Power Supply Question.

I am in the process of making my own power supply for Dan's 5 Amp
driver boards. So far I have purchased all the components to
assemble a supply similar to the one that is shown in Dan's manual.
It has now come time to assemble all of the components to make the
supply and I have a couple of questions. First of all do I need to
isolate the metal feet of the transformer from the case which will
house all the components. On the same note do I need to isolate
everything (driver boards, capacitor, bridge rectifier, db25
interface) from the case? I am new to CNC and don't have an
extensive knowledge of electronics but I am eager to learn. I hope
this is not to silly of a question. I am sure I will have more
questions as I go along. Any information would be appreciated.

Thanks,

Jason