Angib & Others: balance spreadsheet, I'm confused!!!

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Angib & Others: balance spreadsheet, I'm confused!!!

Postby kirtsjc » Wed Jul 26, 2006 5:08 pm

OK, confused :? about some numbers input on Angib's spreadsheet:

Here is my numbers so far:

A = 114
B = 145
C = 49

No D1, D1, D3 or EW1, EW2, EW3 numbers were entered as the trailer is "empty." (explained below in parens)

Tongue is 60 pounds (the spare tire and it's bracket on the curb side, with the jack 6" back from the hitch ball center.)
"Street" side weight at tyre is 300 pounds.

"Curb" side weight at tyre is 325 pounds (because of the battery on that side) giving me a total of 685 pounds to put in weight box area.


So, what numbers (the red ones) am I supposed to input for:

"weight of tongue" and "weight of axle/suspension (currently they set for 5% and 30%).

Using what numbers I can, my weight of 685 pounds does not come out correctly in that I have 445.25 pounds as a result at the bottom of the basic weights section.

Without knowing what I am supposed to enter in place of the 5% and the 30% defaults, my weight on axle is (619 pounds) 90.4%, and my weight on hitch is (66) 9.6% and my weight on each wheel is 310. I also notice that the results say that I have gained 6 (66) pounds from what my weight is on the tounge (60 pounds.)

What am I doing not right? :roll: :cry:

(I did put all three points on a 2X4, leveled the trailer, and then moved the scale around all three points, checking the level each time. I know my scale is good and "accurate", as I was just weighed at the Dr.'s office last Friday, and I set my home scale to match that weight of 200 pounds. I also used a measured stick from the ball center to the scale for "accuracy".)

I thank you all in advance, and await your responses with wormy respiration (baited breath.) :roll: If you wish to send me Angib's spreadsheet showing me where I am goofing up, pelase do so at
kirtsjc @ cinci .rr .com

Thanks again!
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Postby angib » Wed Jul 26, 2006 6:07 pm

If you've already weighed your trailer, then the trailer balance spreadsheet is of no use to you! You've already measured the answers that the spreadsheet tries to give.

You've got 60lb on the tongue (on the hitch?), out of a total of 300+325+60=685lb, so that's under 9% which is a little bit low - the optimum range is generally given as 10-15%. However you're probably quoting the weight of the empty trailer, so when you load it up you want to put any heavy items in the front of the cabin and not in the galley. That will bring your hitch weight up and make the trailer tow well.

Andrew
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Postby angib » Wed Jul 26, 2006 6:20 pm

Now that I think of it, it's interesting (to me, at least!) to see how accurate the spreadsheet was in estimating your trailer's balance, so here it is:

Image

So this isn't too far out (76lb estimated vs 60lb actual).

Andrew
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Postby kirtsjc » Wed Jul 26, 2006 8:25 pm

angib wrote:Now that I think of it, it's interesting (to me, at least!) to see how accurate the spreadsheet was in estimating your trailer's balance, so here it is:


So this isn't too far out (76lb estimated vs 60lb actual).

Andrew


OK, so I now see two things on your picture you did where I goofed:

1) I don't know where I got the 30% on the "weight of axle/suspension" but you are using 12% as a starting number (just re-downloaded your original spreadsheet to find the 12% factor, not my 30%...)

2) The other thing is that I should not be worrying about the difference between the 680 and the 568.55 calculations.

Thank you for your fast reply, and the picture of my results done by you. I spotted the 12% / 30% problem right away!
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