage, and secure with a zip-tie.

5) The  battery and receiver are wrapped in foam for a snug fit. We have also used two  sided foam mounting tape or velcro for this.  As this is a combat plane, we  recommend filling all voids inside the fuselage with foam to protect your  equipment. We also recommend drilling holes in the fuselage on each side of the  battery and receiver, and further securing them in place with a  zip-tie!

6) Switch  mounting and antenna routing are a matter of personal preference. A section of  plastic tubing glued to the inside of the fuselage makes a great antenna guide,  and the switch on the prototype is mounted on the left  side of the fuselage, as high as  possible.

NOTE: Any time you mount the switch on  the side of the fuselage on a combat plane, be sure the forward position is "on"  and it is as high on the fuselage as possible. This helps prevent the switch  from being turned off when
your plane is hand  launched!!!

7) Install  pushrods and set your control surface throws as follows: set ailerons &  elevator - 1/2" to 3/4" up & down (1" to 1 1/2" total). Make sure your  throttle is rigged to shut your engine OFF.

NOTE: When rigging your ailerons,  ensure that the bottom of the ailerons are parallel to the top of the fuselage  WITH THE WING INSTALLED!  Do not allow then to droop (like flaps)!  If your ailerons droop, they  will
drastically affect pitch  trim!

Flying your  SNM:

1) Follow ALL  AMA safety codes!

2) Attach  your wing with at least 12 #64 rubber bands (6 per  side).

3) Make sure  your prop is clocked to stop horizontal, and that your throttle is rigged to  shut the engine off for landing.

4) Have some  one else hand launch your plane until you have it trimmed out properly. IF YOU ARE NOT AN EXPERIENCED PILOT, DO NOT ATTEMPT  TO FLY YOUR SNM BY YOURSELF - PLEASE FIND SOMEONE EXPERIENCED TO HELP  YOU!

5) Fuel up,  have fun, and then go kick some serious butt!

As always,  send pictures if you would like to show off your plane on the SPAD gallery! And  if you have any further questions, please don't hesitate to post them on our  SPAD message  board !