background image

Fokker

 

Dr.1

 

46.7”

 

1/6

 

Scale

    

Page

 

 

5

 
 

 

Copyright©

 

2007

11

   

M.K.

 

Bengtson

  

All

 

Rights

 

Reserved

   

Rev

  

07/11

 

 

Apply

 

glue

 

to

 

the

 

frames,

 

and

 

lay

 

the

 

sheeting

 

down

 

on

 

top

 

of

 

the

 

frame.

 

Pin

 

it

 

down

 

at

 

the

 

center

 

first,

 

and

 

then

 

work

 

out

 

to

 

the

 

ends

 

of

 

the

 

sheeting.

 

Let

 

dry.

 

 

 

Now

 

finish

 

sheeting

 

with

 

the

 

other

 

two

 

pieces.

 

 

A

 

note

 

on

 

choice

 

of

 

glue

 

when

 

using

 

thin

 

ply.

 

Thin

 

plywood

 

soaks

 

up

 

CA

 

glues

 

like

 

a

 

sponge.

 

Once

 

the

 

glue

 

hardens,

 

it

 

makes

 

the

 

ply

 

very

 

hard

 

to

 

sand.

 

You

 

will

 

wind

 

up

 

with

 

uneven

 

sanding

 

between

 

areas

 

hardened

 

by

 

glue

 

and

 

those

 

that

 

are

 

not.

 

For

 

that

 

reason,

 

I

 

suggest

 

using

 

aliphatic

 

glues.

 

Takes

 

a

 

while

 

longer

 

to

 

dry,

 

but

 

it

 

will

 

be

 

much

 

easier

 

to

 

sand

 

and

 

finish.

 

 

The

 

front

 

of

 

the

 

cowl

 

is

 

formed

 

with

 

1/4

ʺ 

balsa

 

sheet

 

pieces,

 

and

 

then

 

the

 

cowl

 

is

 

carved

 

and

 

sanded

 

to

 

shape.

 

I

ʹ

ll

 

do

 

that

 

later.

 

DUMMY

 

MOTOR

 

The

 

Axi

 

motor

 

mount

 

is

 

part

 

of

 

the

 

dummy

 

rotary

 

engine.

 

It

ʹ

s

 

quite

 

the

 

piece

 

of

 

work.

 

The

 

dummy

 

crankcase

 

is

 

composed

 

of

 

layers

 

of

 

laser

 

cut

 

1/16

ʺ 

ply,

 

1/8

ʺ 

lite

 

ply,

 

1/8

ʺ 

balsa,

 

and

 

1/4

ʺ 

balsa.

 

Each

 

part

 

has

 

3

 

holes

 

laser

 

cut

 

through

 

which

 

motor

 

mounting

 

bolts

 

will

 

pass.

 

When

 

gluing

 

the

 

parts

 

together,

 

pay

 

attention

 

and

 

make

 

sure

 

these

 

holes

 

are

 

always

 

aligned.

 

Also,

 

assemble

 

the

 

pieces

 

so

 

that

 

the

 

grain

 

alternates

 

for

 

added

 

strength.

 

 

Now

 

I

 

suggest

 

you

 

count,

 

count,

 

and

 

recount

 

how

 

many

 

layers

 

of

 

1/4

ʺ 

balsa

 

it

 

takes

 

to

 

make

 

the

 

crankcase.

 

You

 

will

 

find

 

it

 

takes

 

6.

 

Notice

 

that

 

there

 

are

 

8

 

pieces

 

supplied.

 

Take

 

two

 

of

 

them

 

and

 

put

 

them

 

out

 

of

 

reach,

 

so

 

you

 

will

 

not

 

be

 

stupid

 

enough

 

to

 

use

 

all

 

8

 

and

 

wind

 

up

 

with

 

a

 

crankcase

 

that

 

is

 

too

 

long.

  

Should

 

that

 

happen,

 

you

 

can

 

use

 

a

 

razor

 

saw

 

and

 

remove

 

the

 

offending

 

piece.

 

Should

 

you

 

still

 

not

 

be

 

able

 

to

 

count,

 

you

 

can

 

reach

 

for

 

the

 

razor

 

saw

 

and

 

repeat.

  

 

 

  

Study

 

the

 

plan

 

and

 

make

 

sure

 

the

 

pieces

 

are

 

assembled

 

in

 

the

 

correct

 

order.

 

Note

 

that

 

there

 

is

 

a

 

1/8

ʺ 

balsa

 

piece

 

in

 

the

 

middle

 

with

 

extra

 

notches.

 

These

 

are

 

for

 

the

 

dummy

 

cylinder

 

construction

 

later.

  

 

The

 

plans

 

say

 

to

 

make

 

a

 

channel

 

to

 

pass

 

the

 

motor

 

wires

 

through,

 

out

 

the

 

back

 

of

 

the

 

crankcase.

 

This

 

is

 

certainly

 

do

able,

 

but

 

I

 

decided

 

to

 

make

 

a

 

hole

 

at

 

the

 

top

 

of

 

the

 

Summary of Contents for Fokker Dr.1 46.7"

Page 1: ... All Rights Reserved Rev 07 11 Fokker Dr 1 46 7 1 6 Scale R C Scale Model Instructions CONTACT INFORMATION Designed by M K Bengtson Prototype by Frank Jaerschky Manufactured and Distributed by Bengtson Company e mail sales aerodromerc com www aerodromerc com ...

Page 2: ...Builder Frank Jaerschky The following is taken from Frankʹs comments in building the model FUSELAGE Assembly starts by gluing together the two 3 16ʺ parts that make the left and right forward fuselage sides There are precut slots and holes for bolts and formers so make sure you open them up I like to use yellow aliphatic glue It gives me time to correct mistakes Makes for a slightly longer build t...

Page 3: ... should have done this step before adding the doublers I like to build both sides one on top of the other separated by plastic wrap or wax paper to make sure they are identical With the doublers I will have a 1 16ʺ gap between the balsa sides if I lay them on top of each other Iʹll just make a temporary 1 16ʺ spacer to go between the sides The rudder assembles easily with laser cut 3 16ʺ sheet pie...

Page 4: ...A square slid up to the outline of the fuselage on the plan is used for alignment If the vertical leg of the square just touches the edge of the longerons you know youʹre ʺOnʺ The balsa cross members were cut to length from the top view and then glued into place Again the square was used to make sure everything stayed aligned The top formers were then glued on top of the cross members The forward ...

Page 5: ...ames and spacers Larger frame on the right is the rear of the cowl and actually forms part of the middle upper wing retention system COWL The ply sheeting is supplied in 3 pieces Instead of butt gluing the sheeting I sanded a bevel on the sheets where the join so that they could overlap a bit and form a scarf joint Once sanded this will be a bit stronger and cleaner than a butt joint Start with th...

Page 6: ...of laser cut 1 16ʺ ply 1 8ʺ lite ply 1 8ʺ balsa and 1 4ʺ balsa Each part has 3 holes laser cut through which motor mounting bolts will pass When gluing the parts together pay attention and make sure these holes are always aligned Also assemble the pieces so that the grain alternates for added strength Now I suggest you count count and recount how many layers of 1 4ʺ balsa it takes to make the cran...

Page 7: ...inch 4 40 bolts that run through the crankcase and bolt into blind nuts in the firewall Small plywood laser cut spacers between the crankcase and the firewall not shown in photos set the down and right thrust Iʹm pretty sure the assembly is quite strong enough as it is But I think I will line each hole with a length of brass tube Iʹm afraid that I may get a bit ham fisted and over tighten the bolt...

Page 8: ... blind nuts into place Iʹve started on the included dummy motor cylinders The crankcase has already been described earlier in this thread The cylinders are made up of a piece of 1 8ʺ sq balsa and some other laser cut balsa disks The disks are glued to the square piece and then the supplied pre printed card stock is wrapped around that assembly and glued in place Then the cylinder is glued to the c...

Page 9: ...oes quite quickly too In case youʹre curious each cylinder took about 42ʺ of thread so thatʹs 9X42ʺ 31 5 feet total Luckily you can reuse the ʺspacerʺ thread if youʹre careful Put a small drop of thick CA on the cylinder Lay both threads in the glue and let harden Trim both ends of the threads Start wrapping the threads around the cylinder Make sure the threads stay parallel and do not cross each ...

Page 10: ... wing mounting plate That is what holds the middle and top wings on This results in an invisible wing mounting system I think there will be enough room between the front of the cowl and the back of the prop so that you donʹt need to take the prop off every time you put the airplane together at the field Moving the cowl 1 4ʺ forward will be enough to release the wing The middle wing mounting plate ...

Page 11: ...ymore There is not enough clearance between the front face of the cowl and the motor shaft to allow the cowl to go on and off So the designer and I scratched our heads about this for a while In the end we decided it would probably be best to have a slot in the lower cowl lip underneath the prop shaft hole To hide the hole I cut a wedge out of the cowl and used magnets to hold the wedge in place My...

Page 12: ...g out Once the cowl is painted I think the part line will be very hard to see especially as the cowl will be black Just a couple of shots of the cowl and primer Picture 1 shows the cowl with 1 coat of primer applied I use Motomaster brand ʺPrimer Scratch Fillerʺ available at Canadian Tire If you arenʹt Canadian Canadian Tire is like a Menʹs dream department store with loads of cool guy stuff and e...

Page 13: ...es The main spars are 3 16 X1 2 balsa The trailing edges are laser cut 1 32 ply with the TE scallops laser cut The distinctive Dr1 ʺSaw Toothʺ leading edge is laser cut from 1 32 ply There are laser cut 3 16ʺ pieces that go on top of the forward main spar between the ribs So when adding the ribs itʹs merely a process of working from one end to the other adding a block a rib a block etc The ply LE ...

Page 14: ...se tubes Although Iʹm thinking of maybe using carbon fiber tubes to save some weight Middle wing is attached to mounting plate with 4 40 bolts and blind nuts installed in mid wing Tab at rear of mounting plate fits into slot in fuselage just forward of the cockpit Slot in rear of cowl goes over the tab at the front of the mid wing mounting plate Cowling is secured with 2 4 40 bolts and blind nuts ...

Page 15: ...ap balsa from some of the laser cut part sheets that is perfect for the job To make sure everything will look good when Iʹm done I put the wing in position on the fuselage and put some plastic wrap between the fuselage and the back of the middle wing to make sure they didnʹt become permanently attached With some trial and error I cut a piece of balsa as wide as I could so that it would sit on top ...

Page 16: ...ouch the iron to the assembly let it get good and hot and let the solder flow into the joint The final result is tough as nails I worked on the cabane struts this afternoon They are made from 3 32ʺ music wire The top wing is attached to the cabanes with 1 8ʺ nylon landing gear straps and 4 40 bolts The bottom of the front struts slide into a 1 8ʺOD piece of brass tubing that is built into the midd...

Page 17: ...op wing in a rib also made out of 2 1 16ʺ ply and 1 1 32 ply pieces I must admit I cheated with the struts It is absolutely essential that all 4 pieces of the cabane struts be the correct length and have all the correct angles Because of this I felt I would have trouble making my bends accurately enough to do the job So after roughly bending and sizing each strut I cut it in half and then chopped ...

Page 18: ...in place A thin bead of CA around the rim makes for a secure tire Paper cones are cut out Use a ball point pen to score each line on the back to make an impression of spokes It is helpful to do this operation on a paper tablet so that the pen makes a good crease Fold the paper along the crease lines to exaggerate the raised lines One of the sections forming a wedge is cut out Make cuts to the cent...

Page 19: ...dered to the axle I then epoxied the tabs to the base The brass has just enough flex to allow a little wiggle I sheeted the top with 1 16ʺ balsa I also made the holes a little over sized in the top sheeting where the wire passes through If the sheeting is right up against the wire any wiggle will crack the sheeting WING SERVOS Hereʹs the aileron servo installation I chose the lazy man method and u...

Page 20: ... edge should look great when the wings are covered and painted And hey the wingtips came out with minimal wrinkles I have started covering the fuselage I was worried about this as there are a few tricky areas namely the area between the lower wing root and the fuselage side It actually came out very well I think Iʹm starting to think I can make Polyspan do anything Just look at the sexy curves it ...

Page 21: ...d around the wire strut This should make things pretty strong I am going to do the front fairing after the model is completed and the upper wing is joined to the middle wing I hate hate hate servo wires flopping in the breeze So my plan is to attach the wings to each other glued the balsa front fairings on then glue the servo wires along the inside of the fairing Then Iʹll wrap everything with Pol...

Page 22: ...t balsa in the form of a side and front profile of a pilot The plan sheet says ʺʺGlue together fill with foam and paintʺ Heck if itʹs that easy I might as well give it a try Iʹm using blue foam as it seems to be much easier to carve with a hobby knife and sandpaper than white bead foam Once I get the pilot to shape Iʹll probably give him some sort of paper mache finish and then add details like bu...

Page 23: ...d a fur collar for those cold missions over the front in pursuit of der Englander I used a pencil to mark out where I thought a fur collar would go Then I used a bead of spackle and a small spatula to get the shape I then used the end of a coarse bristled paint brush and stippled the spackle When itʹs dry and painted I think it will look good too I didnʹt think that Iʹd be putting this much work i...

Page 24: ...ts The battery slides in through the forward most hatch and the top of the pack is retained by the ʺLʺ the shelf will also serve as a place to mount the ESC and RX The bottom of the battery rest on the forward landing gear mount I then glued a piece of 1 8ʺ basswood to the inside of the hatch Once the hatch is in place the basswood piece stops the battery from sliding backwards Itʹs simple and see...

Page 25: ... 6 minutes so up we go again This time I advanced the power more rapidly and it leapt off the ground in no time and pointed her nose up and kept on climbing The next 2 landings ended in nose overs I landed too fast and when the triplane starts bouncing down the runway on the roll out it will eventually find the right bump that flips her on to the nose No damage at all thought The next 5 landings I...

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