[TheForge] Hydraulic Press

[Andrew Vida]

peter fels wrote:
> I'd add that 2 of the 3 100 ton hydr presses i've seen doing hot work
> at full capacity, distorted alarmingly under load. Those 2 were home
> made by competent smiths.

They may have been competent smiths, but if your definition is 
"alarmingly" is similar to mine, then they were not competent engineers. 
  No sin there, but the consequences of ill-designing such machinery can 
be dire.


> Which brings me to pose a problem . 
> Hydraulic presses are by nature slow.

Put enough oomph behind a given cylinder and they can be every bit as 
fast at air.

 > Under pressure, the dies suck
> the heat out of hot work fast. How does one go about either reducing
> the speed of heat drain or increasing the speed of die travel under
> load?

The easiest way is to add more oomph.  Larger power units that move 
larger volumes of fluid with the same force... or more.  There is really 
no other way around this.  You can thermally choke the dies so they do 
not sink heat away into the frame as quickly, but then you end up with 
glowing dies and that can be a problem too.

Have you never seen a high speed hydraulic forging hammer?  Those things 
move with some velocity - looks just like a steam hammer in those terms.