[TheForge] treadle hammer anvils

[Bruce Freeman]

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. =20

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. =20

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-motio=
n 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

>>> pstanley@twcny.rr.com 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>