recent change: 2016-02-24
This kit was designed for the
skilled modeller. The
contains more than 150 pages including 400 images. It can be
downloaded for free! Take Your time and have a close look into this
booklet so You will be able to reliably decide if You will be able to
master this extraordinary rc model. Although the model´s structure
can be managed in only a few days due to the perfect fit of its
parts, finishing the aircraft will need a certain amount of
steadiness anyway. In the end the pride of what You reached and the
easy flying of the machine will make You really happy!
In order to shorten the
time-consuming work of sheeting
CNC-milled sheeting elements for fuselage and cowlings
for the Comet.
The aileron servos are located in frames that can be dismantled,
e. g. to replace a faulty servo.
Filling pieces are provided
at the wing´s side for fixing the hinges.
For safety reasons the fibre glass control
horns are connected with the frontal (balsa) part of the rudder at its full
At RC-Network You will find a thread illustrating
the (hi)story of the prototype (nickname:
The thin tip bows are still designed robust. With a sanding
block their levelling towards the trailing edge is to be worked
All spar boxes are realized as "comb spar
boxes", i. e. comparable to a comb the spar box element is plugged into the wing
along the spar crossing up to a dozen spars at once. This results in a
significant time saving.
The motor- and gear cowlings´ load-bearing formers and frames
are simply plugged in prepared ribs channels after the aircraft
middle section was taken from the mounting frame. Distortions
are hardly possible.
The two plastic straws close to the leading
edge contain 2.5 mm2 high power cables. The remaining tubes contain
the conductors to speed controllers (drive and gear), gear power supply, limit
switches, ailerons and wing position lights.
Seven screws keep the integral main landing gear device in place,
so installation or removal is possible within minutes.
Screw jack drive and electronical speed
controller can still be applied quite easily through the opening.
By dispensing with a removable fibreglass cowling much weight
could be saved.
The landing gear and a
microcontroller can be puchsed in the
SHOP (Set H),
auxiliary frames for grinding and hard-soldering included!
Pine spars are used as the wings´ leading edges, their frontal
edges being a bit broken before sheeting.
The wing lock is done by a plywood pin held
in a corresponding box by a nylon screw.
The two contacting wing ribs are provided
with milled cut-outs so that standard plugs/sockets can easiliy be installed in
their related plastic adaptors (Set E).
The prototype under construction.
The nose was cutted off the fuselage past the
Two doubled and boxed spar pairs run across the large aircraft
midsection guaranteeing the demanded stability and strength of
the wing construction. They furthermore follow two plywood formers, which are in turn resinned to the plug-in
mounts (Strongal/Fa. Petrausch, Set D).
It hardly goes stronger and lighter at the
The flap servos can be either moved and mounted through the
flaps openings themselves or the canopy´s opening. The rudder
crosses or disks can still be fixed to the mounted servo drives through the flaps
Unlike the Comet original from 1934 that came with a dragged skid the
glattCAD model got a simple wheel for reason of a better practicality.
Its final design is left to the modeller, depending on his/her intended scale level.
The steering is done by two steel wires.
Fibreglass control horn, spring steel, wheel, adjusting collars
und wires are included in Sets A and E.
The ducting of the bowden cables through the frames were
determined by construction, so the tubes follow a perfect curve
from the servo to the control horns. The friction in the tubes
and the rudder backlashes are minimized.
A mounting frame for the servos is provided. There is space for
up to four standard servos
(e. g. 2x elevator, rudder, tail weel).
The glattCAD prototype got the shiny black finish of G-ACSP Black Magic
with the golden decals.
Additionally an only 23 µm thin EASYPLOT
® decal sheet complete by transfer film (Set F) can be
You can choose the identification of G-ACSS (red), G-ACSP (black)
or G-ACSR (green).
On 24th of June 2012 the glattCAD DH-88 Comet had
successfully completed her maiden flight. The model flies
very neutral, without tendency to kern or changes of its
Further flight confirmed the machine´s perfect aerodynamic design.
The Comet can be landed slowly at effectively acting
This is amazing, with regard to the strongly tapered wing tips!
Video of the second
The tube frame, canopy and cockpit tub are removable in one
On the backside two small
fibreglass pins grab into the fuselage.
To securely fix the canopy a bowden cable with 0.8 mm steel core
grabs into a piece of balsa under the glare shield.
The cable´s tube ranges forward to the removable nose, from where the canopy can be "remote
controlled". Here the bowden, angled by 90°, lies in a milled nut in
the frame. Accidental slipping-out of the cable is preveted
by the applied nose. No device of the canopy locking is
In order to replicate the canopy´s typical tube frame its
devices, milled from glassfibre boards, are resinated. This
yields a stable framework, to be glued with a transparent canopy
The glare shield
in the cockpit, an area for the instruments panel and a cockpit
tub are prepared for the further design. Balsa is used in a hard
Only five machines of the Comet were built. The red G-ACSS Grosvenor
House is regularly presented on Shuttleworth
Collection´s taxiway -
and even flying! The black G-ACSP
Black Magic is restored at great expense.
With the glattCAD model in 5th scale these harmonious lines had to
be preserved by all means. The wing´s outline was not modified
thus a geometrical twist had to be provided.
Span and fuselage length of the glattCAD Comet
amount to 106", resp. 70". It is powered electrically best.
Following the complete revision of the prototype the take off
weight of the model - depending on the "scalefactor" -
is about 7.3 to 8.0 kg.
In order to save weight with the redesign certain selected pine spars
were changed by balsa ones.
Both the original as well as the Comet model are almost
entirely built of wood. The glattCAD prototype made its
successful maiden flight on 24th of June 2012.
Hence this model has no further fibreglass parts
except the weel pants. The two brushless outrunners (Ø 50 mm/length 65 mm
class, weight 400..450 gr, 250 - 300
rpm/V) can be mounted and demounted through the engine nacelles´
openings. It is fully sheeted with balsa.
The fuselage nose can be removed. It is secured by four guided pen magnets in turn adhering to four flat magnets. They
are glued to four pieces of balsa
(light yellow in the screenshot).
Together with the strong
adhesive force of the rare earth magnets this linear conduction
prevents the nose from bidding farewell on the fly.
The battery pack - fixed
on an fibreglass carrier - is inserted into the fuselage from
Of course it is recommended to install a powerful landing light
to the glattCAD D. H. 88. Modern LED technology is
The prototype has been equipped with CREE MC-E emitters on
"starplatine", being installed to a suitable Fraen reflector (beam angle 32°).
The power is more than 10W.
The lighting is not included in the
De Havilland DH-88 Comet
Especially constructed for
MacRobertson Air Race in 1934 this airplane enjoys a cult
status among us modellers. Her smooth outlines still convince, 80 years old, as if the designer had created them only
You can order the milled
short kit here in the
Manual (German) <-
As can be seen in one of the pictures above, fuselage, vertical fin,
elevators and all rudders are built up on special mounting
frames. This procedure guarantees a twist-free construction.
For weight reasons the spars
in the fuselage, wings and tail are partly made of pine or balsa,
depending on the load. The thin balsa spars assure precise
gradients of the sheeting whereas strength and stiffness are
provided by the pine spars.
The battery slot is delicate and of high strength at the same
time. It allows the fibre carrier to be locked in
different defined positions. For this pupose small holes were
milled centrally. This concept offers the inestimable advantage
of being able to adjust the center of gravity precisely at any
In the front, beneath the
slot, batteries for reciever and landing gear can be stored.
A small platform was provided especially for this purpose.
Further back in the battery slot a slidable abutment can be seen.
The removable vertical pin in the middle allows to displace the abutment.
mm gold contacts are glued into it. While the carrier being
inserted into the slot they automatically make both an
electrical connection and a safe mechanical fixation.
Additionally the battery is secured from falling out in the
The cad screenshot to the right shows the battery carrier
abutment with the 5.5
mm contacts and an aluminium locking pin from a different
Unintentional rotation of the
abutment is prevented by constructive means: A pine rod is
running loose in a related channel but enabling the abutment to
slide fore- and backward. It can be reached through the canopy opening.
Each lead or cable to be conducted over a longer distance in the
model is embedded in a thin-walled tube. For this puropse "sangria"
drinking straws are used. The part positions where the straws
are to be glued had constructively been prepared.
At the rear a high-power led can be installed (e. g. Seoul emitter,
3.5 W) as a position light. Because of the high junction temperatures these
electronical items must be connected to a heatsink using thermal adhesive.
Typically they are bar-shaped aluminium at a diameter of 8 mm.
The frames are prepared for installation. The leds and heatsinks are not part
of one of the Sets offered in the
Another "sangria straw" through the
is provided for ducting the related pair of conductors.
Rudder, elevator and ailerons move in channels.
They are controlled by the using classical
pin hinges (part of Set E). All rudder horns are milled from glassfibre
boards. They are fully integrated and glued to the frontal balsa area in the
rudders thus obtaining a reliable steering.
The elevator unit is built up on a mounting frame in one piece.
It is installed in an intricate construction to the fuselage
without any chance for mounting failure.
The rudder and all ruder blades are prepared
on mounting frames and the upper side is even sheeted there.
All mounting frames can be taken from the build table (nearly) at any time and
be reinstalled without the fear of distortion!