Crossfeed Lead Screw Nut
Harbor Freight 9 x 20 Lathe
The brass nut is 1/2" x 3/4" x 1" long. I used the 3 jaw
chuck and shimmed under the nut to
achieve the proper hole position. ( you can see the feeler gauge shims
at the bottom )
The brass nut is drilled to the proper size.
The brass nut is tapped to 7/16-20 LH using hand power.
The tap is held in the 1/2" drill chuck & tail stock to ensure
it's kept straight.
Here's a tip for tapping with the tail stock. Insert the tap in the
tail stock / drill chuck.
Extend the tail stock full length until it disengages from the threads
as shown above.
The black line on the tail stock ram indicates where the threads end.
At this point the tail stock ram can be moved in , out , & turned
freely by hand.
This allows you to keep the tap perfectly straight.
Finished nut.
Attaching the nut to the cross slide
The original nut shown on the right is made from aluminum. The nut
is attached with a small
phillips head screw from the top of the cross slide and is a very "weak"
design.
I decided to mill a recess for the new nut to "sit in". This allowed
a lot more
material for a new attaching screw.
I used the mini mill and milled a recess. The new brass nut fits
perfectly in this recess.
I just "eyeballed" the cut until the new nut looked to be the same
height as the old
nut when sit side by side. You have quite a bit of adjustment with
the mount so it
doesn't have to be exact.
With the new nut in place I marked the location for the new attach
screw.
I used a 1/4"-20 allenhead beveled screw. With the nut recessed into
the
cross slide you have a lot more threads holding the nut than compared
to
the old nut. Since everything is perfectly square there is no need
for any
adjustments here. All the adjustments can be made by moving the mount.
Top view of the cross slide attaching screw. The small set screw to
the right of the
allen head screw is not used now.
