@Julien , you just need ball screws 
1" circles in 6061. $12 - 0.001
0.125 deep, adaptive with 0.01 left then a bore with spring pass. Left row is set to 0.001, 0.0001, 0.00001 tolerances, right row set the same but exported in mm.
Lines are very very slight but it’s still a really good finish and you’d have to look close. Honestly can’t really tell any differences between the tolerances.
Also pita to take a good photo