Hi Ross

Did you see the Dick Stephen X3 conversion articles on Arc's site?
He turned extensions out of mild steel (with all the clever stuff on for the bearings etc) then machined a narrow shaft on these extensions, to insert and loctite into reamed holes in the ballscrews. Avoids the need for angle grinder / special tooling.

Seems that this is an alternative to

  • machining the screw itself (using proper tooling and skill like John's got)
  • machining the screw itself (using < grinder to de-skin screw)
  • buying pre-machined
  • paying somebody to do it.

As a complete newb I'd probably get pre-machined, but Dick Stephen's method does at least seem accessible.

John