Adding A Column Riser To A Solid Column Mini-mill: Lots Of Questions

[banny tadd]

Ive been modifying LMS 3900. About riser , I used only one LMS 2" riser. But I intend to make own make FC riser at this point.
With 2" riser , I made original CNC conversion on Z axis top , so Z stroke has 280mm. Im satisfying.
About air spring I add pics.