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How to build a 50k ton forging press

construction-physics.com

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Re: How to build a 50k ton forging press

#91

Post by buildbot »

hinkley wrote: post #38
jcgrillo wrote: post #25

Earlier quoted context omitted.

well the next time I need some 130ft thick brackets I'll ask them whether I can use it after hours or on the weekend EDIT: or, according to hwillis' math, 2.5ft thick. I guess those could be useful for anchoring a zipline to the moon or something.

I saw a guy weld 1.5 or 2 inch plate once to repair the bucket on a giant bulldozer. That was… interesting. I was trying to figure out why he left such a big gap until he started welding. He had to fit the head in to lay down layer after layer of welding bead to join the pieces at full depth. How would you weld even one foot of steel?

Explosively? https://en.wikipedia.org/wiki/Explosion_welding

Re: How to build a 50k ton forging press

#92

Post by hinkley »

kragen wrote: post #81
WheatMillington wrote: post #78

Earlier quoted context omitted.

Your viewpoint is rather naive in the mechanical world. OK it's enough to assemble a coffee table, now try an engine with 2,000 parts. Without a manual how can you set bearing clearances? How do you know how much thrust clearance there should be? How do you know which way up a piston ring goes, or how much torque to apply to a head bolt? Machines are extremely complex, and that's before you even touch electronics and…

there's a lot of shade-tree mechanics who have successfully rebuilt engines with thousands of parts. essentially figuring out how to rebuild an engine is similar to figuring out how to build one from scratch, which is within human capacity, particularly with background knowledge. but the guy rebuilding the engine has a lot of hints granted, he'll probably fuck up his first two or three pretty good without haynes or c…

There is a lot of stuff you can do when it’s pass fail. As a pro you have a time limit and you’re bad if you can’t rebuild in X hours.

My dad will tell you I helped him rebuild a bike coaster brake at 14. But the truth is the only decision he made was to buy the repair kit. I got rags and laid all the parts out like an exploded diagram, we cleaned them or swapped them and they went back in the way they came out.

I worked as a bike mechanic for two summers in college. Cars have manuals and maybe the mechanic you work for has them. Bicycles do not. You’re all shade-tree until you’ve seen everything a couple times.

Re: How to build a 50k ton forging press

#93

Post by hinkley »

sushid wrote: post #85
hinkley wrote: post #49

Earlier quoted context omitted.

There’s a UX school that says that if the user needs the manual you fucked up. I mostly subscribe to that school. Mostly. It drives my family nuts that I will assemble a piece of furniture without reading the instructions. But the thing is with a little mechanical sympathy, and a well designed product, there’s only one sensible way for the parts to go together, and if you organize them right while you disassemble it…

Sure, but now you have another bolt and nut configuration that requires a different drill, maybe a new supplier, etc. RTFM!

Bolts and nuts in two different materials/grades are still two separate pieces of inventory to manage.

Re: How to build a 50k ton forging press

#94

Post by MisterTea »

mensetmanusman wrote: post #60
MisterTea wrote: post #27

Earlier quoted context omitted.

I work in an EB shop doing everything from welding, engineering assistance, machine repairs, and complete machine rebuilds. It's quite an impressive process and Ive had parts in my hands that come from some of the biggest names you can think of in aerospace, semiconductor, military, medical and more.

50 kW ebeam?

We have 7.5 kW and 15 kW machines. Smaller chambers but there's plenty of smaller work out there.

Re: How to build a 50k ton forging press

#96

Post by hinkley »

WheatMillington wrote: post #78
hinkley wrote: post #49

Earlier quoted context omitted.

There’s a UX school that says that if the user needs the manual you fucked up. I mostly subscribe to that school. Mostly. It drives my family nuts that I will assemble a piece of furniture without reading the instructions. But the thing is with a little mechanical sympathy, and a well designed product, there’s only one sensible way for the parts to go together, and if you organize them right while you disassemble it…

Your viewpoint is rather naive in the mechanical world. OK it's enough to assemble a coffee table, now try an engine with 2,000 parts. Without a manual how can you set bearing clearances? How do you know how much thrust clearance there should be? How do you know which way up a piston ring goes, or how much torque to apply to a head bolt? Machines are extremely complex, and that's before you even touch electronics and…

Does every car mechanic have the entire Chilton’s catalog or do the mechanics just have to memorize things or look them up on the Internet? My understanding is it used to be a little A and a lot of B, and now it’s a mix of B and C

Re: How to build a 50k ton forging press

#97

Post by MisterTea »

hinkley wrote: post #36
MisterTea wrote: post #27

Earlier quoted context omitted.

I work in an EB shop doing everything from welding, engineering assistance, machine repairs, and complete machine rebuilds. It's quite an impressive process and Ive had parts in my hands that come from some of the biggest names you can think of in aerospace, semiconductor, military, medical and more.

Are they for prototypes? Or how do you service production runs for parts? If for arguments sake it were a part for an AWACS or an aircraft carrier you might only need to make eight or a dozen. But even military aircraft tend to run into the hundreds.

We do production runs with the rare service run. Most parts are one time use as you might imagine. Service work is the rare mold repair.

We are part of a few companies just in time manufacturing so they pay for expedite processing on orders as small a one piece to a few dozen. And we can get production run orders in the tens of thousands.

Re: How to build a 50k ton forging press

#98

Post by thaumasiotes »

NegativeLatency wrote: post #42
thaumasiotes wrote: post #29

Earlier quoted context omitted.

> Blacksmiths had a legitimately intellectual job back in the day! ACOUP noted that blacksmiths might be assisted by unskilled laborers, strikers, who had the actual job of lifting the hammer and hitting the object with it.

Unskilled feels unfair, it requires a fair bit of skill, and you're also learning how to forge while doing it.

> Unskilled feels unfair, it requires a fair bit of skill, and you're also learning how to forge while doing it.

Both of those points are untrue. Strikers are unskilled labor and in general are not learning how to forge. The smith shows where he wants the hammer to fall, and they let it fall there.

https://acoup.blog/2020/10/02/collections-iron-how-did-they-...

> Things were worse for the many strikers and other laborers who were essentially unskilled hired hands or even enslaved laborers (given their depiction in artwork, it seems likely many ancient strikers were slaves) of much lower status and who could not expect to be trained into blacksmiths themselves some day. While some strikers were probably apprentices in training, it is quite clear that not all of them were! These workers would also have been far less richly paid; indeed, the entire point of strikers was to have laborers who could be paid very little but still amplify the production ability of the blacksmith himself.

(emphasis original)

Re: How to build a 50k ton forging press

#99

Post by WheatMillington »

hinkley wrote: post #96
WheatMillington wrote: post #78

Earlier quoted context omitted.

Your viewpoint is rather naive in the mechanical world. OK it's enough to assemble a coffee table, now try an engine with 2,000 parts. Without a manual how can you set bearing clearances? How do you know how much thrust clearance there should be? How do you know which way up a piston ring goes, or how much torque to apply to a head bolt? Machines are extremely complex, and that's before you even touch electronics and…

Does every car mechanic have the entire Chilton’s catalog or do the mechanics just have to memorize things or look them up on the Internet? My understanding is it used to be a little A and a lot of B, and now it’s a mix of B and C

I was using the engine example as an analogy in an apparently failed attempt to help you appreciate the complexity involved. Mechanics in general will feel their way around an issue, but almost universally have access to paid repair databases when non-intuitive and complex issues come about.

Re: How to build a 50k ton forging press

#100

Post by azalemeth »

If you're reading this article, you may wish to know that arguably a "counterpart" to heavy press forging is explosive forming [1] in which a chemical high explosive is used to force a template material against a template. The overpressure generated by the explosive can be equivalent or maybe even greater than heavy press forgings (a 50,000 US short ton force press exerts ≈500 MN force; peak overpressure close to detonating TNT or PETN explosives can be MPa or higher [2] so depending on the geometry of the part they may be comparable) and it has the added "fun" fact that complex cylindrical or spherical shapes can be made very easily and accurately.

The only people I know who have worked with this have used it to make superconducting magnets, explosively forming either titanium or high grades of nonmagnetic stainless (A4, which has µr ≈ 1) without causing marsenite formation due to machining. This includes a major international MRI scanner manufacturer, for one relatively niche product. It's like the "extreme" version of metal spinning [3] – forcing a rotating chunk of metal against a rotationally symmetric mandrel.

[1] https://en.wikipedia.org/wiki/Explosive_forming [2] https://www.researchgate.net/figure/Variation-of-peak-over-p... [3] https://en.wikipedia.org/wiki/Metal_spinning

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