Geoffrey, your quite right they did have a good reputation but they are 30 years old & a lot of things have changed over time. It was broke lol so in the course of fixing/converting it I thought it would be a good idea to look at all the options available, the costs & benefits of making changes could then be looked at. I already know I am going to have to do something with the z axis as it runs on unsupported rails that look to be less than 1/2" plus it is driven by a trapezoidal screw rather than a ballscrew. X & Y axis are belt driven & I don't see me changing that because of the work involved. As I'm still not sure what I will be doing with it once it is completed I would like to try & keep the costs down but if I have to spend some more on it then I'm prepared to do that.