On Thu, 28 Jul 2005 09:13:06 -0700, Koz wrote:

I have an old taiwan made 14 x 40 lathe (late 70's vintage, TWS brand)
which was already pretty beat when I aquired it (free!)

For the most part, things work well and it can maintain tolerable
accuracy for what I do so I would like to replace the one part that
brings it down: The cross feed screw. This screw is fairly typical in
style, several steps, each with different threads journals and keys for
the handles, bearings and such with a bronze nut on the under side of
the cross slide. Bronze nut is split with a wedge that adjusts via a set
screw to take up backlash. The wear in the middle is such that taking
up backlash there makes it tight at the ends of movement. Also, the
arrangement is constantly loosening.

So..here's the question. I know that I can't find an exact replacement
and need to scab together a new system. I can go high end and use a
ball screw, or lower end using something similar to what exists or
somewhere in between. My guess is that the designs haven't changed much
so I might be able to find a similar screw that could be modified from
the Grizzly or Jet parts depts.

Any suggestions on the best bet in the long run (other than buying some
better iron)? I hate to open a can of worms and turn this into a
nightmare project but it really needs to get done soon.

Thanks,

Koz


My fathe rin law has a Taiwanese late, of similar size and age. The lead
screws appear to be made from free machining steel, so wore out quickly. A
few years ago, I got a length of 4140 ground leadscrew from MSC in th
eright pitch (and left hand). He cut off the worn one and welded or pinned
on a piece of the new one. They also had the nuts, which would have had to
be made to fit under the cross slide, but in his case, the bew screw and a
bit of adjustment made it ok. I expect it to last for a long, long time
It was around $US100 for a 3' length
Geoff