how to build a rigid frame on HJ 47 or unibody

[rideglobally]

i have a flat bed HJ 47 1981, i want to attach the camper that i am building to the cab so that it is one rigid unit, in other words by doing this the flat bed in the back will lose it's ability to move independently (twisting) from the cab. my question is; how do i reinforce the body and or the chassis? what i am really trying to do here is to create a "unibody". my land cruiser has a roll bar inside the cab.

here is my link so you can see the vehicle and the "camper" i am trying to construct.
global cruiser vehicle preparation!

thanks

 

[BiG BoB]

I'd use rubber inbetween... If you dont have some sort of flex, you might end up with cracking!

Sean

 

[roscoFJ73]

my question is; how do i reinforce the body and or the chassis?
thanks

You cant really. The lwb landcruiser frames are reputed to be able to flex 3 inches or more diagonally.
In this case ,flex is what makes it resistant to cracking.
By reinforcing it you would only be tranferring the stress to the next weakest part.
Maybe you could support the front of the camper by attaching it to the frame with some alloy legs which would allow it to move a round.

Unimogs have the body touching the frame in only 3 places.

 

[fernandol]

If the cab and the camper are both mounted with the original toyota rubber body mounts I don't see the difference between a pickup with a camper attached to the rear of the cab and a troopie. The camper and cab combo should behave pretty much as a wagon would, sure the body will twist and turn a little as the chassis flexes but I don't think this should be a cause of problems, this happens to every long wheel base truck out there.
Please enlighten me if my reasoning is unreasonable

 

[roscoFJ73]

If the cab and the camper are both mounted with the original toyota rubber body mounts I don't see the difference between a pickup with a camper attached to the rear of the cab and a troopie. The camper and cab combo should behave pretty much as a wagon would, sure the body will twist and turn a little as the chassis flexes but I don't think this should be a cause of problems, this happens to every long wheel base truck out there.
Please enlighten me if my reasoning is unreasonable

Simple wagon bodies are one thing. They are designed by highly experienced engineers who know how to make bodies flex with the frame.
And they stil crack in the floors under hard use sometimes. Some 4wd vehicles like Pajeros have problems in Australia fom the bullbar hitting the body when flexing even with several inches clearance.

What Rideglobally is proposing is joining another construction method and another material onto the landcruiser cab and frame.
Im no engineer but I think dont think it would work. I think he is better off keeping them isolated from one another.
Have a look at the flex btween cab ,camper and chassis on these big trucks.
YouTube - Off road Camper TRUCKS

 

[rideglobally]

thank you this is very helpful, i also looked at the utube, those trucks really flex. what do you think they did on this vehicle Selection and Design do you think the cab is attached rigidly? i have tried emailing them many times can not get a reply.

 

[roscoFJ73]

thank you this is very helpful, i also looked at the utube, those trucks really flex. what do you think they did on this vehicle Selection and Design do you think the cab is attached rigidly? i have tried emailing them many times can not get a reply.

If you look closely at the front supports for the camper,they appear to be resting on the frame mounts. Ths is how I would do it.
Because of the the relatively short tray on your 45,you will probably have a greater proportion of the camper body over the cab.
I would have some supports at the front of the camper,just forward of the front door hinges, resting on the frame.
You would have to have some mounts that extended from the frame out to reach the supports.

I was looking at some similar campers today. They have a big rubber seal underneath the camper that just touches the roof ,but enough to keep the wind out.

 

[rideglobally]

If you look closely at the front supports for the camper,they appear to be resting on the frame mounts. Ths is how I would do it.
Because of the the relatively short tray on your 45,you will probably have a greater proportion of the camper body over the cab.
I would have some supports at the front of the camper,just forward of the front door hinges, resting on the frame.
You would have to have some mounts that extended from the frame out to reach the supports.

I was looking at some similar campers today. They have a big rubber seal underneath the camper that just touches the roof ,but enough to keep the wind out.

if i understand this correctly the camper shell that hang over the cab will be connected to the "support just forward of the front hinge". when you say "resting on the frame" what do you mean? is that a rubber mount to attached that support to the frame or is that rigidly connected to the frame welded or bolted. as i understand that part of the camper that over hang over the cab will not be connected to the cab, there will be a space between the camper shell and the top of the camper and a rubber seal between the bottom of the camper shell and the top of the cab....thank

 

[roscoFJ73]

if i understand this correctly the camper shell that hang over the cab will be connected to the "support just forward of the front hinge". when you say "resting on the frame" what do you mean? is that a rubber mount to attached that support to the frame or is that rigidly connected to the frame welded or bolted. as i understand that part of the camper that over hang over the cab will not be connected to the cab, there will be a space between the camper shell and the top of the camper and a rubber seal between the bottom of the camper shell and the top of the cab....thank

I mean the front camper support should be attached to the frame.
To do this you would have to have a bracket that is bolted/welded to the frame and then comes out past the side of the body to pick up the front camper support.
I would have a rubber body mount on the end of the bracket for flex and to keep the squeaks at bay.

 

[fernandol]

I still think there is no need to go to such an extend to build a simple camper on a small vehicle such as an fj47.
I think the comparison with the trucks in the Unicat video is irrelevant as you're basically comparing apples to oranges. The frame flex on a Land Cruiser is nothing when compared to these trucks.
Here are some campers build with a rigid connection between camper and body, all of them work and have been tried in different conditions and I have never found any reports on problems caused by flexing.

Selection and Design
Willkommen bei Innovation Campers!
Gefi-Travel – PANAMERICANA – Auf der Traumstrasse der Welt von Alaska nach Feuerland

I had some others but couldn't find them right now

 

[roscoFJ73]

I still think there is no need to go to such an extend to build a simple camper on a small vehicle such as an fj47.
I think the comparison with the trucks in the Unicat video is irrelevant as you're basically comparing apples to oranges. The frame flex on a Land Cruiser is nothing when compared to these trucks.
Here are some campers build with a rigid connection between camper and body, all of them work and have been tried in different conditions and I have never found any reports on problems caused by flexing.

Selection and Design
Willkommen bei Innovation Campers!
Gefi-Travel – PANAMERICANA – Auf der Traumstrasse der Welt von Alaska nach Feuerland

I had some others but couldn't find them right now

Its easier attaching the camper to the frame and being sure ,than attaching it to the roof and finding out later it leaks and squeaks.

Even the biggest tree bends in the breeze.

 

[fernandol]

Its easier attaching the camper to the frame and being sure ,than attaching it to the roof and finding out later it leaks and squeaks.

Even the biggest tree bends in the breeze.

Of course everything has to be attached to the frame, what I think is that one can have the camper and whatever remains from the original body of the truck forming one unit, using a platform like a Land Cruiser or Land Rover a properly build camper should be able to flex with the frame much as the original body would.

 

[roscoFJ73]

Of course everything has to be attached to the frame, what I think is that one can have the camper and whatever remains from the original body of the truck forming one unit, using a platform like a Land Cruiser or Land Rover a properly build camper should be able to flex with the frame much as the original body would.

And if it doesnt,it leaks and squeaks all the way around the world. And how do you do calculate how much it will flex and where?

Building a separate camper ensures the vehicle is not compromised by anything but the weight of the camper.

In the event the camper is damaged irreparably (it is an around the world trip and anything can happen) ,the vehicle and its occupants can continue on its way with an entire roof.

Have you seen the proposed camper and the dual cab 45 he is proposing to use? It is nothing like the red 45 or the others in those links

They build a lot of these in Australia too and they rarely penetrate the vehicle body. Even the 2wd camper vehicles roofs are isolated from the camper.

No autobahn cruising here

 

[Bogo]

i have a flat bed HJ 47 1981, i want to attach the camper that i am building to the cab so that it is one rigid unit, in other words by doing this the flat bed in the back will lose it's ability to move independently (twisting) from the cab. my question is; how do i reinforce the body and or the chassis? what i am really trying to do here is to create a "unibody". my land cruiser has a roll bar inside the cab.

It is possible, but not advisable. I'd make the camper back separately mounted to the frame, and use a flexible seal between the cab and back.

As for hard attaching them together, the Winnebago Trekker has a metal cab to fiberglass body joint on a Toyota 4x4 chassis. You will need to use flexible body mounts for the back as well as the cab. The Trekker eventually paved the way for the 4Runner and that is an all metal body. Here is a Trekker restoration project writeup over at 4x4Wire with allot of details.

I too am working on a Micro RV, but my base will be a '94 4x4 pickup. The whole back and its roll cage will be one unit and it will be mounted with flexible body mounts to the truck fame. I'm planning on using an EDPM rubber sheet for the flexible seal between the cab and back. It will be attached to both the cab and back using metal strips and self threading screws. I'll cut out a bunch of the rear wall and roof of the cab. I'll weld in an interior roll cage into the cab for strengthening due to the loss of the cross bar at the back of the cab. The roll cage for the back will provide most of the roll over safety as it has an extension area over the cab.