...driving... stress the cabinet mounting fasteners and brackets. As the cabinets bounce, any joints in the cabinets will begin [... and will continue...] to work loose. ..
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2stu raises an interesting point about dynamics.
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As a vehicle starts away from a stop, one of Newton's Laws comes into play:
* an object at rest resists moving.
(Although Sir Ike said it different, the gist is valid.)
(Irregardless, I prefer my version.)
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The phrase 'resists moving' means your cabinets want to hang around back at the 'STOP!' sign while the rest of the vehicle accelerates a half-block down the way.
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All well-n-good so far.
The 'catch' to the equation happens as the vehicle slows toward a stop:
* all that interior mass wants to continue moving... forward... toward your cranium.
Newton's Other Law -- 'objects in motion tend to stay in motion' -- is applicable.
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For this reason, for our ExpeditionVehicle, we chose a separate cab with a separate box for our quarters.
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An aside:
For plumbers and other contractors, some van converters engineer a stout wall behind the driver area, separating all that flying stuff from your delicate sensitive flesh.
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And some trucks use a 'head-ache rack' behind the cab to deflect wandering cargo.
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Irregardless, I follow the 'three points of contact' rule.
I bolt through the:
* wall, plus
* the floor, and usually
* another wall forming a corner.
Please, note the 'I bolt through', with big flat-worshers and heavy bolts.
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I think screws into sheet-metal is another welcoming entry for rust, loosening of fasteners, and the inevitability of mobile cabinets.
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And with enough mobile cabinets, the 'public clamor' will get the bureaucrats involved...
... and next thing you know...
... The Cabinet Police will 'perform' 'random' 'spot-checks'.
Immediately thereafter, the sign bureaucrats will emplace millions of 'WATCH FOR LOW-FLYING CABINETS' warnings.
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My opinion on your floats?
Video helps explain a good story.