Andrew Mawson wrote:
"Mark Rand" wrote in message
...
I've got a few projects that could usefully start from aluminium
castings. I also currently have 120 ex-server hard disks.

When stripped of all the steel, copper, magnets and electronics the
hard disks yield 12oz-1lb of powder coated or cobalt sputtered
aluminium. Probably in three different alloys (case, platters and
HP/Compaq mounting brackets)

The question is, does the team think that these will be a good
source of casting stock once they've been melted down, de-drossed
and cast into ingots?

If they are a good source of stock I can get more disks, since it's
in my employer's interests to use me to dispose of all the server
hard disks so that we don't have to waste man-hours wiping them or
destroying them when we scrap servers.

Of course, anyone in their right mind would realize that it would be
far more efficient to buy a scrap auto engine or a pallet of ingots.
But these disks are free.

I am starting to run out of places to stick high-powered fridge
magnets though...


Any thoughts or experience out there?


Mark Rand
RTFM

Mark,

The alloy will probably have been spec'ed originally for pressure die
casting rather than sand casting. I did a similar exercise with the
chassis from mainframe printers a few years back - lot of chunky
ingots piled up ready for use. Problem was that when I came to use
them they were a pain - couldn't get the metal to flow uniformly, and
when I ended up with a sound casting it was vile to machine (I was
making a replacement front bearing / mounting plate for a Bridgeport
pancake motor and was cnc machining it) - still using the motor but
that component is not a pretty example of machining !

A good source of decent alloy is pistons - track down an engine
rebuilder and be nice to him G

AWEM

There are several hobby casting groups on yahoo , I belong to the
"castinghobby" one . Those HDD cases are probably a ZA alloy , zinc and
aluminum , mostly zinc IIRC . Andrew is right about pistons , but also
consider extrusions (usually 6061) , wheels and cylinder heads are usually
A356 , and anything cast of aluminum is a candidate for the foundry .
--
Snag
But sell your cans
and buy tooling with
that money . Too much work
for too little metal .