www.nightvisionforumuk.com

A CAD program for doing 2D engineering drawing's I can cadge a copy off

I'm running Window's 7 64bit if that help's

There's free ones ont'net for windows 7, bud

I think Google does one for free it may be called Sketchup.

I've used this one in the past but it does go 3D.
http://www.emachineshop.com/
Takes a bit of getting used to but can produce good results.
The idea is that you design it and they'll quote you a price for manufacture based on your drawings but you don't need to go that far.
I use windows paint now cos my computer's knackered

Pm on the way.