After a lot of head scratching and net searching, I have come up with this model.

25mm rails on Y and X axis
20mm rails on Z axis
45mm square Ali profil bed all bolted together to form bed.
Side plates to add rigidity

Now to see how much it's all going to cost........................................

So far, for all the ball screws, ball screw support bearings, linear rails, linear bearings, 4 micro stepper drivers, 4 stepper motors and motor couplings, it is nudging £1000..................I can lower this a tad by using up some favours and borrowing some bits (permanently.........lol).
Next is to transfer all drawings onto paper and get material and machining quote from my local shop, hopefully get a discount as we use him a lot for stuff at work....................the old saying - "It's not what you know, but who you know".
Will keep you posted on Scrappy and Scrappy2 progress

Stewart

Coming soon - - THE CHRONICLES of SCRAPPY 1 & 2 - - by STEW.
Tweakie.