From Aylesbury, and looking for some help

[Jonathan]

It depends on whether it's still parallel- the accuracy is not just for ease of fitting the parts together, it's also needed to sure that the opposite edges are parallel, so that the compononent has all four corners at right angles.

That shouldn't be a problem if you have an edge which is set precisely perpendicular to the saw to align the part against.

A decent random orbit sander is faster, and the discs can be changed quickly when they wear out.

Fair enough ... I thought you meant sanding by hand which would be slow!

I currently either clamp sheet material at the edges, or screw it to the bed with normal wood screws. Both methods hold it adequately and are much cheaper than a vacuum bed. The only real disadvantage is you have to leave tabs (or position the screws carefully) to stop parts you are cutting out moving. Don't be put off by the software - CAMbam free edition would do what you need and is (in my opinion) very user friendly.