[TheForge] [OT] Re: Cats, boots (Was: chickens)

[peter fels]

To buy them Mike..
You need quoins of the realm.
Port-a-powert clamshell attachments spread a small space ,but aren't parallel.
Machinists have a similar sort of step block set, but they lack the pinion-like tool.
On a recent project, i needed to expand the inside of a shaped copper tube..
Annealed it and went to the Home depot and bought a  rubber bulb ,sewer line plug that inflates with a hose.
I have 130 PSi water pressure and blew out 2 of them before the job was finished.

On Mar 24, 2011, at 2:37 PM, Mike Spencer wrote:

> 
> Bruce wrote:
> 
>> For "wedge" read "screw" and all your objections disappear. 
> 
> I know this isn't what you're referring to but it's related:
> 
> I was fortunate to be able to take "print shop" in 9th grade.  I
> printed up forms for a bogus laboratory that allowed me to order a lot
> of dangerous and otherwise unobtainable chemicals.  But that's another
> story.
> 
> The print shop had really cool devices called quoins, pairs of iron
> wedges which, when put together on a flat surface, formed a unit with
> parallel sides and a toothed groove down the center.  The teeth formed
> a kind of diagonal rack gear.  A corresponding tip on a T-handled tool
> made a pinion.  When the hand-set type was ready to go, it was placed
> on a stone surface inside a steel frame -- a "chase" -- and the extra
> space mostly filled with blocks of polished hardwood.  But space was
> left for the quoins, which were inserted loosely and in pairs on at
> least one side and one end.
> 
> Then you inserted a wrench -- the pinion-like tool -- into a quoin
> pair and twisted.  That forced the wedge-shaped halves to bypass each
> other and exert enormous force on the block of type.  When this was
> done on both sides or all around, the type was "locked in chase" and
> ready to go to the press.
> 
> Alas, I've never come across any of those quoins to put in my tool box
> but I have come across some places where they'd have been handy,
> places where I wanted to exert considerable force from the inside of
> something outward but had severe space limitations.
> 
> In earlier centuries, printers used wooden wedges tapped into place
> with a hammer.  The iron ones, though, always impressed me as a
> landmark of technological and blacksmitherly cleverness.
> 
> I don't *think* that's way off topic.  Opinions may vary. :-)
> 
> - Mike
> 
> -- 
> Michael Spencer                  Nova Scotia, Canada       .~. 
>                                                           /V\ 
> mspencer at tallships.ca                                     /( )\
> http://home.tallships.ca/mspencer/                        ^^-^^
> 
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