CAMEA is a new instrument concept so it is possible that the construction could or maintenance of the instrument would be hampered by technical details. In order to prevent this a technical predesign have been performed. This is not a final technical solution with bolts and nuts but a 3d drawing where the important elements were put into place to confirm that it could be constructed in reality and that it would be possible to get access to the key areas for maintenance. Further the design has been used as a basis for the cost estimate. Since the primary instrument will not be unique the design has concentrated on the secondary instrument.