Boeing B-17G Flying Fortress Combat Warbird Range! Firstly we at Green Air Designs would like to thank you for purchasing one of our 20th scale combat warbird range. The B-17G is not a difficult build, but time must be taken on some of the steps to make this everything that a Fortress should be! Building order is not that important, until the final assembly. Power Set Up GAD 21g 1700KV outrunner – contact GAD Prop 8x4 3 Blade GWS Prop X 4 Cut down to 7x4 for a near scale look…7x4 standard props can be found in most hobby shops or enquire with us (brushless set-up). 7x6, 8x6 on 4-1 gearbox and 280 brushed motors. 4 x 10A Brushless Esc`s / 1 x 40A Brushed Esc 3S 2P 1800 – 2200Mah lipos 6 – 9gm Servos (3x5g 1x9g Min) Ubec to supply at least 4A (Esc Bec not usable on over 4 servos)

Wing Construction

Wing construction is fairly straightforward just take your time over the wiring slots!

1. Shape the inboard edge end of the wing panels with a sanding board. Locate the wing spar. At the thickest part of the wing make a slot to slide the spar into. NOTE: the spar is purely to fix the dihedral angle for the wings. Once happy with fitment, epoxy the white foam wing panels together over the spar.

In the underside of the wing:-

2. Using the drawing, mark out cable runs for power cables and servo cables. Remember that if you are fitting retracts then you will need extra servo cables on both sides. I.e. Left wing will need 1 x esc Rx cable, 1 x retract Rx cable & 1 x flap Rx cable, use Y leads as required. This is obviously copied on the right wing.

3. Using a scalpel and a rule, cut slots for cable runs, using the handle of

the scalpel drag it through the cuts so that pushing cables in is easier. Make sure you use a new or at least a very sharp blade for this or the blade will drag and tear the cores, this is not a problem, but it just makes more mess.

4. For brushless setup, run battery cables out to nacelle positions and servo extensions so that they come out far enough to connect up to the ESC’s. Remember to allow enough cable at the root of the wing so that you can solder the power cables together. MARK the POS +ve cable!

5. Y-lead the motor ESC cables to the centre of the wing so that when the wing is done, only one servo cable exits for the motors.

6. Y-Lead the 2 servo cables from the aileron servo extension cables so

that only one servo cable exits the wing at the root for the aileron control.

7. Using the drawing, mark out the holes for the servos (Aileron & Flap

optional) with a scalpel grout out. Be careful that you only go in far enough so that the servo fits flush with the underside surface of the core.

8. Centralise the aileron servos, and glue into place. Make sure that the servos work in opposite directions. Also make sure that the servos fit flush with the underside surface (before the skin goes on).

9. Now in the underside of the wing you should have all the power cables

and servo cables routed in the wing.

10. Using Aerobond or Copydex, apply glue to the entire bottom surface and allow to dry.

11. Whilst this is drying, apply same glue to inside surface of wing skins

and allow to dry.

NOTE: when you bring the skins in contact with the cores you will NOT be able to separate them again without destroying the skins so dry fit them as many times as you need to, to make sure that you are comfortable with alignment long before they are glued. Also there is washout cut into the cores be very careful not to build this out as you skin the wings. USE THE LEADING EDGE FLAT AS THE GUIDE FOR FITTING THE SKINS

12. When the core surfaces are dry and skins are dry, gently apply skin to topside first and firmly press down. Root to Tip! Often it’s easier to do this off the edge of a table.

13. Locate and glue in the tip support spacers

14. Do this to both bottom surfaces. 15. Once the wings are skinned, apply Epoxy at the root joint to secure

everything.

16. With a sanding block, flatten off the LE of the core ready for the LE strip if there are any un-even steps.

17. NOTE: IF FITTING LANDING LIGHTS THE WIRES & LED`s NEED TO

BE FITTED BEFORE THE LE GOES ON!!!!!! See Landing Light section.

18. Epoxy on LE strip, sand round.

19. Sand round the tips also to that classic fortress shape.

Sand to allow top skin to fit nicely.

Sand to nice LE aerofoil shape.

Tip Supports.

Fuse Construction

1. Tape the outside of the front and rear fuse sides with packing tape and manipulate a curved shape before epoxying or hotglueing

together

.

2. Using Epoxy/Hotglue, glue in all the fuse formers, remembering to keep the fuse straight. F1 through F4, you may need to curve the side skins at F1 as the shape is hard to get unless you do. Do not remove tape yet!

3. Repeat the curving and taping for the other side, glue onto formers.

4. Locate Parts FB1 you can see from the photo how these are aligned. Note: the fuselage is very flexible at this point. This is normal.

5. If fitting a retractable tail wheel now is the time to build and test the unit.

6. The unit is then glued on top of FB1 with epoxy with alignment of the

tail wheel down level with the front of the Stab recess.

7. Glue into place.

8. Repeat for FB2

9. Locate Parts FT1 (4 Parts - 3 shown). Note the forward part shown

here is the hatch. There is a centre hatch (not visible in this pic), Make sure that you do not glue up the centre as this will be part of the hatch you remove later. Use tape if need be to hold it all in place as you glue.

You cannot build any more of the upper fuse until the horizontal stabiliser has been built. 10. Using the stabiliser as a guide, glue on the last part (rear) of FT1 11. Locate FT2 (All parts). The rear section needs to be sanded to fit over

the Stabiliser. Take your time with this so that FT2 travels straight to the tail. Be careful not to remove too much or it will sag and be hard to repair later.

12. Glue the rest of FT2 down. Again use tape as required to hold

everything in place. We recommend that you use UHU Por for lamination gluing.

10. Note the hatch FT2 is glued to the centre of FT1 11. Repeat for FT3.

13. Locate the 3 rear cabin laminations, using UHU Por, laminate together and fit to FT3 level with the hatch rear. Longest part is the bottom and they are front aligned.

14. Locate the 3 hatch tops and repeat as in step 12 and laminate to hatch FT3, Make sure that all parts are straight and fit level with the rear cabin. Note: The front part of the cabin is glazing.

15. Now is a good time to trial fit the wing into the slot, this may need

fettling as required to fit. See pic.

16. Chamfer FB1 & wing joint so that the wing basically drops in place, carefully sand either side of the fuse if it looks like its sitting on the slant. BE VERY CAREFULL TO ONLY REMOVE WHAT YOU NEED AND NO MORE! CHECK TWICE RUB ONCE!!!!!

17. Remove wing from fuse, using 40/60 grit sand in basic shape to fuse. DO NOT GO TOO FAR as final fettling will require a more delicate touch.

18. Refer to stab build for servo fitment in the fuse for elevator. Fit all servo extension cables required NOW (elevator/Rudder/tail retract)

ENGINES

Nacelle Construction – Inner Nacelles

1. Cover the outside of the nacelles with packing tape (makes rolling easier without cracking the skins) remember that these are handed, very easy to make 2 lefts for example You will require parts IBIB & IBOB for both sides, these are marked in such a way that it is hard to build them wrong. See Pictures :-

2. Once covered and rolled as best you can, glue in the formers F1 & F2

Basic construction.

Engine Tops. IT1 & IB1

3. Screw the motors to the wood mounts and epoxy to the inside of the front former. Open up the front former to fit your motor. NOTE: You need to put the wood mounts in such a way that you end up with 1 deg of down thrust. Also the rear former of the nacelles are purely to hold the shape whilst building, this will have to be mostly removed to allow fitment of the retracts.

4. Continue on with the construction.

Engine Bottom Next Layer IB2

Engine Top Next Layer IT2

Engine Bottom Last Layer IB3

Built Ready for Shaping, Repeat for other side.

Engine ring & outer cowling.

Repeat for outer nacelles OB OB & OB IB REMEMBER THESE ARE HANDED!!!!

5. Solder up Esc to motor and check rotation on all engines. 6. Shape up engines & relieve the underside of the top part that goes over

the wing.

RETRACTS

Main Leg Retracts.

1. Locate all of the retract ply & Carbon parts.

Most of this construction is done with CA with some parts doubled up with Epoxy .NOTE THESE ARE HANDED----Do not show off your intellectual prowess like me and make 2 lefts!!!! You can see the recess where the wheel wil retract into on the plates so these have to laid out opposite! 2. Locate the main base plate and the strut supports. CA these down &

Epoxy the outside of the 1/8th supports.

3. Laminate the 2 1/6th actuator arms. (2 per side)

4. Cut off about 10mm of 2mm rod to make the hinge pin ( 2 required)

5. Now we need to make the link arm. Locate parts and CA together.

6. Locate the Thinner end of the link arm and remove a small amount of

inner support (needed for rotation up)

7. Make another short pin to take the link arm.

8. Main leg construction, requires you to locate the lower half parts. CA

together

9. Locate the carbon tube cut to 60mm & the 1/8th link arm mount, insert

into wheel mount you just made. Make sure that the tube comes to within 2mm of the wheel hole. CA thoroughly. NOTE: The hole for the link arm is mounted uppermost!!!

10. Locate and……you get the picture……. TOP MOUNT. CA together…..

11. Insert top mount onto carbon tube, make sure it comes up to just under the hole for the pivot, but not interfere with it. Lay the whole unit on a flat bench, make sure that the top mount is DEAD in line with the bottom or the aircraft will track odd!!

12. Note which side of the aircraft you are building. Glue the 2 spacers to the outside of the bottom mount (wheel spacing so that the tyre does not touch the leg)

13. Cut and fit the pin (3mm rod) to go through the bottom mount for the

wheel to sit on. Epoxy the underside to strengthen the highest stress point.

14. Cut a piece of carbon tube (6mm) to 25mm. This is your top mount hinge pin.

15. Dry fit the hinge pin to the leg, this will be tight, so relieve it a LITTLE, it

should be an interference fit in the leg, but not so tight you can’t get it through the base plate mounts.

16. Slip the leg into place, push the carbon through. Make another 2mm

pin for the link arm.

You should now have a fully functioning leg.

The leg should retract to parallel with the base plate, free off any parts that bind!

17. Servo is hot glued and zip tied to the base plate 18. Make 18swg link with ‘Z’ bends at both ends, Make sure that they are

identical as the legs will not move equally otherwise. A bit of time taken on this bit will yield loads later when fitting them.

19. These units are designed to be fitted as complete, remove as much of the internal formers as required to do this from the nacelles.

20. Check for full rotation when in place!

21. DO NOT GET GLUE ON THE RETRACT MECH WHEN DOING THIS! 22. Repeat for both sides.

Tail Leg Retract.

1. Locate the ply plate. 2. Screw in supplied blue retract mechanism. 3. Glue down the servo (9g)

4. Make up 18swg wire link, this is a bit tricky as it has to go over the mechanism. ‘Z’ Bends in each end.

5. Bend the leg to accept the wheel only. DO NOT BEND IT AS IN THE PICTURE OR IT WILL BREAK WHEN YOU LAND, JUST KEEP IT STRAIGHT WITH A BEND FOR THE WHEEL.

Tail assembly

Ball link

Ball link

To Servo - Bent to clear Stab

Top View

Front View

Side View

Note that the linkage is fitted inside the fuselage so that nothing is exposed.

Tail assembly Stabiliser

1. Slot and epoxy tail cores together with spar.

Laminate skins onto tail (Ref Wing Skinning) Glue on LE strip and shape up.

2. Using Skin etchings as a guide, and using a new blade, remove the elevators from built stab.

3. Make slots and a small groove in the end of the control surface to accept wire link so it fits flush. Keep the slot parts so that you re-glue them back in afterwards. NOTE: The elevator is top hinged so chamfer the lower edge to 30deg to allow full movement.

4. Glue stab to fuselage, check for straightness on fuse before you glue adjust fuse to suit stab as required.

5. Servo position for elevator is not critical. Centralise and glue in place

(solidly as no access is available after being built). 6. Connect up elevator and test.

Fin

1. Locate fin spine parts.

2. Glue in as below and locate fin sides, note etchings for fitment.

3. Glue on rudder spine to skin, follow by gluing on spine assembly.

4. Now this part is a bit tricky. Glue on opposite skin (will require a little

pulling to get to shape) but KEEP THE FIN STRIAGHT, easy to let it drift off. Run some glue along the inside edge of the top part of skin to secure together.

5. Locate rudder skins, glue in spine and supports.

6. Glue on opposite skin.

7. Locate fin strip and glue on, round off with 80 grit.

8. Chamfer leading edge of rudder in ‘V’ for centre hinging.

9. Cut slot in fin for servo horn to move in. Centralise servo NOW!

10. Fit servo inverted in fin, secure with glue. Make sure that the horn can

move easily outside the fin.

11. Connect up servo with 20swg wire with ‘Z’ bends both ends. 12. Centralise rudder and epoxy in rudder horn.

13. Make hole in fuse for servo wire to pass through.

14. Glue on fin.

15. Check movements.

Flaps If fitting flaps, build the wing as described in the earlier section.

1. Locate the 1/8th balsa flaps & supports

2. CA the supports, one on each end and one in the middle.

3. Note: the flaps are handed so check which way up they are built. They should follow the etchings on the wings.

4. Using a scalpel make 3 slots in the rear face of the flap to carry the hinges and CA in place. Note these are 3mm down from the face so that the hinge will glue under the skin of the wing.

5. Using a new blade, mark around the flaps laid on the wings. Carefully remove the lower skin.

6. Using the flap as a guide remove just enough white foam to allow a snug fit . The hinge should be glued in just under the wing surface.

7. It might be necessary to round off the forward edge to allow the flap to rotate down without snagging.

8. Make up 2 x 20swg links from the servos to the flap, ‘Z’ bends in each end.

9. Connect to the servo, once happy epoxy in the flap horn, check that they drop evenly, and adjust as required.

Glassin’ up! Using dowel supplied make up guns (12 in total 60mm long (40mm showing the rest for gluing in place)), paint black and glue through glass. Epoxy into place the glass. NOTE: ALL GLASS WILL NEED TRIMMING TO FIT. Make slot in tail gunners position for servo wire to go through.(moulding) Left and right waist gunner position. Cut out holes, leaving 2mm of fuselage on the inside for gluing to (IT looks good if you recess the fuse enough for the glass to fit flush) NOTE: you may need to gently warm the glass first as it will try to stay flat. G model – Staggered 200mm from LE of tail Starboard, 120mm Port.

The windows are laser cut and etched, for ease of painting, remove the framework (protective film) but leave the windows in place, we smoked the rear of the windows as you don’t really want to see inside, then glue into place.

Engine Cowlings, using 80 grit sand a gentle sloped notch from the rear to give the appearance if having cowl flaps. Sand off edges and glue on engine exhausts

Nose glass, Trim back and match to fuse front, hopefully you should not have fully shaped the fuse yet so you can match this quite easily. TIP: We used a 2” postal tube end, cut out the front former of the fuse, mounted nose weight (5oz) to the rear of it, and glued it in. This can give you a good bomb aimers position and looks like the fuse goes into the aircraft,

Note rough carved Norden bomb sight. Cabin Glass. Because of the curvature of the fuse top, we found it easier to recess the bottom of the moulding into the depron. You can see this in the picture above.

Chin Turret. This is a simple case if trim back (with care!!!!) and glue into place.

Tail Turret (Stinger) this is made of 2 mouldings, one glued over the other and trimmed back to fit on rear of fuse.

Note Tail gunner position moulding and servo wire going through. Ball Turret. Not much to say about that except that it’s sensible to have the guns pointing backwards, not much internal detail required as most of the turret is painted framework. Top Turret: Again I would have the guns rear facing, this turret is pretty much self explanatory, just trim down and glue on. The only worthwhile point is that when you glue the turret down, make sure that is over laps the cabin slightly, it works quite well as a semi catch for the hatch alignment.. Cheek turrets: These are staggered on the ‘G’ Model (Starboard cheek is 30mm back from nose glass. Port is directly behind the glass.

Top nose blister is made from scrap depron to a diameter of 20mm.

Throws

Ailerons – Top to Bottom 30mm Rates Out 40mm Elevator - Top to Bottom 40mm Flaps - Max 40deg Rudder – Max Movement (takes off and land)

Once test flown, cover with a light layer of light filler, rub down smooth and seal with PVA/water mix or 2 coats of Ronseal PU water based varnish and leave to dry. Light sand and ready for paint.

We recommend enamels (Flair/Humbrol), if used carefully. Enamels do yield a very scale look to the aircraft. Check all other enamels (No responsibility will be taken for incorrect use or paints or glues as these can melt the depron).

Centre of Gravity is 50mm – 60mm @ ROOT from Leading Edge.