I had my X pulley tension mount crack so I needed a replacement. I took the CAD models and shrink them down and changed hole sizing to be printable and use the heat press nuts that come with the printer. 

I have upgraded my SV06 plus to use 20t GT2 4mm bore pulleys which are 9mm wide, and 4mm steel rods commonly called steel dowel pins. Steel dowel pins that are compatible are 4mm x 16mm and up to 24mm in length.

I included the original edited step files and STLs for each change. A pair of XY mounts are meant to use one original 4mm heat press nut and 4mm solid dowel rods. The other pair of XY mounts are a direct replacement for original but need two 4mm heat press nuts, which can be removed from broken mounts, and the original 4mm bolt.

Good luck and happy printing.