A few lathes are produced with defects, some just annoying, and others are
very dangerous.
Tail stock movement
Tail stock movement can be solved in several ways the most simple method is to place a piece of ¾" plywood across the bed of the lathe and cramp it with a "G" cramp to the bed to stop rearward movement.
Yet another method is to rust the bed of the lathe, with the hope that the roughened surface will afford better resistance to sliding tail stock.
The last method is to replace the plate which grips the tailstock to the bed with a larger mild steel plate, as the greater the gripping area the better the chance of limiting the movement.
Tool rest movement
Tool rest movement is a little harder to solve, but can be achieved with a little patients. The most simple method is to file flat surfaces on the pin which enters the tool rest assembly.
Another is a combination of the above and removing the bolt or handle which tightens onto the tool rest pin and grind it with a shallow point, to enable it to grip the pin more securely.
Both of the above idea's work but with a slight drawback. The tool rest will tend to align itself to the filed area's or too an indentation caused by the tightening of the bolt or handle.
Dangerous Lathes
Well all lathes are dangerous if not treated with respect, yet some are more
than other's. I have a lathe which because of poor castings and design nearly
removed my eye. The tool rest which is a very poor casting snapped during my removing
the bark off a log I was preparing to turn into bowls. The company in question
retooled the rest to accept a steel pin, and as yet I haven't had any more
problems. I will email anyone whom is interested the name of the
company.
If you have a dangerous problem with any tools you have
purchased. You should report the faults to Consumer Product Safety
Commission at www.cpsc.gov/incident.html
or by phoning 1-800-638-2772