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 Living on the Road :: Wothahellizat Mk2: Construction Diary : #06

Tue 26 Jun 2007

I've run out of both oxy and acetylene so it's into town again. I also have to drop off some steel to be cut for the body mounts, at 32mm thick it's too much for my emerging oxy-cutting skills, I could possibly give it a go but they have to be done right so I think I'll let the experts do it.

I also have to make a home brew today or I'll be in dire straights in about two weeks when I run out of beer.

The trouble is it's so damn cold, how do I keep the brew warm for the first week or so as it ferments? Normally we use our electric blanket, but we haven't brought it with us, so some ingenuity is called for.

I find a cardboard box large enough to enclose the barrel, wrap it with as many towels as I can find to insulate it, then put the barrel of fermenting beer inside. This is a good start, but insulation is not the full solution, something has to top up the temperature every now and then.

I get my heat gun and stick it's nozzle under the box, it's rated at 600 degrees so that should do the trick. It works well, although a small fire necessitates a design modification. I find a length of 40mm PVC pipe from the old truck's sink, insert it under the box and blow the hot air in through that. This keeps the hot nozzle away from the towels.

After that I make a start on the rear body mount.


Some of the components for the rear body mount being marked up.

Thu 28 Jun

Still working on the rear body mount.


The rear body mount partly tacked together.

Sat 30 Jun

Finally the rear body/shockie mounts are done. It's taken longer than I figured but I've had my usual quota of dramas, like the mount wouldn't fit back onto the chassis. I can only assume that it pulled when I welded it, even though I did most of the welding with it in place on the chassis, only doing the underneath welds on the stands.

To get it back onto the chassis I have to cut halfway through the mount to allow it to stretch, then get everything bolted on, and finally weld up the cut.

Throw that in with bottling of the home brew, running out of both water and battery power and therefore having to juggle the pump and generator (The pump uses a lot of power but the batteries are not that charged, I'm charging them with the generator but the pump won't run while the generator is because there's some incompatibility between the two).

Then the inverter overloads, even though there's bugger-all running from it, so I have to isolate it from both the solar array and the batteries to reset it (no reset button that I can see), this also resets the solar regulator and all its memory, so I now have no idea what state of charge the batteries are in.

Then the can of cold gal is blocked and won't spray, etc etc.


Here's the plan.


And here's the final thing. The rectangular tube near the centre and the openings on the right side (shown in red in the plan) will allow the winch cable to pass through the mount. The tube had to be custom made from scrap because I didn't have any RHS of the right size to hand and it was either that or drive into town yet again. The sqaure block in the middle with a large hole is a cut-down piece of a mount from Wothahellizat 1


A close up of one side of the mount, showing the outrigger that will hold the shockie and an original bump stop in place.


Another close up, this time one of the front (ie middle axle) shockie mount.

Sun 1 Jul

Since I'm working on the body mounts let's talk about that for a while.

With Wothahellizat 1 I used the triangle method (discussed soon) and it worked very well as is displayed in this photo.


Trials of the body mounting on Wothahellizat 1.

This is a shot I took of Wot 1 when we were doing some trials about seven years ago. Note the board with the number plate and lights, it's in line with the chassis and the rear wheels. The front wheels are at almost the same angle but in the opposite direction, and the body is somewhere in the middle.

I think this demonstrates very well how much the chassis can flex on some trucks, and this isn't serious off-roading, it's just a drain on the side of the road.

There are two things to think about when mounting the body, how to mount it, and where.

How
Ten years ago I looked around for a suitable mounting system and found these.


There are three parts per mount, seen here as purchased.


And as used

They are made in England and available from Shock & Vibration Technologies in NSW, I can't find a web site for SVT but the mounts are made by Barry Controls at www.barrycontrols.com. These mounts are designed for off road equipment and large trucks, which is why I chose them in the first place.

You buy the two rubber donuts and the steel donut from SVT, then weld the steel donut into an appropriate place on your mount, sit the body on top of the rubber donut, and fasten the whole lot together with a big bolt.


Cross section through a typical installation.

Do this in the right places and you have a mounting system that can absorb the twisting plus isolate the body from much of the road vibration.

After all that time carrying the weight of the old body the rubber donuts don't look as pristine now, but they're still in good nick so I'll be reusing them.

I originally had the steel donuts welded into some large 32mm plates, but they were way too big for my current design and I had them cut down to 170x200mm blocks the other day (seen clearly in the photos of the rear body mount).

Where
There's two methods of mounting a truck body onto a flexible chassis, two recommended by the Department of Transport that is.

These methods are called diamond and triangle, and they allow the chassis to twist without placing undue strain on the rigid body. If the body is a tray that is fairly flexible I don't think it matters much how you mount it, but a motorhome body is a box that is pretty rigid. If it's not then all your cupboards will deform, so we have to isolate that rigid body from the flexible chassis.


The two recommended methods of mounting a body, diamond (top) and triangle.

As stated I used the triangle method on Wothahellizat 1 and that worked well, but I've decided to go with the diamond method with version 2. This is because it will distribute the weight more evenly. The new body is not as strong as the old one so it seems reasonable to support it in more places.

Note: Here's an interesting account of body twisting. http://www.ruf-inc.com/subframe.htm

Mon 2 Jul

Another thing about using the diamond pattern is that I should only have to allow for half the total chassis twist.

With the triangle method the chassis and body are fixed together at one end so the clearance at the other end has to handle the entire twist, 10 degrees in the case of the old chassis.

The diamond is effectively two triangles. As the chassis and the body are tied in the middle, the same 10-degree twist amounts to only five degrees at each end.

Throw in the fact that the chassis is now shorter and we should be better off all around.

That's my theory anyway, and I'm sticking to it.


The middle body mounts ready for welding.

Tue 3 Jul

All the mounts on the rear of the chassis are finished now.


The rear of the chassis showing the rear body/shockie mounts (rear), front shockie mounts (middle) and middle body mounts (front). Confused? Also you can see the rope I've stretched to simulate the winch rope.

Now I just have to do the front body mount and I can put the body back on.

Wed 6 Jul

Today I start building the front body mount. It's pretty much a replica of the rear mount but has no provision for shock absorbers.

It's the usual story of cutting and bending steel and drilling a lot of holes. I run out of acetylene so decide to do the drilling instead. That will fill in the rest of the day and I'll get some gas tomorrow.

With a high-torque drill you have to pay a lot of attention as the minute you lapse it will rip your arm off. It's nearing the end of the day and I'm getting tired so while drilling a 13mm hole in a difficult-to-access location on the chassis I decide stop, rest, and change my grip.

Unfortunately I do it in the wrong order, ie. I relax my grip before stopping the drill.

Result, bit grabs, drill spins, drill tears from my grasp, drill's still spinning with entire weight on drill bit, bit breaks leaving it's end embedded in the hole, drill falls to floor.

All in all not a good result.

Fortunately there's no damage to the drill itself, but the bit is knackered and I have to remove the broken part form the hole.

Thu 5 Jul

Still building the front body mount. I've also had to modify a winch cable roller mount. I have the same problem with this mount that I had a few weeks ago with the compressor hanger, that is, once the air receiver is in place I can't get to the inside of the chassis to access the other end of the mounting bolts with a spanner. So I make a backing plate similar to that previously described, to it I weld two nuts and two bolts. Why this combination?

The mount itself requires three bolts and because of the clearance between it and the roller two of them have to have the bolts inserted from the outside ('A' in the drawing). So these two at least have to have nuts welded to the plate. The third one could as well, but this would leave the plate hanging on the locating bolt when the mount is removed, and if it rotated it would be very difficult to realign it.

Therefore I make the plate to provide me with two captive nuts and a captive bolt ('B' in the drawing), plus the locating bolt. This gives two bolts protruding from the chassis to stop the plate rotating when loose, and two nuts inside the chassis to which I can screw bolts from the outside.


A cross section of the new captive mounting nuts and bolts for the winch rope roller. Note only one bolt and nut shown.

Now I can remove/replace the roller at will without having to deal with the receiver.

Finally I can weld up the body mount and put it in place.


The front body mount in place just behind the cab.


A side view. Once again notice the asymmetric bolt locations, as much as possible I'm trying to use existing bolt holes and if that means it looks a little odd then so be it.

Then I have to replace the air receiver, it's a bugger of a job for one person as you have to hold about ten different objects at once, one of which is large and heavy.

Just as it is getting too dark to see I finally get it all installed.

Fri 6 Jul

Now I can put body onto the chassis, I forget to notice the time when I start so still don't know how long it takes to raise the body on its legs, but it takes a while, maybe over an hour.


The body propped up in place. Note the jack under the bumper bar at the front, this is to level the chassis. There's another one at the rear.

With the frame in place I can start on the other half of the body mounts, the parts that belong to the body. Before I start though I have to level the chassis.

Over the years we've had various springs reset at whatever weight (and distribution of weight) the truck was at the time. Now, with no weight at all, the springs have risen to different heights causing the chassis to have quite a twist even when parked on a flat concrete floor.

I guess we'll have to have everything reset yet again, but not until we have the truck finished and know the final weights.

Meanwhile, If I want to get the body mounted in the right place I have to level the chassis, which I do with some jacks.

Sat 7 Jul

This morning I was all fired up to go into town and buy the four bolts I need to hold the body onto the chassis. That way I reasoned that I would have everything I need to finish the job over the weekend.

Then I realised it already is the weekend. The bolt shop won't be open today so it will have to wait.

Not that I haven't got plenty to keep me occupied, I still have to make the other half of the body mounts, the parts that will sit on top of the chassis's mounts and connect to the frame.

To do this I planned to have some heavy steel cut and drilled to sit on top of the rubber mounts, but then I realised I can do the same job with some left over bits from Wothahellizat 1 and a piece of scrap steel

I weld a 1" nut to one of the old snubbing washers.


Then place a 200mm square 12mm plate with a large hole cut in the centre over the nut and weld that to the nut.


Then flip the whole thing over and weld the washer to the plate.

This assembly, and three others just like it, will sit on top of the chassis part of the body mounts and be welded to the frame. They will provide me with four captive nuts in the body.


A cross section through a body mount. The circled area is the assembly shown in the photos above.

Sun 8 Jul

The mounts are in place on top of the chassis mounts, but now I have to decide exactly how to connect them to the frame, and I confess to being at something of an impasse with this.

I've drawn the frame as just two 3x1" RHS pieces ( in the diagram) but I can't sit the entire weight of the body on just two pieces per mount.

I spend a lot of the day thinking about this and consulting the computer design before eventually starting to cut some steel.

Mon 9 Jul

Every time I watch a current affairs or news program these days I hear of the desperate labour shortage in the remote mining areas of Australia.

Invariably a person or two are pushed in front of the camera and say a variation of, "I used to work my arse off for $3.50 a day, now I get paid $100,000 to drive an air conditioned dump truck".

Heck, we've even met people like this. But when I do a web search for these fantastic jobs I get zero results.

Try it, Google "dump truck driving job western australian mines". You'll get a lot of results pointing to BHP Billiton's career pages, and all manner of employment agencies and at first you think you've hit pay dirt.

But drill down and all the jobs are for senior geologists, mine safety officers, and drill & blast professionals. Or you need experience...

"Applicants must have at least 6 months or more experience on CAT 785, 789 or 793's for the dump truck role"

Not one job for an unqualified grunt can I find. And yet "they" all say they will train you, "We've got people here from all walks of life" says a fellow on 60 Minutes last Sunday.

But maybe it's like it was in the 70's, you had to be on the spot. When I was living in Perth 30 years ago it was a given that there was no point applying for jobs from the capital city, you had to drive up to the mining towns. Well possibly, but a year ago we were in Tom Price, one of the main mining towns and smack in the middle of the Pilbara. You couldn't get any more central to the iron ore mining industry if you tried.

We enquired at the local employment agency and were told there was nothing at present.

Of course we're not in a position to get such a job now anyway, but should be in a few months so I decided to ask the people at CareerOne, probably Australia's largest agency.

I filled out their enquiry form.

Hi,

For a year or so now we hear just about every night on the TV that the mines are crying out for workers of any kind. One of the most often cited examples is that of dump truck drivers. Just the other night some talking head said that there is 100 jobs of this type in Tom Price right now.

My question is, where are these jobs advertised? I cannot find a single job for a relatively unskilled (in this field anyway) worker. All that is advertised are professional career positions.

We'll see what the response is, if any. Meanwhile I did a search on their site for "dump truck driver" and got one result, for a bloody IT manager in Perth.

Later...I get a response but I'm still none the wiser. The link they suggest has hundreds of truck driver jobs, none of which are on mines or in Western Australia. There's tilt truck drivers in Sydney, cement truck drivers in Melbourne, garbage truck drivers in who-knows-where.

But NO dump truck drivers on West Australian mines.

It's no wonder there's a shortage of labour, no-one can find the jobs.

As I said we're not in a position to follow up on a job opening anyway, so I'll leave it at that for the moment. But in a few months time I will revisit this issue so watch this space if you're interested.

Conversely, if you know who to approach let me know.

Wed 11 Jul

I've run out of steel of the size I need to finish the body mounts. I have ordered more but I have to wait for Mick (he and his family are between houses and living in the "house" part of the workshop) to bring it home from work.

He owns the engineering business I get the steel from, and often brings stuff home for me in his ute or even brings the truck. It's a good arrangement as it saves me the delivery cost which would not be cheap out here, but of course I can't demand when things are to be delivered. So I have to wait a day or two.

No matter, I've started on the tool boxes.

I've decided to hang some toolboxes on the chassis and in between the rear axles. These will house some of the heavy stuff like ground anchors, jacks, snatch block, the bead breaker (for changing tyres) etc. This stuff is very heavy and as I'm trying to get as much weight as possible over the rear axles it makes sense to build storage for it there.


The half-fabricated toolboxes. The triangular infills are there to provide strength to the front of the box, but also if the door was the full front of the box it would hit the wheels and not fully open.

Thu 12 Jul

The toolboxes are turning into quite a project.

At around five I get a call from Peter, he's in Katherine with a faulty fuel shutoff solenoid. Can I pull the one off his old motor and freight it up to Kununurra in WA where he will pick it up in a few days.

Fri 13 Jul

I ring to see if Mick can deliver the steel today but it doesn't sound likely, so I volunteer to do the job. I drive into town, post Peter's solenoid, then go around to Reibelts Engineering.

The truck is loaded with junk for a job so the first thing I have to do is unload it. Then I can put my steel on and drive up to the workshop.

All this, plus getting a gas bottle filled, takes about four hours, I won't get much done today.

Sat 14 Jul

I'm struggling a bit over the way to connect the body mounts to the actual body. The theory is simple enough, just weld them to the frame, it's easy when you say it fast.

But exactly what gets welded to what, and how do I make everything strong enough?

I start with the mounting points ('a' in the drawing below) of course, then weld in some basic connections (b) to the existing frame and follow up with more to strengthen strategic points (c).

In general I'm happy that this has spread the force pretty well from the mounts out into the frame.


Mouse over the legend text to see the different levels of mounting and bracing.


The rear mount and associated framework.


One of the middle mounts.


And the front mount.

The reason there is so much steel at the back of the frame (in the rear mount photo above) is that there will be a lot of weight there. This is the lounge room which has the double whammy of having to support 800kgs (1800lbs) of water in tanks, and a 100-odd kilogram motorbike with very little structure as the walls are large shutters and therefore almost entirely void space.

To help support all this I've also added some bracing (d) in the form of 75x6mm flat bar welded vertically under (or over depending on the access) some of the frame RHS. This will double the web depth of the selected members and therefore presumably double the strength.


Some 75x6mm bracing under one of the frame's cross members.

Sun 15 Jul

Dave dropped in this morning to see how things are going. He cast his expert eye over what I'd done and asked a couple of questions but as usual didn't comment much, except to say "It's gunna be strong then", which I'll take as an approval.

Tue 17 Jul

I've added gussets to each mount, mostly because I can, and partly because I just want to ensure things are strong enough.


Looking down into one of the mounts, showing the four triangular gussets.

The trouble with not being an engineer is that I have no way to calculate the stresses, so I just make something so it looks about right, then add a bit.

It seems to work although I often make things too strong, and therefore too heavy. However the alternative is to make them too light and weak so, within reason, I'll go for heavy.

The last Wothahellizat body was extremely heavy, but it never even looked like breaking. Here's hoping this body will stand the test of time.

One of these mounts is underneath the shower base and I had planned to put an inspection panel in the shower in case I ever needed to check out the mount. The trouble with this is that should the panel ever leak the mount will fill with water and I will not know.

Dave suggested a good idea the other day though, forget the panel and fill the mount with grease. As there is nothing to inspect apart from a captive nut, and that will be covered with grease and unable to rust, there should never be a reason to inspect it.

I still feel a little uncomfortable never being able to view the top of the mounting bolt though, and I may want to add a lock nut to the top of the mounting bolt, in this case I will need access.

We'll see.

Wed 18 Jul

Without the steel to finish the mounts I've been working on various parts of the body.

I've added much of the support for the floor and should be able to lay that before long. I've also built some of the crawl through from the cab.

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