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Adrift in the Green Room - Our Camper Build

25K views 109 replies 24 participants last post by  tmodler 
#1 ·
About time we got this started.

Our Vehicle - 1987 u1300 ambulance. OM366A, fast axles, about 70k Kilometers when we bought it.

About us - Heather and I are planning a two year journey from Santa Cruz to South America, Ideally starting around Jan 2015. Our plan is to hug the coastal roads, surfing and providing free health care to those communities the whole way down. I'm leaving my job in hospital medicine, and Heather is a talented lawyer, coastal protection activist, and fledgling nurse :)

Our blog should be launching soon, AdriftintheGreenRoom.com

Here's our truck, Don Silvestre'

Wanted to say in advance that we greatly appreciate all the wisdom and insight accumulated on this forum. It has become very clear we couldn't complete this project without it.

-Scott and Heather
 

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#2 · (Edited)
When we bought our rig, it was located in Colorado, so we had a fun test ride coming back to California, and figuring out the vehicle's idiosyncrasies.

There were a few 22" trout caught along the way. But we still dont talk about the ill fated, 600 mile, next to last day, destination Barstow, portion of said journey :)

A few things were readily apparent.

Sound deadening - Absent
Starter - erratic
Fuel gauge - innacurate
Unimog Love - present
 
#3 ·
When we got her back to town, we tore into planning what we'd like to have.

Vehicle modifications

Large cab to camper pass through
Rear cabin extension
Pop top

We placed an order with AV for some fun goodies, including a CLAAS (in transit).
 
#5 · (Edited)
We really wanted a large cab to cabin pass through. Heather's logic was the sheer quantity of sandwiches I'd need while driving, and the hassle of stopping to get into the back. The plan was hatched.

We got some seats out of a newer sprinter, and then some swivel adapters from eurocampers.com

Here is a pic with the rough pass through and the seat swiveled into the cabin. Please excuse the metal work, we took several passes, enlarging the hole each time to our liking. The last pass was rather sloppy.
 

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#6 · (Edited)
Given the size of our pass through, we'd planned to have an internal roll cage installed. We took it to a really respected local roll cage builder who advised against. Basic sentiments were that the Cab was quite rigid as it was, and barring roll over, really didnt need much reinforcement. He advocated just installing a thin walled frame around the opening. We elected to install a thick walled cage welded to the back side of the cab (in the area between the cab and cabin). I feel like a mile of bead was welded attaching the front side of the cage to the cab. We are tackling the back side and then the sheer support in the corners this weekend.
Here are a few preliminary shots. Im a novice welder, so please dont zoom in on my welds :0
I had a skilled neighbor come over for the day while we were putting this together and give us some guidance.
This is where the work currently stands. Next step is to reinforce this sheer response on the cage with some corner extrusions, and then replicate the cage in the opening into the cabin. The thought was that mirrored cages in the pass through should be quite strong in the event of an accident. I was very impressed with how much rigidity just adding the first cage has given us.
 

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#7 ·
I am curious to see how this works out.

C.
 
#12 ·
it sometimes amazes me that amateurs do this, and despite a profesional engineer advising that it isnt required still go ahead thinking that they know best, the strength in the back of the sbu cab is in the folded and jogled sections you cut out and triedto replace with a bit of rhs box, also how are you going to acomadate the movement between body and box, its going to be a hell of an umbilical
 
#15 ·
Here is a pic with the bottom cross-member in place. We are adding some corrugated steel between the angles formed in the bottom two corners of the cage to add additional rigidity, and then doing something similar in the upper to corners.

@kimosawboy, you are correct. We explained our use and he thought adding metal was nice, but unnecessary.

As an aside, we fully understand the implications of the strength elements we've removed. I've quite a bit of engineering background, though not vehicle specific, and we consulted a local expert prior to embarking.

Our original plan was to build a di-meric buckminsterfullerene cage out of diamond titanium alloy. We'd then planned on welding all orifi closed and pressurizing the inside with a perfluorocarbon liquid mixture rich in oxygen allowing us to breath in the pressurized liquid environment, not unlike what they did in "The Abyss".

Not only would this have created ideal impact resistance conditions, it would also allow us to drive the Mog to the Mariana Trench, some 10.9 km below the surface of the ocean. I've heard it's lovely in person.

However, practical considerations like how would I eat Heathers sandwhiches in the liquid oxygen environment, and fuel efficiency concerns while carrying 17,839.6 liters of our perflourocarbon ultimately forced us to change course.

We appreciate all comments, but please keep in mind our intended use. We essentially wanted an RV with an ample reserve of 4wd capability and space, that allows us to go all the places we want to go in ease. Trucks far weaker than ours do this trip routinely. It wont be as strong as Mercedes built it to be, but it will be fun, comfortable, and hopefully, appropriate for our intended use.
 

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#20 ·
I would imagine that cab noise will be significantly higher at highway speed and it will be a challenge to reduce the noises coming from engine, driveline AND camper box.
I wanted to do a pass through on my 1300 doka camper but realized that it has a much larger unsupported surface area than a regular cab and would really weaken the cab. I will remove one of the rear windows and have my wife practice throwing sandwiches through the opening. This kind of sucks because a large pass through is really practical for comfort, space and security.
I have seen others with very large pass throughs. You will have to think hard about the bellows or material between truck and camper. Neoprene flexes well and has some insulating properties.

Good luck with it.
 
#21 ·
I wanted to do a pass through on my 1300 doka camper but realized that it has a much larger unsupported surface area than a regular cab and would really weaken the cab. I will remove one of the rear windows and have my wife practice throwing sandwiches through the opening. This kind of sucks because a large pass through is really practical for comfort, space and security.
I have seen others with very large pass throughs. You will have to think hard about the bellows or material between truck and camper. Neoprene flexes well and has some insulating properties.

Good luck with it.

In a regular cab a person could always upgrade to the larger "AG" back window, then your not doing any more cutting than was available at the factory, large enough for even the mighty hoagie sub and to dive into the cab should you need:

Plus, this truck just looks cool








 
#22 ·
"Oh, no way to get a proper sandwich through THERE, Obadiah ...."

"Well, when I say a "pass thru" I mean we just had a hole in the back of the Cab...."

"Oh, you were LUCKY ! We HAD no back of the cab atall, just a hole where there once was
A cab wall..."

" pure luxury ! We were evicted from our hole where there once was a cab wall...."

Ay, and you try to tell the young surfers of today, and they won't believe you..."
 
#23 ·
IIRC from the body builder handbook, MB have a diagram that shows what can and should not be cut - and the member underneath the rear window is one of them. I would not be able to get that passed by an engineer here in Australia because of the OEM saying don't cut it.

Not saying it would fall apart, but it would no longer comply with the regulations here, I would have loved to cut mine down level with the floor, but we are not allowed :(
 
#24 ·
Well, it seems that nobody is going to say it, so I will.

I typed a longer reply explaining it more, but BW seems to have not accepted it.
Long story short (forgive me if this sounds curt, but I am not going to retype all that crap):

The rear wall element under the window provides sheer strength to the cab (counters the torque of the cab moving about).

I know you are not worried about rollover protection, but since the factory cab provides essentially none in the first place, the rear wall's structure is there for other purposes that you need to put back into your design.

Specifically, I would be concerned about the lack of structural support resulting in the cab twisting and cracking the windscreen. You need a rear wall design element to put the strength back in that cutting the support under the rear windows out removed (and, no, sorry, the 1.5" tubing around the perimeter of the opening does not provide this. The tubing is more of a beefy trim ring to attach your passthrough conduit to. You need design elements in there to create a rigid plane on the back of the cab.)

I suggest you draw up a FBD and look at the torque on the cab, and how much force is not on the windscreen. You can also look at whether you feel cab shocks would lessen this force.

I respect what you are trying to do, and it is your (and Heather's? or just Heather's? not sure) truck to do with as you please so feel free to dismiss me as an a$$hole, but I do think you have made a mistake cutting out the entire back wall of the cab with the plan to keep it open.

In addition to the structural issues, I don't understand how the passthrough will work (500mm of movement is a lot of material to have in the passthrough, where is it going to go when not articulated).

As I said, I look forward to seeing how this works out, the idea is pretty neat. I would suggest that you get an engineer involved with the structural element of the cab so that you don't have unexpected flex and end up either cracking or popping out the windscreen.

C.
 
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#25 ·
This not so new Unicat mog http://http://www.unicat.net/en/pics/UM8FHAS-Unimog4x4-sh-2.php seems to have done some travelling with a fairly large walk through, even encroaching into a higher cab roof too, and certainly has a windscreen in place in the pics ;) Maybe that was just lucky timing though :p


From a camper usability point of view, rotating seats facing the dining table perhaps saves some useful camper floorspace depending on matching floor/ceiling levels, and they may end up being the most comfy seats in the vehicle once finished if not all sweaty and dusty :eek:

Its not a cool idea for keeping heat in or out of the camper box though, you can't insulate the cab windows as well as the camper windows and body can be, so you might need more energy to keep it warm in the back?
 

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#26 ·
What is the new plan for the rear body (since the ambulance body is now for sale)?

C.
 
#27 ·
Its been a bit of an odyssey, but the short of it is we have a new subframe coming from 4Ward 4X4 out of germany with a few of their components, and are now in the midst of a building a new cabin out of composite material (transonite). The plan is to build a flat bed on the subframe with full length storage boxes and then set the cabin on that. The new subframe is 7cm lower than our existing, and our box is low roofed as well. Finished height will be under 10ft, and about 21 ft long.

Our new cabin design functions somewhat like the Pangaea LT from GXV, its a hard sided, 'box within a box' raising roof design. Marc from XP campers is a friend, and has been helping us with it. He is also helping with the flat bed. Much of the design layout is borrowed from his stellar campers. Worth a visit to his shop if you get a chance.

We should end up with a fair bit of weight savings, our new box and subframe are calc'ed at 1500 lbs, plus the weight of our flat bed, which we don't know the weight on yet (but it will be less than a standard one as it is just an aluminum box resting on our subframe with long sliders and drawers).

After working on modifying the ambulance box for a few days, I was left feeling It would be less work and a better end product to purpose build something from scratch, rather than try to modify what we had. Somewhat like the remodel old house, versus build new one debate. Everything was in a different place than I would want it if building from scratch, and prepping that old glued and painted metal for welds isn't very fun ;) And if we were going to do that, I was much more comfortable with composite work, with more of my background in the shop in carpentry and surfboard shaping than metal working.

In the meantime, we finished re-enforcing the pass through, got engineering sign off on that (we have a 'near' roll cage from their assessment. Would survive a low speed roll), and finished mounting our new sprinter swivel seats.

Also installed our CLAAS, maaan what a difference. Tons of thanks to Rally Truck for his help on that one, we were missing a few parts and he saved the day with advice and wrenching.

In the midst of it all, we had to leave our shop, aka tent in the driveway, apparently our landlord was less than enthralled with our truck ;) Got a new warehouse to work out of a block from the house which has really sped up our progress.
 
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