| Tue
2 Oct 2007
I'm taking a break from shutters and working on the front door today.
I'm hanging the door from gate hinges but as I
don't want any fittings to be visible from the outside I've mounted
the hinges inside the body and extended them with a semi-circular
arm that allows the door to swing out.
Animation showing the door opening.
The gate hinge and semi-circular
extension, all just tacked together before proper welding.
Having got that working I look into using the
lock from the door on Wothahallizat 1.
The door lock is installed.
There, now we're at lockup stage.
Thu 4 Oct
The other day, while Mark and Gail where here, we put the roof sheets
on but left them overhanging the body. The most obvious overhang
is at the front where we had a lot of extra material and today I've
fold it over the front of the roof.
The front overhang after folding,
it will be trimmed when I decide exactly where to trim it.
But the rest of the roof overhangs by about an
inch and I originally planned to fold the excess down over the aluminium
cladding to provide a waterproof seam, however I also want a gutter
as we plan to collect rain water with this truck.
Also, the old idea would have allowed the aluminium
cladding to touch the steel in several places, most especially where
the rivet pierces the material. This may lead to galvanic corrosion.
The terms galvanic corrosion and electrolysis
are often intermixed. In galvanic corrosion there is a flow of current
generated between dissimilar metals when they are touching while
in the presence of an electrolyte.
Electrolysis is a similar process, but in this
case the electrical current is from an external source.
There are other issues at play that affect the
amount of galvanic corrosion, for example the distance between the
touching metals on the galvanic table and the relative sizes of
the objects, but I've seen the results of steel touching aluminium
and it's not pretty, so in general I'm trying to nip these problems
in the bud.
So I decide to fold the excess up instead of down
and add a 50mm steel bar all along the edge of the roof to both
act as a gutter and a fixing point for the solar panel mounts.
The original idea (left), and as
it will be done (right). In the new version the materials that touch
are steel, whereas with the old version steel and aluminium touched.
Note that although the roof is steel it is galvanized
so I guess the steel gutter is actually touching zinc. In fact all
three metals are quite close on the galvanic table so I may be being
a bit paranoid, but I've never seen problems between steel and zinc
and have between steel and aluminium so better safe than sorry I
guess.
Having done the roof folding it's time to lift
the body from the chassis again so we can paint underneath and do
a few other small jobs.
The body is getting heavier and the legs are straining,
they also sway alarmingly with the slightest lateral movement. As
I plan to be working underneath for the next few days we decide
to X-brace the legs by welding some RHS between them.
The X-bracing temporarily welded
to the legs.
My cheap 60kg-rated wheels are starting
to feel the pressure.
We ease the truck from under the
body.
As
an added safety measure we also sling the body to the overhead crane
beam using our plasma rope we recently bought for the winch. This
stuff is amazing, 50m (162 feet) of the 11mm (<1/2") rope
weighs just a few kilos, is rated at 12.7 tonnes (28,000lbs) and
even though it is all coiled up it hardly tangles at all.
50 metres of 11mm plasma winch rope.
The old steel cable was much larger at 16mm (5/8th"),
was too heavy to lift without mechanical help, and was all but impossible
to handle.
With the body safely secured about 1400mm (55")
off the floor I can work on the underneath for the next few days.
This is the last time the body will be off the
truck, until I build version 3 that is :-)
Sat 6 Oct
With the body off is seems
like an opportune moment to weigh the chassis again. I weighed it
a couple of months ago of course but that was before I added all the
tanks, body mounts etc.
Last time it was 6 tonnes, what will it be now?
This time it's 6.5, not bad considering the amount
of stuff now hanging off the chassis.
Now I know that I will be able to weigh it again
when the body goes back on to find out exactly how heavy that is.
I spend the rest of the day spray painting the
underneath of the body.
Sun 7 Oct
More painting, this time it's the chassis. It's amazing the difference
a coat of paint makes, it's like having a new truck and $50,000
cheaper.
Mon 8 Oct
Another job that needs doing while the body is off the chassis is
to drill some holes for the plumbing, specifically the hoses running
from the utilities area to the two tanks (actually there's six tanks
but they are plumbed as two banks, so I guess we have two banks
of tanks, or two tank banks).
I could of course just run the hoses under the
body but running them through the body should look neater and provide
more protection.
I have two designs for this part of the plumbing,
one that fills and drains to and from each bank with separate hoses,
and the other that fills and drains with via a single hose per bank.
I can't really decide if there's any benefits
either way from a plumbing point of view, but the decider is the
number of holes I have to drill. With a choice between 10 and 20
holes (really 20 or 40 because each RHS beam requires two holes)
the single-hose option gets the nod.
Four of the holes, in the spot where
the hoses hang a left into the utilities area.
The same holes after insertion of
some short lengths of steel pipe. These pipes will be welded and
caulked to seal the interior of the beams.
Thu 11 Oct
In between painting various
items I've been working on the step runners.
I plan to have the steps slide out from under
the body and so I have to make some runners. I'm doing this by having
some 40x40x4 RHS slide out from inside some 50x50x4 RHS and if you
do the maths you'll realise that this gives a 1mm clearance so these
two sizes are a pretty good match.
More about these runners later when I build them
but for the moment I have to make the outside parts as these bolt
onto the body and it's much easier to make all the brackets without
the chassis in the way.
Three of the four outside RHS lengths have to
have a long slot cut in them to accommodate brackets for the steps,
a simple enough process involving scoring a couple of lines and
cutting with a thin cutoff wheel.
There is one thing to realise about RHS though,
RHS stands for Rolled Hollow Section (although I've also heard Rectangular
Hollow Section) and as the name implies it is made by rolling steel
into shape and welding it. This leaves the section under some tension
so when you make a long cut along its length it will tend to splay
apart.
The slot has been cut in a length
of 50x50x4 RHS.
Looking from the end you can see
that the side that has been cut has splayed by 1mm.
This is probably not a problem for this application,
just making my 6mm slot vary from 6mm where it starts to 7mm at
the open end. However it's something to keep in mind if you do need
the section to remain truly square.
I may still press the sides back together later,
I'll see how things work out.
Fri 12 Oct
For the time being I'm finished with the step runners so I unbolt
them and put them aside for later. I then spray all the new mounting
tabs under the body.
Initially I planned to just spray the roof and
back wall of the cab as the rest can be done with the body on, however
we've decided to re spray the entire cab now and get it over with.
The rest of the day is spent with me pulling parts
off the truck, Chris cleaning them, and me spraying them.
By day's end we have quite a collection of nicely
painted truck parts. I've also removed the doors, bonnet, windscreens
etc. from the cab.
Sat 13 Oct
First priority today
is to get the winch sheave block finished. It doesn't need much as
most of it was bolted together weeks ago, but while I'm in a painting
frenzy I've decided to pull it apart and paint all the parts and they
are now ready for reassembly.
Yes I know, painting pulleys is a bit anal, but
they look so good, and anyway with any luck we'll never use the
winch. Even if we do, maybe the plasma rope won't scratch the paint.
The sheave block with its top plate
removed. The winch cable comes from the centrally-mounted winch
(yellow) through the rear body mount to the sheave block, then either
around two of the sheaves, back through the mount and along the
chassis to pull forwards (blue) or straight out to pull backwards
(red).
Once that's done I concentrate on the cab, removing
the seats, engine cover, internal panels, bumper bar and just about
everything else.
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