[TheForge] Answers to the questions posted earlier about the Bull Hammers

[GHS]

Ralph, 
At least I think it was you, Ralph, had
some questions about the Bull Power
Hammer.
I posted Tom Troszak, its developer, and
sent him a copy of your post to
theforge.
I got this novella in response.  I hope
that this answers the questions.

Dear Mike,

Thanks for the copy of the posting.  I
don't think I quite understand
the description of the problem, other
than the fact that the guy didn't
like the hammer after 30 seconds of use.
Since I do not have time to
participate or even lurk on discussion
lists, please post this to your
group and invite anyone to contact us.

The Bull hammers do not operate like a
mechanical hammer, or a
Kinyon-style hammer. If someone is very
used to the operation of their
own hammer, the Bull hammer will
definitely feel different at first. The
use of the treadle on a Bull hammer is
just a completely different
paradigm from the treadle on a Little
Giant, and requires a slightly
different mindset or approach. I wanted
the Bull hammers to be more than
just a drawing hammer, and I started
with a completely different concept
in mind. The fine control (during
drawing) is better than any hammer I
am aware of, and the Bull hammer can
strike single blows, identical
repeating blows, fast, fast light
planishing blows, and clamp for
twisting. 

Interestingly, people who have never
used any hammer before at all (even
non-blacksmiths) can usually draw a
taper on a paper clip on the first
try (or perform the matchbox trick)
using the Bull 125, due to the
exceptional control. 

The guys who expect (or want) the Bull
hammer to act exactly like "their
hammer at home" are the ones who are
sometimes a little surprised at
first. I watched some experienced
powerhammer blacksmiths trying out the
Bull 125, and observed a trend. 
Blacksmiths who have mechanical or
self-contained hammers are used to
standing on the treadle of a their
hammer to achieve full power for
drawing. 

As you push the treadle of the Bull
hammer down, the hammer strikes
faster and harder, but the further down
you go, the shorter the strokes
get, and eventually the hammer stops
cycling and clamps. This may be the
"jackhammer mode" that the guy was
talking about. Perhaps if he had
taken a few minutes to play with it, he
would have figured out that full
power is found at about 75% of the full
treadle movement, not at the
bottom. I call it "surfing" the treadle.
Single blows are achieved by
"tapping" or stomping quickly on the
treadle. The blows can be light, or
soft, or identical repeating, depending
on the throttle setting

Of the particular blacksmiths I watched,
three out of four picked up on
the deal right away, but the fourth guy
never could find the "sweet
spot".  So I came back to the shop and
made a few mods to the linkage
and came up with a "no-clamp" mode for
drawing which allows the treadle
to be depressed fully, and the hammer
just keeps on cycling at full
power. This mod has been included on all
new Bull hammers, and can be
retrofitted to the older ones. I think
it will help smooth the
transition for people who are expecting
"the same old response" when
they stomp on the treadle of a Bull
hammer.  But, if you are only using
a Bull hammer for drawing tapers, you
are definitely missing 4/5 of the
fun and advantage of owning one.

If I understand correctly, there was
also a question floating around on
how the pneumatic controls on the Bull
compare with the controls on a
Kinyon-style hammer. 

The answer is simple, the controls on
the Bull hammers are really not
related at all to the controls on a
Kinyon-style hammer. I had not seen
Ron's design before I made my first
hammer, so I started with my own
ideas. Ron's design is brilliant, but I
am kind of glad I had never seen
it when I started, because it would not
have worked for what I was
trying to achieve.

The Bullhammer pneumatic controls are
actually simpler than the
Kinyon-style hammer. The pneumatic
system consists of:

(1) 4-way 5 port valve - spring return
(used as the pilot valve)
(1) 4-way 5 port valve - double air
pilot (main valve)
(1) Throttle valve (on the exhaust side)

That's it. The reason that the bull
hammers are able to do all of the
different things (strike, draw, planish,
clamp, etc.) is because of a
simple clever mechanical linkage (patent
pending, by the way) between
the ram and the pilot valve. The
relationship between the movement of
the treadle, the throttle, and the ram
can be configured (in about a
second) to achieve all of the different
actions. 

Using a double air-pilot main valve (on
the Bull) gives a snappier
response than the spring return valve
used on the Kinyon hammer,
mounting the cylinder rod-end-up (on the
Bull) takes care of the
diffential pressure issue, gives much
better control, a faster cycle
rate (all other things being equal) and
uses less air to boot. 

There are NO other regulators, "pressure
sensing switches", voodoo, or
imaginary crap. If anyone wants to know
how it works, look at one. We
keep a couple of demo hammers in our
shop, anyone is welcome to visit
and check them out. We have more than
300 hammers around the world
including, USA, Canada, Mexico, UK,
Australia, Switzerland, Iceland,
Phillipines, and more on the way. Unless
you live on an asteroid (or
Antarctica) you are probably within a
day's drive of one.  Just call and
tell us where you are, and we will
gladly put you in touch with the
nearest customer. 

If any "backyard bombers" on the list
really want to see what is going
on, all they have to do is call and
pretend like they are interested in
buying a hammer, and they will get a
copy of the video. Even if you are
not interested in buying one for real,
we would appreciate the
opportunity to show you the profound
difference of the Bull hammer. You
could even be brave and just say you are
building a hammer and looking
for advice...

Lastly, but certainly not least(ly), we
would like all of you on the
list to know that we are pleased to help
with homebuilt hammer projects.
Quite a number of homebuilt hammers have
been constructed to take
advantage of our standard die system,
and we have fabricated some custom
dies for home built hammers. 

I am actively developing a complete
"power unit" including a ram,
cylinder, and the control mechanism
based on the new Bull 75 hammer
design, this would be sold complete and
ready to bolt or weld onto a
homebuilt or "junkyard" frame. This unit
would have all of the same
control features as the standard
production hammers. If anyone is
interested, please call and we'll add
you to the list, and notify you
when the units are ready to ship.

Sorry we missed Abana, we are just too
busy. We have many hammers on
order, we are hiring more help to
increase production, and I am
traveling to Mexico to train and set up
in some factories there, and we
now have a Bull 250 in production...
busy, busy busy...

Thanks,
Tom Troszak

P.S. If anyone is interested, we have a
website:
http:www.bullhammer.com  
and there are quicktime movies of the
Bull 125 doing drawing,
planishing, etc:
http://www.bullhammer.com/bullmovies.htm 
There are also some new projects
illustrated: 
http://www.bullhammer.com/bullprojects.htm

-- 
my website is
http://www.execpc.com/~ghs/