Bantam cross slide screw replacement

I'm currently sorting out a Colchester Bantam 1600 lathe which has had a hard life. It's had the headstock drained and flushed, leaks fixed, driven pulley re-sleeved after a poor repair job. It had a hard life but I think sorting out the worst of it will give it a new lease of life. One of the most annoying things is the worn cross slide bronze nut and screw: it has 90 degrees of backlash which makes parting off really dangerous as the parting blade tends to dig in easily.

A new cross slide screw was made longer than the original which is a 9/16" x 5 tpi double start screw out of 1214 steel which was then heat shrink fitted into the original screw's spline and threaded end. Once that was fitted, the backlash was down to 60 degrees rotation. Tonight I finished making a new bronze nut to suit: it only took three attempts, mainly sorting out the home made carbide tipped threading tool which needed extra clearance on one flank. The original nut has a mounting hole at right angles to the screw axis which leaves a pocket full of swarf and dirt that the oiler port will force back into the thread when oiling it....seems almost designed to fail. I plan to make a second nut to run in tandem on the screw to provide adjustable backlash which the original setup is missing.

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