If you're comparing/shopping for a light duty metal lathe, consider the
overall characteristics of the 7x10/12/14" mini lathe models to see if a 7x
would fufill your needs.. and they generally have a threading dial.
The 7x minis are widely used by a large following of DIY-HSM types with many
modifications and upgrade improvements easily found online.
The Shop Fox and Microlux 6x10 models are micro models which will have some
limitations and workpiece size restrictions which may become disappointing
The basic versions are lacking a compound slide and don't appear to have a
method to disengage the carriage from the leadscrew (handwheel on right
The basic threading method of make a cutting pass, then back out the cross
feed, reverse/back up to a starting point.. has already been mentioned, and
is widely used by many small lathe owners.
There are other aspects, such as always resetting everything so gear and
feedscrew backlash doesn't cause mistakes.. although backlash is a main
consideration when using most metalworking machines.
These setting adjustments aren't complicated, just a matter of always
keeping in mind that the settings are made after the backlash has been
"taken up" or passed beyond.
So after the workpiece diameter has been turned to the correct size, the
cross slide dial is typically set to zero with the tip of the thread cutting
tool just skimming the area to be threaded.
The compound slide, preset for an appropriate angle (for SAE, Acme or
British threads etc) will also be adjusted past the backlash point, and it's
dial is typically also adjusted to zero.
The apron leadscrew feed is engaged at a point beyond where the actual
thread cutting is to begin, so that as the spindle power is applied (by
motor or hand crank) the backlash in the gear train will be taken up before
the thread cutting tip contacts the thread area on the workpiece.
The zero setting on the cross slide dial makes it easy to return to the same
in-feed position after the cross slide is backed out far enough to clear the
thread's cut depth, when returning/reversing the leadscrew to carry the
carriage to the next starting point.
The zero setting on the compound slide makes it easy to see how far the
cutting tool tip has been advanced into the workpiece.
The threading dial indication relative to the point of engagement for the
carriage feed will differ depending upon the pitch of the desired thread,
and the specs of the leadscrew and the thread indicator's gear.
FWIW, lathes utilizing change gears are generally capable of cutting more
thread pitches than the user manual or supplied thread charts will show.
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