Tongue scale?

[patis]

Does anyone have experience with this tongue scale?
Sherline Trailer Tongue Weight Scales

[Ag&Au]

Originally Posted by patis

Does anyone have experience with this tongue scale?
Sherline Trailer Tongue Weight Scales

Yes,

I have one. It works fine. I set it on the platform of a good automotive floor jack and the top in the ball socket on the tongue. You can buy additon guages that you can swap out on the main body. I have 0-1000 and a 0-5000 Lb guages.

Ken.

[boondockdad]

Yup. Works great. Be sure your trailer is dead level, for an accurate read.

[Ag&Au]

Originally Posted by finalcutjoe

Yup. Works great. Be sure your trailer is dead level, for an accurate read.

I have heard that said before. But, as I figure it, even if you are a whole ten degrees off, your result is only going to be off by 1.5%. That was done with high school trig. Anyone care to prove that wrong?

Regards,
Ken

[RLS]

Hmmm, does your equation include the axle weights (different pre - loads of the suspension) and what length the ball is to the axles?

[Ag&Au]

Originally Posted by RLS

Hmmm, does your equation include the axle weights (different pre - loads of the suspension) and what length the ball is to the axles?

The change in distance from the axle(s) is what causes the 1.5% Since we are measuring tongue weight I can't see in what way the preloads of the axles affect it. In the case of dual axles I would use the center of where the two tires touch the ground. It appears to me whatever the front axle contributes will be canceled by the opposite action of the rear axle.
My equation is: the new weight = level weight * Cos(angle the Front of the trailer is high).
The rules are that you can't disprove it without a better equations.
Ken

[RLS]

Changing the rules already I am talking about dual axles. When the ball is lower than level, it puts more load on the front axle which makes the tongue weight less than what it really is. if the ball is higher than level, the rear axle is putting more load on the tongue. Sorry, no equation. I think that is why it needs to be level. The more it is out of level, the more variance in tongue weight.

[Ag&Au]

Originally Posted by RLS

Changing the rules already I am talking about dual axles. When the ball is lower than level, it puts more load on the front axle which makes the tongue weight less than what it really is. if the ball is higher than level, the rear axle is putting more load on the tongue. Sorry, no equation. I think that is why it needs to be level. The more it is out of level, the more variance in tongue weight.

That makes sense, but what is interesting is that effect counteracts the change I was computing and I'm sure effects it more. The only point I am really trying to make is that I believe if the trailer measures anywhere close to level with a simple level, then the measurement is going to be close enough for government work. I should know, I worked for the government for 43 years. Maybe that explains something. At least it ought to convince anyone that it is futile to use logic with me. When I get less lazy I will make an equation to compute that effect for some typical trailer and post it back here.

Regards,
Ken

[r carl]

I think you should weigh it at the height it is when its hooked up to the tow vehicle.

[Ag&Au]

Originally Posted by r carl

I think you should weigh it at the height it is when its hooked up to the tow vehicle.

In my case, I try for that to be level. And if it looks level to me, then, by gosh it is level.

Ken