boblynch said:
Doug,
Thanks for the link. Sorry, but I probably didn't phrase my question correctly. If someone were to use a camper that extends over the Fuso cab, what camper to cab clearance should they allow to prevent the camper from hitting the top of the cab when the frame flexes during offroad travels? See the picture of your rig earlier in this thread. It looks like about six inches. In your extensive buildup did you determine a more accurate number?
Thanks and enjoy your trip.
Bob
Bob,
OK, sorry for the misunderstanding, I thought you were asking about cab tilt.
If you were mounting a camper nose over the cab then a couple of things are determined.
1. You would need to have the rigid end of the 3 point pivot frame behind the cab. That would match the front of the camper, to the greatest extent possible, to the cab's rotation.
2. You need to allow for the frame flex between the front 3 point pivot frame attachment point and the cab hinges. That's quite a long distance in the universe of Fuso frame flex.
The Fuso frame is very, very flexible. The rear of the cab is going to flex on the rubber rear cab latche points. The front of the cab will twist with the front ends of the frame rails, which extend past the front axle springs attachment points. Let me reiterate, the distance you are talking about here is about 1.5 light years in the universe of Fuso frame flex.
We never tested and measured that frame point to cab flex because we were not putting anything over the cab. The only thing I can offer is what you can see in our full articulation tests and the amount of flex you can see in the garage in those shots. The garage flex is happening in less than 4 longitudinal feet of Fuso frame. And part of that 4 feet is our box section frame extensions that flex a LOT less than the stock frame.
I wish I could offer a more detailed assessment or empirical data.
I would recommend that if you are considering that design it is imperitive that you build a test box outlining the camper dimensions, mount it on the frame as you intend to mount the camper and take the chassis out and put it through full articulation in both axle rotations.
That test would cost you a few hundred in channel and some welding time and could save you a very expensive broken camper nose and tweaked cab.
Until this community builds up a more extensive set of test data on the Fuso and its frame this world is all about physical testing.
Speaking of which, Darrin may have done this cab flex test. It would be worth contacting him. The worst he can say is no.
Doug