On Jul 18, 11:56*pm, "DoN. Nichols" wrote:
...
* * * * 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.
...
* * * * * * * * DoN.

Here's a newer model of mine:
http://www.dataweigh.com/products/pr...ProductID=4671
Both were missing the shackle attachments, likely the reason they were
sold cheap.

The indicator point slides on a ~45° ramp on a rotatable plug which is
the gain adjustment. The indicator mounting clamp is the coarse zero
and the scale can be rotated for the fine zero trim.

As a chrome plated factory-made product it's nice and compact but I
think a ring would be easier to machine smooth enough to remove
surface defects at home, and a hydraulic cylinder with gauge easier to
calibrate from measured dimensions.

You could weigh the front axle of your vehicle on the truck scale at a
scrapyard and then use it for your calibration weight.

jsw