Piccole Ali

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2009 Piccole Ali – Stra’ (Venezia) - Italia

AEROMODELLO RADIOCOMANDATO

RADIO CONTROL MODEL

NORTHROP P-61 “BLACK WIDOW”

VQ MODEL NORTHROP P-61 “BLACK WIDOW” ARF 90

Apertura alare / Wing span: 2260 mm

MOTORE A SCOPPIO / GAS POWER

2-Tempi / 2-Stroke: 0.75 – 0.90 ci (X2)

4-Tempi / 4-Stroke: .90 - 1.20 ci (X2)

Produttore / Manufacturer: Distribuito in Italia da:

www.vqmodel.com www.piccoleali.it

www.piccoleali.it …passione pronta al volo !

2009 Piccole Ali – Stra’ (Venezia) - Italia

Il P-61 “Black Widow” fu il primo aereo Nord Americano ad essere progettato fin dall’inizio per il ruolo dicaccia notturno. Quando arrivo negli squadroni di combattimento, verso metà del 1944, gli obiettivi eranopiuttosto scarsi.

Northrop dovette impegnarsi notevolmente con il P-61 “Black Widow”, di molto il più importante contratto maiottenuto. Soddisfare le prescrizioni del committente per un velivolo con tre membri di equipaggio fu una delletante sfide affrontate dal team di progettisti. Per l’intero 1941 – a dire il vero, per tutto il conflitto- emerserocontinue variazioni ingegneristiche che ritardarono lo sviluppo del P-61. Le armi furono ricollocate, serbatoiaggiunti, superfici di controllo riprogettate.

Le consegne iniziarono nel Maggio del 1944 quando il 348^ Squadrone Caccia Notturno (NFS) ricevette iloro “Black Widows”. Il P-61 aveva una manovrabilità eccezionale, considerate le dimensioni, grazie agliampi flaps molto ben progettati.

Il modello

Avete adesso la possibilità di possedere e di pilotare un pezzo di storia dell’aviazione. Il modello è

sobriamente rifinito ed è di gran lunga la miglior riproduzione ARF del P-61 disponibile nel mercato.

Parecchia attenzione è stata dedicata al sistema di “flaps” uno dei punti di forza del velivolo. Si tratta di una

EDIZIONE LIMITATA, non perdete l’occasione ! Potrete inoltre arricchire il livello di dettaglio in base alle

Vostre preferenze.

Il modello è indirizzato all’aeromodellista con esperienza nel pilotaggio dei bimotori. Il modello non è adatto

come primo bimotore.

Caratteristiche generali

Robusta costruzione in balsa e compensato delle migliori qualità

Accurato rivestimento in speciale film polivinilico per maggior realismo della riproduzione

Alettoni/Spoiler completamente funzionali

Flaps funzionali

Prese d’aria in fibra (non funzionali)

Collegamento delle semiali per mezzo di tubo in alluminio per maggiore facilità di trasporto e montaggio

Naca motore in fibra di vetro già dipinte di fabbrica

Riproduzione IMAA Legal 89” (apertura alare)

Mitragliatrici (simulacro)

Predisposizione per i carrelli retrattili (opzionali)

Manuale d’assemblaggio passo-passo in italiano

Caratteristiche tecniche – VQ Model P-61 Black Widow ARF 90 RC

Apertura alare 2260 mmLunghezza fusoliera 1710 mmSuperficie alarePeso 8380 – 9280 gMotore a combustione interna Con elica bipala / 2-Tempi / .60 - .75 ci x2

Con elica tripala / 2-Tempi / .75 - .90 ci x2/ 4-Tempi / .90 - .120 ci x2

Motore elettrico ----Radio 6 canali minimo

13 servi minimo

Accessori inclusi

Cappottine abitacolo

Serbatoi

Ogive

Ricco pacchetto hardware

www.piccoleali.it …passione pronta al volo !

2009 Piccole Ali – Stra’ (Venezia) - Italia

Non incluso

Motori, servi, carrelli retrattili, colla, pilotini, tubo per la miscela

Prodotti correlati

VQ Model P-61 Black Widow ARF 90 “Lady in the Dark”

VQ Model P-61 Black Widow ARF 90 “Jap-Batty”

Motore ASP S91A RC

Motore ASP FS120AR RC

TwinSync by Wike RC: l’affascinante e realistico suono di due motori sempre sincronizzati…ed in più una

speciale funzione sicurezza

Carrelli retrattili ad aria compressa con gambe ammortizzate

Visitate il nostro negozio online / Visi tour webstore: www.piccoleali.it o scriveteci /contact us at:

info@piccoleali.com

Aeromodello radiocomandato / Radio Control Model

VQ P-61 ARF REVIEW

By Sam Parfitt (from www.rcwarbirds.com)

Page 1

Well, she finally arrived, along

with the retracts (retracts are

bought separately). Since I did

the VQ P-38 construction article,

Twinman suggested I do the

build article. The good news is

that he promised me twice the

salary that I got on doing the P-38

article! I just got a new laptop so

hopefully all goes well and

everything is loaded as planned.

She arrived in two boxes (one on Monday and the

other today). After Monday, I had visions of a lost box,

never to be seen again, but it finally arrived.

They came with no additional packing on the outside

but everything is well packed and secure inside and

all arrived in good order. The smaller box has only the

center fuse and canopies. The other box has the rest

of the goodies

The retracts were ordered from Mike

(VQ) and are Spring Air. The retracts do

not come with struts but the struts are

included in the P-61 ARF.

The first package has the manual and

decals (really stick ons).

The next package has the struts and guns. The

struts look very sturdy.

Next are the two booms.

Some people call it shelf

paper but I like it: lots of

detail and it doesn't

wrinkle in the sun.

Real nice gear doors.

Inside top view.

This picture shows the

gear doors.

Next out of the box are the cowls. Nice

heavy duty fiberglass.

As you can see, the OS FX .91's won't

have to be sticking out to kill the scale

look.

Here are the cowls and nose

cover along with my engines.

I'm using J-tec's JT-903MX

where the exhaust slants back

45 degree's so little will be

showing on the inverted engine.

Those small fuel tanks have to

go: they'll only give me about 5

minutes on those .91's!

The business end of the boom: plenty

sturdy.

Next out of the box are the rudders

(hinges included). Very light.

Construction of the rudders are all wood

(the entire ARF is all wood).

Don't know what those white things are

(drop tanks?) but there are about 6 of

them(hmmm; room for my fuel!).

All the hardware came out next:

rods,

engine mounts.

1" aluminum tubes for the wings.

More machine guns(!!!)

nuts and bolts packages.

Real nice gear door hinges.

Gear wires (pitch!).

No wheels but I believe it's 3" for

the nose and 3.5" for the mains.

Next was the center wing

(top view). With flaps (as

does the outer wings).

No weathering like on

the P-38.

Center wing (bottom

view). 2 access hatches

for the flaps.

Page 2

Next is the horizontal

stab. Very light(built up).

pre-hinged.

The outer wings are last. The

bottom one is the top view (you

can see the spoilers: cool). also

flaps and ailerons. The top one

shows the bottom view.

This is the box of 28 or so servos ready for my P-

61 (never have too many servos).

I'm using Hitec HS475HB. They're 76 oz torque for

6 volts. More than enough for flying this plane and

when at least 13 servos are needed, at 18 bucks

apiece,

saves a lot of money over more expensive servos

(I'm using a JR 8103).

For the low profiles needed for the spoiler/aileron

combo, I'm using Hitec HS-77 (also 76 oz at 6

volts).

I'm starting with the outer wings instead of

the center wing that the manual starts

with, because it has the spoiler and I had

to see how that works first.

The servo cover farthest away from the

wing tip is for the outer wing flap. I mark

each cover as I take it off with an arrow

showing which part is pointing to the front

and also its purpose. (Screws are already

holding the covers on: another nice

touch).

The servo mounts are already glued in.

Looks like they did that because they are

at an oblique angle to the cover and they

didn't want us to hose it up.

As you can see, the servo fits the mount

perfectly. The mount seems very secure

but I'm going to put some epoxy on the

mount anyway (just to make sure!).

I use a Dremel tool to drill the holes for

mounting the servo,

I temporarily put a thin piece of the servo

box flap between the servo and cover

while drilling the holes. This keeps any

contact with the plane so less vibration is

transmitted to the servo and possible

feedback to the receiver.

The pin hinges are glued into the flap and

glued into a block of balsa that slides into

a square hole in the wing.

Never seen this before but very ingenious.

The center cover is for the

combo spoiler/aileron

servo. This mounts in the

wing and not on the cover.

Here I'm using HS-77

(ordered two of them and

should be arriving in a few

days).

Another nice touch: spoiler

and aileron from one

servo. Watch when drilling

the holes that you don't go

through the top of the

wing. The only safe way

from keeping from doing

this is to put a small piece

of metal between the

mount and top of the wing.

Here's a picture of the spoiler in

the up position (cool stuff).

Next is gluing the flap to the wing.

This is how I did it to insure that all is

aligned and moves freely(you don't want

to glue these incorrectly).

I used masking tape to tape the flap so it is

aligned with the top of the wing.

I like to stick the tape to my leg first to

reduce it's adhesive qualities.

Use good 3-M tape and not stuff that's

been in the garage all summer.

This side view shows a nice smooth

transition from the wing to the flap.

There should be a very fine line between

the top of the back of the wing and the top

of the flap.

The profile picture shows that VQ did their

homework: the back of the wing isn't flat

like on most ARF wings.

Now that the top is aligned, put straight

pins into those blocks of balsa from the

bottom of the wing to temporarily hold

those hinges at the correct location. Now

remove the tape and insure there is free

movement down for the flaps.

Pins in the bottom of the wing

Tape removed.

If all moves freely, you can tape the flap

back up and wick thin CA between the

balsa blocks and wing. This should insure

you have no turbulence from large cracks

between the wing and flap nor any binding.

NOTE: I tried to move the spoiler up but it

wouldn't work. Found out that I must have

put too much CA on the flap hinge and it

glued the spoiler to the wing.

Easy fix: a razor blade cut it loose (only

about 1/4" long).

Put a piece of wax paper between the

spoiler and wing or put it in the up position

when CA'ing the flap hinges.

So far, I'm impressed with the design work of this ARF: Some people may think the price ishigh but all those fine details added thus far makes this a cheap plane.(HMMMM, for me to design and build spoilers: that will take me about 20,000 hours, notcounting calling on higher powers to stricken it down!)

We're going to need 2 'Y' connectors for the flaps since we

have 3 servos to connect. I just double checked the outer

wing servos: also need a reverser for those. Might as buy

2 or 3: we may need them with coordinating 2 rudders &

nose wheel and the horizontal stab has 2 servos.

Also, noticed that it is going to be difficult to adjust the

connecting rod from the servo to the flap on the outer

wings. The servo is mounted on the cover and I don't think

that plastic ball joint is adjustable. An easy way would be

use two channels: your call. (we may need a 12 channel by

the time we're done: especially if we make the pilot wave!).

This is the top view of the center wing with

the flap servo mounted(it faces to the rear-

just as the outer wing flap servos do).

There is a rectangular hole in the top and

bottom of the wing where the covering has

to be removed. The manual doesn't

mention the hole in the bottom but the

covering has to be cut away so the bottom

of the standard servo can fit in the

mounting. The two covers removed on

each side of the center servo has two 90

degree control horns already mounted

with easy connects. One end of the 90

degree control horns will go to the center

servo and the other side will go to the

flaps.

I noticed about a 1/32 to 1/16" play between the hinge balsa blocks and the holes in the

wing. I put some slivers of balsa in them to make a tighter fit and for better adhesion for

the CA. As we did with the flaps on the outer wing, follow the same procedure for the

center wing using tape and pins. All my hinges connecting to the flaps were already glued

in but it doesn't hurt to check yours: with 65 planes built times how many hinges? Esc:

there's bound to be one or two missed. Same goes for the ailerons: mine are already glued

in but there could be some missed by the 'gluers'. Also, check that ball socket on each

flap: a little CA on the nut won't hurt (easier now than when the planes flying!).

Here's a 'DUH' statement but just in case someone doesn't know:

The brass grommets that go through the rubber mounts on the servos, the rounded end

contacts the wood mount while the sharp end is for the screw head to contact. Reversing it

can cause the sharp end to cut into the mount when the screw is tightened (servos moving

in their mounts while plane is flying is not good).

Bottom of the center wing

with the servo sticking out.

I mounted the center wing

to the fuse to make sure

the servo doesn't hit

anything. All looks good. A

nice tight fit exists

between the fuse and wing.

I worked on hooking up the

flap servo to the flap

(makes sense!) on the

outer wing. I had to replace

the rod that comes with the

ARF: very brittle and broke

on a 90 degree bend.

Another one did the same.

I recall the P-38 had the

same problem. I had to put

a small S curve in the wire

to keep from binding and

to align the servo arm to

the flap socket. I'm holding

the cover outside the wing

so you can see the

alignment. This picture is

the up position.

This shows the relative

position of down. The rod

moves about 1/2".

Having the cover turned

upside down, you can see

the bends that I needed.

The rod is 3 15/16" long

from servo arm bend to

center of socket.

Of course there's a lot of

variables from my setup to

yours but it gives you a

ballpark area.

Flap up.

Flap down.

If that should be enough down!

I'm working on the rest of the flaps in

these pictures. I had to enlarge the hole

where the brass socket moves on the

flaps. Even if you miss doing it before

gluing them on, there's plenty of room to

enlarge the hole after installing them.

Flaps up.

Inner wing flaps:

I couldn't find any rod in

the ARF that seemed hefty

enough to connect the

servo to the two 90 degree

horns so I pulled one out

of my 'stock pile'. This

goes together surprisingly

quickly. One servo in the

middle connected to the

two 90 degree control

horns. Connect the 6" long

rods with the sockets to

the flaps, adjust and all

done.

Flaps down. That should be sufficient!!

I see why Twinman says the P-61

flies so much better than the P-38!

I couldn't wait and jumped to the last step of building. I dry fitted everything together to see

what it looks like: GREAT , WHAT ELSE!

The center wing, two booms and horizontal stab go together just like the P-38 did: perfect fit

on all parts. I left 1/8" of covering where the horizontal stab is jointed to the booms and just

pushed the stab into the recess. I figured this would keep any covering from coming off in the

future. Put the horizontal stab between the booms before connecting the second boom: Once

the two booms are attached to the center wing, there's no slop in there to be widening the tail

of the booms for the stab.

Booms and center wing and fuse are all connected with nylon screws. The horizontal stab is

connected with metal screws. The stab is symmetrical with duplicate patterns on both sides

and can be put on either side up.

What a GREAT LOOKING PLANE.

Page 3

This shows the center wing flap servo connection

viewed from the top.

The center

wing

bottom

view

showing

the

positions

of the 90

degree

arms with

the flaps

up.

The center

wing

bottom

view

showing

the

positions

of the 90

degree

arms with

the flaps

down.

The long dowels in the center wing

for holding the booms on. Just

keep pushing them in until they

stop. This will give you about an

inch sticking out. Slop lots of

epoxy in the hole and on the dowel

and stick it in. The dowels fit

perfectly into the center wing, but I

had to enlarge the holes a skoch in

the booms for the dowels to slide

in.

There was slop in the center wing holes

where the short dowels are epoxied. To

insure alignment after the the epoxy and

dowels were put in, I slide outer wings on

about 1/2" from the center wing. (a 1/2"

away to insure that no extra epoxy made

my 3 piece wing a one piece wing!) This

kept the dowels perfectly aligned until the

epoxy dried.

The 12 oz tank that came with the ARF is

the top one. I replaced it with a Sullivan

Flex-tank, slant style 16 oz tank (FSS-16

No.743).

The length of the tank fits perfectly in the

space but it is about 1/2" wider than the

area cut out for the original tank. I used a

razor saw to enlarge it. I cut 1/4" off each

side of the former. (that black hole in the

middle is a hole in the fire wall that I talk

about later).

The enlargement that I made is in front of

that.

This is the front view through the opening

in the firewall to see where I put the saw in

to cut off some horizontal wood to make

the bottom flat where the tank will rest.

I've never seen an open area this large in

the firewall before. It could be for air

circulation. Not sure if we're going to get a

lot of fuel in here. May have to seal this off

when we get to mounting the engine.

Tank dry mounted

and servos

mounted in the

right boom (viewed

from the pilot's

position).

From top, down:

rudder, throttle and

elevator servos. I

moved my throttle

servo to the left of

center since my

engines are being

mounted inverted.

The black guide

tubes are extra

long and have to

be cut shorter to

connect the rods

to the servos.

The left boom is

the mirror image

for servos:

From top, down:

elevator, throttle

and rudder servos.

While I'm watching a bowl game, I thought

I'd check the retracts. Neither the nose nor

the mains fit the mountings. The

mountings are the correct spacing but the

formers that hold them are going to have

to be cut.

I Used the razor saw to cut a larger hole

(slot) in the former. Then I found that the

rod that protrudes out the side of the

retract is in the way so I had to put slots in

the side of the mounts. I used a dremel

tool to remove about an 1/8" deep and 1/4

by 1/4" wide and long. This is the left

boom.

All's well in the universe again!

The nose gear retract mounting area had to

also be trimmed.

Here's about a 3/4" by 1.5" piece of former

removed.

Order of assembly for the

Spring Air nose gear (No

instructions came with it

so this is my guess!).

One of the retract

assemblies says 'nose

gear' on the top side,

although I can't find any

difference between any of

them!

(These names are made up

by me: don't know what SA

calls them)

Strut, strut insert, steering

linkage, brass sleeve,

steering linkage shaft,

retract.

The brass sleeve is a skoch larger that the steering linkage shaft so the retract will tighten

around the brass sleeve, leaving the steering linkage shaft to rotate. Tighten the steering

linkage to the steering linkage shaft. Put the strut insert into the strut, tap two set screws

and tighten this to the steering linkage shaft. Twinman says that Mike (VQ) says big 'no' on

putting the steering servo upfront. Makes sense after thinking about it (won't retract that

way)!

Other boom had 1 mount glued out of

alignment and I had to make indents not

only for the rotating shaft (center) but also

the two end screws that hold the assembly

together.

No big deal: just used the dremel to grind

it down.

The initial holes are drilled. First I used a

center punch to dimple the wood so the

drill doesn't wonder. Second, I used a

small diameter drill bit to get the initial

hole drilled.

I then drill the final hole with the proper

size drill bit. This increasing bit sizes

dramatically increases accuracy. (also

only way to properly drill through metal).

All retracts screwed in. Presently, only put

two screws in for now. Later, when I get

the struts on and check for alignment, I'll

then drill the other two screw holes. (if I

did this in the right order, I wouldn't have

to do this!). (my 'radical side' doing what

moves me at the time instead of the proper

order).

Speaking previously of possible hinges

not being glued, here's a mount in the

nose that was only dry fitted. A little epoxy

fixed that up.

I put a medium Robart air

tank in. The hole in the

former is an exact fit for

the tank but there's not

enough room to slide it in.

I used my razor saw to cut

a piece out to slide it in

and I can glue the cut

piece back in later.

The tank on the right came with the Spring Air's

400 set. As you can see, the volume difference is

significant, and important when moving retracts

this size!

I've learned in wood working, never measure when the you

can transfer measurements directly. Trying to measure

say 13/32" (hmmm, just a hair over that)....forget it! In this

case, I use these.

Can't get any more accurate than that! (which is

important for mounting engines).

Again, I center punch it to initially guide the bit.

While it's not necessary, it makes accuracy much

easier by using a mini-drill press.

As with the gear mounts, I drill a pilot hole first.

Then over to the regular drill press (also not

necessary but easier) to drill the final hole.

Some may find this a little anal but I tap and use a

locking nut (plastic insert) to hold the engine to

the mount. The tap will have the bolt, thread and

bit size on its shaft ( in this case: 8-32, #29).

There's a lot of vibration up there on the business

end and it's no fun having it come loose: not to

mention safety (but I will!).

Front view. Temporary mounting of engine to the

firewall. The firewall has 'centering' lines on it. The

engine shaft should align on the center of their

intersection. The top mount corner had to be

trimmed so it wouldn't interfere with the fuel

adjusting screw. Part of the opposite mount will

have to be trimmed for the muffler. The muffler will

have to also be ground down on the corners near

the mount in addition to the area close to the

throttle so the connecting rod can move freely. I

will also have to drill/tap a screw with a hole drilled

through the screw for pressure to the tank. This J-

tec muffler does not come with this (not sure

why!).

Side view.

Top view.

With cowl on. The engine cylinder head

just clears the inside of the cowl. I will

probably have to cut a hole for the glow

plug. Later, I will install a remote set of

wires a foot back (or so) to route 1.5 volts

to the glow plug.

Page 4

We need access holes to run the

wires from the booms to the center

fuse where the receiver will be. I

cut a 1/2X3/4" access hole in the

center wing. This needs to align

with one of the holes that are in

the ribs. The hole is 1/2" to the

right of center and 3 1/2" back

from the leading edge. Note:We're

cutting all holes on the bottom of

the wings. This picture shows the

hole for the fuse. We can always

enlarge it later if need be.

(From woodworking, I've found it

easier to take a little more off than

try to add it back on!)

This is the boom hole. Left boom (again in

relation to the pilot). This one is also 3 1/2"

back. It is a little bit off center between the

two mounting dowels. There is a rib right

between the two dowels so I shifted the

hole about an 1/8" over. Don't make these

holes too wide because the booms have

very wide triangular supports running on

both sides of the boom (obviously to give

the booms strength).

Making a hole over these will be useless

since no wires will be able to be there.

Here's a side picture showing the hole in

relation to the ribs. That hole in the rib is

where we'll use the 'ol wire with a hook on

the end' routine to pull the wires through

the center and then up through the boom

holes.

Right boom hole. In this picture, you can see the

rib that we want the hole to be next to it and not

over it.

When pulling the wires for the boom, it may be

difficult to get the wires off the hook and through

this hole so we may have to enlarge it later.

Flap wiring is shown here.

I needed the servo

reverser AFTER

the first Y

connector. The

order for the wires

starting at the

receiver is: A Y is

first. The left leg of

the Y goes to the

left wing flap. The

right leg of the Y

goes to the servo

reverser. The

reverser side then

gets another Y and

these two leads go

to the center wing

and the right wing

flap (clear as

mud!).

Flaps up (wings still on their backs).

Flaps down. (must be hooked up right, it works:

amazing!). I initially put the reverser as the first Y

but that didn't work. A little trial and error always

works well with low voltage electricity versus

trying to use this method on a new house outlet!

Note that those center flaps are at about 95

degrees (might have to reduce that angle!).

Enough to make a grown man cry! (need wireless like they have for pc's and the keyboard

and mouse: Twinman: you want to get researching on that, please!). Besides the servo

reverser for the flaps, we also need one for the elevator. I was thinking we might need one

for the rudders but visually going through the servo motions, it looks like just a regular Y

will do (we'll find out later when we actually hook up the rudders!). The engine throttle

servos also just use a regular Y harness. We'll still need to route the retract/brake lines

through the center wing. Since the nose gear, retract and brake servos are all in the fuse,

we can test all that stuff later. Everything has been tested OUTSIDE to remove any bugs

before we start routing that mess through the wings. As usual, we'll electrical tape all

connections, pull them through the holes (hopefully) and then label each one as we get it

through. How many and what length? Don't ask: too many variables. Just get lots of each

length (like servos, never have too many servo extensions ....and Y harnesses....and servo

reversers!).

Now we'll start on the spoiler/ailerons.

Using the piano wire with a hook, we pull

the spoiler/aileron wire through the hole in

the center wing and out the side of the

wing.

After normal installation of the low profile

servo (again, make sure you don't drill

through the servo mount and out the top

of the wing), the special connecting rod for

the spoilers has to be made. Since we

can't have the spoiler going up when the

aileron is going down, we need some way

of disabling the spoiler for this to work

properly. Fortunately, VQ has figured that

out by using a spring. On the PUSH

movement of the servo, the servo arm hits

the collar and pushes up the spoiler. On

the PULL movement of the servo, the

servo arm needs to move but not bind, as

it would if it was connected directly to the

spoiler rod.

The spring allows the arm to move freely

on the PULL motion. Cool!

As you can see in the picture, I had to put a bend in the connecting rod to get it to work.

The bend was so the rod can go under the sheeting of the wing. The manual shows the rod

just to the edge of the access hole. I found this caused the spring to be too compressed

and not functional. I had to cut a new longer rod. The rod is 3.5" long from the ball joint

end to the other end of the rod. The first collar (for the PUSH movement) is 1 7/8" from the

center of the socket hole. This is then slipped through the E/Z connect hole on the servo

arm. The spring is then put on and then another locking collar on the end (whew!!).

The E/Z connect doesn't use a set screw since the rod has to move freely. You have to take

the control horn off the servo before putting all this @$#% together on the E/Z connect.

Then slide everything into the hole, screw on the control arm to the servo and put the

socket onto the socket ball. I'm finding these black plastic sockets to be very loose so I'm

going to have to replace them. Hopefully, someone makes sockets the same size as the

socket ball so the brass socket ball also doesn't have to be replaced. The socket ball is

brass so it's good quality. Again, put a little AC on the nut holding the brass socket on to

prevent it from coming loose in flight.

You can now connect the rod that goesbetween the servo and 90 degree controlhorn. All the E/Z connects are alreadyattached to the 90 degree control horns. Iwanted to replace all of them with othertypes of connections but I'm finding thatthe screws holding the 90 degree controlhorns to the mounts don't come out.I'm guessing that the screws and nutswere all attached BEFORE gluing themounts in.Removing the horns would be difficult todo and it, unfortunately, means we have touse the E/Z connects. Just make sure youfile a flat spot and locktite it.

The aileron control

horn is now

connected in the

usual way

with the control

horn holes for the

clevis to be aligned

up directly over the

edge of the aileron.

The clevis's appear

to be good quality.

All we need is to

put a piece of large

fuel hose over it to

make sure it stays

closed.

NOTE: over time,

some pilots have

found ARF control

horns to age and

crack.

Your call on

replacing them. As

with all flying: all

surfaces and

materials should

be checked

BEFORE flying:

not only for the

planes safe return

to terra firma, but

also for our safety.

Routing the wires in the center wing.

Here's some the filters/chokes that can be

used to filter out that chattering that you

can get on your servos. The top one is an

in-line filter. Then there's JR's barrel and

ring filters Hitec's servo has the wires

twisted. Another way to help filter out

unwanted servo chattering. I'm using a

PCM receiver which works very well on

filtering out chattering.

(there's a lot of debate on whether PCM is

good or bad: I favor them).

Here on the center wing, I

used the hook on the right

to pull the other hook out

of the hole once it appears

down in the hole (the left

hook was inserted into the

end of the wing and

pushed in so we can attach

the wire to it and pull the

wire through the wing).

One of the extension wires

twisted before pulling it

through the wing.

The final product.

Wires from the receiver are going into the center hole. Each boom hole has the rudder,

throttle and elevator extensions. Each end of wing has the flap and spoiler/aileron

extensions. I also ran the retract air lines in. Spring Air only uses one air line (a spring in

the cylinder pushes the retracts down). (hmmmm, I forgot to run the brake air line: back to

the workbench!). I also had to enlarge that center hole an inch toward the leading edge to

get all the wires in. (took all afternoon just to do this). Everything is labeled so all should

go OK when we start connecting up all the servos.

I put the wing

tubes on the center

wing. Used their

screws (20mm or

about 3/4" in

English). The

center section is

just about done

except for working

on those sockets

Back to working on the engines. After

putting lots of epoxy on the firewall (inside

and outside), I transposed the engine

mount distances to the firewall. I used a

13/64" drill bit and put the blind nuts in

from the back and tightened them into the

firewall using one of the socket head bolts.

Without the rudders attached yet, it was

easier to just set the boom vertical on its

tail on the floor and then drill the engine

mount holes.

Engine mounts mounted. I cut about 1" off the

front of the mounts so they wouldn't show when

the cowl is put on.

Both engines and

mounts are done. I

had to trim one

engine mount for

the fuel adjustment

valve and the

muffler.

Oblique view with the cowl

on.

Page 5

First, I had to fill in the hole in the

firewall with some balsa and

epoxy.

This is a good time to make sure

none of those engine mount bolts

are sticking out the back (very

hard on fuel tanks: I learned the

hard way!).

I had one sticking out on each

boom since I had to narrow the

mount a skoch to allow for muffler

room.

I drilled and tapped holes for the pressure

to the fuel tanks. A couple 6X32 aluminum

bolts does the trick. I find ACE and other

small hardware stores has an excellent

selection of small screws that HD and

Lowes doesn't have.

I had to drill a 1/16" hole through the

aluminum screw. I cut the heads off first. I

then use two nuts and tighten them

against each other to keep the bolt from

spinning (also to hold the bolt in the vice).

Center punching the screw and using a

good quality bit are essential, plus exact

perpendicular to the drill table (there's not

a whole lot of slop allowed when drilling a

1/16" hole through a bolt that's only about

an 1/8" diameter. The aluminum bolts are

cheap though so no big deal if you break

through the side. I drill half way through

from both sides to reduce this risk and I

use cutting oil to keep friction down

(especially essential when drilling steel to

prolong the life of those bits). Even if you

break through a small amount, a little JB

weld will fix her up (just make sure you

don't block the vent hole up!).

Bolt with hole (minus nuts) put in the

muffler with JB weld. One nice thing about

having to put your own pressure tube in

the muffler is you can put it that is

convenient for how the engine is mounted

on the fire wall. In this case, it points up

and away from all the 'clutter' on the other

side of the engine mounts.

I'm partial to the '3 line' method. Fuel,

pressure, fill/drain.

The vent/pressure is the top line. The

fill/drain is the front clunk (got to use the

ARF tank clunk). The engine line with

clunk in the usual place in the back.

The trusty H2O test. Plug up 2 holes, put

the tank in water and blow and hope no

bubbles appear. Of course, it's easier to do

it now than when the engine goes out in

flight!

Tank mounted with the

usual foam. No need to

secure it since I found that

the center wing will put

pressure on the top of the

tank and the back former

will keep it from sliding

back. This was the easiest

tank mounting that I've

ever did. Usually it's a pain

to get those line through

that small hole and then

secure the tank. This was

quick and easy. The fuel

and pressure lines are 6"

and the fill/drain line is 9".

NOTE: I'm using different fuel tanks that came with the ARF.

I'm using slant front tanks. The original tanks won't give you this problem. I finished up on

the tanks but I didn't have a good feeling on the second tank. It felt a little tight near the fire

wall. After pulling it back out, one of the lines got pushed against the brass tubing and was

cut. With the 3 tube method, I had 2 of the tubes on top at about 10 and 2 o'clock and the

third at 6 o'clock. The bottom tube at 6 o'clock came through at a good angle through the

hole in the center of the fire wall. The other two tubes were too high so I took the tank out

and bent the 10 & 2 o'clock tubes down about 45 degrees. This was just right and when the

tank was put back in, the 3 tubes aligned with the center hole in the fire wall. There's

enough room to see the tubes coming out and I made sure they weren't twisted with each

other and then connected them up to the muffler and engine and let the fill/drain tubing

hang down. I took the other tank out and did the same thing to it.

I used a foot long bit to drill through the

fire wall and next former for the throttle

servo control rod.

We're raising the center throttle servo it so

it clears the outside servo. I took one of

the blocks for the fixed gears and cut it

into 4 pieces, sliced it down the middle

and then I cut each part in half and sanded

them. With such small parts, I stayed away

from the big power tools and used my

scroll saw.

Left: initial piece of wood- Right: final

product.

A little epoxy and the throttle servo will

now be 3/8" higher.

There's now enough room to connect the

throttle rod up to the servo with the short

side of the servo control arm facing to the

rear of the plane. I used the white plastic

tubing and the thin black control rods with

a 'Z' bend that were in the ARF box.

Several bends were needed to get around

the boxy muffler. A side benefit with this

thin rod and the many bends was the

throw of the servo arm and engine throttle

didn't have to be exact. On full throttle, I

get a slight bend of the wire but since the

wire connects to the engine throttle at

almost a 90 degree angle to the rest of the

rod, it acts like a buffer.

Final check routing

through the wires

that we'll use in the

center wing. After

the plane is put

together, it may be

very difficult to

adjust only one

engine throttle so

you may want to

use two channels.

I'm banking on the

thin throttle wire

and that 90 degree

turn allowing me to

make some small

adjustments by

bending the wire. I

normally use a

plastic clevis and

adjust it at the

engine throttle end

but that muffler

just doesn't allow

for such luxuries.

When I tried to put the struts in the spring

air retracts, the struts are a little too big in

diameter, even when the set screw on the

retract is completely removed. I ended up

putting some masking tape 7/8" from the

end to protect the gray paint while I hand

sanded the exposed paint and some of the

metal off.

I'm sure we'll have to do this again since

it's unlikely that the length of the strut is

exactly what is needed. (good time to get

some quality bonding time with the other

half by having her sand one strut while

you do the other one!)

GPS: general purpose stuff.

On the left is the foam cord I get at

home depot that I'll use to put

inside the tires to keep them from

going flat. Center is homemade

sanding sticks: white glue different

grades to a paint stick.

Right: 'magnetizer' from Rockler

woodworking store: nice to

magnetize all those screw drivers

to hold those small screw while

putting them in tight places.

The 3 hinges were already glued into the

rudders on my ARF. All I had to do was cut

three slots in the vertical fin. The slots are

already under the covering so not too much to

do here. I made a flat side on one end of a

popsicle stick and pushed the epoxy into the

slots. Put a little oil on the center of the hinge

pins and pushed the rudder's hinges into the

slots. Nothing unusual on the control horns

either.

The lower control rods are for the rudders.

The outer servos in the booms are for the

rudders. The clevises appear to be good

quality so I just slipped on a piece of fuel

tubing first and then slid the rod from the rear

into the black pre-glued plastic tubes.

(the top servo in the picture

is for the rudder). The black

plastic guide tube had to be

cut back to the next former

to allow movement of the

control arm. For the rudder

servo, I used Dubro's super

strength servo arms. After

aligning the rudder to

neutral and also first making

sure the servo arm is at

neutral by turning on the

receiver and transmitter, I

used a felt tip to mark the

rod where it goes over the

servo control arm. I then put

the usual 90 degree bend at

the felt tip mark and cut off

the excess about 3/8" down.

I put the 90 degree bend at

3/4" out from the servo shaft

and used an E/Z link to hold

it on.

As you can see, I'm getting

max rudder movement.

Needed if one engine goes

out. (later, we'll paint all

those white parts black so

they don't 'stick out' so

much).

Normal stuff here. Control horn on the

horizontal stab. Both sides of the stab are

identical covering and airfoil so pick the

best side. I put the control horn at a slight

angle toward the boom to make a smooth

transition to the push rod.

Next, I connected the

horizontal stab to both

booms.

The screws are 1" long. Each ends of the horizontal stab have pre-installed blind nuts. Test

out the screws before connecting the booms. One end of the stab on my ARF had the blind

nuts at a slight angle (not 90 degrees to the rib) so the screws had to go in at an angle. You

don't want to force the screw in and cause the blind nut to come free: I've done that before

and the only cure is to cut the head of the screw off so it can be fixed. I cut the covering

inside of the rudder, where the stab is attached, about an 1/8" in. This allowed the stab to

push that covering under it so it makes a nice clean appearance and also unlikely to tear in

flight. The recesses on the outside of the rudder where the screws heads go are easily

seen with the slight indentation of the covering. An x-acto knife was used to put an 'X' cut

at this spot. Both control horns mounted. I use a manual modelers drill: going through

balsa doesn't need anything more than 'hand' power.

The top servo in the

picture is for the elevator. I

taped the horizontal

elevator to the rudder in a

neutral position, hooked

up the clevis's to the

control horns and, like the

rudder, used a felt tip to

mark the push rod directly

over the hole in the servo

control arm. Bend it 90

degrees, put it all together

with a E/Z link and she's

'good to go'.

Testing the elevator:

Elevator in neutral

position.

Elevator in down position.

I cut a small notch in the

former just behind the

center throttle servo using

a razor saw. The 3 servo

wires and 2 airlines (3

needed if you're not using

Spring air retracts and also

installing brakes) come out

of the center wing directly

over the servos. I was

concerned about these

wires eventually/possibly

getting entangled with the

servo arms. To prevent

this, the wires and airlines

go through that notch and

connect with the 3 servos

on the 'retract' side where

there is lots of room. I

used plastic ties to hold

the servo wires together

and routed them through

the same former where

there already exists a large

hole.

Pretty straight forward on this. I used

electric tape to tape the servo wire

connectors to the wires coming out of

the center wing, inserted the center

wing dowels into the booms, aligned

the wires and airlines in the slot we

made, and put the 4 nylon screws in.

Putting the booms on her nose made it

easier to access the retract area to

make sure all the wires and airlines are

in that notch and nothing is being

pinched. For now, the retract and brake

lines are just looped out of the center

hole of the center wing. We'll cut them

later for connecting to the air valves.

Leave several inches of air line sticking

out of each boom so we can easily

connect them up later. That 'rats nest'

connecting to the receiver isn't too bad,

considering how much 'stuff' we're

operating!

Checked out all the

servos and all's

working good.

Drop tanks.

Figure I might as well paint them

up so they are thoroughly dry by

the time we use them. Use 240 grit

or finer to rough up the surface of

the plastic to give the surface

some 'tooth' for the paint to stick

to. First coat is primer. Any of the

spray paints at HD or Lowe's in a

can will do, but we'll need to use a

fuel proof clear coat for the last

coat. Primer is important: it's

virtually impossible to get a

smooth coat of paint without

primer.

Second coat: Black.

As with the primer, it's best to put

on several light coats than try to

cover it in one coat (also, less

likely for the paint to attack the

plastic).

Page 6

Retract system

Cut a new servo tray to lay over

the old one in the main fuse. In

the middle will be the standard

nose steering servo. Flanking the

nose servo will be two micro

servos (Hitec HS-81) to control

the retracts and brakes. I'm using

the micro servos so I can get 3

servos in the same place as the

normal two servos. Top left is the

Spring air control valve. Below

left is the Ultraprecision brake

valve.

Gluing in the air

tank and the new

servo tray. I moved

the tank back as

far as it would go

to make room for

the new servo tray.

Something to do while watching

the game:

There weren't enough decals cut

on the sheet to do the whole

canopy, but there's enough decal

left on the sheet that you can just

cut some more strips and use

those.

I'm putting all my

air and charging

outlet in the nose

of the fuse. Along

the inside is black

plastic used for

auto wire

protection. It has a

slit on one side to

put all the

wires/lines in.

The fill valve and robart's pressure gauge.

I had to

cut 1/2"

off the top

of the

strut so

the wheel

would fit

inside.

Retracts up. Retracts down.

Setting up the nose strut is presenting

some problems.

As you can see in the picture, the masking tape (the edge away from the wheel) is where I

have to cut the strut so the plane sits level to the ground. the black line above it is where

the internal cylinder is to put pressure for the oleo action of the spring. As you can see, we

have to cut below that black line. Presently, I'm figuring I can push that internal cylinder

down about 1" so we can connect the strut to the retract. I'm also going to have to cut the

spring shorter so it still works on the oleo.

I'm setting up two nose struts using the

7/16" that came with the P-61 ARF (top one

in picture) and a 3/8" strut that I had as a

spare (bottom one in the picture).

There's only a 1/16" difference in the diameter but as you can see in the picture, the overall

size and appearance of the 7/16" strut is much beefier that his smaller sister. The nice

thing about the 3/8" is no cutting is required. Comparing real pictures, the 3/8" strut and

wheel appears more scale with the 2 3/4" wheel. It may not hold up as well though if you

start going off the runway and into grass. The bulk of the weight is definitely on the mains

but being out front, severe turns at a high speed or heavy grass as high speed may do it

in.

Working on the 3/8" strut first:

I using my vise, versus using a hammer, to

push the 'plug' into the oleo. (the 'plug' being

the sleeve with a hole in it that makes a

perfect fit to the male end of the retract). I've

taken the oleo apart so not to damage the

offset weld (it can't take this kind of

pressure). I also put a piece of wood at the

other end so the end is not damaged by the

vise. I rounded (beveled) the end of the 'plug'

so it is easier to align and get it to enter the

strut.

I male end of the nose retract is a skoch

larger that 1/4" in diameter so I used a

17/64" bit to drill out the plug in the strut. (I

used a small square first to make sure the

strut is perpendicular to the drill table). As

usual, I used cutting oil to keep

friction/heat to a minimum. After drilling

the hole, all that was needed next was to

put the strut back together again. (holes

and tapping will be done later to hold the

strut to the retract).

Nose gear: 7/16" diameter strut modifications.

To get the plug out that

holds the spring against

the bottom of the strut,

I had to use a center

punch to knock it out.

I was initially worried that it may be welded in there, but my fears soon faded when theplug came out very easily. We won't be using it again because the bottom of the plug thatattaches to the retract will now be compressing the spring. We have to do this due to theamount of the top of the strut that is cut off. I cut off 2 3/4" off the top of the strut with adremel cut off disk

The plug (sleeve) that comes with the 7/16" strut

is too large in diameter to go into the strut (at

least, on mine it was). I had some pieces of a

3/8" strut laying around and this is about the ID

(inside diameter) of the 7/16" strut. I used a 1"

piece of the 3/8" strut and two of its plugs

(sleeves) to put into the 1" piece of 3/8" strut.

Again, I used the vise.

Here is the 1" piece of 3/8" strut with the two

plugs in them. We now have to drill out a 17/64"

hole in the center as we did for the 3/8" strut. I

had to sand the paint and some of the metal off

the outside of the 1" piece of 3/8" strut (we

shouldn't really call it a strut since it is now just

a larger plug (sleeve). To make sure that this

new plug is not too large to go into the 7/16"

strut, keep sanding the outside until it fits 3/8"

hole in a drill gauge ( a drill gauge just has a

bunch of holes in it indicating what size hole

each one is). Once the outside diameter fits

through a 3/8" hole, I can now press fit the plug

into the top of the 7/16" strut.

NOTE: since I had to sand the 3/8" piece of strut to get it to fit, you might as well just use

the original plug (sleeve) that came with the 7/16" strut and sand that one down until it's

3/8" in diameter. I did the sanding by putting the sleeve on a drill bit so it could move freely

and then held it against the disk portion of my table belt sander. The sleeve rotates when it

meets the sanding disk but this way, it evenly sands the entire surface.

A little care must be taken when putting metal to a fast moving disk! I used a small chisel

to keep the sleeve from coming off the drill bit and pushed the sleeve lightly against the

disk platform to help slow it down a little bit while the sanding disk does its job (this was

the only way I could think of evenly sanding the surface of the sleeve: I'll do stupid things

like this around sanders where the worst I'll get is an abrasion on the skin, Never around

cutting blades!). Always wear eye protection.

Since I moved the plug lower to where it used to be to put pressure on the spring, I had to

do some additional cutting so things wouldn't bind. The lower part of the strut that holds

the wheel, I cut off 1/2" off the top male part that slides into the upper female half of the

strut. I also cut 1" of the spring off. This seems to be about right as the oleo still functions

(amazing, luck perseveres again!).

3/8" Nose strut.

Here we have the 3/8" and the 7/16" nose struts made up. If one doesn't work, I'll have theother for a backup. The 3/8" is easier to make. The 7/16" can handle more stress. It's 'yourcall' on which is better for the parameters of your field and flying experience. Both oleosfrom the bottom to the top (not counting the wheel) is 6 3/4" long. The larger wheel on the7/16" strut made it a 1/4" longer

7/16" Nose strut

For the nose strut, we need to drill and tap

for two set screws (two to make sure if one

fails, we have a backup, Freely translated:

lets not hose up our 2000 buck plane)

Here's the pilot holes drilled on the nose

strut for the set screws. (This tapping not

needed for the mains since the whole strut

goes into the retract).

After using a #40 drill bit to drill the final

holes in the strut, we tap the two holes. (A

well stocked hobby shop should have

packages of a drill and a tap as a set).

(remember:make sure you use some oil

when drilling and tapping).

After drilling and tapping, the set screws

can now be put in.

I just noticed that the main wheel sticks

out. Those black plastic pieces in the ARF

are going to be functional. Looks like we'll

later cut a hole in our gear doors and glue

the plastic covers over the hole to cover

the wheels. (hmmm: picture 38 in the

manual shows the procedure)

The nose retract and strut are installed.

The retract must meet the back of the

retract wooden mount. This is necessary

so the steering control arm has room when

the retract is up (you'll see this in the

second picture). I also had to trim the one

former holding the back of the wooden

mount. You have to cut the side off so the

control arm can move by it, and also so

the back of the retract sits all the way back

on the end of the wooden mount.

Nose strut up.

Here you can see

how far back the

retract is from the

front former. You

can also see the

room needed for

the steering arm as

the arm goes

below the top level

of the retract

wooden mount.

Note that all

3 struts

have the

oleo

scissors

toward the

front of the

plane, as

with the

prototype.

If your

retracts

bind: check

that you

have the set

screw all

the way in.

Also,

loosen (one

at a time)

each of the

four screws

that hold

the retract

to the

wooden

mount until

the retract

moves

freely. The

last screw

loosened is

causing a

bind. You'll

have to

shim that

corner up

before

tightening

the screw.

Left main up. Right main up.

Page 7

Running wires from the battery up to the

nose on/off switch and back.

I connected the

retract, nose

steering and brake

servo to the

receiver. Looks

like the nose is

backwards to the

rudder, so either

another channel or

a servo reverser

(I'm going

reverser). The

brake is a dial and

on the front right

(aux 3) of my JR

radio. I've opted to

use aux 3 over aux

2 which is on the

front left.

I'm going on the assumption that, after landing, my left hand will be busy steering the

plane so my right hand can control the brakes. When taking off, my left hand will again be

busy steering. My right hand shouldn't be busy until the plane goes several feet. Any ideas

on this...besides growing another hand? This may be just what each of us is comfortable

with, also the limitations of the transmitter.

I plan on putting the receiver where you presently see it in the picture between those two

formers in the picture. I also have the battery in the same place but down beside the air

tank. I'm putting another battery on the other side (1400ma, 6v each). I'm starting with the

batteries here and hope they won't have to be moved to get proper CG.

Retracts and

brakes with

pushrods

connected. I

hooked up the

retract and brake

valves to the micro

servos with some

1/16" thick wire

with Z-bends on

each end. The

micro servos are a

good choice for

these since we

only need 3/8" -

1/2" throw to make

them functional.

Since I had the

retracts 'hooked

up', I thought it

would be a good

time to check out

the CG. The

manual says CG is

3-3 1/2" back from

the leading edge of

the wing. The end

of the screw driver

points to where I

put a piece of

black tape. I split

the two extremes

and put the tape at

3 1/4".

Here's a

low angle

where I'm

using foam

to support

the plane

while the

retracts are

up. I put

the props

on and just

taped the

cowls to

about

where they

will be

(presently

the cowls

won't fit

over the

engines

with the

mufflers on

the

engines).

Top view.

Got most

of the

things still

not added

sitting

about

where they

are

suppose to

be. Well, I

can forget

about

putting

those

batteries in

the center

of the main

fuse. I had

to move

back a

good inch

to get CG.

The batteries are now going into the nose. I put both of them up front and the CG is now

about a 1/4" back from where it needs to be. I think some heavy spinner nuts should do it.

There's plenty of room in that fiberglass fuse so we can add lead to that later. When

mounting those engines, a little farther forward won't hurt. I remember how light the

horizontal stab was when I was assembling it to the booms.

It's amazing how something so light can offset the business end with all those motors, etc.

('give me a place to stand and a lever long enough and I will move the world', Archimedes).

I'm glad I wasn't building this from scratch, I probably would have needed to add 10 lbs to

the nose.

Here, both battery switches and charging

jacks are in the front servo hole. I thought

that I needed two 'voltwatches' but it

appears that the 'juice' goes through the

receiver from one port to another, since

when either battery is turned on, both

'voltwatches' came on. So save your self

some $$ and just buy one. The air valve

and gauge is on the right.

Foam was lined in that hole on top for two

1400ma, 6v battery packs.

With both batteries in the hole, there

wasn't room to wrap each battery pack but

the foam lining in the cavity should work

for vibration reduction.

I had to put a couple notches in the former

so the two 5 cells packs would fit.

Bottom of nose.

I'm using a common kitchen door latch (at

Home Depot or Lowes) to hold the nose

cone onto the front of the fuse (need easy

access with all the connections up there).

I'll build up a wood brace in the nose to

mount the male end of the door latch.

There's not a lot of wood to connect the

latch so I used 1/8" ply and made a 'U'

shaped piece to hold the latch to the fuse

Here's all the wires

and air lines going

along the side of

the fuse. I cut extra

holes in each

former to route the

wires through and

to hold them in

place.

I took out the black

auto tubing

because it couldn't

hold all the 'stuff'

going up front.

Once we're sure

all's good, we'll

use some plastic

ties to hold

everything

together.

Now, I'm working on that door

latch to hold the nose onto the

center fuse.

I slid the nose on 1/8" ahead of the

panel lines on the fuse nose.

(The nose isn't symmetrical, the

flat end goes on top).

With the make part of the door latch on the

female end (rollers), I measured from that

1/8" forward of the panel lines to the end

of the door latch. Mine was 5 1/8" so I now

know my mount has to be that far down in

the nose.

Bottom of picture: I used a piece of cardboard and kept

trimming it until it fit to the depth that I wanted. Top of the

picture: I then used the cardboard template to trace on

1/4" thick piece of balsa and kept sanding until it finally

laid in the recess of the nose at 5 1/8" down. Those paint

sticks with 80 grit paper glued to them made quick work of

any sanding that was needed. I put 4 holes in the balsa for

any future buckshot we might pour in for nose weight. I

marked a straight line on one end (flat side of nose) of the

balsa to keep the orientation the same in relation of the

balsa to the nose.

Side view of the 1/4" balsa mount.

I used some shoe polish and put it on the back

plate of the male end, pushed the nose on to get

the imprint and drilled and screwed her on. Works

great. (The spouses lipstick should also work well:

blame it on the kids! her fault anyway: you don't

leave your tools laying on the counter!) I epoxied a

1/16' piece of plywood on the balsa to give the

screws a little more solid surface to grab onto.

Steering.

Used two pieces of

white tubing

(supplied in ARF),

and cut them 12"

long for each side.

I kept the white

tubing 1/2" behind

the back of the

retract so the

steering arm

wouldn't hit them

and also room for

the pull/pull wires

don't bind.

I drilled holes in

two of the formers

to hold the white

tubing. The

pull/pull wires are

connected in the

usual way: looped

through the

steering arm and

back through the

brass tubing and

then back through

the brass tubing

again and then the

brass tubing was

crimped.

This shows the

retract down. The

white plastic

tubing keeps the

wires way to the

sides so the strut

and wheel don't

hang up on them.

This shows the retract up.

The white plastic tubing

goes through the large

existing hole in the first

former after the back of the

retract. As you can see,

this allows the white

tubing to flex, if needed.

Retract back down.

The white tubing has gone

back to its original

position.

Here's the details for connecting the wires

to the servo end. Same double looping and

crimping of the brass tubing.

Standing for the first time with functional gear, strut and steering. The center fuse has

been been attached with the two nylon bolts. Not bad on getting all those wires into the

fuse. The receiver went on one side of the air tank and I pushed the wires on the other side

of the tank. I pulled the receiver antenna out the back and plan on connecting it to one of

the vertical fins as in the prototype. The contact surface of the fuse to the center wing is

pretty wide so I had to use a piece of that left over white tubing to push a wire or two so

they weren't being pinched between the fuse and center wing. I checked the air brake valve

and it's working. All struts have the 'scissors' pointing forward. I used the original strut for

the nose wheel and have the smaller one set up as a backup. (gettin' there!).

Cowls

I made a cardboard

template taped to the

boom so it won't move

when we take the muffler

off and slide the cowl on.

After cutting holes in thetemplate, I folded thetemplate back, took offthe muffler and slid thecowl on and put thetemplate back down overthe cowl. I initially cut asmall hole for the mufflerand head of the engine inthe cowl, and then slidthe cowl back on to makesure we are in the'ballpark. If you look realclose, you can see thefelt tip marker lines forthe engine head on thecowl.

The holes are enlarged a

little more and the cowl is

put on again to make sure

the glow plug is in the

center of the hole.

Sliding the cowl on I had to

make a cut all the way

back for the muffler. In the

picture, one side of the

cowl lifts up to get it by the

muffler.

I put masking tape on the

booms so I could make a

mark 'X' inches back from

the pre-installed cowling

blocks. After sliding the

cowls on, I knew how far in

the mounting blocks were

under the cowls and drilled

holes at these locations. I

did one hole at a time and

put a screw in the hole to

insure the cowl didn't

move, including checking

proper distance for prop

clearance.

I used Du-bro's cat no 531 no 6 X 3/4" button head sheet metal screws to hold the cowlson. Although not exact (couldn't find any), I used Harry Higley's big hubs 5/16" X 24 NIN516hubs. After sanding with 240 grit and priming, I painted the props black with yellow tips.

Shield installation.

The front fiberglass shields (covers) go

just behind the cowls. I had to cut part of

the front off (hidden when mounted) so it

would form around the boom.

Here it is mounted.

The manual says

to epoxy it but I

like using the

button head

screws. The ones I

uSed are Du-bro

#526 (#2X1/2" ) or

#525 (#2X3/8" ).

Looking at the end

of the center wing

for guidance, I put

the screws in

where there were

stringers, etc. I

noticed that the

leading edge has

plywood

sandwiched in it

for strength. (you

can see it in the

picture).

Rear boom fiberglass shields (covers): I

drilled 10 holes in each cover. Again,

aligning the holes where stringers, etc

were showing on the end of the center

wing rib to give the screws some 'meat' to

hold onto. Later, I found I could just use a

manual hand drill to put extra holes in: The

part on the boom needed two screws to

hold it against the side of the boom.

The back shield is

mounted. There is an 'R'

and 'L' in the inside

corners of each shield.

Although they look

identical, I put the 'R' on

the right boom (from the

pilot's view). In the picture,

you can see the 'R'. (the

front shields are

symmetrical).

Page 8

Gear Door Hinges

I tested the ARF hinges on a piece of balsa and couldn't find a suitable solution to using

them. Instead, I got some sonictronic hinges out that I had left over for the P-28. These

seem much better.

The key on the hinges is having the hinge pin along the top surface of the door and fuse.

The door will rotate along the axis of the pin.

If the pin is below the surface, the door will bind.

The ARF hinges have a base that is on both sides of the pin whereas the Sonictronic hinge

base only goes to one side of the pin. This allows us to get the pin very close to the

surface of door and fuse.

I used Sonictronic's #132, tri-cycle door kit. The Sonictronic set has a sprung hinge which

is used on each door. This forces open the door. I believe there is only 1 set of sprung

hinges in each set so you'll have to buy 3 sets. The rest of the hinges set can be used on

tail draggers. I had to cut notches in the fuse so the hinge pin can be at the surface of the

fuse. That notch is 1/8" deep or a skoch less and also a skoch wider than the hinges. You

also want a flat surface below that notch for the base that will be epoxied to it. As with the

ARF hinges, I drilled 4 holes in each base so the epoxy can ooze out and form rivets.

The front hinge is sprung

and the back one isn't.

Inside view.

The door is epoxied to the

fuse.

Both doors in.

The spring forces both

doors open. One control

horn has been epoxied in.

The elastic string (wal-

mart's sewing section) will

be tied between the two

control horns and the strut

will pull it down along with

the doors (in theory!).

Doors open with

elastic band

across the two

control horns.

Doors closed.

(Miracles never cease, it works!!) I still have to epoxy in the black plastic covers onto the

gear doors.The wheel goes below the surface of the gear doors on the nose wheel so no

cutting is needed on the gear doors.

Door hinges (mains)

First picture:

We're not so lucky with the mains: the doors have to be cut for the wheel. The brakes

offset the wheel so it is not exactly in the middle between the doors so I had to cut each

door differently. If you're not using brakes, your cuts should be symmetrical on both

doors.

Here's the inside

view of the black

plastic cover. It

has to be trimmed

so it doesn't hit the

wheel.

All cover doors and

gear doors 'dry fitted'.

Gear doors for the

boom. The sprung

hinge is on the

right.

Gear doors for the boom. Outside view.

No cutting here: just epoxy them on (with holes in the hinges for better holding power).

Installation on the

boom.

Used control horns with the elastic to close the doors. I had to epoxy 2 more control horns

on with the new ones higher up on the doors (where the doors meet) so they would close

completely. Since the strut is to one side, the strut puts unequal pressure (at a different

angle) on each door. Too compensate, I had to put move the control horns up. Since the

control horns are are now on the far side of the doors, you could probably cut them so

they are stubby (with just one hole) so they wouldn't be so noticeable.

Gear doors cut

away for the wheel.

With plastic covers

glued on.

Doors open with

plastic covers on. I

also had to cut the

plastic covers so

they wouldn't hit

the wheel. Usual

procedure for the

plastic covers:

sand the edges

and then epoxy

them on. Paint the

insides before

installing them:

unfortunately I

didn't think of that

before installing

mine so I'll have to

brush the paint on

instead of spraying

it on.

You need to cut the bottom of the nose

cover so the gear doors can close.

Each wing gets 2 screws

on each side. A drill bit

was used to drill a smaller

hole in the metal wing tube

via the already existing

holes in the bottom of the

wing.

I used Dubro's #383,

#4X3/4" socket head sheet

metal screws to hold the

outer wings on. I like the

socket heads over the

phillips since they are less

likely to slip/strip the

heads and you can put

them on real tight.

Decals

Decals were added. Not a

whole lot of work here.

After putting the numbers

on the tail, I cut some

small squares from the

cockpit decals and put

them on the screw holes

that hold the horizontal

stab on.

Don't do what I did and put

those red rectangles in the

wrong place. After

checking my reference

book, they should be

between the red lines on

the wing between those

two white circles (where

the red 'dots' go).

I took liberty on the nose

art. Since my on/off, air fill,

etc are under the nose

(and removable), I had to

put the female behind the

nose cone and the 'lady in

the dark' completely on the

nose cone. Putting part of

each on the cone would

result in them never being

aligned.

P-61 Flys!

P-61 in her maiden form: ie, no cowls and retracts stay down.

What the pics don't show is the first REAL maiden flight. I took off and she immediately

banked left: able to control her but barely: needed 10 clicks right aileron to fix. Then only

half a lap, the right wheel and axle was hanging there by the brake line. The dam pit crew

didn't tighten the set screw!! I had three other pilots around me which helped a bunch.

With the doors and the unlikely possibility of the retracts going all the way up, it was first

decided to land on the asphalt runway.

Another good point made was once the right struts touched the runway, she would have a

tendency to go to the right. That was good so I was ready for it. I used about 40% flaps and

she landed nicely. I was surprised at how little metal that was removed on the bottom of

the one retract: I would guess about 1/64". The set screw was still in there and not even

damaged so that shows how little metal was scraped off. I flattened the axle (which I forgot

to do while assembling her) and took her up again.

Flew great and she landed very lightly on all three retracts at once: looked cool. She lands

pretty easy and slower than the B-25. Watch those takeoffs; get plenty of flying speed

before taking off and make that climb nice and gentle. Both with the B-25 and P-61, I

started the throttle slowly and then gained flying speed.

ps: I'm the ugly one on the right!