[TheForge] treadle hammer anvils

Fri Jan 10 10:52:05 2003

Bob,

    Bruce gets very defensive about    HIS grasshopper.
I agree with you, I don't think the comments were that snide.
But then again , isn't he from N.J.? :~)


dan tull
georgia
abba, afc, S.C. psba, obg,sofa
----- Original Message -----
From: <[email protected]>
To: <[email protected]>
Sent: Friday, January 10, 2003 9:41 AM
Subject: Re: [TheForge] treadle hammer anvils


> bruce,
>
> no doubt you are correct but...how many spencer style swing arm hammers do
you think have been built? how many grasshoppers?
>
> 'how many' may not be an indication of 'how good' (they sell truckloads of
twinkies) but it is an indication of something.
>
> i didn't think phil was denigrating your grasshopper or being snide. he
was just posting his preferences. that's okay.
>
> thanks for your comments on this subject.
>
> bob s.
> ________
>
>
> >As the designer of the Grasshopper, I have to take issue with this
statement.  I'm not at all impressed by your denigrations of the machine.
I don't know whether you intended to be snide, but that's how it comes
across in writing.
> >
> >The Grasshopper is a very simple design.  If you think it's complicated,
you haven't looked past the surface.  Most of the seeming complication is
really (1) the two front-mounted adjustment (which I consider very important
safety features, but which could be simplified considerably by making them
accessible only closer to the points of their actions, and (2) the small
additional complication of the apparatus (eccentric pulley) that renders the
ram completely weightless.
> >
> >In judging the complication of a machine, consider the MOVING parts.  In
the case of Spencer-type swing-arm hammers, there are six moving parts:
Ram, two arms, treadle, connecting rod, and spring(s).  In the case of the
Grasshopper, there are 8 moving parts:  Ram, two arms, two cranks, two
struts, treadle, treadle pulley and cable, and spring(s).  In the Spencer
vertical TH, there are 14 moving parts:  Ram, 8 guide wheels, one arm, one
strut, treadle, connecting rod, and spring(s).  (I've counted multiple
springs as one moving part because in principle a single spring could
replace multiple springs.)  Both the Spencer-type hammers and the
Grasshopper hammer have adjustments.
> >
> >On the Spencer-type swing arm machine, the head height and the connecting
rod can be adjusted, but only from the side.  On the Spencer vertical-motion
machine, the connecting rod can be adjusted, but only from the side.  On the
Grasshopper, there is no need to adjust either of these, but the treadle
height and the "kickback force" (needed only in a weightless treadle hammer)
are adjustable from the front.  My principal reason for placing these at the
front, at the cost of a few more parts and a  little more effort in
fabrication, was to avoid the devastating accidents that can happen while
adjusting a treadle hammer.  Safety first.
> >
> >If you think these "complications" aren't worth the trouble, then you're
fooling yourself.  (You're free to fool yourself as much as you wish, just
don't expect to propagate it over this group without rebuttal.)
> >
> >BTW, many of us have gimpy knees, rendering TH's difficult to use at
best.  The Grasshopper is by far the best treadle hammer for persons who's
knees are no longer as good as they were at age 20.
> >
> >Bruce Freeman
> >NJ
> >
> >>>> [email protected] 01/09/03 06:26PM >>>
> >Hi Bob -
> >
> ><snip>
> >    The grasshopper is to darn complicated a contraption(I spend most of
my
> >time in hi-tech advanced manufacturing and automation) and I guess I like
> >things simple when I'm home in the shop. It looks like a nice science
fair
> >project. If you want to diddle, then the grasshopper will be interesting.
> >Keep it simple. The leg exercise you get will be a benefit anyway - heck,
> >I'm gettin' older and my wife seems to be gettin' faster!! :o))
> ><snip>
> >
> >
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