[TheForge] heavy metal math/c frame press

[theforge@mailman.qth.net]

Thanks Andy,   this was my understanding, based on researching and  
building several hydraulic devices, but didn't want to post until I 
could go back and make sure there wasn't loop hole somewhere.   As I 
recall, there are two big areas in hydraulic systems that can lead to 
danger.  One is allowing air to get into the system, the other is 
allowing your hydraulic fluid get hot enough to start vaporizing into a 
gas.  Both of these cases allow the system to "store" energy that could 
be a hazard.  The critical temp depends on the fluid.  When I built my 
front loader, I included a temp gauge on the resevoir.  Anothe point 
here, is since most hydraulic systems depend on the resevoir to cool the 
fluid, you need to size it large enough to do this.  You also need to 
seperate the pump pickup from the return.  Not an issue wiith low cycle 
devices, but for something like my loader that gets a continuous workout 
it is critical.  

BTW, one inch plate should work fine for the press,  the trick is how 
much and in what specific configuration.  That is not a simple 
engineering exersize.. 


Charles

Andy Vida wrote:

>	Hydraulic oil is a non-compressible fluid, as is water.
>	This means that zero energy is stored in its mass as
>	it comes under pressure.  The only stored energy in
>	the hydraulic system will be located in the conduits
>	as they expand under load.  These are comparatively
>	very rigid, therefore energy buildup in them is small
>	in terms of volume.
>
>	Once a line fails the pressure falls to zero virtually
>	instantaneously. 
>  
>