Bigfoot 10.4--where's the beef?
So put the camper on scales today, been wondering what the weights were and a few others are probably also. I imagine bigfoot is too. The tag on the back of the camper says 3220 with propane, ...
Forum Discussion
3 tons wrote:
Wrong formula...Percentage of weight on jacks has nothing to do with COG, because it totally disregards the lever affect of the cab-over overhang...
To arrive at COG, one first has to convert distance from the front cab-over overhang into moments, as follows:
1) Weight on front jacks x distance from the extended front overhang edge (to arrive at first moment).
2) Weight on rear jacks x distance from the extended front overhang edge (to arrive at second moment).
3) Add first and second moments together to arrive at total moments.
4) Now divide total moments by gross weight to arrive at COG, this the distance from front overhang edge reference point.
Of course this will change a bit when tanks and LPG, etc are full...
In OP’s example as follows assuming cabover overhang distance is say 80” from center of front jack and say 203” estimate from overhang to center of rear jack (abstract guesstimates only based on BF 10-4 model number)...
1) 2057 x 80” (estimated) = 164,560 moments
2) 1617 x 203” (estimated) = 328,251 moments
3) Total moments = 492,811
4) Divided total moments by total weight of 3,674 = COG 134.13” from front overhang edge (reference point)...
This can also be done with the camper on the truck (though yielding a different COG) using the front bumper edge as a reference point and measuring to the center of each axle...
3 tons
Nothing wrong with the simple formula. The COG will always be proportional to where weight is applied to the ground. If you redo your complex method using the OP’s stated distance between the jacks of 137” you’ll find you arrive at the exact same number.
The “lever action” of the overhang is already reflected in the increased weight measured on the front jacks.
