Campin LI wrote:
Ron,
Please don't be astounded by anything I say. I'm just a guy who comes to the forum to get advice and I try to reciprocate from time to time by giving some. I meant no disrespect to you, sorry if you took it that way.
I am on the "other side" in construction. I do not have the technical background to analyze and design things but I am very interested in it and I believe I have the ability to follow along. Most of my knowledge is based on trial and error without the math analysis. That is probably why I bounce back and forth between variables within the same paragraph. I also don't have the desire to ponder over the perfect words so that they can't be twisted to mean something I did not intend to say. For instance above, all I meant was usually a factor of safety is used as in sometimes there is not one. I actually don't know what you twisted it into other than saying there is no such thing as usually when determining a factor of safety or something to that effect.
That being said, the only intent of my post was to make people aware that specific to RVing, the variables in the analysis can be under constant change, and nothing more.
My last paragraph was meant to be a joke. Sorry you didn't get it.
Regarding the underlined portion of your above post: You say all you meant was usually a factor of safety is used as in sometimes there is not one. What you actually said is found in the underlined portion of the post below.
In the underlined text, you
also said there was a 33 1/3% factor of safety involved.
I took your statement to mean that when a FoS is assigned, that FoS is equal to 33 1/3%. And, my comment was directed at the assertion of a single, specific Fos.
In your above explanation of meaning, you do not include the specific FoS value.
I found your FoS value of 33 1/3% to be problematic because you later said (also underlined below) the same FoS should be used when analyzing weights. Does this mean that it is okay for a weight to be as high as 133 1/3% of a rating? I thought you were advocating keeping all weights well below 100% of their respective ratings.
As regards your final paragraph about the 1 ton dually -- I took that paragraph to mean you believed a TV with large excess towing capacity would be completely stable even if its trailer were swaying all over the place. It's good to know your point was only to make a joke.
Ron
Campin LI wrote:
Thank you for taking the time to put this utility together. As long as the person reading through it can understand the math, it is a great way to learn what the weights are and what the effect of the weight has on the setup.
The only thing I would add is that it should be used as a learning tool, not as a tool to analyse a setup once to see if you are within limits. If you are concerned about limits, generally it means you are close to them. The reality is, every camping trip, the trailer is loaded differently based on location, duration and number of people. It is also loaded differently on the way to your destination vs the way home. Over the years, you accumulate more things in the trailer and it becomes heavier. Depending on the length of the trip, more or less items will be in the truck, the list goes on. As an example, my V10 Excursion has a 44 gallon fuel tank located behind the rear axle. Dependent on how much gas is in the tank, the dynamics change during the trip.
Usually when engineers design things or analyze them to this degree, there is a 33 1/3% factor of safety involved. That factor of safety usually covers things like uneven load, shifting weights, etc. I never see the factor of safety included in these analysis and that is why some people end up not being happy with their setups. The factor of safety was probably (I don't know for sure) included when the limits analyzed with the utility were set by the manufacturers, so I believe there is some wiggle room either way with respect to weight limits, but the same factor of safety should be used when analyzing your weights. I'm not saying a 1 ton dually is needed to tow a popup, but rest assured, when the owner says he doesn't know it's back there, he's telling the truth (even if it's swaying all over the place)
