S3021 Airfoil

full flying stab

Mar 22 Finished Covering and configuring Spoilers ,
Hand toss as well, required lead in area front of battery, as well as some under
battery to
balance, app, 3/8" behind center of wing rod

AUW was 1415 grams ,  50 ounces

Like to build one of these?

I will have the following available

 

Price List

Wing Kit
  • complete rib set
  • leading edges

$ 55.00

Option A  (Misc Tube and Rod) Add $7.50

  • 2 x 1/8 tube
  • 2 x 11/32 tube

 

Fuselage Kit
  • Built side panel, with 3 Nylon Tubes
  • formers F1 thru F10
  • nose block
  • Hatch hold down bracket
  • Tow Hook reinforcement
  • Plastic Canopy

 

$ 55.00

Option A  (Misc Tube and Rod) Add $ 8.50

  • 1 x 1/8 tube stab pivot
  • 1 x 1/8 tube, wing incidence
  • 1 x 11/32 tube
  • 2 x  stabilator pins
  • 1 x  incidence pin
  • 2 x 1/8 tube, stab
  • 2 x 1/8 tube, stab

P.S.

This write-up is a work in progress, and is not complete.....

my writing skills need to be honed, like to help?

 


 

 

Getting  Ready to Build

  • you'll need a building board, app 50 inch long by 12 inch wide, a board  twice this size would be better, then both wings can be worked on at the same time
  • gather all the parts you'll need, pre cut spars and shaped pieces will help speed up the assembly process
  • the plane is built as 6 basic assemblies, wings, fuselage, stabilator, rudder, cowl, rear hatch, and then of course there is the sanding, painting and covering, installation of radio gear and the  Final Assembly

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Fuselage Build

    • 5/16" Dia steel wing rod x 6" Long
    • incidence pins for stab, Steel 1 of 3/32 x 3 1/4 and 1 of 3/32 x 2 3/4
    • 1 req wing incidence pin Steel 3/32 x 2 3/4
    • 1 req brass wing rod tube 1 5/8" long x 11/32" O.D in fuselage
    • 1 req 1 5/16" long x 1/8 O.D. brass incidence pin tube in fuselage
    • 1 req. 1/8 O.D.x 5/8 brass tube for stab pivot
    • 3 x nylon tube, rudder, stabilator, and antenna
    • 2 x 1/16 cable, rudder and stabilator

     

gluing in the nose block, I use 30 minute epoxy, bring up to the lines on the fuse insides, and flush with the top edges..

Note the down side of the block

 

fuselage rear top balsa , being glued on 1/4 balsa sheet  x 3/8 wide at rear and 1 1/16 inch at front

17 1/2 long

Set fuselage on board , and use a square to hold fin perpendicular to board before gluing

 

 

1/8 plywood, 1/2 wide x  3 3/4 long for tow hook stiffener plate..

Fashion a 1 inch long slot down the middle to accommodate a 4-40 (or suitable) tee-nut for the hook..

this gets epoxied in place between formers F5 and F6,  flush with rear of F6

 

 

 

 

 



Wing Build

  • cut 4 spars 1/8 x 3/8 spruce, 23 13/16 " for inboard panels

  • cut 4 spars 1/8 x 3/8 spruce, 22 7/16 " for outboard panels

  • cut 2 sub spars 1/8x 1/4 spruce,  21 1/4"
  • brass tubes 2 of 1/8 O.D. x 5/8 for incidence pin 
  • leading edges 4 x 24" long, cut length to suit
  • spruce trailing edge cap 2 of  3/32 x 1/4 x  24 for inboard panel
    • spruce trailing edge cap 2 of  3/32 x 1/4 x  26 for outboard panel
  • balsa trailing edge 4 of  1/4 x 1 x 24 long
  • brass wing rod tubes 2 req.  2 1/4 inch long, 11/32 O.D.
  • brass wing incidence pin tubes 2 req 1/8" O.D. x 5/8" long

 

Notes

for longer wings 

-- add 1 rib to each inboard panel, for each additional 6 inch increase in wingspan

for a 118 Inch wing, add 3 ribs to each inner wing panel.

That will give a 18 inch stretch  to the Standard 100 inch wing


 

pin the bottom spars, both main panel and tip,  in location, a 4 foot level will help keep it straight on the plans

 

 

select the 1/4 x 1 trailing edge pieces, and trim the ends to the appropriate angles and pin to building board in position, using ribs as place holders

 

glue a sheet of 1/16 x 3 x 24 to the front edge of the spar for the bottom leading edge sheeting.

Note : Cut the end of the sheet at the root rib to the required angle, and it will help in placing the balsa root rib later

 

 

glue the 1/16 sheeting into the center aft position, between the spar and the 1/4 x 1 trailing edge

 

using the pre cut shear webs as spacers, place and glue the ribs in place

 

balsa root rib being glued in, us a dihedral jig to set at proper angle 3 Deg beyond 90

 

formed leading edge being glued to front of ribs

 

 

 

placing shear webs on outboard panel, cut in pairs and glue in same spot of both outboard wing panels

 



joining the inner and outer wing panels, a 4 ft level works great to jig both panels prior to gluing the 1/16 plywood brace

 

Diagonal braces cut and ready to be glued in

30 pieces, cut from 3/32 balsa , 3/16 wide x 7 inch long

trim to fit prior to glueing

 

glue in wing joiner cross tie braces, 2 per wing
-3/16 x 1 1/2 x 12 Balsa will make 4 pieces , as required

 

3/32 x 3/16 diagonal braces, diagonals can be cut nicely with a single edge blade

wing end caps











 

 

Stabilator Build


  • 2 req. 1/8 O.D.x 1 1/8  brass tube
  • 2 req. 1/8 O.D.x 1 1/4  brass tube 
  • 2 x 1/8 ID  Collars with set screw

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    Rudder Build

    R1   4"  1/4 x 3/16 Balsa

    R2   6"  1/4 x 3/16 Balsa

    R3   5"  1/4 x 3/16 Balsa

    R4   10"  1/4 x 3/16 Spruce

    R6  6"  3/4 x 3/16 Spruce

    R7   2 of 9"  3/32 x 3/4 Balsa Tapered at Top

    R8   2 of 4"  1/4 x 3/32 Balsa

    R9 2 of 1 x 1  1/16 PLY

    R10 Ribs 24" of  3/32 x 3/16

     

     

     

     

     

     






    Canopy Frame Build


    canopy frame assembly front portion

     

    cowel frame assembly front portion

     

     

                                                                                                                                  Elio December 2011