[TheForge] treadle hammer design

[Bruce Freeman]

Greetings, George.

My responses are set off below with ">>>":

 george.dixon@mindspring.com 01/24/03 10:52PM=20
Greetings again,
Ahhh, debate.....

"The old abana plan hammer ... is far and away the best hammer I have =
used.  It is a simple striking tool, as treadle hammers were intended to =
be."

>I take issue with the last phrase you use.  Treadle hammers were =
>ORIGINALLY intended to be simple striking tools.  That's fine, and I have =
>no argument with that.  But the implication of your remark is that to =
>take TH design beyond this point is somehow wrong or self-deceiving.  =
>Such an attitude is not a progressive one.

First, I stand by the statement.  Second, an "implication" and an =
"attitude" must be read in to be found.........plus the key word is =
"simple", not "intended"..... some striking tools are simple, some are =
not. =20

>>> C'mon, George.  Who do you think you're kidding?  Your  "as treadle =
hammers were intended to be" sticks out like a sore thumb.  Try to tell me =
you weren't intending to be provocative!

And, lastly on this aspect, no-one ever has mistaken me for "progressive".

>>> Which is fine.  I'm quite glad that folks like you are around to =
maintain traditional approaches.  I'd hate to see them lost.

as to the comparison;  nothing can beat a trained striker - period
no treadle hammer can follow a tool-head at every angle the smith sets it. =
=20

>>> Hmmm... Sounds like a challenge to rise to.  I did a pretty good job =
of this with the Weightless Hammer....

as to the 'ol abana plan vrs other machines (having not used a "grasshopper=
")

>The usuall swing-arm treadle hammer * swings perhaps a 50-lb to 90-lb =
ram;=20
      True - mine is 80

* hits in various places depending upon the height of the work and tooling =
(but has a large enough face that it can usually hit the tooling)=20
	Nope-the variance in 'places hit' is zip..it hits the tool every =
time.

>>> I think you missed my point.  There's a limited distance in which the =
swing-arm ram is over the anvil at all.  As it comes down it moves forward =
until it is completely over the anvil.  If you use short tools like Clay =
Spencer demonstrates, this is no big deal - the hammer will be low enough =
to hit the tool.  But if you used a tall guillotine tool on your treadle =
hammer (okay - so YOU don't use guillotine tools, perhaps, but others do) =
then you might be on the hairy edge of hitting the top die at all.

* - OR - requires adjustment to the height of the work + tooling (which =
means stopping what one's doing, going around to the side of the machine =
and adjusting at least two mechanisms);=20
	Nope, the 'ol abana plan is non-adjustable=20

>>> But the "new abana" plan, namely Clay's swing-arm model, IS adjustable.=
  Just not easily.

* has a fairly limited stroke, throat and clearance around the anvil, =
limiting the work that can be done on it.=20
	Nope: throat =3D 12" to center, stroke is 12+" and the anvil is =
utterly accessible (hollow, with a slot to return the drift). I have yet =
to hit a "limit on the work" it can do.

>>> However the Grasshopper has at least 15" clear in all directions, and =
the first obstacles are the anvil supports, below, and a single 1/8" =
cable, behind.  All other obstacles are even further away.  The Grasshopper=
 also has a 34" stroke, though naturally you'd need some of that to gain =
speed.  Nonetheless, you could put a 12" object (work + tooling) on the =
Grasshopper's anvil and hit it dead center with a full-force swing.  That =
simply can't be matched by any other treadle hammer I've seen.  All others =
use work-arounds.  (Don't get me wrong:  There's nothing wrong with =
work-arounds.  And Clay's short tools are safer, as well as fitting better =
in a treadle hammer.)

* costs the blacksmith considerable effort in fighting the springs.
		Nope: The 8 lifting springs are set once, when the hammer =
is built.  The spring arms are set once, when the unit is built.
The head can be actuated with the flexing of the ankle whilst sitting on a =
bar stool for light work and layout. I have not adjusted springs in 10 =
years.  =20

>>> Some set of ankles you must have there, George! :^)  This could depend =
a lot on how your springs are set.  If you mainly do light work, your ram =
at rest probably sits about 12" above the anvil.  Then light work would be =
easy.  However, if your springs were set for heavy work, you might need a =
longer stroke for momentum, in which case the springs would have to be set =
to raise the ram higher.

>>> I've seen Clay after a demo looking like he'd finished a work-out at a =
gym.  Not exhausted, but clearly he'd been working.

>>> I've read discussions of using a rubber pad or even a spring at the =
top of the stroke to reverse some of the momentum of the rising hammer.  =
I've seen hammers for which such a provision might make sense.  No such =
thing is necessary for the Grasshopper.  A minimum of energy is used to =
raise the ram.

>>> I note with interest that you advocate a hollow anvil.  I don't agree. =
 I designed the Grasshopper to be hard-hitting, and it needs the solid =
anvil for that.  (I've plagiarized Clay's anvil design, with a hardy hole =
from which tools can be retrieved, satisfying somewhat your requirement =
for the anvil.)  The Grasshopperuses a 250+ lb anvil, and brings a 55+ lb =
ram down on it.  Any lighter an anvil and there'd be no point in such a =
heavy hammer.  I've been unable to do any head-to-head comparisons, but I =
suspect that the Grasshopperis the hardest-hitting of any available TH =
plans.

The aforementioned abana hammer is also very inexpensive, by comparison, =
to build.  A more complex, potentially much more expensive treadle hammer =
most likely will not amortize its added cost in added impact value.

>>> No doubt simpler TH's are cheaper to build.  But I seriously doubt =
that's a major consideration.   Much of the material for any TH can be =
scrounged, and folks most in need of a TH are probably well used to =
scrounging.  You get what you pay for.  (But then who am I to tell YOU =
that?!)

>>> Thanks for your response.

>>> One final irrelevant note:  I  keep saying "I" designed the Grasshopper=
.  That's not  quite true.  I designed all the mechanisims, but were I not =
working with a very talented weldor, my good friend Marshall Bienstock, =
this machine would never have come off at all.  At best I might have put =
it together from WOOD (no kidding).  Marshall saw the flaws in my ideas =
every time and set me straight.  So much of the design of the machine is =
due to his knowlege, not mine.

>>> Bruce Freeman