Garry,
I, too searched the net for a freeware CAD package. Luckily for me, I have a laptop which runs Linux OS (ubuntu), where software is 99% free and LibreCAD (and its clone QCAD) are both simple, effective CAD packages, which read and write .dwg and .dxf filetypes – i.e. AutoCAD compatible. I also have Draftsight both computers, but although it is a comprehensive program, I find it too complicated to produce the sort of drawing I, and it sounds like, you, are trying to make. When in the UK last Christmas, I picked up some parts in a Maplin store. While waiting to be served, I was tempted by a disp[lay of DVDs near the till. One was TotalCAD2D/3D and set me back the princely sum of £7.95! It's fully-featured and comes with a very good help file, supports multiple filetypes and is quite easy to learn. I don't know if it was a special, one-off offer, but I would recomend it, if you can get hold of a copy. If you don't like it – you won't have spent small fortune.
John