On Sun, 21 Aug 2005 21:13:42 +0100, "Triker"
wrote:


"Don Foreman" wrote in message
.. .
On Sun, 21 Aug 2005 19:40:10 +0200, (Nick Müller)
wrote:

Helpful audience!

Today, I made my first spinn-casting with zinc.

It was just a first test shot to see what I can do wrong and what I did
already do wrong.
So the mold was just a plaster mold [1] and the zinc was just some scrap
zink sheet metal for roofing. That zinc proofed to be good enough and I
will use up all the rest before going to the costy zinc I ordered.
At least, the spin caster was a success. I had no other motor at hand,
so the disk is rotating with nearly 1400 RPM. Direct driven! The disk
has a diameter of 12". I thought more g-force = better surface.

334 G's!

How do you know that?

Google on centripetal acceleration. There are lots of sites. One is
http://www.ac.wwu.edu/~vawter/Physic...etalForce.html

You do need to keep track of your units. Then, 1 G = 32.2
ft/sec^2 or 9.807 m/sec^2.