Off Truck Camper Leveling

Ah, tandem axle, would compressing the back spring tend to push down the tongue and increase the T weight? Seems like it would.

I'll try steeper angles on the scale test and also do it with 1/3 unsupported like a TC. But not for a day or two.

When I do tilt before load/unload it is to make sure it goes in and out of the bed without hanging up.

One nice thing about Adventurer and Eagle Cap campers is that the center of gravity is marked individually for all of them as they come off the line. Of course COG will change as you load the camper, but at least with COG clearly marked you can get a better idea of how to pack the camper. The owner manual does recommend raising the front a few inches when loading and unloading, but knowing where the COG is makes things a bit more comforting.

Yeah it's tandem, I just wouldn't have expected a 80lb increase in the small change required to uncouple. The coupler is probably 15' in front of the front axle, and it's a equalized suspension.

I know when we are setting up my dads TC it feels more stable with the front up 2", but it's a smaller 850 without a lot of weight or length compared to some of the bigger campers.

ah64id wrote:
The tongue weight had me rather confused as well, but as I raised and lowered the jack on the scale the weight change. My thought is that it took more force to hold it higher, but I can't be certain.

I need to reweigh my tongue since moving some things around, maybe I do some extra tongue weight tests.

How many axles does your trailer have? If it has two, that's why the tongue weight goes up as you raise the tongue. You're pivoting the trailer around the axis of the rear axle, removing weight from the front axle, and distributing it between the tongue jack and the rear axle. If you had a scale under the rear axle while you were raising the tongue, you would see the weight go up there as well.

You're not going to see the same weight shift on a truck camper standing on four jacks (provided you're maintaining approximately equal loading of the jacks) because none of the supporting points are becoming "unloaded" simply by lifting the nose of the camper.

:):)

Raften wrote:
So all this seems to center around center of gravity and I can't come up with a experiment for that right now. But I did do a test that seems to call into question the weight shift idea.

I got out my trusty gram scale and a eight inch steel rod. I supported each end on the very end while level, one end on the scale and the other to a small adjustable height table from a chem lab. I recorded the weight of the scale end while level. I then elevated the table end about 15 degrees and recorded the scale end weight again.The area of contact on each end of the rod was the same for both times. Guess what, there was no weight difference. I admit this was a redneck test but it showed me something. That something seems to mean you need a much bigger angle to expect any kind of weight shift.

Still trying to get a grip with the increased tongue weight by raising a mere inch. Just does not compute for me given my redneck test.

Interesting test, I wonder how the results would be if the one set of legs wasn't on the end. After all we probably all have been on the downhill side of a box on the stairs.


The tongue weight had me rather confused as well, but as I raised and lowered the jack on the scale the weight change. My thought is that it took more force to hold it higher, but I can't be certain.

I need to reweigh my tongue since moving some things around, maybe I do some extra tongue weight tests.

So all this seems to center around center of gravity and I can't come up with a experiment for that right now. But I did do a test that seems to call into question the weight shift idea.

I got out my trusty gram scale and a eight inch steel rod. I supported each end on the very end while level, one end on the scale and the other to a small adjustable height table from a chem lab. I recorded the weight of the scale end while level. I then elevated the table end about 15 degrees and recorded the scale end weight again.The area of contact on each end of the rod was the same for both times. Guess what, there was no weight difference. I admit this was a redneck test but it showed me something. That something seems to mean you need a much bigger angle to expect any kind of weight shift.

Still trying to get a grip with the increased tongue weight by raising a mere inch. Just does not compute for me given my redneck test.

There is no weight behind the aft jacks, which means it doesn't take much weight in front of the fwd jacks to take a lot of weight off the aft jacks. The weight is also higher up, having greater leverage.

It would be interesting for someone to find a closed scale an unload their camper to get the weight on the rear at level, and 2-4" above level. Then find out how much weight a 200lb person in the sleeping area removes from the aft jacks (it will be greater than 200lbs based on the location, just like a 700lb snowplow adds more than 700lbs to the front axle based on location and leverage).

Think about carrying a couch up the stairs, an extreme example, but the guy on the bottom has more weight. Even if it's a tall guy and a short guy on flat ground the short guy is holding more weight. It doesn't have to be much of a difference, just enough to offset any people sleeping or moving (more moving) fwd and above the pivot point.

Just because someone hasn't tipped over doesn't mean your close to tipping over, and it's hard to tell someone that level is better when the manual tells you to always have the front higher. Look at the math, 2° will hardly be felt by the occupants but I bet a scale would show you it's worth it.

But most certainly the bigger, longer, and heavier the camper the harder it would be to unload the rear legs enough to tip.

But the argument for the fridge isn't really valid based on the fridges operation range.

Just as point of reference, raising a TC three inches on a eight foot jack spacing tilts it 1 degree, 46/47 minutes. That is the trig I came up with but even though I spent 40 years figuring XYZ problems my age may have addled my thinking.

X2 for both NRA and Dak way of thinking.

I would never attempt to discredit anyone's statements on this subject.

That said, I would NEVER purchase or sleep in a camper that had to be so perfectly balanced to avoid tilting/crashing forward that an inch or two up or down (or a few extra pounds after a heavy meal?) could cause it to do that! I also would be totally paranoid to roll over in bed or ....ahem.... conduct other activities up there for fear of causing a horrific incident! Tornadoes, hurricanes, loading the cabover bed up with cement bags, bricks or 50 big people, acts of God, etc. withstanding! :)

Dak

I can maybe see it happening (nosing over) with a much smaller, lightweight camper, but not with one the size of mine or Raften's. The 1121 weighs around 5K lbs, and 75-80% of it's weight is behind the front jacks.

Some member here who's smarter than I am with making these kinds of calculations determined that it's just not possible to put enough people in the cab-over to make the camper tip forward.

Wind, tornadoes, earthquakes, and energetic activities in the cab-over aside, I don't think there's much to worry about. I don't think having the nose a few inches higher vs. level is going to matter On my camper, that is. Everyone should make their own risk assessment.

:):)