SIG Wonder, Building And Flying Instructions

Page 1: ... a bit of old time control line combat influence in the design as well The design presented here actually evolved from many years of Wonder Type designs starting with 1 2A versions back in the early 1980s There have been swept wings straight wings single tails twin tails and tripple tails The basic idea has never changed however I wanted dirt simple models that featured a shoulder wing for easy ha...

Page 2: ...many different glues available today for model construction that it can be confusing to even the experienced modeler To simplify matters most glues can be classified as one of four basic types Fast cyanoacrylate adhesives abbreviated as CA such as Sig CA easy to use water based wood glues such as Sig Bond yellow and Sig Super Weld white super strong but heavier two part epoxy glues such as Sig Kwi...

Page 3: ...ls 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 their correct position Whe...

Page 4: ...Corner Braces Skid Sides 1 1 2 Triangle x6 Cowl Filler Block Balsa 2 1 x1 1 2 x9 Wingtips Special Cut Balsa 1 3 16 x3 8 x36 Tapered Trailing Edge 2 3 16 x1 1 4 x12 Tapered Ailerons 4 3 16 x1 x3 Cowl Sides Pre Cut Plywood 1 3 32 x2 3 4 x6 Birch Ply F 1 Aileron Servo Mounts ASM 1 1 8 x2 3 4 x9 Lite Ply Formers HP Hatch Lip Spinner Ring Sawn Plywood 1 1 16 x7 8 x2 1 2 Birch Ply Wing Hold Down Plate H...

Page 5: ...straightedge and a sharp modelling knife to trim the sheets To help make the sheeting fit against the leading edge hold the knife at a 15 or 20 degree angle while cutting the front edge of the sheeting as shown in the photo 4 Glue the leading edge sheeting to the leading edge using a bottle of thin CA with a long applicator tube Apply slow CA to the tops of the wing ribs and the upper spar then pu...

Page 6: ...sa bottom center sheeting 11 a Carve and sand the wing leading edge to shape For best stall characteristics you want a nicely rounded leading edge as shown on the plans Use a long sanding block to make certain the curvature is consistent along the entire length of the wing b If necessary touch up the trailing edge with a sanding block so that it s flat and straight c Cut off and sand the spars lea...

Page 7: ...d with 80 grit sandpaper 6 The rest of the block can now be carved and sanded pretty much like a normal rounded wingtip Be sure to strengthen the trailing edge area of each wingtip by soaking then with thin CA Smooth things up with a hand held piece of 150 grit sandpaper WONDER WHY there s no dihedral brace or sheer webs in the wing Answer All of the spars and sheeting in the Wonder wing run the f...

Page 8: ...s as necessary to blend smoothly together FUSELAGE CONSTRUCTION Basic Fuselage Assembly 19 a Glue together the two die cut 3 32 plywood F 1 pieces using Kwik Set epoxy or slow CA Use a heavy weight of some kind to hold the two pieces perfectly flat while drying b Mark the vertical centerline and thrust line on the F 1 assembly using the cross section on the plan as a guide c Determine the spacing ...

Page 9: ...ace on the formers check the alignment of the fuselage over the top view on the plan When satisfied glue both fuselage sides firmly to F 3 and F 4 26 a Tape former F 1 in place on the front of the fuselage and again check the alignment over the top view on the plans Notice that the correct amount of downthrust 4 deg is built in automatically by lining up the front face of F 1 with the front edge o...

Page 10: ...o the balsa hatch 32 a With the hatch still in place use the plans as a guide to carefully mark the location of the two hold down screws Drill completely through the hatch and the hatch plates at the marks with a 1 16 drill bit b Remove the hatch then redrill the hatch holes with a 3 32 drill bit The holes can be countersunk for the flat head wood screws using a sharp 1 4 drill bit Strengthen the ...

Page 11: ... using the plan as a guide Drill through the wing and the wing hold down blocks at the same time with a 5 32 dia drill bit Keep the drill perpendicular to the top surface of the wing so the heads of the nylon bolts will seat flush against the plywood plate 39 a Remove the wing and tap the wing hold down blocks with a 10 32 tap You can apply a few drops of thin CA to the holes to strengthen the thr...

Page 12: ...ll require something of a custom cowl Besides a balsa cowl allows you to cover the fuselage right up to the spinner ring with no seams Actually you can leave the cowl off with no adverse effects on flight performance it just won t look as good 45 a Glue the die cut 1 8 lite ply spinner ring to the front of the cowl making certain it is aligned with the spinner backplate Notice that the spinner rin...

Page 13: ...pe of your choice Bevel the leading edge of the elevator sand the trailing edge round and trim each tip about 1 16 to clear the fins 49 If you are building the Russian the Angel or the Patriot you need to hand cut the fins from the two sheets of 1 8 x4 x10 balsa Edge glue the sheets then cut the fins out using the pattern of your choice Add the 1 8 sq spruce stiffeners sand the sides smooth and ro...

Page 14: ...hen covering solid wood surfaces like the fuselage sides better results can be obtained by starting at the center and working toward the outer edges allowing air to escape as you iron Experienced modelers know that oily engine exhaust likes to creep into every crack it can find which means special care must be taken to keep the hatch area as fuel proof as possible When you cover the hatch be sure ...

Page 15: ... the hinges aren t perfectly straight or centered in the slots they ll work fine regardless of their final position 53 a To set the hinge gap deflect the elevator to the maximum amount needed For best control response the gap should be as small as possible but big enough to allow full movement of the control surface without binding b Easy Hinges were designed to use Thin CA any brand for maximum g...

Page 16: ...the wing and the rear portion glued to the stabilizer Temporarily pin the canopy parts in their proper position on the assembled model then attach the front and rear canopy parts to each other with a piece of tape on each side Now the canopy parts can be lifted from the model and their top edges sanded round at the same time so they will match perfectly when installed Remove the tape cover the can...

Page 17: ...wn in the diagram Mark the balance point on the bottom of the wing with tiny lengths of striping tape Shift the radio gear or add weight as necessary to bring the balance point into the proper range Trying to fly with the balance point too far forward or too far aft is much more dangerous than the slight increase in wing loading caused by adding nose or tail weight Always balance the model with an...

Page 18: ...of the other versions were an offshoot of the Standard Its most distinctive feature has to be the down turned vortex wingtips The wingtips probably don t do much aerodynamically for a model of this size but they do look good and generate lots of comments from fellow modelers Covering the Standard The Standard color scheme is easy to see in the air thanks to the bold white stripes on the top of the...

Page 19: ...servos aren t as big as standard servos but they re bigger than micros The throttle and elevator servos are both attached with servo tape The 250 maH battery had to be installed next to the elevator servo under the hatch to offset the weight of the big engine It s held in place by the servo on one side and a scrap balsa stick The aileron servo is mounted to the plywood aileron servo mounts ASM Not...

Page 20: ... a crossflow plain bearing engine that s ideal for sport models like the Wonder It s not the most powerful 15 on the market but it s built well starts easy and runs reliably flight after flight It s best feature is the angled needle valve that helps keep your fingers away from the propeller while adjusting the mixture The wood propeller shown in the photo was something of an experiement It actuall...

Page 21: ...unction of the wing and stabilizer The silver leading edges are 1 x16 1 2 strips of trim material Center the strips on the leading edge so that there is an equal amount on the top and bottom wing surface The outboard end of the silver stripes should end at the yellow wingtip The silver leading edge pieces for the fins are cut from trim material using the pattern shown on the plan Engine Installati...

Page 22: ... the white about 1 4 over a glass plate Iron just the seam with the edge of your iron which should be set at a fairly low temperature Lift the joined pieces from the glass and iron it onto the wing like it was one piece of covering material The rest of the model is covered with white supercoat Now for the fun part Cut 1 5 8 wide stripes of red trim material and adhere them over the white as shown ...

Page 23: ...g to keep up with the airplane maybe it s time to throttle back and explore its mild mannered slow speed characteristics One of the Wonder s unique flying traits is something we call Wonder Bob Gain some altitude bring the engine to idle then slowly feed in up elevator until you have the stick all the way back and hold it Even at this low airspeed you should have enough aileron control to keep the...

Page 24: ...of gasoline or a bottle of poison Remember that it is possible to lose control of a model airplane Do not fly in locations where the model may hit people or damage property if loss of control occurs Check your model and equipment regularly to insure it is in safe operating condition Copyright SIG Mfg Co Inc SIG MFG CO INC Montezuma Iowa 50171 0520 LIMIT OF LIABILITY In use of our products Sig Mfg ...