The far end of the Sherline Y-axis leadscrew isn’t supported, which really doesn’t matter much because the motors can’t drive the screws all that fast. But, if you’re like me, you think about dropping something heavy on the screw and maybe bending it just enough so it doesn’t work.
What to do?
The next time you replace the bellows covering the leadscrew, add a scrap of plastic with a suitable hole bored in it. Measure your leadscrew (metric & inch diameters differ!), poke a hole with enough clearance to make you happy, then cover one side of the block with double-stick tape.
Run the Y axis to about 30 mm from the far end, unbolt the motor mount, slide the table forward, put the bushing on the screw, slide the table back, affix the bushing to the column, screw the motor mount in place, and you’re done.
If you’re really fussy, make sure the bottom of the plastic block bears on the frame, but that’s in the nature of fine tuning.
This will cost you a bit of precious Y-axis travel, but the bellows need about that much space to fold up and you’re not losing much more than you already have.
The end of the X-axis leadscrew isn’t supported, either, but you can’t drop anything on it.
Sherline hot-rodders with super-fast high-torque nitro-breathing motors run the risk of bending the leadscrew by having it whip around, but that’s a whole ‘nother subject.