Build Thread: Burni

[SPF40plus]

Hey everyone, it's time to start compiling information on the build of our FTS700 or FTS12 (Burni) in the one place. After a few threads with specific discussions it is time to get everything in the one place. First, so I don't forget and second, so people looking for ideas can see what does and does not work. This site has been a valuable source of info for me, so I hope this thread helps someone else looking for a project or solution to a problem.

Before I post up photos I see that I can link to external image hosts, but that means the images may not be available in the future. Is there a way to upload images directly to this site so they appear in line with the text?

 

[SkiFreak]

Simple...
Use this icon to insert an image from your computer.

 

[SPF40plus]

Simple...
Use this icon to insert an image from your computer.
View attachment 773114

When I try that all I get is a dialogue with the option to insert a link. Am I missing something?

 

[SPF40plus]

When I try that all I get is a dialogue with the option to insert a link. Am I missing something?

Ok, just tried a browser other than Chrome. I see there is also an icon for uploading an image. Thanks.

 

[SPF40plus]

So this is where we started, ex NSW rural fire service vehicle with heat damage (see plastic trim below window):

 

[SPF40plus]

We intend to use this truck as a camper for our family of four.

We have removed all the fire service equipment from the tray.

We are about to get the chassis extended by 800mm to give a wheelbase of 5000mm (currently 4200mm):

1. The downside of this is that the turning circle increases to approximately 21m (currently 18m), and the ramp over is not as good.
2. The upside of this is that we can fit a useful size camper on the back for a family of four.

I have seen a few of these trucks with campers on the back, and bikes, tyres and other things hanging off the back of the truck. Since looking into this, it appears that many of these vehicles are over length and cannot be registered or pass a COI (certificate of inspection) with these things in place. They also provide fodder for transport authorities and police to hand out fines.

My understanding is that rear overhang on a heavy vehicle cannot extend beyond a dimension which is 60% of the wheelbase, from the centre of the rear axle. In the case of Burni this means 4,200 x 0.6 = 2,520mm, with an overall maximum tray length of 5,075mm. With a box on the back, with would be the equivalent of a 16 foot caravan.

With the chassis extension in place the tray length can be up to 6,350mm. With a box on the back, this would be the equivalent of a 20 foot caravan.

The extension also means that we either need to extend the tray, or build a new one. This is still an open question.

If you are looking at a truck and considering the space you need, if you want space for more than 2 people to live for more than a week or two, there is a reason that there are few (if any) options available from manufacturers - the dual cab or crew cab trucks are not long enough to fit the camper without the chassis extension. Another consideration is that national parks and trails are maintained to ensure accessibility for fire service vehicles. These generally do not exceed 3.2m in height (other than aerials), and anything taller than that will likely mean that you need to do the clearing of tree branches to gain access. Also consider that the tray height is about 1250mm loaded, and if you have a camper with a ceiling height of 1800mm, then with the floor structure below, and roof panel thickness above, you are already at this height. Then if you add 70mm for super singles (385/65 r 22.5), 50mm for solar panels and 10mm for carpet or other floor covering then you are more like 3,300mm and still don't have the headroom necessary for a tall person.

No doubt some of you reading this will be thinking that a pop-top is a good idea. And it might be. For us however, since the rain over the last couple of years, we have decided not to use any canvas or other fabric in any part of the structure of the camper, especially if it needs to be packed up while wet (we have had enough of cleaning mould). The consequence of this decision means that we will have a overall height of about 3,400mm and things like awnings need to be considered beyond what is commercially available. We'll also need to pack a pole saw.

 

[Curtis in Texas]

I want to keep up with your build, so color me subscribed.

It may not work for you, due to your overhang legality, but I solved my motorcycle carrier on the back of my Camper by building an upscaled version of a bike carrier that was designed by a guy I knew here in Texas back in the 70's called the "Red Ant Cyce Carriers". You can do a search in the US Patents Web Site to find it.
I copied the pages and have them in my computer if you're interested, I can send them to you. (A Lot of pages for here)
IT makes loading a motorcycle a lot safer and simplier.

 

[SkiFreak]

No doubt some of you reading this will be thinking that a pop-top is a good idea.

If you are not having a passthru, a hard sided poptop is not really a technical challenge and this negates the need for any canvas.

 

[SPF40plus]

If you are not having a passthru, a hard sided poptop is not really a technical challenge and this negates the need for any canvas.

I take your point. It does limit other areas though. the reasons we decided not to do this are:

1. The camper is going to be removable, so we can take the truck on more difficult tracks. This requires legs to hold it up. The legs need to support about 2.5 tons, including fuel, water, grey water tanks and batteries. This means they are too large and heavy to remove. So we are using telescoping legs, and the extension needs to be 1600mm, with sufficient overlap of the internal and external tube, this means we need 2000mm of tube, which is above the tray height. So the pop top doesn't help with this. There are alternatives, but they take up more space, and are more annoying to deploy. For the camper to sit below the cab of the truck, it would need to compress down to 1500mm.
2. To get down to 1500mm, if the camper is 2000mm tall, there is a swept height of 500mm. We want storage above the windows along the corner of the walls and ceiling. We could do this if we didn't attach the storage to the walls and just had it suspended off the ceiling, but this does reduce the depth of the storage, and makes it more likely to cause a leak in the joints between the walls and roof panels. The tops of the shower/bathroom walls also need to be attached to the ceiling, and it also limits the height of appliances like the fridge. It means that one of the bunks can't have a designated storage area too, which then starts arguments about fairness and both small people wanting to be in the bunk with the fixed storage area for their stuff.
3. We are going to have a deck that folds down at the rear of the truck, and this is cantilevered off the rear wall. The frame in the walls needs to be capable of supporting this, and having an open top structure makes it more difficult to brace.
4. Sealing the pop top on corrugated roads would be a challenge particularly in the areas with bulldust.
5. We would need 4 or 6 linear actuators to lift the roof, and these would need to be synchronised. This is not impossible, but is expensive and slow to deploy.

One or two of the above would be okay, and I was initially willing to deal with a few of them to get the height down, but when we considered all the issues, and the effect that these had on our use of the camper, we decided not to use this option.

 

[SkiFreak]

Sadly, there is rarely ever a "perfect solution" - there are always compromises that have to be made and accepted.
You obviously have a good idea about what you want, so you just have to decide on what you can and cannot live without.

Point 1
One option could be using hydraulic rams to lift lower the camper body. A self contained pump and reservoir should not be too space hungry and telescopic rams are common components.

Point 2
As I see it, this is more of a personal preference for the layout, rather than a technical roadblock.

Point 3
I don't believe that this is too technical of a problem, but without actually seeing the setup I am simply making an assumption.

Point 4
Life is full of challenges, but I don't really see this as a major one of them.

Point 5
There are Chinese clones of the Linak actuators which are more than capable of doing this task. There are also solutions available to keep the actuators synchronized, but yes, there is a cost to doing this.

At the end of the day, an expedition camper build comes down to what you want to achieve and how much money you want to spend.
These things absorb money as fast as you can throw it, so having a plan is always a good place to start.

 

[SPF40plus]

Sadly, there is rarely ever a "perfect solution" - there are always compromises that have to be made and accepted.
You obviously have a good idea about what you want, so you just have to decide on what you can and cannot live without.

Point 1
One option could be using hydraulic rams to lift lower the camper body. A self contained pump and reservoir should not be too space hungry and telescopic rams are common components.

Point 2
As I see it, this is more of a personal preference for the layout, rather than a technical roadblock.

Point 3
I don't believe that this is too technical of a problem, but without actually seeing the setup I am simply making an assumption.

Point 4
Life is full of challenges, but I don't really see this as a major one of them.

Point 5
There are Chinese clones of the Linak actuators which are more than capable of doing this task. There are also solutions available to keep the actuators synchronized, but yes, there is a cost to doing this.

At the end of the day, an expedition camper build comes down to what you want to achieve and how much money you want to spend.
These things absorb money as fast as you can throw it, so having a plan is always a good place to start.

You are totally right. none of the issues I listed are deal breakers on their own. But with all of them weighing on the decision, it is just going to be easier to do it the way we have decided, and more resilient to abuse. My family is hard on gear (except me of course ), so building something that is readily able to be repaired in the field is important.

I don't think it is just how much money you want to spend, I think it is also how much money you want to spend over and over to keep things in check. This has been a major factor in our approach. Have you seen Dan Campion's creation on his youtube channel? While it is totally awesome what he has done, I cringed at just about every shot of a moving part that wasn't a pin pivot, because I know what happens to moving parts on the trail. Especially when you get dust, salt, gravel, water, and then sand in the mechanisms.

I have asked the question in another thread about slide mechanisms, as I was hoping to be able to make the living area bigger by using slide outs. But again, once I worked through it and received some good feedback from others, we decided not to do that as it was asking for trouble. If all you are going to do is go on some dirt tracks and travel on sealed roads, it probably doesn't matter at all. But that is not what our plans are.

 

[Ultimark]

Not quite the same truck, but in the same class (MR) this has had an 800mm chassis extension. The extension is between the cabin and the tipper body. Trust me when I say have seen this moving around, sharp or even looking like sharp corners are diabolical.

Ramp over, while it is running small wheels so there isn't as much height as your truck, is bad even on driveways. Wheel base is slightly longer than your projected at 5200mm, but even shortening the wheelbase by 200mm should be a bit of fun in some places.

By the way, it's not my truck.

Could be an interesting build, I'll watch this with interest.

 

[SPF40plus]

Not quite the same truck, but in the same class (MR) this has had an 800mm chassis extension. The extension is between the cabin and the tipper body. Trust me when I say have seen this moving around, sharp or even looking like sharp corners are diabolical.

Ramp over, while it is running small wheels so there isn't as much height as your truck, is bad even on driveways. Wheel base is slightly longer than your projected at 5200mm, but even shortening the wheelbase by 200mm should be a bit of fun in some places.

By the way, it's not my truck.

Could be an interesting build, I'll watch this with interest.

Thanks for the post.

That looks brutal, do you know what kind of truck that is?

I've had a look at some of the non 4x4 isuzus and they range from 4,600 to 6,000+ mm for wheel base. I know the extra wheelbase is going to have its drawbacks, but its what needs to happen. I note that the MAN LM2000 has a wheelbase of 5120mm, so I take some comfort from that. These are commonly used for the larger 4x4 fire trucks.

With the super singles fitted, Burni has a ramp over (break over) angle of 27 degrees. Compared to a Jeep Wrangler at 22 degrees, this is still pretty good.

Also, I learnt to drive in a Kenworth W900, so by comparison Burni turns on a dime.

 

[SPF40plus]

So just for fun I remember now why I don't use my tig welder outside ?

I was trying to put some patches in the roof where the flashing light plates obviously got pulled out at some point. Tree?

I was on my last couple of mm of weld and a gust of wind came through (blew away the argon) and I blew a hole though it. Not to be deterred I had almost filled that hole and it happened again.

So I've spent the last couple of nights reaquainting myself with using a mig on 0.6mm sheet metal. More interesting things pending.

 

[SPF40plus]

I've always avoided using a mig welder where I can help it. But I have borrowed a basic machine with inductance control. It can make a real difference for welding edges. I just tried welding along the edge of some .6mm sheet with inductance turned all the way down and at 11.8v and at 3.5m/minute and I can use a manual pulse to run the whole edge without overheating or warping the panel. That's pretty neat.

Compared to welding with inductance from 50 to 70% welding the edge was uneven and too hot.

I concede mig has its place.