Start with preparing a micro bulb frame and a guidance piece. Both will
be used to route the wiring later. Use the PDF drawing in
link as guidance to
bend both parts
from 1mm brass rod. Open the PDF file, print the drawing at
100%.
Now prepare the back light bulb. Cut the lamp wires of a 6V 115mA
or 70mA micro bulb to a length of 7mm. Prepare 2 lengths of PTFE wire
both 300mm long. Remove insulation layer from all 4 ends over a length
of 4mm, tin the wires and solder the wires to the micro bulb. Do not
use too much solder. On one wire
slide a length of 10mm shrink wrap 1.6mm up to the bulb. Shrink the
shrink wrap. Make a length of 10mm shrink wrap 2,4mm. It slides over both
wires up to the micro bulb. Shrink it. Finally make a length of 8mm shrink
warp 3.2mm and shrink it over the previous fitted shrink wrap against
the micro bulb. The upper 8mm should now fit nicely into the 4mm
lamp hole and the lower 2mm in the 3mm roof hole.
Next prepare the cab
light bulb. Cut the lamp wires of a 6V 40mA micro bulb to a length
of 6mm. Prepare 2 lengths of PTFE wire both 230mm long. Remove
insulation layer from all 4 ends over a length of 4mm, tin the wires
and solder the wires to the micro bulb. On one wire slide a length of
10mm shrink wrap 1.6mm up to the bulb. Shrink the shrink wrap. Make a
length of 10mm shrink wrap 2,4mm. It slides over both wires up to mico
bulb. Shrink it.
The mico bulb is fited to the bulb frame with a length of 10mm shrink
wrap 3.2mm according to the picture below. Take note that the frame is
not symmetric and that the bulb slides over the shorter end. Finally a
length of 8mm shrink wrap 1.6mm is
fitted holding both wires against the frame like in the picture.
Micro bulb frame with cab bulb fitted, guidance piece and back light bulb
Remove the Darjeeling lamp from the roof. Guide the wires of the back
light bulb from above the roof through the 3mm hole until the
bulb fits into the hole with the last 2mm shrink wrap. Fit lamp,
guidance
piece and M3 screw. The soldered on piece of 6.5*4mm brass prevents the
wiring sticking out from under the roof. Make two lengths of 15mm
shrink wrap 1.6mm and shrink these around both wires and the 1mm
messing rod of
the guidance piece according to the picture below. While shrinking,
cover the painted roof with some cloth and paper to prevent it getting
damaged
by the hot air necessary for shrinking.
Darjeeling lamp, guidance piece and back light bulb with wires fitted
Make a length of 15mm shrink wrap 2.4mm and slide this over the bulb
frame starting from the free end without bulb. Ease it over the 90°
corner which needs some fiddling and twisting of the shrink wrap. Next
push the 2 wires from the cab bulb through the shrink wrap. Now
position the earlier prepared roof plus micro bulb frame like in the
picture
below. Put the bulb frame on top of the roof and push the 2 wires from
the
back light bulb through the same shrink wrap. Make sure you make a nice
not
too large S-shape as in the picture. You may have to twist and
torque the wires quite a bit to route them nicely against the roof.
When satisfied shrink the shrink wrap. Finally shrink a sort piece of
shrink wrap close to the corner of the micro bulb frame. Again cover
the roof while using the
hot air gun.
Slide a piece of 30mm shrink warp 2.4mm over wires and brass rod and
another piece of 30 mm shrink wrap 2.4mm over the 4 wires only. Do not
shrink these!
Solder the wires onto a 3 pin socket
strip; one wire from each microbulb is soldered to the mid pin. Do not forget to
slide pieces of 8mm shrink wrap 1.6mm where applicable. Shrink the
shrink wrap. It should look now as in the picture below (3 pin socket strip not shown).
Roof with all micro bulbs ready to be fitted to the body
The roof with the micro bulbs is now fitted to the body. The brass
frame sits simply pressed under the roof hinges inside the body (see picture below). Fit the hinge
one side at the time while pressing the brass frame at that side
under the hinge. Check the roof
opens as it should. Try the lamps with a 4.8V battery and enjoy the end
result. The wiring to the receiver goes directly down just
before the hinge and then inside the room where the
receiver sits.
Roof with its micro bulbs fitted to the body