Syd, just maybe the bigger crucible that you used is not lining up
with the flask!!!
Just because the bigger crucible looks like the one that came with
the machine, does not mean that it was made for your machine.
Many crucibles that seem to look alike, may actually have different
heights to the neck of the crucible, check it out or even better,
why don’t you try contacting the manufacturer of the casting machine,
which I believe you said was NEY.
For the amount of money that you spent on this casting machine, I
would think that they should be able to help you.
Lucas Dental Co
18 Herkimer Place
Brooklyn, NY 11216