Thanks guys for the help so far. ive scrapped and started from scratch. Ive based it heavily off the pics you posted Jazzcnc, they where a great help and have used 20 Hiwin rails as suggested. Ive done everything in 20mm ali and doubled up on the aluminium profile now. Ive still got a fair bit to draw like the lower frame and bed and stepper mounts with belt drives, and y axis ball screws. Unfortunately im off for a short break so im going to have to go cold turky from solidworks for the next few days.

im going to have to find a good source of 20mm plate next. I was talking to a close family friend about my project who is an ex tool maker so now i have access to his machine shop now which is a great help.

Thanks again all

Trev