Frame Failure

Bowti wrote:

TXiceman wrote:
From an engineering stand point, that is a poor design without a doubt. There should have built a proper subframe to mount the suspension from, but that is more steel, more weight and most important....more cost.

Ken

Many manufacturers have cut weight from their product while making them stronger and lighter, by better engineering and design. Going to thicker heavier material is not always the answer. Also recalls and warranty work are not cheap.

Then maybe the mfrs should think about that =before= they build some of the schlock they do. Oh, wait; they =do= think about it but just say, "build it; what are they going to do, sue us? We can keep them in court until they die if they try it." :M

Lyle

wing_zealot wrote:
Just curious, did you have the stabilizers down and setup before you put the slide out?

X2 Have to have a solid base BEFORE the slides are to be extended. Lippert really pushes this in their manual.

Bowti wrote:
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For example, trailers all have cross bridging, gussets, and box plating to add strength to critical areas. In this case maybe adding a box plate to the I beam in the effected area and moving the cross bridging to this boxed area could add measured strength without adding prohibited cost or weight.

In the case of our 2005 Cardinal 29WBLX there were lattice racks cross member from side to side between the I-beams. In the axle area behind each wheel the lower angle iron of the lattice rack landed about 3/4-1" above the lower flange of the I-beam so that the belly pans could sit on top of the I-beam lower flange in the axle area. This caused cracks in the vertical web of the I-beam and four different locations in the axle area. After the repair and cross braces were installed it towed like it was on rails.
Chris

TXiceman wrote:

RustyJC wrote:

Bowti wrote:

TXiceman wrote:
From an engineering stand point, that is a poor design without a doubt. There should have built a proper subframe to mount the suspension from, but that is more steel, more weight and most important....more cost.

Ken

Many manufacturers have cut weight from their product while making them stronger and lighter, by better engineering and design. Going to thicker heavier material is not always the answer. Also recalls and warranty work are not cheap.

With all respect, looking at the OP's photos, I don't believe his is one of the cases you describe.

Rusty

I have to agree with Rusty. There is good design and yes you can make things lighter and stronger at the same time. But so many of the RVs are not designed this way.

Ken

First, I agree that we are looking at a poor engineering here.

What I was trying to get at, is the excuse that seems to be so prevalent, is if trailer frames were made stronger they would be too heavy and so expensive, that no one would want to tow them or be able to afford them.

I will still contend that a products strength through design (even a trailer) can be improved without adding excessive weight or cost so that no one would want to buy it.

For example, trailers all have cross bridging, gussets, and box plating to add strength to critical areas. In this case maybe adding a box plate to the I beam in the effected area and moving the cross bridging to this boxed area could add measured strength without adding prohibited cost or weight.

RustyJC wrote:

Bowti wrote:

TXiceman wrote:
From an engineering stand point, that is a poor design without a doubt. There should have built a proper subframe to mount the suspension from, but that is more steel, more weight and most important....more cost.

Ken

Many manufacturers have cut weight from their product while making them stronger and lighter, by better engineering and design. Going to thicker heavier material is not always the answer. Also recalls and warranty work are not cheap.

With all respect, looking at the OP's photos, I don't believe his is one of the cases you describe.

Rusty

I have to agree with Rusty. There is good design and yes you can make things lighter and stronger at the same time. But so many of the RVs are not designed this way.

Ken

Bowti wrote:

TXiceman wrote:
From an engineering stand point, that is a poor design without a doubt. There should have built a proper subframe to mount the suspension from, but that is more steel, more weight and most important....more cost.

Ken

Many manufacturers have cut weight from their product while making them stronger and lighter, by better engineering and design. Going to thicker heavier material is not always the answer. Also recalls and warranty work are not cheap.

With all respect, looking at the OP's photos, I don't believe his is one of the cases you describe.

Rusty

TXiceman wrote:
From an engineering stand point, that is a poor design without a doubt. There should have built a proper subframe to mount the suspension from, but that is more steel, more weight and most important....more cost.

Ken

Many manufacturers have cut weight from their product while making them stronger and lighter, by better engineering and design. Going to thicker heavier material is not always the answer. Also recalls and warranty work are not cheap.

From an engineering stand point, that is a poor design without a doubt. There should have built a proper subframe to mount the suspension from, but that is more steel, more weight and most important....more cost.

But I see lots of RVs with a similar design on the spring hangers. I guess they have been more fortunate than the OP.

Ken

WNYBob wrote:
It really gets me going when the frame mfg puts out a publication, LIP p135 Rev A and RV mfg ignore it.

It is worst than you think. When I had my problem and contacted the trailer manufacturer about it, they had never seen or heard about the Lippert document until I provide a copy to them.

The spring hangers on the OP's trailer are about the worst I have seen. That trailer manufacturer could upgrade their trailers by switching to a Lippert frame. And that seems like a joke, but is not!

Good luck with the fix.You could see issues coming with that set up and you would not have to be an Engineer to even Realize it .What a JOKE!!!