A couple of interesting things to think about.
One of the primary tools of any machinist for clamping irregular shapes
is a clamping set such as
http://www.littlemachineshop.com/pro...ProductID=1144.
Many pieces are too big or awkward to easily stick in a vise. A
clamping kit contains bolts and nuts to fit in the t-slots on the table
of your machine, and special bars called strap clamps. The strap
clamps fit over the bolts and hold the piece with one end. The other
end has serations on it to mesh with a step block which supports the
clamp. This should take care of your clamping issues. Be inventive.
Fixturing and setup are 98% of machining time.
Secondly, tooling is an issue. I don't know what came with your
machine, but you will probably need to acquire (buy new/beg/borrow/buy
surplus) equipment such as collets to hold tooling and tooling such as
end mills in different sizes and types, as well as basic drills and
other tools. Also precision measuring tools such as calipers and
micrometers may be necessary, depending on the type of work you are
planning to do.
I can't really comment on cast iron machining but I do know that it
requires specic tecniques to machine well. I'm sure other members of
this group will be able to fill in this info.
Hope this info is helpful.
woodworker88