Merkabah: MB 2626 AK 6x6 tipper to expedition truck conversion

[pairospam]

Hi:

Just a little update to show the present state of the project. You must never loose your faith and keep working no matter what. After many problems an a lot of hard work I put the cabin back on the frame today. Lots of connections to make and lot of fun ahead.

I am happy.

Cheers.

Pairoa

 

[Czechsix]

Very nice! Glad to see you're still hammering away at it.

 

[Sitec]

Good work!

It's going to be brilliant! Keep going, as you have a truck that looks like a truck again!

 

[geckoadventure]

Cool the build is still going - I was wondering if I would finish my VOlvo or you would finish your MB truck first looks like mine is now in front.

 

[MadBkr]

Well done! Keep up the good work

 

[Jostt]

Amazin job, I hope you finish as in the 3D draws you plan, are you thinking to build yourself the cabine?
Suerte y animo despues de todo el trabajo!!!

 

[pairospam]

Thanks, guys.

I plan to finish the truck, make it run on its own wheels and make all the torsion tests to be sure to design and buid a completely free-torsion platform to build the Box upon.

The panels are already here at a friend´s place. My father will help me to assemble and furbish the living box when the time comes. Hope it will be soon.

Greetings from Chile.


Pairoa

 

[Czechsix]

Sounds good. Just don't fall into the same problem that others have fallen into when building torsion free boxes.

 

[pairospam]

Which is....?

 

[Czechsix]

Which is....?

Some vehicles have very compliant suspensions, some have very compliant frames, some have a combination of both. Problems ensue when superstructure designs give different flexibility than was originally designed into the vehicle frame - a classic example is someone running a Unimog derived superstructure on a frame that's not designed to flex as much as a Unimog.

For example, a smaller FUSO with a frame that's designed to be somewhat limited in flex. The thing is that the limiting factor, to a great extent, is the superstructure. It adds stiffness and lets the frame last longer under load. Remove that stiffness, put the frame under full load and run it over terrain that maximizes torsional stress and the frame eventually breaks faster than if it was limited. All the trucks I've seen have integrated their approved superstructure designs into the frame calculations, none have been designed to run only as a cab and chassis.

I think your truck is short enough, stiff and rigid enough that you won't have any issues with any coach of reasonable size. As long as it's in good shape to begin with, which might be something to consider. Lots of these trucks have had a tough life prior to our grabbing them. Some already have rust, rivet issues, distorted frame members, etc.

The good thing about running a truck that's the size of the one you have is that it's extremely heavy duty for your application. The bad thing is that it's extremely heavy duty .

Everything's a compromise, the torsion free box concept is also a compromise.

 

[Sitec]

The two rear axles on your truck are designed to carry around 17 tonnes.. With a coach/living body on the back, you will be around half of that. I'd be thinking of removing several of the rear spring leaves and replacing them with a spacer of matching size to the amount removed. This will retain the ride height whilst softening the ride. I plan to take several leaves out of both the front and rear springs in mine.
Re mounting the body to the chassis... I would suggest getting the truck mobile, and then drive it into a situation where the chassis twists 'off road' and see how much it moves. This will show you how you will have to mount your body. Even a heavyweight 6x6 will have twist, and the body will need flex mounts... Some good info here. Loving the Merkabah story. Keep going!!


http://forum.expeditionportal.com/threads/25494-pivoting-frames-and-mounting-campers

 

[pairospam]

Czechsix and Sitec:

Thanks a lot for your concerns. Well... the truth is that the relationship between the frame and the Box has been a special issue on its own as long as this project has been alive. I have changed my mind at least a couple of times, and it is not said it may not change again.

Believe me when I say that I have taken into consideration every known aspect of the problem, at least known by me, and I have made a lot of research during the almost seven years since I bought the Merkabah.

As wisely stated, everything is a compromise, and you can have really good engineered but poorly executed solutions and simple solutions perfectly applied, and the result on the long term may, of course, vary from excellent to disastrous. Can give you examples of any kind to make laugh and to make you cry.

Ah, and I have indeed taken out a lot of leaves from both front and rear suspensions, added sway bars to the first and third axles, put shock absorbers to the second and third axle and a second shock for the front one, put air suspension to the whole truck and put also suspension to the front of the cabin, all because of the super heavy duty original nature of the truck.

There is no perfect solution, that´s the only rule. But you can have a lot of fun (and trouble) trying to find it, eh?

Best regards.


Pairoa

 

[Sitec]

Wow! There's some hours and thought gone into all of that! Well done!! I will be very interested to see the body going on and how it's done!! Hurry up, as I want to see the end result!

 

[Jostt]

Very good job what you made in the front axle , the neumátic spring is a pesent foto your back....in any case about the torsión subframe , your case its not extreme because your frame is not a light truck like one Unimog, its made It for a Big amount of tones, so the torsión by It self is low, negative point is how It copy the Terrain, but whit a simple diamont subframe sould be perfect for your truck, good luck

 

[MadBkr]

Any updates?