SIG Somethin' EXTRA N477SC Instruction Book Download Page 23

b. With the tailwheel in place, the rudder can now be hinged to the vertical fin and fuselage. Follow the directions given in the 

INSTALLING EASY HINGES section.
 

Tail Supports

 
The tail support system used on the Somethin Extra provides an added measure of support and rigidity to the stab and fin. 
As it does for full scale aerobatic aircraft, this system allows the model to be flown through extremely violent maneuvers 
without being concerned with the integrity of the tail group. It is easy to make and looks very nice on this particular model. 
We would urge you to include this support system on your model.

84a.

 
From your kit contents, locate and have ready four (4) 2-56 x10" Control Rods 
(threaded one end), four (4) Solder Links and four (4) 2-56 clevises. Use the full-
size Cross Section at F-7 drawing on the plans for patterns and cut the two top 
support rods (7-3/4" long, each) and the two bottom support rods (6 long, each).

 

b.

 
As shown on the plans, both the solder links and the clevises need to be modified 
by cutting off the pinned arm of each, leaving only the arms with holes. This is 
easily done with a "Dremel Tool" and a carbide cut-off wheel.

c.

 
Starting with the two upper supports, solder a solder link to the top unthreaded 
ends of each of the two rods. Using the plans as a pattern and a pair of pliers, 
bend part of the solder links arm to fit flush to the side of the fin, at its hardpoint. 
Thread a clevis onto the threaded ends of each rod. As shown on the plans, use 
pliers to bend a part of the clevis arm to sit flush to the top of the stab. Use a 2-56 
x3/8" bolt and nut, provided in your kit, to temporarily hold the two rods in place to 
the fin at the hardpoint - do not tighten yet. Thread the clevises in or out to match 
the holes in their arms with the holes in the stab hardpoints.

 

 

BUILDERS TIP: For a really nice 
look, use a good metal polish, such 
as "Simichrome" or "Flitz" to polish 
these support wires and solder links 
to a high luster, chrome-like finish.

d.

 
The two lower support arms are made in the same way. The only difference is 
that the inboard solder link arms will overlap each other and be attached to the 
fuselage with a single 2-56 x3/8" bolt passing through the holes in each link and 
into the hardpoint at the bottom rear of the fuselage.

e.

 
When the support arms are made, they can be mounted in place to the fin, 
stabilizer and fuselage bottom. We suggest using a thread lock product on each 
of the 2-56 bolts before assembly. Doing this minimizes vibration problems.

 

Landing Gear And Wheel Pants

 
The unique landing gear used with the Somethin Extra design looks great when 
dressed up with the wheel pants provided in your kit. These wheel pants are not 
difficult to assemble, add a great deal to the overall look of the model and work 
extremely well on either paved or grass flying fields. Use these steps to produce 
a very tough, functional and nice looking landing gear set for your model.

 

 

85a.

 
With the exception of the wheel pants, ply wheel pant mount, 4-40 x3/8" bolts and 
the 4-40 blind mounting nuts - install your 2-3/4" dia. main wheels to the 
aluminum landing gear using the hardware shown in the cross section detail 
drawing on the plans and supplied in your kit. When properly mounted, the 
wheels will turn freely but will not have excessive side play on the axles.

b.

 
Locate the left and right sides of each wheel pant. Apply thick CA glue to the 
edge of one pant half and glue it to its mate. Do this carefully, matching the sides 
as closely as possible. Hold the parts firmly together and spray accelerator on the 
joint. Use your "Dremel Tool" and a drum sander to carefully clear out the 
molded-in wheel clearance area at the bottom - do not take out too much, it is 
better to sneak up on this opening. As you clear these openings, periodically 
check the fit by placing the pant over the tire.

Summary of Contents for Somethin' EXTRA N477SC

Page 1: ......

Page 2: ...ered to provide you with an enjoyable building experience The plans were developed using our powerful CAD Computer Aided Design system To insure absolute accuracy the individual parts themselves were then generated using these same plans through a path directly to our computerized laser cutting system This methodology produces incredible accuracy minimizing and or eliminating the need to prepare p...

Page 3: ...nate fumes Sanding Blocks And Straight Edges It has been correctly said that the difference between a good model and a great one is sandpaper and the knowledge of how to use it In these instructions you will note that we often mention sanding blocks T bar sanders etc You will definitely need several sanding blocks to build this model If you don t already have one do yourself a favor and purchase a...

Page 4: ...2 6 32 x1 1 2 Round Head Bolt Wheel Axles 4 6 32 Lock Nuts Wheel Axle Assembly 2 6 32 Hex Nuts Wheel Axle Assembly 7 6 32 Blind Mounting Nuts Landing Gear Motor Mount Attach 8 2 x1 2 Pan Head Screws Control Horn Attach 6 6 Metal Washers Wheel Axle Assembly 1 Piece of 1 x8 Fiberglass Tape 18 SIG Easy Hinges Ailerons 8 Elevators 6 Rudder 4 Miscellaneous Parts 1 7 8 O D x15 1 4 Aluminum Tube Wing Joi...

Page 5: ...od Ink will invariably leach through your film covering material and could ruin the finish Use a well sharpened 2 pencil for best results Use a small piece of masking tape and a pen to identify each of the various laser cut parts To do this refer to the Key To Laser Cut Parts drawings Note that the outlines of the actual laser cut parts themselves have been purposely interrupted at various points ...

Page 6: ... ...

Page 7: ...bs on the bottom rear 3 From the laser cut parts in your kit locate wing ribs W 1A through W 7 and the two plywood aileron servo trays that fit between ribs W 3 and W 4 Check each rib to make sure that each of the laser cut holes are cleared out vent holes etc Now is also a good time to make sure your aileron servos fit into the standard servo cut outs provided in each of the ply servo trays If re...

Page 8: ...ed spar provides gluing surface for the center sheeting and the cap strips We have found the easiest way to glue the leading edge sheeting in place is to do it in two steps 1 Start with the leading edge glue joint where it mates to the top rear face of the 3 8 leading edge Apply a bead of glue along the entire length of the sheeting on its front edge only Fit the sheeting in place to the top rear ...

Page 9: ...he exposed back half of the spar Carefully position this sheet to minimize high spots gaps etc Use weight or pins to secure in place and spray with accelerator BUILDERS TIP When edge gluing two pieces of sheeting off the structure it is always best to sand the resulting joint smooth on both sides with a sanding block before gluing the sheet in place This practice minimizes high and low spots bumps...

Page 10: ... to the contours of the wing Sand the face of W 1A smooth avoiding contact with the two exposed tube ends Trial fit the ply W 1 rib in place to W 1A NOTE When the W 1 rib is in place with the female wing receptacle tube inserted into its corresponding hole the rear 3 16 dia wing locating dowel holes in both W 1 and W 1A will line up exactly Use the 3 16 dia dowel in your parts bag as a temporary f...

Page 11: ... the laser cut aileron control horn holes top and bottom to reinforce these areas Lay the cut piece of fiberglass in place over the holes and flood the tape with thin CA glue until the weave is full Allow to set and repeat the process with the other side of the aileron Repeat the process on the remaining aileron Use sandpaper to lightly sand the glass smooth BUILDERS TIP After cutting the fibergla...

Page 12: ...cedure with the two holes on each side of the stab Save the excess drilled dowel material as it will be used during fuselage construction 30 The tail group is now basically assembled We suggest that now is a good time to sand these assemblies In order to sand the fin rudder and stabilizer elevators assemblies uniformly use masking tape on one side only to temporarily attach the rudder to the fin a...

Page 13: ...ermine the required spacing between the two engine mounts to fit your particular engine Use a pencil to mark that spacing onto the face of the firewall Example If the width of your engine s case is 1 3 8 then divide that figure in half 11 16 and mark the face of the firewall with the 11 16 measurement on each side of the vertical centerline Use a triangle to draw two parallel lines one at each 11 ...

Page 14: ... these openings as required and to drill the required holes for mounting them to the tray Once the tray is ready glue it in place to the fuselage side just above the 3 16 dia rear wing locator dowel hole and to F 4 engaging the rear tab on the servo tray in the top cut out in F 4 IMPORTANT With both fuselage sides properly in place the rear 3 16 dia holes for the wing root locating dowel on each s...

Page 15: ...r fuselage formers Because of the rudder and elevator pushrod orientation they must be installed in the correct direction The cross sections on the plans show these formers facing forward toward the nose this is the correct position for each former Locate the 1 4 x1 2 leftover length of balsa that you were asked to save in Step 27 This piece of scrap will now be used as a spacer at the rear of the...

Page 16: ...op Rear sheet FTR in place from the top rear face of F 4 to the front face of F 7 This is easy to do by first fitting FTR securely in place to the fuselage and using thin CA glue with a thin applicator extension applying the glue from the inside of the fuselage Glue the Fuselage Stab Mount FSM in place behind F 7 into the fuselage sides Lightly sand the top surfaces of these parts smooth with a sm...

Page 17: ...space the rail 1 16 above the fuselage side and secure it with pins from the outside of the fuselage Take your time and make sure it is uniformly spaced 1 16 above the side of the fuselage Repeat this process on the opposite side with the remaining rail Glue the ply hatch base onto the tops of each rail aligning its edges with the fuselage sides and holding its forward end with the 5 16 dia hole i...

Page 18: ...nto the fuselage This is done by first engaging the rear dowel into the locating hole in the F 4 Cap centering the locating rails and pressing the hatch in place There should be very little gap at the front of the hatch If the fit seems too tight lightly sand the face of F 2T 68 Locate the remaining length of 5 16 dia center drilled dowel As shown on the plans this dowel fits into the front of the...

Page 19: ... fuselage with rounded edges on the bottom and at the nose Take your time and do a good job At this point you need to make a decision regarding the covering technique for this model We are aware that some modelers prefer to cover the stabilizer fin and fairing blocks separately off the fuselage and glue them in place afterwards While this technique may work for some we prefer to glue these surface...

Page 20: ...ch the two motor mount arms to the firewall Without the muffler installed place your engine onto the motor mounts and locate it to the previously drilled holes with at least two of 6 32 x1 bolts without nuts You will likely note that in order for your engine to fit in place with the muffler attached the right fuselage side must first be trimmed to accept the manifold We suggest about 1 8 clearance...

Page 21: ...e cover of this kit is fairly easy to accomplish In the case of the wing panels stabilizer and fin we used the plans themselves to develop the color separation lines patterns These patterns were drawn on drafting vellum directly over the plans taking care to keep the color seams over solid wood The pattern was then taped over both colors of covering film one underneath the other and cut using a me...

Page 22: ...ng panels using the same method as the elevators Again be careful to make sure that the correct aileron is hinged to its correct wing panel control horn holes on the inboard side of W 3 NOTE The rudder will be hinged using the same methods in this section after the tailwheel has been installed in the FINAL ASSEMBLY section FINAL ASSEMBLY Canopy Some builders may wish to install a pilot If so it sh...

Page 23: ...or a really nice look use a good metal polish such as Simichrome or Flitz to polish these support wires and solder links to a high luster chrome like finish d The two lower support arms are made in the same way The only difference is that the inboard solder link arms will overlap each other and be attached to the fuselage with a single 2 56 x3 8 bolt passing through the holes in each link and into...

Page 24: ...m into the mounting plate f Apply glue to the inner face of the mounting plate and glue it inside the wheel pant with its two mounting holes lined up with the two holes drilled in the pant use the 4 40 x3 8 bolts to tighten the plate to the inside surface of the pant g Note that if any of the ply mounting plate is exposed in the pant slot it needs to be trimmed away with a sharp 11 blade to match ...

Page 25: ... nylon tie wrap through the holes provided in the tray This method is simple lightweight and effective It also provides excellent access to the receiver servo receptacles with the canopy hatch removed The receiver antenna is fed through the antenna tube exiting at the bottom rear of the fuselage We would also suggest using the radio manufacturer s antenna strain relief included with your system As...

Page 26: ...lder the link in place and reconnect the completed pushrod to the aileron servo and nylon control horn 95 Locate the 18 length of metal throttle cable a solder link a nylon R C link and the 2 56 x3 4 threaded brass coupler Slide the brass coupler onto one end of the cable and solder it in place Thread the nylon R C link in place onto the threaded brass coupler From the firewall side insert the cab...

Page 27: ... independent movement of each aileron to control roll This is a versatile mixing feature as long as the pilot maintains elevator input as required ELEVATOR FLAP ELEVATORS and FLAPS Elevator to Flap mixing is also a good feature It interfaces the elevators to the flaps allowing both surfaces to work together When mixed together the flaps travel downward while the elevators travel upwards at a progr...

Page 28: ...l hang lower This can have a negative effect on how this or any other model flies and will show up in certain maneuvers It should be corrected The quickest fix is to add small stick on weights to the lighter wingtip until model hangs level A neater method is to cut a small hole in the wingtip place the lead inside securely and recover the area No matter how you do the job a laterally balanced mode...

Page 29: ...nited States is the ACADEMY OF MODEL AERONAUTICS commonly called the AMA The AMA SAFETY CODE provides guidelines for the safe operation of R C model airplanes While AMA membership is not necessarily mandatory it is required by most R C flying clubs in the U S and provides you with important liability insurance in case your R C model should ever cause serious property damage or personal injury to s...

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