I am in the process of converting my LUX dove-tail milling machine to CNC and hit a problem with getting the ball screw to fit in the top bed. The ball screws used are NSK and mounted within a mild steel block which in turn is to be bolted to the relevant slide.
After some machining of the mild steel block the lower ball screw assembly was mounted fine, but the one used to operate the top slide was found to be in contact with the underneath of the top slide. To obtain a clearance approximatly 2-3mm would need to be taken off the underneath of the top cross slide casting.
The thing I am worried about is removing any metal from the top slide casting may create problems in the future with the casting deforming etc. One option I suppose would be to use smaller diameter ball screw but I have tried to retain the same shaft diameter as that fitted previously which is approx 22mm, hence quite a large ball screw/mounting.
The other area I am unsure about is the turns per inch being only 5 for the ball screw where the original assembly (acme screw thread??) was considerably more. Could this result in a loss of precision??
If anyone could offer advice it would be greatly appreciated as its taken 2 years to get this far and I really could do with it finishing before my wife throws it and me out!!