Hi All - Got the Z Axis detailed out ready for drawing stage. Did a quick FE to see how its travelling and its bonded stiffness works out at 91N/um which is very stiff. In reality the structure is about 50% efficient, so say 45N/um and then its still stiff. This is at full 200mm extension. If I get time I'll do a full contact analysis. The peak stress is in the rails at 41MPa and being high strength steel this is a very low stress. I've applied 100kgf at the clamp and the tool tip deflects 0.1mm in this condition. Happy with the stats so far so now to get the saddle up to scratch. Peter