On 2011-07-18, wrote:
On Sun, 17 Jul 2011 04:43:07 -0700 (PDT), Jim Wilkins
wrote:

On Jul 16, 11:18*pm, wrote:

[ ... ]

My 10,000 # load cell is a pressure gage on a cylinder like this:
http://www.harborfreight.com/10-ton-...ram-95979.html

I had to go to YouTube to see what this does. Is there much call for
moving 10-ton objects 11 mm? However, I can see the use to measure the
load exerted. Do you have a special pressure gauge filled with liquid?

Not just the inside of the gauge, but also the area behind the
glass -- presumably to both add damping to the movement, and to reduce
the shrapnel if it fails.

You might find a spring scale for weighing fish/deer/moose in a
sporting goods store.
http://www.harborfreight.com/hand-he...ale-97227.html

Oddly enough that was the only bright idea I had myself. It may be the
only practical one, too :-)

Actually, maybe not. Don N gave me another idea: Rather than
strengthening the bar that holds the screw use the same one and
measure its deflection by a dial indicator.

This was not to measure the deflection of the screw or the
frame, but rather the deflection of the frame built around the dial
indicator. A simple example is a short length of steel pipe large
enough to hold the indicator, with the indicator mounted to one side,
and the point pressing against the space to the opposite side. You
either apply force between the mounting point of the indicator and the
opposite wall, or at 90 degrees to that -- in which case the measured
diameter increases instead of decreasing.

The trick is calibrating it -- which requires known forces to
measure.

Others would be a heavy chunk of steel machined to be an open
'C', with the indicator measuring the distance between the ends of the
'C' -- and the force applied to lips of the 'C'. Again, you will need
some way to calibrate it.

Here is one on eBay -- but one without a dial indicator built
in. You have to have some special electronics connected to it to
measure the output -- or know enough about electronics and have enough
test equipment to build your own -- and be able to look up the connector
pinout and such from the maker (if still in business).

eBay auction # 380337072665 -- $299.99

Enjoy,
DoN.

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