"Rod McInnis" wrote in message ...
"basskisser" wrote in message
om...

Your current thinking is correct, if all things equal, AND if you
didn't consider the torsion of the spring.

What?????

The torsional forces can not have any effect on the trailer balace as long
as the wheels are round or allowed to rotate.

Bull****. Are you telling me that if you have a moment arm, and apply
a torsional spring constant to it, that it won't try to rotate about
the axis of the axle???????? If that is true, then a torsion spring,
and it's ensuing torsional constant, aren't doing any work.

Again, if you put the wheel
at the center of gravity of the boat, it will be balanced.

No, it would need to be at the center of gravity of the boat + trailer.




Trouble is,
when this is done, will the boat's C.G. be at the C.G. of the trailer?

Probably not. Which is why you would want to use the C.G. of boat + trailer
for any calculations.

Duh.....that's why I asked...geez... AND, how do you know WHERE that
center of MASS will be?


See, you could load the boat on the trailer, and the CG of the boat
could be far enough behind that the tongue has a negative load.

A universally true statement. Take any boat and trailer, load the boat far
enough back and the tongue weight will go negative.

So, now you want to talk about center of mass as opposed to center of
gravity?

What's your point?

My point is, he didn't mention the relationship between the center of
mass of the boat, and the center of mass of the trailer.
What is YOUR point? I notice you've not interjected one thing to help.

"basskisser" wrote in message
om...

The torsional forces can not have any effect on the trailer balace as
long
as the wheels are round or allowed to rotate.

Bull****. Are you telling me that if you have a moment arm, and apply
a torsional spring constant to it, that it won't try to rotate about
the axis of the axle????????

Nope. If the wheel is free to rotate (which it will be unless the brakes
are applied AND the wheel is somehow contrained from rotating) then there
will be no moment about the axel.

There will be a moment about the torsion bar, which is NOT the axle .

If that is true, then a torsion spring,
and it's ensuing torsional constant, aren't doing any work.

Correct! Any engineer would be able to tell you that the forces exerted by
a spring (including a torsion bar) do no work when they are at a steady
state condition. A spring will store "potential" energy. While it is
holding that engery it does no work. Work requires a force applied over a
distance. Just an applied force does no work.


Duh.....that's why I asked...geez... AND, how do you know WHERE that
center of MASS will be?

Well, geeze, he said very clearly that he put the boat on the trailer
(actually, he said he put the trailer under the boat) such that the boat was
sitting on the trailer as it was expected to be. Thus, any measurements he
takes will be for the boat + trailer. What each one individually is doesn't
matter for the purpose of this discussion.

So, now you want to talk about center of mass as opposed to center of
gravity?

Nope. On level ground and constant velocity it doesn't matter. To expand
the discussion to include an "accelerated frame of reference" is a lot more
work.

My point is, he didn't mention the relationship between the center of
mass of the boat, and the center of mass of the trailer.

Which is totally irrellavent. He only needs to be concerned about the two
together, which he has taken care of by putting the two together when he
made his measurments.

What is YOUR point? I notice you've not interjected one thing to help.

My point is that some of your comments are false and do nothing but confuse
the issue.

Rod

On Mon, 26 Jan 2004 01:23:21 -0500, "Gary Warner"
wrote:


So the axels that we have are torsion axels (no springs). They will just
attach
directly to the underside of our trailer. The thing is, it's not just a
straight
across axel. Well, the axel goes straight across, but coming from the
center of the axel is a 6" arm that goes back to the spindle. In other
words,
the tires are off-set 6" behind where the axel is.

For a picture go to this web sire (really an Adobe PDF document)
and see page 5 (the 2,300 lb to 3,500 lb Torflex axel).
http://www.redneck-trailer.com/pdf/A/810torflex.pdf


PUZZLER: Does the axel "balance" the weight over the
axel or over the wheels? .

Put another way: Say we had a rectangular frame 20 feel long and
it was perfectly balanced at the 10 point. (No boat or anything on
it yet.) So a straight across axel put at the 10' point, it'd basically
balance. But with our axels, where the wheels are off-set 6"....do
we put the AXEL at that 10' point or do we have the
WHEELS at that 10' point.

Our current thinking is that it's the wheels. It's pretty hard to test
because of the weights involved and we have to weld the axels on
(not bolt 'em) so we'ld like to get it right the first time.

Looking at the specs and not knowing the exact weights involved
(boat/motor and trailer frame), my opinion would be a tad forward of
the wheel's centerline, but with reservations. I have a suspicion
that if you did some basic experimenting, you would find the weight
transfer somewhere between the wheel and axel - more likely towards
the axel than the wheel, but again, not knowing the weights, I can't
say for sure.

Later,

Tom
S. Woodstock, CT
----------
The years will bring their Anodyne,
But I shall never quite forget,
The fish that I had counted mine
And lost before they reached the net.

Colin Ellis, "The Devot Angler" quoted
in A. R. Macdougall, Jr's "The Trout
Fisherman's Bedside Book" (1963)

"Gary Warner" wrote in message ...
So the axels that we have are torsion axels (no springs). They will just
attach
directly to the underside of our trailer. The thing is, it's not just a
straight
across axel. Well, the axel goes straight across, but coming from the
center of the axel is a 6" arm that goes back to the spindle. In other
words,
the tires are off-set 6" behind where the axel is.

For a picture go to this web sire (really an Adobe PDF document)
and see page 5 (the 2,300 lb to 3,500 lb Torflex axel).
http://www.redneck-trailer.com/pdf/A/810torflex.pdf


PUZZLER: Does the axel "balance" the weight over the
axel or over the wheels? .

Put another way: Say we had a rectangular frame 20 feel long and
it was perfectly balanced at the 10 point. (No boat or anything on
it yet.) So a straight across axel put at the 10' point, it'd basically
balance. But with our axels, where the wheels are off-set 6"....do
we put the AXEL at that 10' point or do we have the
WHEELS at that 10' point.

Our current thinking is that it's the wheels. It's pretty hard to test
because of the weights involved and we have to weld the axels on
(not bolt 'em) so we'ld like to get it right the first time.

Gary

Seems to be a pretty good explanition and info on page two of the PDF
you link to unless I am reading the thing wrong. Otherwise, I think
the best bet would be to call them and ask them to clarify for you.
Scotty

Thanks all for the replys.

I will call the company and ask them too, but I always like
the comments and thought processes I get here.

"Gary Warner" wrote in message
...

Thanks all for the replys.

I will call the company and ask them too, but I always like
the comments and thought processes I get here.



Since the axle is fixed to the frame, it is part of the frame. The spindles
go where the axle would go if it were straight across. Consider the vector
through the center of mass of the boat and trailer. It should be just
forward of the center of the spindles which is where the upward vector from
the ground passes up. The remainder of the torque is supplied by the force
upwards on the tongue. Just remember that the sum of the torques about any
point must be zero. So pick a convenient point and draw the force vectors.

del cecchi

On Mon, 26 Jan 2004 13:33:17 +0000, Gary Warner wrote:


Thanks all for the replys.

I will call the company and ask them too, but I always like the comments and
thought processes I get here.

...then you are one sick and twisted individual!

Lloyd

Lloyd Sumpter wrote:

On Mon, 26 Jan 2004 13:33:17 +0000, Gary Warner wrote:


Thanks all for the replys.

I will call the company and ask them too, but I always like the comments and
thought processes I get here.

...then you are one sick and twisted individual!

Lloyd


This from a man who used to have a relationship with a woman known as
Vinyl Valerie.

--
Email sent to is never read.

"Lloyd Sumpter" wrote in message
...

I will call the company and ask them too, but I always like the comments
and
thought processes I get here.

...then you are one sick and twisted individual!

Lloyd


You know, you aren't the first person to make that observation

"Gary Warner" wrote in message
...


PUZZLER: Does the axel "balance" the weight over the
axel or over the wheels? .


Over the wheels.

To be precise, over the point at which the wheel contacts the ground, which
had better be directly under the axel.


A thought just crossed my mind: You should also check the tongue weight
when the trailer is empty. From your description it sounds like you won't
have a problem, but I have seen trailers built for a center engine boat that
had negative tongue weight when the boat was NOT on the trailer.

Rod