- The chassis undercarriage and sides were printed
(minimum 50 hours of printing time), finished and
squished together.
|
|
- The printed/finished/assembled
buffer-bar/buffers/couplers were attached to the
aluminium chassis plates.
|
|
- The final versions of all the body sections where
printed (minimum 240 hours printing time) at the
appropriate resolution (see Github
for detailed instructions) then tested/fettled to
ensure a loose join with the aluminium chassis plates
and a tight join with each other at the body sides
(ignoring any gaps between the roofs); the ASA of
sections 5, in particular, had shrunk at the corridor
end and hence the "clips" needed some easing to fit
easily over the aluminium chassis plate.
|
|
- With body sections 1 and 4 fitted to the
aluminium chassis plate the positions of the fixing
holes were marked, then the body sections were removed
and the 6 mm holes were drilled in the aluminium
chassis plate. The chassis undercarriage was loosely
fitted to the aluminium chassis plate (supported by
resting the buffer bars at each end on blocks of wood)
and, using a bolt in the central 6 mm hole to
keep it still, the positions of the holes were traced
on the undercarriage. The undercarriage was then
removed and 6 mm holes were carefully drilled
through it too at the trace marks. 15 mm
long M6 bolts were pushed up through the undercarriage
and the aluminium plate holes then square nuts were
test fitted to the bolts in the nut traps of body
sections 1, 2 and 4, ensuring the body sides (now
all of them fitted) were not pushed apart by the nuts
and trimming away any parts of undercarriage that
fouled the clips along the base of the body sides when
the bolts were tightened. I spent a long time on
this so that I would have to handle the painted
end-product as little as possible. For the
powered unit, the central hole in the chassis is used
for wiring so I drilled an additional 6 mm hole,
about where the two undercarriage halves join, to hold
the undercarriage firmly to the aluminium chassis
plate, the square nut in this case being held in place
on the aluminium plate using cyanoacrylate
adhesive. To allow room for a wide electrical
connector I drilled-out the central hole, through both
the aluminium and the undercarriage, using a
21 mm diameter hole saw, which just fell within
the boundaries of the undercarriage box.
|
  
|
- The final versions of the cab fronts and cab roofs
were printed (minimum 50 hours printing time) then
tested/fettled for fit.
|
|
- Enough units of polycarbonate mould were printed
for a complete DMU roof and then, to hold them in
place, they were glued in a line to two lengths of
scrap aluminium (left over from the milling of the
chassis plates) using an epoxy that specifies it can
withstand temperatures of 100 C. Note: I
tried cyanoacrylate adhesive, which said it was good
to 180 C, and an epoxy that was meant to
withstand boiling water but both allowed the aluminium
to came away once submerged in boiling water, maybe
because the polycarbonate flexes under heat; it didn't
matter too much though - the styrene sheet, once
fitted into the mould, kept the polycarbonate sections
in place.
|
|
- Two pieces of black 0.5 mm thick styrene sheet
106 mm by 567 mm were cut to form DMU roofs
and these were moulded in the polycarbonate moulds
under heat then test fitted to the body sections.
|
  
|
- The battery was strapped into place using three
cable ties with some fabric electrical sleeving pushed
over them to ensure the battery was not pinched; use
of a nice narrow cable-tie means that there was no
fouling of the seats that will be inserted later.
|
  
|
- The control electronics were positioned in the
chassis box and the LokSound unit (with its very
delicate wires) and patch-board were fixed into
position with sticky pads; the other boards it was
sufficient to just wedge into place.
|
 |
- The assembled bogies, powered and unpowered, with
their printed/finished driver's steps, were attached
to the aluminium chassis plates; before doing so I
made a final check that the mounting holes were dead
centred on the aluminium chassis plate and corrected
with a round file as necessary. I also re-checked the
height of the buffers against another item of rolling
stock and ensured that nothing fouled the
bogies. I made a short cable terminated in a JST
connector to connect to the motors, ensuring it was
unable to foul anything, using a mains terminal block
cable-tied to the bogie as an intermediate.
|
 
|
- All of the seats, in the types/quantities required
by the seating plan,
were printed (around 40 hours printing time),
finished and painted. I used a file on the
straight-backed seats to remove the splaying from the
3D printing process at the base of the back, making
them completely flat for gluing.
|
|
- Two pieces of black 0.5 mm thick styrene sheet
were cut, one 73 mm x 570 mm (for the motor
open second) and one 73 mm x 403 mm (for the
motor open second brake) to fit on top of the
aluminium chassis plates and between the body
sides. Holes were cut in the sheets for the
various fittings, including the battery strap, using a
sharp knife.
|
|
- The seats with curved backs were glued to the
styrene flooring sheets according to the seating plan using
plastic weld, test-fitted body sections being employed
as necessary to achieve correct alignment and ensure
no fouling.
|
|
- The internal partitions were printed, painted and
test fitted.
|
|
- The seats with flat backs were glued to the
partitions according to the seating plan using
plastic weld, test-fitting the body as necessary to
ensure no fouling.
|
|
- The cab fronts and cab roofs were very carefully
finished (again, a test window fitted and removed)
then painted (including the control panels). The
underside of the cab roofs were painted with a
metallic paint (Humbrol 11) in order to reflect the
internal cab lighting.
|
    
|
- The wiring, including all the LEDs with their
in-line series resistors insulated with 1.5 mm
heat-shrinkable sleeving, the 5-way inter-coach
connector and the junction boxes in the cabs, were
made and test fitted/powered, the main cable
inside a 5 mm diameter expandable PET
sheath. I took particular care to get the
passenger lights into good positions, not fouling the
partitions or the speaker.
|
  
|
- The forward and rearward headlights, forward lights
on top, were glued into position in the cabs with
cyanoacrylate adhesive.
|
 
|
- The sides of the body sections were carefully
finished, a test window fitted and removed from each,
then masked and painted; the roof will be covered with
styrene sheet and so required no finishing. Note: any
hinge or door stop that had been accidentally shaved
off was reinstated before painting with a tiny piece
of ASA scrap, glued into place with a generous amount
of plastic weld and then shaped with my Herzo.
The outside of the "clips" and the cross-struts inside
the body were painted matt dark grey (Humbrol 32)
to help them disappear.
This step took by far the longest time, probably
around a month of evenings including time off for good
behaviour
|
|
- "Glass" was added to the body sections and cab
fronts, each strip 30 mm wide for the body
sections and 35 mm wide (subsequently trimmed
with a scalpel) for the cab fronts.
|
 
|
- After clearing any overspray off the edges with my
Herzo, the body sections and cab fronts (but not cab
roofs) were glued to each other with cyanoacrylate
adhesive and, afterwards, any visible plastic was
touched up.
|
|
- The long handles were painted as required to match
their locations.
|
 
|
- All handles, long and short, were fitted and glued
into position with a blob of thick cyanoacrylate
adhesive and touching up any visible plastic around
the drilled holes with some paint on the end of a
cocktail stick.
WARNING: when applying cyanoacrylate to the rear of
the door handles in particular, fogging may result on
the nearby window panes. This can be largely
removed with rubbing alcohol on the end of a cotton
bud. Since I was modelling a train with
single-glazed windows returning full of people from
their Cardiff shopping trips on a damp Saturday
afternoon, the remaining fogging was merely
scale-accurate condensation for me but if it is
undesirable consider using Loctite 408, blowing air
through the carriage while gluing or masking the
inside of the nearby windows with Humbrol Maskol.
|
  
|
- For the guttering strip running along the sides and
around the front of each carriage I was originally
intending to use 1 mm square-section brass wire
but it proved very difficult to get kink-free so, at
the last minute, I changed my mind and purchased three
1 metre strips of 1.5 mm square-section ASA from
4D
Model Shop, used the heat of a hair drier to
allow me to bend it appropriately, carefully glued it
into place along the sides with cyanoacrylate adhesive
and then equally carefully applied a couple of coats
of paint to match the body in each area.
|
  
|
- The moulded black styrene roofs were glued into
position. Plastic weld alone didn't work as it
did during testing, possibly because there was now
paint around the edges of the roof above the
guttering, getting in the way of the weld.
Instead I applied a generous quantity of plastic weld
on the centre of both roof surfaces (where there was
no paint), positioned the roof so that it fell within
the guttering, ensuring that the cab roof could still
be clipped into position and removed, then
weighed-down the roof to affix it. Then I turned
the carriage over and applied cyanoacrylate adhesive
at the edges, working my way along and holding until
fixed. Afterwards the guttering needed touching
up again.
|
   
|
- The ventilation shell tops were painted matt dark
grey (Humbrol 32), leaving the lower portion
unpainted in order that they can be glued into the
roof. While I had matt dark grey paint handy I also
painted the exposed ASA where the main roof joins the
cab roof to stop it shining through the crack between
the two.
|
|
- Holes were drilled in the roofs for the ventilation
shells and these were glued into position with thick
cyanoacrylate adhesive, applying just a small amount
of glue to the stem to tack them in place and then
turning the carriage over and applying a further blob
of glue into the hole. The shells were arranged
such that their line of symmetry ran along the length
of the carriage. Once mounted they were given another
coat of paint.
|
 
|
- All of the remaining electronics bar the cab lights
were fitted: the passenger lights and the speaker in
its holder secured with cyanoacrylate adhesive, the
"junction boxes" secured with Araldite standard; the
wiring was arranged such that it was as invisible as
possible when viewed from the outside. Since
there was very little space I plugged the cab lights
in as well at this point, even though they won't be
glued into position just yet.
|
  
|
- The two main internal partitions were fitted next:
grooves were filed in them to accommodate the passage
of the electrical wiring and then the partitions where
glued into position, cyanoacrylate adhesive being
applied at the roof and the base, the sides left
unglued to ensure no fogging of the nearby windows.
|
|
- With the cab lights plugged in, the cab
partitions/walls were filed/fitted/glued into position
behind them. The cables of the cab lights were
then glued to the cab partition walls, arranging them
such that the cables/lights did not foul the cab roof
when it was clipped into position and again care was
taken to avoid fogging of the windows due to the
cyanoacrylate adhesive.
|
   
|
- The magnets that attach the corridor joiners were
glued into position inside the section 5 bodies
(existing weak glue scraped off and replaced with
cyanoacrylate adhesive) and then the final two seats
with straight backs were glued into position in the
back of the motor open second with cyanoacrylate
adhesive.
|
  
|
- Following a test fitting of the bodies to the
chassis plates the long internal cables were tacked to
the body's cross-pieces/partitions here and there with
cyanoacrylate adhesive in an attempt to keep them at
floor level.
|
|
- The windscreen-wipers were attached to the cab
fronts using Loctite 408 with a hair drier
blowing air away from the "glass" over the joint to
make really sure there was no fogging, then the top
surface of the wipers was carefully painted matt dark
grey (Humbrol 32) to hide the glue.
|
|
- The visible parts of the bogies and the visible
sides of the aluminium chassis plates, in particular
the sticky-out step bits, were painted matt dark grey
(Humbrol 32).
|
|
- After using some rubbing alcohol to clean all of
the windows of any fingerprints etc., no smoking signs
(Fox Transfers
FRH10019/3) were applied to the inside of the windows
according to the markings
section below. Moving each transfer on the end
of a toothpick, I arranged the lines on the tea-towel
I was resting the body on to make initial alignment as
easy as possible before turning the model the right
way up to make final adjustments to the position of
the transfer while looking at it from the outside.
|
 
|
- The assembled bodies and styrene sheets holding the
seats were finally bolted onto the aluminium chassis
plates.
|
|
