"Jon Elson" wrote...
A master precision level is accurate to about .0001" per foot, not exactly
sure what that converts to in arc seconds. I use an electronic level that
is good to a couple arc seconds, and it is more sensitive than I actually
need.

Jon


I make that master level accurate to about 1.7 arc seconds... and a minute
of angle is about 3 thou"/foot so a couple of orders of magnitude away

Dunno if anyone can give a *quantative* answer though? Currently the Big Toy
isn't in working order (still have to hook up the VFD and interface to the
original switchgear and 3-speed motor) so I can't do a parallel-turning
test, but it appears to be level to less than 20 m.o.a. across the boring
table, about 1+1/4 degrees head-down due to a sloping shed floor, and
(possibly thanks to the 2 tons of Old Iron) less than 10 m.o.a. of twist?

Cheers, thanks for the info,

Dave H.
--
(The engineer formerly known as Homeless)

"Rules are for the obedience of fools, and the guidance of wise men" -
Douglas Bader