Thanks.
Bert
Chris
"Bert" <no_...@thank.you> wrote in message
news:ljm8d1dhuoomrrj0s...@4ax.com...
http://www.carolinaknives.com/
Cheers,
Kelley
Pete Stanaitis
--------------
>I haven't run across any
>new hydraulic forging presses sized and configured for a small artist
>blacksmithing shop
Are there such things ? Hydraulic presses have high static forces but
are slow acting. Forging is generally done with hammers, either
manually, mechanical triphammers or pneumatic - a relatively light
hammer travels fast, giving a blow with lots of momentum but minimal
long-duration force. The effect on hot metal will be quite different.
Andy Dingley wrote:
There certainly are, I have one. I first thought to post a web link to
BonnyDoon Engineering, but they seem to have stopped offering their
forging presses to focus on jewelery presses. I made mine based on plans
from Jim Batson. Norm Larson carries the plans (larb...@impulse.net).
Mine is a C style, jaws open on one side, backed up with an 18" web I
beam. It is motorized and will reach 30 tons (36 ton design value, but I
haven't found the increase necessary). The hydraulic pump is a log
splitter pump which has two speeds, moving 4x as fast until the pressure
trips it into 1x rate. With this kind of pump, a 2HP motor will propel a
30 ton press at about an inch per second. I originally set it up for 2"
per second, but found this much too exciting for things like bending.
The 1" per second is the unloaded travel speed (and usually the hot
bending speed). During actual forging it slows to about 1/4" per second.
A motorized hydraulic press completely changes the way you think about
thick pieces of metal. It is trivial to take a piece of 3" solid round,
8" long and squish it into a grapefruit sized chunk. You only get one
shot at forging a given section of steel, but with the right tooling you
can do some pretty complex forming in one stroke. Your tooling is much
simpler--no impact, so you just weld up pieces of mild steel.
Where a hydraulic forging press really shines is in making pattern
welded steel billets. It is completely trivial to forge weld an 8" x 2"
x2" billet. Weld it once and the weld is good enough to draw it out on
edge without any delamination.
A fun tool. If you make much pattern welded steel, I really think you're
foolish if you don't have one. If I were doing it over, I would
probably go with an H frame style. Batson has an addendum to his first
plans which goes into some of this. Norm Larson can tell you about both.
If you're thinking of making one, the log splitter pumps are insanely
noisy at 3500 rpm, run them at 1750.
Steve
>>On Wed, 13 Jul 2005 02:53:11 GMT, Bert <no_...@thank.you> wrote:
>>
>>>I haven't run across any
>>>new hydraulic forging presses sized and configured for a small artist
>>>blacksmithing shop
<snip>
>A fun tool. If you make much pattern welded steel, I really think you're
>foolish if you don't have one. If I were doing it over, I would
>probably go with an H frame style. Batson has an addendum to his first
>plans which goes into some of this. Norm Larson can tell you about both.
>If you're thinking of making one, the log splitter pumps are insanely
>noisy at 3500 rpm, run them at 1750.
Steve,
I've been leaning toward a C-frame, thinking the additional access
would translate into increased versatility, so I'm intrigued that you
would opt for the H-frame. What advantage does the H-frame offer,
other than potentially being stronger and more rigid for a given
structural weight?
Is the noise from the log splitter pump anywhere near as loud as a
comparably sized power hammer? Are you aware of any other suitable
pumps that would be quieter?
Thanks,
Bert
>depends on how "small" an artist you are. You can buy a 20 ton
>hydraulic press from Harbor Freight and lots of other places for less
>than $200. Then, if you have an air compressor, you can replace the 20
>ton bottle jack with an air powered jack that fits right in there.
>Works great. I added a 1 inch diameter by 1 inch throw air cylinder to
>the air power jacks release valve and put valves for both up and down on
>the floor.
> Even without the air powered jack, these presses sure do the job. It
>just depends on how fast you want to go.
>
>Pete Stanaitis
How fast do I want to go? Fast enough to finish forging before the
metal cools significantly. I don't know what minimum speed would be
required, but Batson's design uses two-stage pumps that provide a ram
speed ranging from 1 to 4 inches per second (unloaded). What kind of
speed are you able to get with the air-powered jack?
Bert
>A quick Google search turned up this company who appear to sell a 24
>ton press.
>
>http://www.carolinaknives.com/
>
Thanks for the link Kelley. At least now I know that *someone* makes
them, though I think I'd rather have a C-frame design rather than the
H-frame design used in this press. I'm also a little apprehensive
about all those exposed high pressure hydraulic lines -- it wouldn't
be pretty if a piece of red-hot steel rubbed up against one!
Bert
>Not too sure if this will help but try Bonny Doon
>www.bonnydoonengineering.com
>
>Chris
I actually built a press similar to the smaller Bonny Doon press a
couple of years ago. It's great for cold work (punching or forming
sheet copper, for example), but it's way too slow to be of practical
use for hot forging.
Pete Stanaitis
----------------------------
Bert wrote:
My press is built on a 7' piece of 18" web I beam, reinforced on the
front edge with a piece off of a road grader 1" thick and 8" wide, top
to bottom. It seems to me that you could do a couple of different things
with an H style. You could make a "tabletop" model with *much* smaller I
beams that be almost as versatile. You could also make one with large
side beams spread farther apart, potentially giving you a much larger
pressing area. That said, I don't have any limitations with my C, and
don't know of anything specific I'd like to do with an H that I can't
with a C. I guess a smaller unit appeals to me, no real advantage.
If you have a problem, you should be able to work around it by rotating
your dies (maybe making a 90 degree set).
My friend Steve Rollert built his C style with the cylinder underneath,
driving the lower anvil upwards (usually the top is driven with the
bottom fixed). This sounds pretty weird, but it really works pretty
well, and cuts your I beam length almost in half. Another idea.
Log splitter pumps are rated in the catalog for their gpm at 3600 rpm. I
originally set my press up for 3600 rpm and 2" per second. Not only was
2" per second way too exciting, but a log splitter pump at 3600 rpm just
screams. It is hard to believe it will survive long. I dropped down to
1750 rpm and was much happier. The noise a press makes is continuous,
while most power hammers are impact, hard to compare them. I have a 50kg
self contained air hammer. Its noise is pretty much continuous and about
at the same level as the hydraulic press.
At 1750 rpm, the noise is tolerable without ear protection; probably not
good for you long term. I wear ear goggles anyway as loud continuous
noises tire me out. I'll bet more expensive pumps get quieter, but don't
know. Keep in mind that the pump doesn't have to be right at the press.
It could be through the outside wall of your shop, or close by but in a
sound deadening box. Heat dissipation is mostly through the oil rather
than air flow (the oil reservoir needs to be large enough to shed the
heat caused by friction).
Steve
Speed is neccessary for general purpose forging with a hydraulic press.
I do not make knifes so I can not speak to knife making. I have two
pumps for my press one for die pressing and one for forging with a valve
that selects the pump source.
The die pressing pump is a two stage 1 1/2 hp pump that produces 3500
psi to a 6 in cyinder ~50 tons.
The second pump is a 1.00 cu single stage gear pump (I believe) powered
by a 7 1/2 hp motor and produces 7 gpm at 1500 psi into a 6 into
cylinder to produce ~21 tons. The 7 1/2 hp pump moves the cylinder at
about 1 inch/sec. This press is a little slower than a manual fly press
but much more powerful.
brad
http://www.dfoggknives.com/hydralic.htm
[sic]
It sounds like a lot of the pumps/flow rates have been pretty high.
Moving a 5" cylinder at 1"/sec only takes like 0.25GPM, which can be
had with a pretty low HP motor.
Check out
http://www.surpluscenter.com/Hydraulic.htm
for some calculators, etc. Seems like there would be a a lot of room
for playing around with speeds, etc with most designs.
don
A 5" cylinder at 1" per second requires 19.6 cubic inches per second
pumping rate.
A gallon has 231 cubic inches in it, so you need to pump 0.085 gallons
per second, or 5 gallons per minute.
At 1500 psi, this takes about 5HP.
Steve
Ahhhh...I know where it is. The location would be in my brain.
I was using the calculator to generate inches/minute, but reading it as
inches/second since that's what I was interested in. What's a factor
of 60 between friends?
I was a little surprised to have calculated such a low number in the
face of the other specs, but I didn't bother to check my work.
Thanks for pointing out my error. I guess I'll go trade that 1/2
horse motor in for something bigger now...
don
Steve
I always hate to see rubber lines around hot metal too. It's not as
dangerous as it seems since they are steel reinforced. However, it
smells really bad when you hit them with hot metal. You can cover the
lines with braided stainless sleeving to protect them.
Cheers,
Kelley
"Bert" <no_...@thank.you> wrote in message
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