Rod,

I really like this idea. I think it will be easily doable with the
materials,
scale, and setup we have. Thanks for taking time to draw out that
picture.

Gary


"Rod McInnis" wrote in message
...

"James Gemmill" gemmilljim@hotmail,com wrote in message
...
make a tripod bridge with the scale as one foott of of the tripod.
Multipy the weight shown by three. Use two by sixes and two by fours
for the tripod.


Why a tripod?

My concern is that it over constrains the problem, and you could end up
with
a major error it the weight was not distributed evenly between the three
legs. I suggest using a lever approach instead:

|______| - object being weighed
V=====^================V - lever
ground |scale|

| a | b | - the
distances between


Multiply the reading on the scale by the ratio of b/a. For best results,
make the points of contact (ground, scale and weigh point) as small as
possible so that there is less ambiguity on the distance measurements.

Rod

"Gary Warner" wrote in message
...
Rod,

I really like this idea. I think it will be easily doable with the
materials,
scale, and setup we have. Thanks for taking time to draw out that
picture.

Another feature of this approach is that if you are not sure what the weight
is you can start with a really long lever, then slide the scale point
forward until you are in an appropriate range on the scale. In general,
being as close as you can to "full scale", without going over the limit,
will give you a more accurate measurement.

Rod

Well ... I'll probably get shot for this but ... my boat/trailer weighs in
at about 3000 lbs and I guess I have about 60 lbs tongue weight (because I
can lift it with a bit of effort ... hmmm ... maybe I'll go measure it later
when I'm out setting up the block heater plug in ... man it feels cold
today) which is nowhere near the recommended 10% min. Anyway, by moving the
trailer tower back by about 1/2 inch thereby reducing the tongue weight each
time the boat was in the drink, I arrived at the current setting which is
more stable at highway speeds than when I first started (up to 100 kmh is
very stable even in mild crosswinds, at 110 that uncomfortable feeling sets
in). My opinion the 14" radial (trailer) tires set at 45 lbs contributes a
lot to the stability. Another thing ... because I trailer everywhere, I
chose a trailer with rollers (makes launching in various conditions easier)
and by setting the rear rollers as far apart as possible but still
supporting thet I/O properly, I lowered the height (albeit only slightly)
which I think also contributes to the stability. Additional info ... I'm
trailering with a 3100 lb Cherokee (rated 750 lbs tongue weight).

So assuming your boat/trailer is about 4000 lbs, and assuming proper
wheels/tires for the job (I'd guess you have a tandem), maybe try the 200
lbs to start ...




"Gary Warner" wrote in message
...

We're building our trailer and are in the process of deciding
where to place the axels so that the tongue weight comes out
to 400 to 500 lbs. Our bathroom scale only goes to 200 lbs
or so. And we can't move the trailer & boat to go use the
truck scales at the local yards. Looking online, scales that
go to 500lbs are $600 or so.

So, any ideas on how we can do this measure and/or where to
find (buy or rent) scales without spending too much $$$?

Thanks,
Gary

Gary,

You should be able to rent scales from your friendly local scale dealer.
Most maintain a rental fleet for industrial cycle counts - the higher
capacity scales are used to count castings and other heavy items. You will
have to decide how much money is too much.

Mark Browne

"Gary Warner" wrote in message
...

We're building our trailer and are in the process of deciding
where to place the axels so that the tongue weight comes out
to 400 to 500 lbs. Our bathroom scale only goes to 200 lbs
or so. And we can't move the trailer & boat to go use the
truck scales at the local yards. Looking online, scales that
go to 500lbs are $600 or so.

So, any ideas on how we can do this measure and/or where to
find (buy or rent) scales without spending too much $$$?

Thanks,
Gary

Consider constructing a simple and crude balance type scale. You would need
a fulcrum, a stout plank or piece of steel and some free weights. Set the
desired weight on one end, fulcrum in the center and set the tongue on the
opposite end. Adjust axel position until the scale is more or less balanced.

We're building our trailer and are in the process of deciding
where to place the axels so that the tongue weight comes out
to 400 to 500 lbs. Our bathroom scale only goes to 200 lbs
or so. And we can't move the trailer & boat to go use the
truck scales at the local yards. Looking online, scales that
go to 500lbs are $600 or so.

So, any ideas on how we can do this measure and/or where to
find (buy or rent) scales without spending too much $$$?

Thanks,
Gary

On Sat, 6 Dec 2003 09:01:48 -0500, "Gary Warner"
wrote:
We're building our trailer and are in the process of deciding
where to place the axels so that the tongue weight comes out
to 400 to 500 lbs. Our bathroom scale only goes to 200 lbs
or so. And we can't move the trailer & boat to go use the
truck scales at the local yards. Looking online, scales that
go to 500lbs are $600 or so.

So, any ideas on how we can do this measure and/or where to
find (buy or rent) scales without spending too much $$$?
============================================

Here's a link to the scale that I bought when I was going through the
same excercise as you a

http://www.sherline.com/lm.htm

It's a nice compact little unit that works well, and costs a little
over $100 if my memory is correct. The other suggestions regarding
construction of a balance beam or a tripod will also work, albeit with
slightly more effort.

So, any ideas on how we can do this measure and/or where to
find (buy or rent) scales without spending too much $$$?

Thanks,
Gary


Check out this site: http://www.sherline.com/lmbook.htm#refrn9

They offer a 0-1000 pound scale for $110 retail.

Thank you all for great ideas. Not sure if we'll buy the one
for around $100, make a "H" or tripod, offset with weights
on the back end, or just rent some from a scale company.
But in any case, all great ideas. Thanks!

More detail: Boat + trailer will be about 5000 to 5500 lbs.
We're planning hard to get the boat as low as possible -
without anything hanging too low to the ground. Looks like
the transom will be 28" off the ground. That's because there
is a prop guard that hangs another 18" below that ... leaving
2" clearence to the "cow catcher" that protects everything,
we're 8" off the ground. Don't think I want to go any lower
than that.

Yep, it's a tandem.

We're thinking 400 lbs tongue, so a little less than 10%
tongue. Tires are 14" radials.

Gary

PS: Al Sharpton on Saturday Night Live tonight...that should
be funny no matter what your political bent.




"Gary Warner" wrote in message
...

We're building our trailer and are in the process of deciding
where to place the axels so that the tongue weight comes out
to 400 to 500 lbs. Our bathroom scale only goes to 200 lbs
or so. And we can't move the trailer & boat to go use the
truck scales at the local yards. Looking online, scales that
go to 500lbs are $600 or so.

So, any ideas on how we can do this measure and/or where to
find (buy or rent) scales without spending too much $$$?

Thanks,
Gary

On Sat, 6 Dec 2003 17:17:36 -0500, "Gary Warner"
wrote:

We're thinking 400 lbs tongue, so a little less than 10%
tongue. Tires are 14" radials.

============================

For what it's worth, we ended up a tad over 10% on the tongue weight
and a little extra air pressure on both the trailer tires and rear
truck tires (+5 PSI). With that combination it was rock solid at 75
mph on smooth road, with minimal cross winds. Before the adjustments
it started getting scary just over 55 mph.