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10K psi and 2.5K psi hydraulics


#1

was: Enerpac hydraulic pump

I’m interested in seeing what Kevin Potter comes up with using 2,500
psi hydraulics, not because I plan on going that route, but because
it’s an idea that was interesting to me a long time ago, before I got
set up with proper 10,000 psi hydraulics. Set up properly with 10K
hydraulics. 10,000 p.s.i. hydraulics set up properly, I should say,
because at first my setup wasn’t all that proper, at least not in the
aesthetic sense. The first one was a hand-pumped, 50 ton cheapo…but
I digress. Before I even had a press, way back in the Dark Ages, the
midlle-later 1980’s, back when I was working with the guys who
couldn’t afford to pay me, so they made me a partner, back when I
first started …but I digress some more… way back then, we went
to meet a guy who explained to us in very simple terms how to set up
a press with garbage-truck haydraulics. Niether Dave Updike or myself
understood much about what the guy was saying, except that it was
going to be easy, just get a big ol’ pump and a big ol’ ram and weld
up a big ol’ press frame and there you go. So we got the hand-pump,
50 ton jack press instead. It was later, when I was ready for some
upgrading, that I was talking to Lee Marshall about using these
industrial, 2,500 psi systems, and I remember a little about him
telling me why he went with 10,000 psi systems instead. Something
about the bulky, noisy pumps needed to deliver 20 -50 tons at the
lower pressure. So now I’m interested in what Kevin comes up with,
and what Lee has to say as far as refreshing my memory about the
details of that comparison.

Dar
Shelton www.sheltech.net


#2

Im a bit confused with your post.

The way I see it is hydraulic pressure is the pounds per sq in
delivered by the pump, subject to its design limits and and relief
valve setting.

The load in pounds or tons will therefore depend on this pressure
times the dia of the cylinder.

this for example on my coining press, with a 9in piston running at
max pressure of 10,000 psi pump pressure, will give me a total load
available of 284 tons. ie pi R squared. I can apply this over what
area I want, within the limits of the press construction and tooling.

I can tell you its a die breaker!!.

Just taking an ole truck pump a big ole cyl and some steel work
welded up is asking for trouble.

do the math, and over build it.

Your messing with lots of energy. could lead to a nasty accident. If
youve never seen a hyd hose burst at 2500 psi. you better not be in
the way.

Hyd presses have their limitations, they deliver energy slowly in
comparision to a drop hammer.

These will give 100 tons by impact in a 50th of a second. They do
work a hyd press cant do.

My medium drop hammer can fall some 3ft, with a hammer weight of
275lbs. Ideal for hot striking in a collar. Beautiful results. Better
than coin proof quality from our royal mint.


#3

There are only a handful of companies making 10,000 psi pumps. They
are used for special purposes like low volume intermittent use.
Aside from these few makers, the rest of the world is using low
pressure systems because they are reliable, quiet, inexpensive, easy
to repair, and safe. If 10,000 psi systems were so great they would
be used in airplanes, dump trucks, trash compactors, industrial
hydraulic presses and all manner of hydraulic applications. The
reason they were invented is for compact high power use. It is
convenient to go out and buy a small pump and cylinder, I have done
it and it works, but not for long and when it goes out there are
very few places that will fix these pumps. I know because some of my
customers have had to get them serviced and so have I, and so has
Dar.

I didn’t like what I was told and neither did my customers. The
pumps are basically disposable even when they cost thousands of
dollars.

I figured I needed to fix this problem so I made a small compact
system. It is 1hp, 2,500psi, 110 volt, pumps a half gallon per
minute, it is totally re-buildable and is a fraction of the cost of
a 10,000 psi system. You can plug this into any outlet in your
house-no special plugs or electric needs. It is not noisy. It is a
little bigger but not by much, I could make it even smaller but I
want to use standard off-the-shelf stuff. The system is US made. The
only part I am not sure of is the orange pendant switch because it
had no manufacture data available. I have been using thesesystems
for years in very harsh ways and they have not failed. The only
systems that have ever failed have been my 10,000psi systems and
they cost a fortune to repair and I had to send it out, it took them
months to get around to fixing it. My new system could be repaired
in minutes or with a phone call and the parts can be found locally
all over the world.

By making it more affordable, more people will be able to make more
efficient use of their hydraulic presses.

Kevin
www.potterusa.com


#4

Potter USA, Kevin’s 2,500 p.s.i. hydraulic setup

Hey Kevin, I just watched the demo video and have some
questions/issues. It all looks and sounds hunk-dory but you scared
even me (or especially me ?) when you said you made your own ram.
Making one’s own ram is not something one usually wants to consider
having to do when one contemplates acquiring a hydraulic system, at
least I’m pretty certain it isn’t something many (or any) jewelry/art
metalsmiths get excited about when they get excited about hydraulics.
So please explain more about how you built your own cylinder and how
buildable such cylinders might be for those not as mechanically adept
as yourself, or how available and affordable such cylinders might be
for those not particularly mechanically adept at all. Next, I have an
issue with speed, if I were to contemplate contemplating acquiring
such a system, because I have a need for speed, and lots (but not
unsafe amounts) of it. How much bigger and more costly might it be to
have a pump that moves the ram 2-3 times as fast, and takes as little
as 5 seconds to get to, say, 50 tons ?. If you are going to offer low
pressure systems as an advantageous alternative to the high pressure
ones we’re used to, there are some relatively tough questions out
there that you’ll have to have answers for. Like starting now,
because I am actually contemplating getting a pump to replace my
Enerpac that croaked, and if I can get a pump and a ram for less than
just a pump would otherwise cost, I’m interested. The 1/2 gallon per
min= ute flow rate you state does sound like an awful lot, but is
that the rate at high pressure?. the PT and Enerpac pumps I’ve had
are multi-speed and deliver less volume at high pressure, which is
fine, because generally the work is engaged at the point of contact
and the high pressure ‘gear’ kicks in and the ram doesn’t have to
really travel any more, only needing to build up pressure. Next,
there’s the issue of control mechanism; for me, you’d have to offer a
foot control that doesn’t need to be pushed one pedal for up and one
for down, which means I’d want a single acting, spring-return
cylinder, and a common on/off foot switch. Also, you say that the
pump in the video can pump 5,000 p.s.i., but does that mean the
system is meant to operate at 5,000 p.s.i., with plenty of headroom
for safety. The hose I get for for 10,000 p.s.i. is tested at 20,000,
and all the fittings, etc, all have similar headroom, so what are the
numbers behind your demo system?. If I get a 5,000 p.s.i. pump, where
has it been tested to, and can I expect to operate it long-term at
5,000 p.s.i., or is it merely tested and rated at 5,000, but expected
and intended to be used at 2,500?. This matters not just for obvious
reasons, but because of the matter of deliverable tonnage when using
the same cylinder as was being used at 10,000, but switching to 5,000
(or 2,500). I’m perfectly set up with my 25 ton presses that move at
about an inch per second, and take 5 seconds to reach 25 tons, but
the pump that does that takes a little longer when asked to push my
50 ton ram . Common sense (and physics, actually) dictate that 5,000
p.s.i. would only deliver 25 tons in a ram that delivers 50 tons at
10,000 p.s.i., so I have to ask about this too. I’m sure I’ll think
of more things, but if you want to email me with a general estimate
of what I’d be looking at pricewise for a setup to replace my 50 ton
ram and pump, I’d greatly appreciate it. Five seconds to full
tonnage, single acting, spring return, foot switch. These are all
features I take for granted, but wouldn’t expect you to incorporate
into production models. But I think that these are all important
considerations for you, in your effort to offer alternatives to what
we’re familiar with. Thanks (and you’re welco= me (winks)),

Dar Shelton
sheltech.net


#5

2500psi system

Hi Ted the hydraulic system in my press is fully engineered and
tested, I did nothing more than select the components to work
together. I built the cylinder using tubing that is manufactured for
the hydraulic industry and pistons and glands that are designed to
work with it. The cylinder is welded by a certified pressure vessel
welder. He also does the frames. The royal canadian mint has one of
my presses and GM has one of the 50 ton versions.

There are several hundred in use all over the world it is not just a
bunch of metal welded together with a truck pump. I have seen many
of those and they are scary, did you by chance watch the video are
we talking about the same thing here.


#6

Yes, ive seen your video and as your a commercial press maker, you
im sure will have done your math and testing to cover your public
liability risks.

I was replying to Dan Shelton’s post where he said he had friends
that suggested he make his own press, out of scrap truck parts and
structural steel left overs. Thats fine IF you know what your doing,
but if you dont,as I said, your asking for trouble.

If you feel I was making some sort of criticism of your work, I was
not.

As for doing structural steel work, yes I have the workshop to do
this and the equipment.

I mentioned my drop hammers.

They are standard Hazelwood and Dent Birmingham jewellery quarter
tools, designed to be permanently installed in a factory. Mine date
from 1880. however I decided I wanted to make one fully portable, so
I could take it to an event, like the Dorset Steam fair, where 50,000
people come over 5 days.

there I would mint a commemorative plaque with it FOR the event AT
the event.

To make the drop stamp fully portable ie, dismantleable, it weighs
over 1ton, I had to do all my own steel work. the base on which its
built is an all welded frame from which everything else is built up.

As no one had done this before, I had to develop a design that
replicates its factory installation.

The anvil alone weighs 1000 lbs!.

Then there are the logististics of transportation assembly, its
exhibition display tentage etc.

so I have the appropriate commercial truck into which everything
fits. Was it worth doing?

no question!

The first time I did that was in 1989.

Didnt stop minting for the 5 days. produced 1000 which sold off the
hammer. So as Ive said before If you have the equipment, you can do
almost anything. Throughout the 1990’s I had more work for this
equipment that I could cope with. Getting back to hydraulics, most of
what I have is standard 2500 psi agricultural tractor stuff. Any rams
I might use are of existing hydraulic systems like JCB back actors.
My arc welder is a 200 amp 100 % duty cycle oil filled running off a
20 kva diesel generator. all big kit. Nothing’s broke yet!! Currently
building a 20 ton log splitter.

Hope this helps.
Ted.


#7

Hi Dar, good questions.

I will start with the cylinder. I would not expect a jeweler to be
able to make a hydraulic cylinder. I make them because I build
hydraulic presses. Here are the details. I start with with a piece of
honed steel tubing it is ST52.3 it has a half inch wall thickness,
then I machine an endcap for the bottom, the piston is an off the
shelf item- it is ductile iron with 2 sets of seals. The rod is made
of induction hardened chrome rod it is 1050c with a rockwell of 72
and a yield strength of 100,000 psi. The rod is 2 inch diameter. I
then thread the housing to accept an off the shelf screw in double
sealed gland. I machine ports for the dual acting cylinder that way
you have power up and power down. Spring return is a waste of time, I
can set the ram at any position and leave it.

The hoses are 5,000 psi Parker Hanifan hoses with stainless fittings
swedged on. The pump in the video is a low volume pump. You can
easily up the speed with a higher gpm pump. I run a 22 gallon per
minute pump with a 20 hp motor and 20 gallons of oil on my forging
press. If you go with a 1 gallonper minute pump you could double the
speed of the one in the video and still use 1hp.

There are foot pedal attachments for the solinoid switches or
pendant control. To get a 50 ton press with good speed you will need
at least a 1-2 hp motor and a 1-1/2 gallon per min pump. Since you
are doing production I would get a pump with a filter. The pumps are
adjustable. There are hundreds of different models available with
different pressure and flow characteristics. There are 2 stage
versions with a high pressure side and a high volume low pressure
side. There are single stage pumps, they usually need more hp.

If you want a 50 ton system it could be put together for $1,500
bucks if you have the cylinder. A cylinder that would produce 50
tons would be 6 inches in diameter with 3500psi. That would get you
98,000 lbs of force roughly. A 6 inch bore, 8 inch stroke cylinder
off the shelf, made in USA is about 600 dollars. If you want to go
big you can get an 8 inch bore cylinder for about 1,500 bucks. These
are commericially produced cylinders nothing special or hard to
find. The big question is do you need 50 tons for every push or are
you really only using 25 tons. If you are using 50 tons on every
push it is no wonder your pumps died.

To make a system that lasts you need lots of oil and filters. I have
found that my pancake dies need about 6 tons to push and all the
other jewelry type things take less than that. Embossing and coining
can take all 20 tons.

For coins bigger than a nickle in size I need 50 tons and for stuff
the size of a quarter and up I need 100 tons to get a nice
impression. Enerpac stuff has its place, I use the stuff but not for
high production. I just finished a 100 ton table top press today and
it uses an enerpac 100 ton cylinder and pump but it is going to a
shop that is doing lamination and it won’t be run all day everyday.
Here is a video of it.


#8

As far as drop hammers or pneumatics for what I use a press for,
neither one is a very good choice. With pancake dies, even though I
usually don’t temper them particularly hard, they are still somewhat
brittle and don’t like the shock of sudden impact with force behind
it. That’s why you’re not supposed to use hammers on them. Flywheel
presses, punch presses, and clicker presses are also not ideal for
pancake blanking, for the same reason, though this isn’t to say that
fast-acting presses are strictly verbotten. You’re just asking for
trouble when you start banging on these dies, mostly, and especially
on ones with any sort of intricate design. Then there’s the issue of
spreading the force out over the entire work area of the die, which
is exactly what the large, flat steel platens in all the ready-to-go
presses do. I’m not familiar withdrop hammers, but I expect it would
be easy enough to adapt the business end of one so that it
distributes the force evenly over a large are, so again, it doesn’t
completely rule them out for pancake blanking. Next comes the area
where most of the jewelry metalworking is done, as far as using
presses, as far as the individual user and small companies go, as
opposed to mass production factories, and that’s the area of forming
and embossing. What most of the people reading this are familiar with
is using urethane pads and forming tools that are readily available
or fairly easily made, and they’re familiar with using hydraulic jack
presses or the Bonny Doon or Potter equipment. I’m sure some are
familiar with drop hammers and would know which applications might be
suited for either drop hammers or hydraulics, but I imagine many more
average bears know about jack or hydraulic (yes, a jack is a
hydraulic device) presses than know about drop hammers, but that
isn’t even the point. The point is about the convenience, and mostly
the control of force, the ability to instantly control the amount of
force applied, that gives hydraulics a big advantage, in my opinion.
I don’t have anything against drop hammers; I’m just not sure I
really have a use for one, since I already have hydraulics. As far as
pressure ratings and tonnage, so far in my posts I’m almost always
referring to 10,000 p.s.i. systems, since that’s what I have, so my
50 ton or 25 ton ram delivers the stated force when it’s being pumped
with oil at 10,000 p.s.i… I briefly started to talk about it another
way in asking Kevin all the questions I just did, like saying that my
50 ton ram would only deliver 25 tons if it was only being pumped
with oil at 5,000 p.s.i. . This should clarify my statemnts about it.
I don’t like getting all complicated with figuring ram surface areas
and diameters and all that; I just go by the stated tonnage of a ram,
working at a given pressure. Deliver 10K psi to my 10K psi,25 ton
cylinder and it pushes with 25 tons of force over the area of it’s
ram’s end. Givemy 10Kpsi, 50 ton-rated cylinder 10K psi and it
delivers 50 tons, butif it only gets 5K psi of oil, it only pushes
with 25 tons of force, or if it only gets 2,500 psi it can only push
12.5 tons.

Dar Shelton
www.sheltech.net


#9

I think Ill need to clarify what drop hammers were developed for.

so first a bit of history.

The birmingham jewellery quarter grew in the late 1800’s on the back
of the riches created by the wealth of the British empire. By then it
was already mechanised for production runs of many hundreds of
identical products as follows.

In the absence of hydraulics, all processes of delivering energy
were mechanical.

so for the initial blanking out of shapes, hand operated screw
presses called fly presses were used with what is called open tooling
this was a punch in half hard steel screwed up into the sliding part
of the press which registered in a die held down on the press base in
a bloster.

these presses were accurate to the point where the punch would
consistently align itself accurately over many hundreds of blanks.
The dies were always made from crucible steel fire welded to a
wrought iron base usually an inch thick. this was hardened hard.

so when the punch became blunt, one removed it hammered it to swell
it and broached it through the die.

These presses were also used for bending doming folding upsetting
edges. almost no limitation to what tooling one could put in them.
The best maker was Sweeny Blocksidge, and I have several of these.
Beautifully made and precise to 1000th in.

They range from 1 ton rating to 10 tons. however they would not nor
were used for the next much more energy intensive forming. this is
where the drop hammer came in.

Basically this is a cast iron weight ranging from 50 lbs to 250lbs
sliding between guides also of cast iron, set up abve a cast iron
base usually 10 times the hammer weight also in cast iron, builtonto
a very hard base of cement and stone.

the lift mechanism was a sisal or hemp rope over the top of a cast
iron flanged lift wheel some 2ft in diameter driven by the line
shafting it was fixed to.

the operator was in a trench in front of the base so the working
height was at waist level.

He pulled the rope down onto the lift wheel which by friction lifted
the hammer to what height he needed to do the work.

he let the hammer fall and caught it on the rebound with the rope
and set it in the parking position with the safety catch. Then changed
the work piece for a fresh one. Made mainly by Hazelwood and Dent.

The hammer usually had a flat hardened face insert for one sided
work with the die in concave reverse relief held down on to the base
with 4 very large screws set parrallel to the base face.

these dies were also made from crucible steel fire welded to wrought
iron and carved by hand by deaf and dumb workers.

For a 1 in dia button die the face was 2in across by 3.5 in high by
3in dia at the base.

I have a lovely collection of these victorian dies all still
useable. Drop hammers range in energy from 10tons up to 100 tons.

for double sided work like coining, the hammer also has a relief die
set up into it.

then it starts to get really tricky.

Alignment becomes crucial to achieve precise results.

It can be done and once set up wil give many thousands of clear
strikes. the Quarter had many hundreds of these set up and still has,
doing work the simplest of ways over 100 yrs since installation.

I have 3 of these H & D drop hammers, the middle weight one takes
different hamers from 80 lbs to 275lbs which does virtually all the
jobs that come to me.

My needs are somwhat different to a factory installed hammer. As
mentioned in a previous post I wanted to make them transportable so
I could take them to an event to mint at the event FOR the event. so
my build of this piece of equipment had different terms of reference.
Thats another story.

The dies I and clients comission are made from the best Swedish
Grane tool steel, cut on a Dekel 3 d engraving machine hardened under
Vacumn and are of superb quality.

the 1st one I comissioned has done 20,000 impressions and is as
sharp as it was when new.

As for making my blanks prior to minting, I now use power crank
presses ranging from 6 tons to 25 tons.

the dies for these are the same as the fly press dies. there
interchangeable. I dont use any pancake dies. Preferring the
traditional punch and die setup.

I had the opportunity to use the dies of Paul Vincze, a scuptor and
medallist.

to use these I needed to up the tonnage from 100 to 250. I hunted
down a hydraulic press in Birmingham and brought it back to my
workshops. Does a great job.

however for mass production of coinage then were talking 500 tons,
100 a minute auto feed. Not in the art medal world at all.

Best product run was a 40th anniversary plaque of 2500. hot struck
in bronze. Nicest run was 500 fine silver coins, Biggest run was 12,000
pewter coins.

Most satisfying was a button die for a charitable cause. Everyone
involved did it for free.

so what do I make? my CV lists most of the work over a 10 yr time
frame. A lot has happened since then. Tho next year plans are afoot
to mint some lovely designs by a Danish Sculptor. Just love making
things!!

Ted.


#10

Thanks for the answers, Kevin. I have more questions, but I’m going
to wait until I look further into 2,500 psi systems. I’m leery of 10
or 20 hp motors for pumps, but a lot of that is surely because I’m
only using 1, 1/2, and (formerly) 1.5 hp pumps now for my 10K psi
presses. I’m thinking “doesn’t a 10 hp motor just gobble up
electricity?”.

Anyway, I’ll get more serious about ‘low’ pressure when it comes time
to repair another expensive high pressure pump. I am going to
disagree (more like elaborate) on some of your numbers about pressing
things. You say it takes 6-7 tons for (most) pancake dies, but I know
that that figure is derived from the fact that your dies are meant
more for thicker metals. Since the ones I make also cut as thin as
people need to go, a lot of them cut their parts with much less than
6-7 tons. I usedto use a 3-ton arbor press for small blanking jobs,
say , pieces 2" in diameter or less, in 22 ga or thinner metal. I
could get a little bigger or thicker with a cheater bar on the arbor
handle, but 3 tons really isn’t much good for anything but the
lightest-duty blanking. I have a 1-ton arbor press on my
die-breaking-in table , and a lot of times, part of breaking in
entails blanking out a few parts in thin metal, to help loosen up
brand new dies, so that they are operable.This (obviously) means that
many small parts can be blanked out with only a ton or two. IIRC, the
original RT screw press only delivered 3-5 tons (what someone from
Rio told me eons ago), and the larger one (both unfortunately
discontinued) about 5-7 tons. Of course, back when that equipment was
new, nobody (almost nobody) was making RT dies to cut bracelets or
buckles.

(Shameless self-promotion alert!) Why the original RT saw couldn’t
even handle a piece of steel big enough for a buckle, much less a
bracelet, so it was off to the invention/reconstruction ward for me,
around 1987, to build a saw that I could cut big dies on, and a few
short years later, I got that fateful call from Lee Marshall, with
that spiffy new (now old and unavailable) sawguide. At the other end
of the (jewelry-sized) blanking spectrum, it’s been rare that I make
a die that takes more than about 15 tons to blank. I don’t recall
ever having one that wouldn’t work on my 25 ton press, and that
includes a fork in 14 ga silver, a comb with about 30" of sawing in
16 ga ss, and some big animals about 6" by 4" in 18 gacopper. I think
I did a 3" circle in 1/8" steel that took about 20 tons. As far as
embossing, I’ve come across a lot of jobs where 20 tons isn’t even
close to enough. The kind of press forming I’ve done gazillions of
parts of is about the simplest kind of embossing, the kind that I
first started doing by soldering wire designs onto pancake dies, to
make one step cut/emboss dies. The first big job like that was a
butterfly about 5" by 4" with complex, fancy line designs embossed
into the wings, pressing into a 1/4" 90a urethane pad. I was using a
20 ton jack in a BD press and taking it up to almost 20 tons,
thousands of times in a few weeks.= That jack gave out after a
month, and I switched to industrial hydraulic cylinders at that
point. The main job I have now for my 50 ton press is for a person
who makes rusted steel, Spanish-tin-work style, religious and
decorative items, averaging about 2" by 5", with many over 6" and one
giant cross that’s 9" by 5". These have lots of deep lines embossed
into them and most take 30 - 50 tons, so I am taking the press up all
the way for hundreds of cycles at a sitting, and when things are
cranking, a couple hundred an hour. They all work fairly well at 50
tons or less, except the giant cross, which barely forms to an
acceptable degree, and would love another 25 -50 tons. But even small
items can take more than 20 tons. I used to doa lot of parts for
someone who made little animal faces and other decorated embossed
designs, and those had lots of little detail made form shots and
wires. What took the most pressure was pressing them into
polycarbonate plastic, to get the crispest detail, as opposed to
urethane, which left a less sharply defined impression. So sometimes
even small items in thin metal want more than 20 tons. One of the
many reasons I tell people with the intention of forming metal in a
press , that it’s better to start out getting more press than you
think you’ll need, and 20 tons, instead of 12, is worth it and
they’ll be glad they have it, and if they want to blah blah blah,
then think about getting 50. One more thing, in answer to a question
posed about air/oil hydraulic presses. I did use this kind of pump
-and it is a pump, one that uses compressed ari to pump oil to a
hydraulic cylinder or jack- very early on, before I went to straight
electric hydraulic pumps. You can use either kind of pump to run a
cylinder, the advantage of an air/oil setup is that it’s simple
comapred to an electric pump, and all the work is done by the
compressor. Many people have air compressors, but not many have
electric hydraulic pumps, so it can be a lot less expensive to set
up. Compressors and these air/oil units are much less costly than
electric hydraulic pumps. I wouldn’t call them high capacity, at
least not the smaller opnes I used, or ones that are inexpensive and
use moderate amounts of air. I remember Northern Tool used to sell a
20 ton air/oil press, everything but the compressor, for around
$1,000, and I got some specs regarding it’s speed, and they were
favorable. That company doesn’t carry that press anymore (not last I
checked), but the air/oil units themselves are not uncommon. Like
with any system, electric or air, it’s wise to learn a bit about flow
rates and pressure and such, to make the right choice for one’s needs
and one’s budget. We had a funky setup with two air/oil units rigged
in tandem to one press, to gain speed, but it was…funky, and leaked
a lot, so i’d suggest looking for a bigger single unit if speed is an
issue. I’ve known a fair number of people over the years who have
gone this route, and as the first step up from manually operated (
hand cranked jacks or pumps) it’s a pretty good option, for a modest
gain in speed at a modest cost.

DS
www.sheltech.net


#11
I think Ill need to clarify what drop hammers were developed for.
so first a bit of history. 

Very interesting. Of course, drop hammers, or trip hammers, were
used for other purposes long before the 1800’s. Some are single
stroke, and many were powered by water for repetitive strikes. It’s
said that the first (in China, sometime BC) were inspired by the
mortar and pestle.

Many towns in the US have a Triphammer Road, probably named for a
mill or forge.

Al Balmer
Pine City, NY