Most of the uses in a home shop would have no problems with the
cheaper sets. There are ways to increase the accuracy of using them,
one being to have them calibrated and have a list of known errors,
adding and subtracting the errors to come up with a known stack, but
for most use this is over kill. For setting up a sine bar, or a
height block, even measuring groove widths, the accuracy of a better
set isn't really needed, that's gage calibration stuff. About the
only thing you might notice, the blocks won't wring together like a
good set, not really a problem, some of the older more expensive sets
won't either after several years of use. More problems are caused by
math errors in the stackup than are caused by errors in the blocks.
The ENCO set I bought came with a calibration list. Using our good set at
work (which just got back from it's yearly calibration) and the Helios
supermic (which has a resolution of .00001, though is probably only good
to .00005) it seemed to be an accurate list. The worst deviation from
nominal on the list was .000024 oversize.
The set I got wrings a hell of a lot better than anything we have at work
right now. The sets there are a few years old, but my new set takes a
fair amount of effort to get the blocks back apart.
That ain't bad. Far more accurate than anyone measuring work in a
home shop environment would normally need.
Yup. So did the Fowlers we had, for about a year. Monochromatic
light and optical flat told the story pretty well after that.
Ted mentions the space blocks, I have a set of those also and use them
more often than my set of blocks. (Detroit Gage, Grade 2, I'm kinda
not prone to put them at risk.) Space blocks normally being sold as
fifty millionths, far more accurate than anything I'm about to attempt
anymore. Time to let the young squirts have at it. DoAll makes a
nice gage setup for using the blocks, I have one, but find if I need
that, I'm more prone to letting someone else do it. (It's nice being
Absolutely!! It's amazing how often they come in handy. In fact,
it's well worth having/buying two or three sets, in my opinion. Try
one, and then keep your eyes open for any sale priced deals.
I have a set of the "Made in China" cylindrical ones that cand be
stacked using supllied Allen head set screws. I compared several
different stack arrangements against a 1"x1-1/2" Brown and Sharp
parallel using a granite surface plate and a height gage with a dial
gage reading tenths mounted on it. None of the arrangements I tested
indicated more than one tenth error. I'm very satisfied with them for
my work. IIRC, I got mine from KBC.
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