[TheForge] heavy metal math/c frame press ERRATA

[John Husvar]

John Husvar wrote:
> Grover Richardson wrote:
> 
>> Agreed.  But still, a stream of liquid (or gas) can cut you in half 
>> (under
>> certain circumstances, and 10 ms of stream can still push oil under the
>> skin).  Remember back when they did injections in the early 70s with
>> pressure, no needle.  I'm not trying to be paranoid, however if 
>> someone is
>> taking on a system with which full knowledge is not known (which may 
>> or may
>> not be the case here), caution is advised.  I regularly get called to fix
>> things with little or no documentation.  It gets interesting 
>> sometimes<G>.
> 
> 
> Agreed. It's always a good idea to learn as much as possible about 
> anything one might attempt home-building, especially known failure modes 
> and their prevention/protection.
> 
> Yep, I sure do remember those needleless injectors, and walking between 
> two pairs of Navy Corpsmen who seemed to take a hideous delight in their 
> jobs.:) Was earlier than 70s though -- 1965 for me, Parris Island, SC.
> 
>>
>> Oh, it's just a current sample of 100 MA, but they forget to mention 
>> that if
>> the resistor breaks, then the full 35 kV is across the test equipment.  I
>> saw that one coming, and the result of ALL the components blown off the
>> circuit board, only little wires standing up, like a bad grass cut.
>>
>> I also have seen the result where they took schedule 80 2' diameter 
>> pipes,
>> and piped the output of 2 50 hp blowers into one pipe, and then shut the
>> pipe off<G>.  
> 
> 
> Lesee -- Pressure X Area == ? X blah,blah,blah, == stress at extreme 
> outer fiber ==
> 
> Darn, that was a long time ago! Too long it appears and I ain' agonna go 
> dig out them books!
> 
> Not enough info, but if you're talking about two 50 HP compressors' 
> output into 24" diameter pipe of much length -- could be a big Oops!
> KaBOOM! :)
> 
> If not compressors, what kind of blowers? Usually fans or squirrelcage 
> blowers will just stop moving air when the pressures on both sides 
> equalize. Seems like they'd equalize way before reaching the yield point 
> of the pipe material.`

I mean when the pressure in the pipe exceeds the fan's air moving 
ability. Still seems that'd occur way before the pressure in the pipe 
reached yield.

> 
> Just curious, not arguing.
> 
>>
>> We all can say, well that is just an isolated incident.  But then, as I
>> remember, folks tend to put shields up on their little giants.  Seems 
>> that
>> the isolated incidents of springs breaking is feared<G>.
> 
> 
> Just good sense. It's a known failure mode and somebody found a way to 
> prevent it or protect against its hazards.
> 
>>
>> By the way, if you have a 48X or faster cd player in your computer, don't
>> sit with your eyes level with the player.  I had a bad disc in mine, it
>> broke while spinning, and exploded, literally, taking the front off the
>> player in the computer.  I have pictures.  I did NOT see that one 
>> coming<G>.
>>
> 
> I've heard of that, but thought it might be an urban legend. Guess not. :)
> 
> 


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