| Drawing S1- Running Plate,
Tanks, Cab etc. |
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1. Sole/Running Plate |
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| I was in the mood for a bit of tin-bashing
so decided to make a start on the platework. This is mostly specified as
16 swg brass sheet but I shall be using 1.2mm steel sheet throughout which
comes from the skip of a local fabricator (with their permission, of course)
and is galvanised. I do all my marking out, cutting drilling etc first,
then get rid of the zinc by pickling in citric acid before final clean-up
and assembly. Paint does not adhere well, if at all, to galvanising even
though it appears to be one step backwards with regards to rust prevention.
I'm making a few changes here because the rivet detail on the drawing is
wrong and the base of the side tanks are the actual running board. First
job was to calculate the actual rivet spacings - 515 thou instead 0f 500
thou - and I also added some extra rivet detail not shown on the drawing.
This is a top view of the latest "00" gauge version of the "O2" from Bachmann
and this malachite green livery is only available from the Isle of Wight
Steam Railway. I've checked the rivet detail at Havenstreet and it is very
accurate. |
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There are six pieces in all, two from the
front buffer beam to just short of the tanks, two to the centre of the cab
doorways, one piece for the rear footplate and bunker combined and, finally,
the small front central panel providing access to the oil reservoir. These
are the first two sections cut and drilled. I've made the separate running
plates for the sides and the cab footplate as well, once again spacing the
rivets to match the prototype. There won't be many pictures of this work,
it's just simple cutting out and drilling of holes. The tanks will be stand-alone
items that fit to the soleplate. This overview shows the first five panels
bolted together and sitting on the frames. |
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The final panel is the front cover and I've made this
as a single panel as per drawing. In real life, there is a hinged section
that gives access to the ends of the cylinders but this isn't large enough
to get to the oil which hides below so a deep scribed line will mimic the
join. It has a couple of tight bends in it to match the shape of the frames
and these were formed by bending around some 5/8" dia bar for the first
one, then around 9/16" diameter bar for the second one. I don't have a bender
so this has to do. |
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When it comes to simple drilling, I don't
always bother to clock out the component accurately. I just load against
parallels and wedges set in the table slots, then set up the DRO by eyeballing
a scribing needle held in the drill chuck. Within five thou is plenty good
enough for decorative rivets. This is the front panel nearly complete. I
can't set the finished depth until the smokebox is made and will put the
lifting knob in once the final size is known. All the rivets will be fitted
when I'm happy there is no further work to be done to any of the panels
but, for this front panel, two of the rivets will be soldered in with tails
underneath to act as locating pins into the top of the buffer beam. All
the others will be cut and hammered flat underneath. |
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2. Side Tanks |
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Although most people seem to make their water
tanks from brass for obvious reasons, I'm staying with the steel sheet.
The Britannia tender was drawn as a sealed-for-life tank under the coal
shute so that had to be rust-proof but there is full access to the inside
of these side tanks because of the removable tops. Therefore, I'm going
to try and line the inside of the tank with latex or similar when the panels
are fixed together. Most of the panels are straightforward rectangles but
the outside panels curve upwards towards the roof for a short distance.
I used the boring head set at the correct radius to form these curves as
I think it's easier this way but they could have been cut freehand because
there is beading to be added later which would hide imperfections. |
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I'm using 8BA countersunk screws to fix the
tanks together and now everyone can see where all that brass angle I made
was used. I have made a separate inset panel for the bases so that the tanks
can be removed intact from the loco if ever needed. The first tank is built
up and the parts for the other are in a heap on the bench. To fix the tanks
to the soleplate, I have silver-soldered three 2BA screws, with most of
the heads removed, to the baseplate so that the tanks can be nutted from
below. Matching holes were drilled in the soleplates. |
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The tank tops needed the filler pipes fitted
and these were made from mild steel bar, turned with a locating spigot and
silver-soldered to the lids. And, finally, a couple of pictures of the tanks
sitting on the soleplates, the last one with the filler caps rested in position.
There is a lot more work to do on the tanks but this is a good start. |
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3. Front Splashers |
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The front splashers include the leading sandboxes
and I'm planning on making these functional. I've made a couple of changes
to the sand valves but that's for later. The main part of the fabrication
consists of four pieces, the curvy bit which runs from the back to the underside
of the top panel, the top and end panel with the bend and the side and inside
panels which are both the same. I'm really annoyed with myself because I
accidentally deleted four photos of the individual parts and the set-ups
for soldering so the first couple are the panels silver-soldered together.The
two side panels were clamped around two spacers to hold them square and
the curvy part, made over-long at both ends, was soldered first. Then it
was dressed flush with the top and the bent section, also overlong at both
ends, soldered on and dressed back when cool. The inside panel is recessed
so that they fit up against the frames although there is a cutout needed
at the front. The large hole is for the filler pipe to be fitted to and
the smaller one the top of the valve assembly. There is also a hole shown
on the drawing for the feed water pipe but I won't put this in until the
boiler is done. |
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There is a floor piece to separate the sand
hopper from the wheel splasher which is shown brazed into place. I'm going
to keep mine unsoldered but a good fit because, once soldered, there is
no further access to the sand valve. The floor piece is screwed to the soleplate
to locate the main assembly over but, now that I've tested it, I'm going
to solder a lug on at the front to hold the sandbox down onto the soleplate.
Two screws already hold the back end in place. After that, I made all of
the small parts assocciated with the sandboxes and fixed the filler pipe
to the top with silver-bearing soft solder; I didn't fancy bringing the
assembly back to silver-solder temperatures again. The last picture shown
the filler caps and the top of the sand valve but I haven't fitted the spindle
yet. |
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4. Bunker |
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Continuing with the platework, I have made
some of the bunker and cabin parts and the first part to be made was the
rear spectacle plate. Most of these items are simple marking-out followed
by cutting and filing to shape and this one has to follow the underside
of the roof. I used my Abrafile to cut the shape, then cleaned it up with
sanding drums and files. The windows were cut out with a hole saw, then
finished with the boring head. I get a couple of free penny washers as a
bonus. The sides were next, the rectangle just sawn to size and two of the
curves formed once more with the boring head. There is a cutout where the
panel that spans the doorway fits and this was milled out with a small cutter
to ensure a nice square corner. |
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The bunker rear panel was a little more difficult
because of the two bends and me not having a bender / folder to use. A variety
of clamps, vices, metal bars and large hammers were all used to beat the
thing into submission. Suprisingly little swearing for this one, I must
be getting the hang of this lark. Here, it sits between the two side panels.
The various holes for the lamp irons and number plate were drilled, along
with all the fixing holes for the jointing angles. More of my home-made
brass angle was cut to suit and the three components fixed with 8BA countersunk
screws. These allow me to assemble and disassemble at will, but will be
filled with putty before any painting starts. The grey finish is where I
have dissolved away the zinc in citric acid, followed by soaking in phosphoric
acid for the protective layer. |
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The two pieces that bridge the doorways were
made next and have been joined to the rear spectacle with brass angle. I'm
planning on making this whole section removable so there will be some changes
to how DY has drawn this area. For the moment, it just rests in place with
a couple of clips to get a visual. And, finally, a view from the rear quarter
showing how the basic shape is coming together. I never used to like tin-bashing
much but it's quite satisfying when so much comes together in a relatively
short space of time. |
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5. Bunker Bulkhead |
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I've now made the bunker forward bulkhead
along with the two seat boxes, the shovel plate, coal hole door, door rails
and the ledge which extends back to the rear spectacle plate. As can be
seen, it's all simple cutting and drilling. The brass angles are riveted
to the platework with the heads on the inside. On the visible side, they
have been hammered flat into decent countersinks and filed flat. I've added
extra angles around the base so that the bunker assembly can be screwed
to the rear soleplate. This is the bunker assembly screwed together with
the coal hatch sitting in the runners and the top ledge attached to the
bulkhead. |
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With the rear spectacle plate set in position,
I can now mark out and fix the other angle to it. The angle will rest on
the ledge when in display mode but will not be fixed to it. The spectacle,
door arches and roof will be removed as a unit when it is on the track.
I can also replace the two temporary side angles with narrower ones to match
the crossways angle. I wasn't happy with the spectacle plate - it was a
little out-of-square - so I've remade that. The replacement angles have
been made and are mitred to the crossways angle, and this time I've riveted
them to the spectacle plate. This is a simple setup for creating mitred
ends. |
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I've also made the locating arrangement for
the fronts of the doorway panels. A section of plate has been silver-soldered
to the inside of the panel and a catchplate made for the lower section,
held in place by the fixings for the exterior handhold. It's basically an
adaption of the permanent fixing that DY had drawn. The tabs need to be
marked and cut to fit the slot milled in the back of the catchplate With
the tanks and the bunker bolted into position, I was able to make the tab
to size and there is also a little movement available in the catchplate
holes to allow for fine adjustment. And one more photo showing the bulkhead
with the coal plate and hatch in position. The spectacle plate looks better
now, as well, with the narrower angle. I just have to drill a couple of
holes and solder some a pair of locating pins to the crossways angle. |
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6. Window Guards |
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Calbourne has two protective covers over the
rear spectacles to stop coal breaking the glass. There are a couple of ways
one could make these but I chose to make mine from a solid billet rather
than try to solder bars onto the cover plate. DY suggests the same in a
note on the drawing and Nigel has made his in a similar fashion. Two billets
were cut from 2" diameter mild steel bar, each about 5/16" long. This is
a job that lends itself pefectly to soft jaws and a set were machined to
suit. The jaw recess is only 45 thou deep but plenty enough to get a good
hold on the material. The billets were faced on one side and the o/d turned
to 1.850". Then the billets were reversed and the other side faced to leave
them 1/4" thick. Again, the o/d was turned to 1.850". Next, the inside of
the billets were bored using two different boring bars and finishing with
a third boring tool with a large radius. |
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The billets were reversed in the chuck and
the outside turned first, followed by the external radius which was blended
in by eye. The flange thickness is 1/16", hence why the jaws are only bored
45 thou deep. From here, it was over to the mill with the chuck and the
waste milled away to leave the protective bars. The drawing is wrong because
DY shows six bars over the windows but Calbourne only has five. It may have
had six in earlier times but that's not what I'm modelling, I'm representing
the loco in it's current form. |
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Four slots were cut using a 1/4" diameter
end mill, working down in 25 thou passes until the cutter just touched the
flange. By moving over 5/16" on each slot, I finished with bars that were
1/16" thick. The final two sets of passes on the outside formed the outer
bars. Some additional filing was required because of the underside radius
but they've come out looking not too bad. These will be cleaned up properly
later and, once painted, should look quite respectable. |
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7. Footsteps |
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There are four sets of steps on the loco and
they are all the same so four pieces were cut from the material and also
a piece of MDF to act as a support. I've sawn out the shape on the MDF because
I've found that the milling cutter speeds I use for the steel are too high
for the MDF and it scorches, overheating the cutter. The dust is pretty
awful also and I usually wear my respirator mask when using this material
but it is nice and flat and takes good clamping pressure so I'm happy to
use it. |
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I thought it easier to do all four as a stack
and put the single bend in later on. After working out where the centre
of the radii were, I used a 12mm end mill to rough out the waist / waste
(both being appropriate here) followed by the boring head which had been
preset to cut 1.250" diameter. A third clamp was added near the middle before
removing the right-hand one to allow acces for drilling the rivet holes.
The two steps will be fixed with 1/16" diameter iron rivets after the zinc
is removed. |
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Eight treads were made next, four of each,
bending the backs first followed by drilling the rivet holes and, finally,
curling the ends upwards. The top of the steps were bent but the fixing
holes will be drilled once I decide how to fix them to the underside of
the running boards. The parts were pickled in citric acid before riveting
together. These are the four steps ready for fitting. |
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8. Air Reservoir |
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Calbourne has air brakes and the air reservoir is a prominent
tank on the left-hand side of the loco. A piece of brass tube was purchased
for this which was cleaned up with emery cloth and faced to length. A pair
of bungs were made for the ends from some 1.1/4" diameter brass rod, skimming
the o/d and forming the front reccess with a special radius tool. A 7/32"
diameter hole was also drilled for the air inlet. The front was further
reccessed with the same tool and the air connection point tapped 1/4" x
40 tpi before the cap was parted off. Two were made, one for each end, and
will be silver-soldered into place. |
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I wanted a decent-sized chamfer on the backs because these
will be soldered from the inside and this will keep the solder in place
during the heat-up. These are the parts, ready to solder together. A pair
of rings, from 1mm silver solder rod, were made a nice fit to the bore of
the tube. One of them is in the tube already. The ends of the bungs were
coated with correction fluid to stop the solder wandering away. |
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Flux was painted on the inside of the tube and around
the perimeter of the bung, then the solder ring inserted into the tube a
short way. The first bung was pushed into the tube until flush and then
set up in the hearth. The bung was a nice, sliding fit and I'm doing one
end at a time. All the flux and the solder is inside and heating was done
from the outside. I've kept the tube as upright as possible to encourage
the solder to flow all round, rather than pooling at the lowest point. It's
not a very good picture but I can see that the solder has melted and flowed
into the joint. |
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The other end was set up in a similar fashion but, this
time, I wasn't be able to see the melt and had to rely on watching the colour
of the tube to know when I had reached temperature. The workshop lights
were doused and I heated until the tube was a little past dull red at the
bottom. This was taken after I had put the torch down. It was impossible
to tell if I had full penetration from sight alone so, after giving it a
good soak, then cleaning up all round, I hooked it up to my hydraulic test
kit. The drawing calls for testing at 100psi but I've pushed it up to 200psi
and it held this for fifteen minutes before I let it down. |
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9. Next Item... |
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