Your presumption is correct, opposite ends.

I have one faceplate with both lh and rh threads cut on the same bore.
With my variable speed Delta/Rockwell the faceplate will spin off when I
stop the lathe - not a pleasant experience when you have a heavy turning
block on board. Based on my experience wih this cleap face plate (from
Harbor Freight or Grizzly or one of their competitors I don't remember
which) I would not recommend a double threaded faceplate. Maybe a
quality product could be double threaded and perform suitably, I tend to
doubt it because the contact area is reduced by the extra cuts needed to
get the other thread.

Bottom line, get the insert for inboard use and if you ever want/need to
go outboard then get the lh insert.

Dan


Lynn Coffelt wrote:
I've been lurking, waiting for someone to ask this question. Apparently I'm
the only really ignorant one here, so here goes.

Do some lathes have LH and RH threads on the spindle? (on opposite ends I
presume)

Lynn (green lurker)

"Frank A." wrote in message
...

I've had my lathe since Easter and I'm ready to buy a scroll chuck. So

far

I've been using homemade wooden faceplates thanks to Darrell's Feltmate's
tips.

I need help with the insert. I need a 1 x 8 tpi insert and have 2

choices;

1 x 8 RH and 1 x 8 R&LH.
I know I need the RH but why wouldn't I want a R&LH? Is there a draw back
to the combination insert?