lockheed p-38 lightning - greenairdesigns.com · lockheed p-38 lightning . micro combat warbird...
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Lockheed P-38 Lightning
Micro Combat Warbird Range! Firstly we at Green Air Designs would like to thank you purchasing one of our micro combat warbird range. These little planes are not for beginners but, if flown by a competent pilot, you will have hours of incredible fun. These little planes are of the highest agility. We suggest you fit the GoBrushless GBV series of motors. In tests, we have produced over 1-1 power to weight, with great vertical performance. Power Set Up GB V motor - 12 mags, wound in either 22t Delta or 10T double wind Wye (Wye being easier to do, and more torque) X 2. GAD 21g outrunner – contact GAD Prop 5x3/6x3 X 2 3S 340/700 lipos. Either 2x340`s or twin 700`s or single 1500 pack Light build only!!!
Wing Construction
Aileron Rod Line
L.E Glues on here
Aileron linkage, Bearings
Length 230mm
Height 12mm
Servo linkage again made from 22g wire and fitted through bearing in top of aileron linkage.V`s for adjustment once fitted to servo.
Aileron Shaping (Enlarged)
Boom Slots
Ply DoublersCA`d to both sides of spar
Ply Spar
Depron Ribs 1 through 4
Servo position (inverted in wing)
ESC
NO METAL TO METAL CONTACT, MAKE SURE ALL BEARINGS IN LINKAGE INSULATE RODS!
Sand to allow top skin to fit nicely.
Sand to nice LE aerofoil shape.
Wing Construction is very straightforward!
1. Glue bottom wing skins together. You can tell bottom skins from top skins as the top ones are wider to accommodate the curvature of the ribs!
2. Build from the centre to the tip.
3. Using epoxy for all parts here, glue in ply spars then longest ribs.
4. Then ribs and continue to tip.
5. Remember to use packing tape to hold the curvature onto the ribs as
you glue them.
6. Once all spars and ribs glued to bottom skins and set, make aileron linkage (the linkages have to be very close together as they have to fit inside the fus and this is very narrow), and inset into ribs. Don’t forget to fit white bearings onto aileron linkage before you bend it, the linkage will then move smoothly when glued onto place.
7. Sand the tailing edge with a block almost to a feather so that when the
top skin is fitted, it leaves the TE at 3.5mm thick.
8. At this point you may wish to put ESC`s in the wings and run wires out to booms and centre point, the reason being that CG position of this aircraft is not easy to achieve unpainted (this is optional).
9. Also fit Elevator servo extension lead through wing ready for
connection to RX and servo.
10. Once happy that the aileron linkage is fitted and smooth operation is obtained, make a small hole for the servo linkage end to go through the top skin and glue top skin into place starting with the TE, packing tape so that once you pull the skin over its held tight. Make sure you have good coverage of epoxy on all ribs and spars and NOT on aileron linkage.
11. Using thinners or, very carefully, epoxy glue both sections of aileron
together. These are slightly larger than the hole they are supposed to fit into, trim so that these are free moving but not sloppy fit!
12. Mark around the sections inboard and outboard of aileron so that you
have a shape to sand to. Sand only using a block!
13. Fit cut down Aileron hinges, glue hinges in with epoxy and make sure you have full range of movement.
14. Glue on LE Strip using loads of packing tape to hold in position until
set.
15. Using packing tape, glue together TIP outboard of rib, and sand a rounded section into the tip.
16. Using sanding block again, sand in the LE aerofoil shape. Also using
block, sand the underside of tip to create a small amount of washout. Wings now complete.
Boom Construction (Part 1)
Outb oar d
In bo ard
P ly motor plate
S ervo (St arboard boom on ly)
Cu t hatch once bui lt
for servo ac cess
Ele vator rodG
BV
motor m
ounted in ply plate
Depr on end plat es
Boom Construction (Part 1 continued)
1. Gently manipulate sides and bottoms of booms to follow contours before gluing together.
2. REMEMBER THERE ARE 2 BOOMS AND ARE MADE IN
REFLECTION OF EACH OTHER!!!!!!!!!
3. Using packing tape, start with the bottom, glue sides on, then front top nose then full top.
4. Make holes for motor on motor plate, check they are vertical and glue
in place.
5. Laminate front depron parts.
6. Using motor bells as guide, make clearance in front depron parts and glue to ply plate. Do not forget to make holes for wires to go through.
7. Repeat but remember to make opposite for other side. You don’t want
two left hand booms!
8. Put basic shape in with 80 grit paper. (Round off top and bottoms, flow into nose).
9. By now you will have realised that there is no way that your going to
get the wings in the holes…..
10. Cut along marks shown to remove top part of boom. Use only a very sharp or new blade for this.
11. You can now trial fit the booms onto the wings. Notice location blocks
of booms so that you can get the booms onto wings straight.
12. NOTE: The wings will be tight fit so fettle as required to get a nice snug fit.
13. Once happy with fitment, trial fit removed part of boom. This may also
need a small amount of fettling to sit down properly, which is normal. All these parts were designed for interference fit. Glue in motors. Make sure you have about 1 deg of right thrust.
14. Once all this done, its time to test out the motors and connect up.
(VERY important as once booms glued into place you cannot get at the wires so double check everything now! Check rotation!!!!!!!
15. When happy with rotation, we can glue in wings to booms….
Cut through here with very sharp blade.
Boom Fitment
1. Connect motors to Esc`s, check rotation!
2. Using stabilizer as guide make sure that booms are parallel and straight before gluing.
3. Slide wings onto booms, making sure that the elevator servos
extension cable lies in rear of starboard boom.
4. Epoxy bottom of wings at connection, put weights on top of wings to make sure of full contact.
5. Once set, glue down removed parts of booms. Again using weight for
full contact. Tail assembly
Epoxy on balsa strip for added regidity
Mylar 2mm strip hinges
Control Horn
Tail assembly (continued)
1. Sand stabiliser to symmetrical aerofoil shape.
2. Sand rudders to symmetrical aerofoil shape.
3. Slot carefully with sharp blade for hinges and epoxy into stabiliser.
4. Carefully ease elevator into place and slide in stab. This should lock the shape of the p-38.
5. Once happy with alignment of stab and rudders, check rudders are
vertical and epoxy assembly into place.
6. Make slot and glue in elevator control horn.
You should by now have something that is starting to look like a p-38!
Central Nacelle This is where things get a little tight! Not much room in a 32” P-38.....but it all fits!
Make from scrap last.
RxServo
May beed to trim out to allow for easy servo operation
Batts
Trim out hole
Nacelle sides Nacelle bottom
Nacelle top
Nacelle sides
Nacelle topRemovable part for batts access!
Cut out once built fro access Laminate to upper part.
Nose block laminations
Magnets
Central Nacelle (continued)
1. Gently form curves in sides and bottom of nacelle.
2. Using packing tape epoxy together.
3. If need be trim out some of the sides to allow batts to go back a fair way.
4. Epoxy in the nose front top.
5. Epoxy on next layer. Cut out centre part to allow access for batts, Rx
etc.
6. Laminate using thinners the cut out part to upper layer centrally for location.
7. Laminate all nose parts and epoxy into place. Yes it would be easier to
use a lump of blue foam here, but in the interests of C of G positions we need to get as much weight back as far as possible. Depron is lighter.
8. Put basic shape in with 80 grit and finish with 180 grit.
9. Trial fit to wings, you may need to trim out a section at the rear to allow
for easy and full movement of aileron links. The way that the nacelle is designed is that it again is interference fit. You may need to trim out front edge of aperture and a small indent into LE of wing for snug fit. This also allows it to slide fully back!
10. Trim down and glue canopy onto top layer. Make sure that you have shaped the top first!
11. Fit magnets using epoxy to hold down hatch.
Finishing Up
Make an elevator link and connect up to servo. Remember to centralise all servos before fitting links to them as getting aileron links are impossible afterwards!
Replace hatch over servo after fitment and testing. Using Velcro, put a small piece in both sides of nose to hold batteries in place. Put another small piece to hold RX connect up and test!
Throws
Elevator Rates in, 20mm, Aileron 20mm. Rates out MAX Aileron movement. No change to elevator.
Once test flown, cover with a light layer of light filler, rub down smooth and seal with PVA / WATER mix leave to dry, light sand and ready for paint.
We recommend acrylics…..but you can use enamels, if used carefully. (No responsibility will be taken for incorrect use or paints or glues as these can melt the depron).
Centre of Gravity is 30mm – 35mm @ ROOT from Leading Edge