Yeah I'd rethink the position of that switch too.
The last thing you want to do is lean over the chuck to hit the stop. If for any reason it grabs an item of loose clothing that estop isn't in the best place
Mounted on front panel, feed cable brought in through back of stand, then output from NVR switch into original Myford multi-way connector which feeds the drum switch.
Hmm, so it's 0.2% off when compared to a true 1.5mm pitch, which is about 0.003mm per revolution.
Over one metre, this works out as an error of 2mm ( 1000mm * 0.2 / 100 )
For screwing a nut on (or screwing into a hole etc), I think it'd be fine, but I probably wouldn't use it as a lathe leadscrew etc, if that makes sense.
Having said that, I'm hoping that someone more experienced can shed some light on this. My gut feeling says it'll be fine, AS LONG as the thing you're screwing this piece into hasn't got an excessively long thread.
Basically, if the "slop" between the threads actual form of the screw, and the "true" form of the nut thread, is larger than the error, then I think it should fit together.
0.2% is 2 thou over an inch. You're not going to notice that turning fasteners. Your leadscrew almost certainly has more wear than that from it's least-worn section to it's most-worn anyway.
The Leadscrew "play" if it's in-out is just the flexability of the Leadscrew and looks fine.
Going by the state of the hand wheel, I would say it's had a good whack at some point. The leadscrew is quite soft, so take the hand wheel off (don't loose the cross drive pin that fits in the slot), use your DTI to find the high point on the shaft and tap with a SOFT FACE HAMMER, remembering to align the High point towards your body, so that you are tapping towards the machine bed, where the bracket is well supported (put the nut back on before you start to save accidentally damaging the thread).
You can straighten the shaft by hitting the handwheel, but as it's made from cast iron I would not recommend it (even though thats how it got bent in the first place).
Depends what you mean. They don't affect the spindle speed - the changewheels are there for setting the pitch for screwcutting or the feedrate for turning. Not that there's any difference between the two (apart from the shape of the tool) really. Screwcutting just generally uses a much faster feed rate than turning. You get a smooth turning finish by using a tool with a nose radius and setting your 'thread pitch' to less than the nose radius so it's always removing what would be the crest of the threads if you used a v profile tool, also when screwcutting you have to use the same start point every pass, with turning you need not.