There’s still quite a bit of machining that goes into a CNC mill build of this ... He picked up the set of three ball screws on eBay for $180. Two of them drive the X axis with the third moving ...

Unwilling to deal with the accumulation of chips in the expensive ball screws of his homemade CNC router, [Nikodem Bartnik] took matters into his own hands and created these DIY telescopic ball ...