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Hydraulic Press Material Requirement


HammerMonkey

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I am in the planning phase for building my hydraulic powered forging press still. I have Jim Batson's book and I have looked at several builds posted here and elsewhere. I was talking with a friend recently and mentioned that I was planning this build and looking for a place to source some steel I beams sized per Mr Baston's recommendations, and what I see others using for their presses, found in my research.

My friend asked me what size press I wanted to build. I told him 18 to 20 tons in an H frame configuration. He wondered why I wanted to use such chunky large I beams if that was all of the capacity I would be using. He walked me over to his Harbor Freight 20 ton hydraulic press and showed me how lightly it was built. He postulated that there should be no difference from a manual hydraulic press, to a motor driven hydraulic pump powered press of the same capacity... he said the more expensive presses that were of the same class as his were not built substantially different.

Here is a pic of his type of press. it weighs only 165 lbs or so and is made of relatively light channel and angle iron. No I beams anywhere.. It actually looks quite flimsy IMO.

5a9707ffbd01f_press20ton.thumb.jpg.56db96aa2d5efb70e56d4f862c3acc0c.jpg

Even the 50 ton version is built similarly... No I beams, just channel and angle iron... and 100,000 lb capacity.

5a97096f081ae_press50ton.thumb.jpg.95aa1d0e97ae6408ea2f2c8150b8e3bb.jpg

I am sure that there must be a reason for the necessity of larger heavier components used in powered hydraulic forging presses... Can anyone help me with understanding why this would be?

Thanks,

Scott

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Besides the fact that HF stuff tends to bend and yield when you are at capacity and the number of cycles can be much higher with a motor driven systems and so fatigue plays a greater part?

HF stuff uses what we used to call "Sears motor ratings"---IE the top number seconds before catastrophic failure and not the continuous duty rating.

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30 minutes ago, ThomasPowers said:

Besides the fact that HF stuff tends to bend and yield when you are at capacity and the number of cycles can be much higher with a motor driven systems and so fatigue plays a greater part?

HF stuff uses what we used to call "Sears motor ratings"---IE the top number seconds before catastrophic failure and not the continuous duty rating.

No argument about HF quality (or lack thereof) But, as I stated before: " ...he (My friend) said the more expensive presses, that were of the same class as his, were not built substantially different..."

To this point, here is a picture of a couple of highly rated  20 ton Hydraulic presses that, from what I see, are probably made of the size and type of material that is typical for this rating of manual hydraulic press.

5a97162b401b0_71RrMkDjxL._SL1500_.thumb.jpg.3e020f2ac33485e7cfbdecf90f1dc5c5.jpg

5a9714f7d987d_41VzQ0ejxL.jpg.80a80be352ba9053979b11e62a08f2bb.jpg

In fact, I cannot find a picture of a manual 20 ton hydraulic H frame press that is built anything like the forging presses we see being built and or sold for blacksmithing.

So, do you think it is purely the number of cycles & repetition that drives the significant design differences?  I am not sure...

I am not an engineer, but I have worked building, inspecting and testing large commercial aircraft for over 30 years.  I know a little about weight, structure, high cycles, and fatigue. Specifically,  strong & efficient (often light weight) design are usually more robust than beefy structure alone. If this were not true, airplanes would never get off the ground due to the weight of the iron girders they would have to be made of.

Any other thoughts or experience?

 

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I generally can't tell from pictures what gauge of steel is used for the commercial ones; you can have heavier tubing and still the same outward appearance. My thoughts?  We Blacksmiths have a long and proud history of overbuilding stuff!  I remember going to the Circus Museum in Florida, USA and one exhibit was about a blacksmith/wagon maker that the Circuses preferred as he terribly over built his wagons---if others would use 1/2" stock for his wagon tyres he would use 1" and everything likewise. A circus could overload them and not worry about a failure mid tour.

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The press frames of dubious parentage are designed close to their point of failure and have alot of flex because of this just bear in mind that your press frame is not unlike a bow as in bow and arrow and the more flex the more stored energy to throw any item if you have something get thrown of break under your press. I recomend that you make your press frame as ridgid as you can, go around a steel fab shop that does structural steel work and offer to make a donation to their social fund or bring beer/donuts/dancing girls or any other enticments and its amassing what can happen as offcuts just get binned usually Cheers Beaver

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The difference between a mechanic workshop press, besides if it is made in China or India ...  and a forge press is not the nominal capacity in tons, but the way it is used. Those workshop presses are designed to push a bearing out or to press a bush in as a one off operation, they are not designed for continuous industrial use. 

A forging press by its very nature works continuously up and down at a very fast speed, and imparts continuous stress on the frame and goes from zero to full capacity in a matter of seconds over and over for the duration of the forging process. Those presses wouldn't last a day if subject to such treatment. People get them to work simply by underperforming and doing things extremely slow.

If you are going to build your own press, listen to those who have built their own press like the one in the book (not me). Steel is relatively cheap in the scheme of things when you consider the small amount required. You are not building a shed, just a little frame. The difference in price will be forgotten very quickly yet an undersized frame just like a slow pump will make your blood pressure go up substantially. :)

Bribing the fabrication shop or the steel merchant for his offcuts with (legal) incentives is not a bad idea either. 

I can get "I" beams from demolition at half price from new. Just needs a bit of cleaning with a wire wheel. 

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Shady,

A Forging Press NEEDS to be fast acting, so it can still move the piece that you wish to alter shape, BEFORE IT LOOSES IT'S HEAT!!!!!! The Hydraulic Presses in the pictures above are very slow acting. You will be able to calculate their movement by using a Calendar, not a Stop Watch.

The least expense for a Hydraulic Press can easily turn into a waste of money, thus creating the potential for creating a cost factor of more than double for a correct Forging Press.

Cheapest cost does not equal sensible buying.

Neil

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Lol... Don't misunderstand me. I most certainly am not considering building something flimsy. I just was musing on the differences between these presses and asking if someone had an explanation for the dichotomy in design. To me, the difference in the design of the "Very Best" shop presses, vs our forging presses of the same tonnage, is extreme.

When I take on a project to build something, my OCD really kicks in and I am the poster child for over-engineering/building. lol

 

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13 hours ago, BeaverNZ said:

a donation to their social fund or bring beer/donuts/dancing girls or any other enticments and its amassing what can happen as offcuts just get binned usually Cheers Beaver

I really need to try this!

Thanks for the tip Beaver.

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Part of the issue is that the standard H frame presses assume you can balance the loads--basically center the part accurately so loads on the frame are primarily in tension.  Steel in tension is S t r o n g.  In a forging press, nothing is ever perfectly balanced--no matter how hard you try to perfectly center the work, speeds and nature of the work will mean the frame is under all sorts of off-axis forces trying to turn the frame connections into a pretzel.  Because of the nature of forging work, you need to build to WORST case rather than best case scenarios.

Additionally, most people rolling their own forging presses use welded construction.  For the average joe, that's easier with a bit more meat in the metal.  Less worrying about welding distortion or burn through plus the ability to put on a lot more fillet for strength where needed.

And...steel is relatively cheap on a one-off design.  It's not like you are worrying about shipping costs on 20,000 units or labor to form, shear, and punch that many initial parts while having to meet a price point.  Better to do it once too heavy than do it twice+ too light.  Heavier also gives you the option for upgrades without starting from scratch.

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10 minutes ago, Kozzy said:

Part of the issue is that the standard H frame presses assume you can balance the loads--basically center the part accurately so loads on the frame are primarily in tension.  Steel in tension is S t r o n g.  In a forging press, nothing is ever perfectly balanced--no matter how hard you try to perfectly center the work, speeds and nature of the work will mean the frame is under all sorts of off-axis forces trying to turn the frame connections into a pretzel.  Because of the nature of forging work, you need to build to WORST case rather than best case scenarios.

Additionally, most people rolling their own forging presses use welded construction.  For the average joe, that's easier with a bit more meat in the metal.  Less worrying about welding distortion or burn through plus the ability to put on a lot more fillet for strength where needed.

And...steel is relatively cheap on a one-off design.  It's not like you are worrying about shipping costs on 20,000 units or labor to form, shear, and punch that many initial parts while having to meet a price point.  Better to do it once too heavy than do it twice+ too light.  Heavier also gives you the option for upgrades without starting from scratch.

These points make the most sense to me.  I think that the cycling/fatigue points made earlier are also not without merit.

Thanks fellas.

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  • 3 months later...

I’m in the design phase of  building  my own air hydraulic bottle jack forging press. I’m hung up on on thing as I don’t know anything about hydraulic engineering. I’ve got to 20 ton air hydraulic bottle jacks and I’m unsure if incorporating both jacks will increase the presses squeeze force by double? I have a background in steel fabrication so  I’m not concerned with the construction. Any input would be great thanks guys!!!

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Welcome aboard Dazed guy, glad to have you. Using two jacks, especially air over hydraulic would be very hard to balance and any imbalanced forces will tend to reduce efficiency and increase structural stresses. 50 ton would be a good weight jack and air over hydraulic makes them reasonably fast. Speed counts, the steel looses heat fast in contact with cold steel.

However 20 tons will work if you make your dies small enough say 2" or less. 

Somebody else here might know a trick to make a two cylinder press work though.

Okay, I've contained myself as long as I can. In which country is "Highspire?" It's an intriguing name. 

Frosty The Lucky.

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Frosty where are you? Im very Curious  to me why Highspire sounds Intriguing. And. Found an entire hydraulic pump and ram arm system from an old mini excavator. I have an acquaintance that is an heavy equipment mechanic /servicemen. He and I looked at everything last night and he told me we can set it up so hydraulic power will push and pull the press so it can be almost as quick a stroke as if it were a purpose built forge press. I plan to video the entire process however it’s likely I won’t have it completed before winter. My budget is 200 is dollars. So far I’ve spent nothing. Everything I have so far Ram/Pump free,4hp 220 electric motor, for dies I have 6ft of railroad track. I think I’ll spend most on nuts,bolts, belts and pulleys. I just keep my eyes on Craigslist and freecycle for everything. With a lack of money, patience becomes currency. Thank you all for your advice.

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Meadow lakes, Alaska hits on a web search you can check out the map and pics of the area. I just successfully (I hope) extracted my foot from my mouth. I replied to your latest post before reading the previous one. Sometimes when I open a thread it goes to the last post rather than the next one I haven't read. 

The name Highspire inspires mental images in me, it's a name begging for a story and I like to write. 

Frosty The Lucky.

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