From: Robert Bastow <"teenut"@ hotmail.com>
Subject: Re: 1,2,3 blocks setup & monograph &/or text
Date: Tue, 25 Apr 2000 12:34:51 GMT
> Most of the 1,2,3 blocks you buy are hardened. We don't really need
> hardened, we just kiss them off on the surface grinder if they're out
> some. For our purposes they don't have to be exactly 1.00 or 2.00. They
> can be any needed size as long as they're accurate.
As a LOOONNNGG time T & D Maker, Machine tool Fitter and Job Shop
Machinist/Owner I can assure you that SOFT 1-2-3 blocks that are NOT dead
square, accurate and made to aliquot dimensions, are as useless as tits on a
bull..AS 1-2-3 BLOCKS!!!
There is a definite need in any Tool Room or Jobbing Shop for lots of
PACKERS..The more the merrier, in as many different sizes as possible. It is not
Economically possible to have them all ground and hardened. Indeed it isn't
even desireable as, many times, the set up may require cutting or drilling right
through the workpiece and into the packing materials. In a jobbing shop any
offcut eventually becomes short enough to toss into the
Pairs of parallels are another, separate requirement. To be of any reliable
long term use they must be hardened and accurately ground in pairs. The best
ones are accurate in two dimensions..say 1/4 x 1/2 or 3/8 x 3/4. Their value is
increased enormously if they are ground to accurate, aliquot dimensions as then,
two or more can be stacked together to equal a thir one. Better still they have
holes drilled in the larger ones..for lightness, and for ease of bolting during
1-2-3 blocks serve a separate and specific purpose for which it is mandatary
that they are hardened and ground accurately in pairs..but also to a common
dimension so that two or more PAIRS can be used together.
Yes they can be used as simple parallels, but their main, intended use is as
high precision set up, layout and inspection aids. They are usually found in
the Toolroom or Inspection/Metrology Lab.
Two 1-2-3 Blocks, on their own have limited use..They should, at least, be
equipped with a set of screws or studs of varying lengths so they can be bolted
together in pairs to form custom sizes, angle plates, vee blocks etc.
A complete set, as supplied by Jig Borer Manufacturers like DeVlieg, S.I.P.
Hauser, Deckel and Moore Tool are invariably in sets that include (at very
least) one or two pairs of 1x2x3 blocks, 1/2 x 3/4 x 1 1/2 and possibly even 2 x
4 x 6. All as accurately ground and lapped as Gauge Blocks and complete with a
full suite of studs and accessories. With these a "Custom Made" fixtur or jig
can be rappidly and accuratel put together.
> Our uses are getting whatever we're grinding off the table of the
> surface grinder or way grinder, so we can mic for thickness. We put our
> blocks 25% of the way into or under our parts and grind accordingly.