Hi,
From the look of the SX2 on the Axminster website, this machine in the Z department appears to be the same as the Warco MiniMill. In which case….
As already been said, to engage/disengage the fine feed it is necessary to push/pull the three-handled lever sideways to engage/disengage the the splines.
Unfortunately, it may not end there as on my machine, a friends machine, and that of someone else who asked for help on this site, the fine feed knob, it’s drive rod and the worm drive may well be tight almost to the point of being unusable.
If you refer to this thread: Disassembly of MiniMill/X2/XJ-12 Ballbearings started by MarcuSweden 15/04/2010, you will find near the end some photos taken by me showing what I had to do to get mine working half-way decently.
Regards,
Peter G. Shaw