I just didn't feel happy with the above with the screws being so close to the cross members and reducing the size of the cross members so I think back to square one and to the screw on the outside and then I was thinking I can probably bring the 4th and put on the inside of the rails and then If I ever really need to use the hole bed including the small area the 4th take up I will just have to un bolt it but having it on the side means i could have some sort of locating plate that stays fixed to the machine to aid relocation on the motor end and then then the tail stock will need to slide anyway so that should be fine.

if anyone has any comments or ideas I think I will go ahead and draw the final design.

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