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Jim Wilkins[_2_] Jim Wilkins[_2_] is offline
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Default Digital Scales, Recalibration?


"Kristian Ukkonen" wrote in message
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Actually! The easy way is to use PULL instead of push there..
A digital fish scale or such ready-made-cheap-load-cell could
then be used directly to pull the cable a known amount (angle).
Then it becames a vector sum of the forces, I think..

Of course, it is not an on-line measurement, but one-shot..


That is an advantage since it doesn't have to be waterproof.

It will have to account for the bending resistance of the cable as
well as the geometry, unless you use webbing.

The last time this subject came up, it quieted after I suggested a
pressure gauge on a pullback ram.
http://www.chinahydraulicjacks.com/b...ram_201056.jpg

I put the gauge on a tee so it can apply the tension as well as
measure it. It's long and heavy and awkward to use, and the short
stroke won't take up the droop and stretch on a long steel cable, but
it's enough to test fittings.

The weight of this gear is very significant when you try to hold both
cable ends together with one hand and screw in the final shackle pin
with the other. I use a 2" ratchet cargo strap hooked to the fixed
anchor and attached to the cable with a prusik loop to pull in the
slack.
http://www2.worksafebc.com/i/guideli.../guide11-2.gif
Pull the strap through the split pin to tighten the line hand-tight,
then secure it with the ratchet, a one-hand operation. On mine the
ratchet lever can pull up to 1000 lbs for a short distance.

jsw