From Aylesbury, and looking for some help

[Lord Kitchener]

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

Well, the movable fence is the reference edge, so if it doesn't move accurately, if one end moves a little further than the other, then it won't be parallel to the cutting line. An edge that was at right angles wouldn't help if it was a narrow piece, for instance 565 x 80

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.

Well, I am still considering it, so will bear that in mind, thanks.