The L/R makes no difference compared to just the RH. It is just an adapter
that is threaded with both RH and LH threads. When you screw it on the
inboard side of the spindle the R threads engage, screw it on a LH thread
and the other (L) threads engage.
Put it on the spindle but don't tighten it more than just enough to hold it
on. Put some pressure against the chuck as if it were a turning tool
against a workpiece and turn the spindle in the normal direction. You will
notice that the chuck tightens itself on the spindle thread. There is no way
it will loosen while turning. The situation with electronic braking is a
bit different in that if the braking is particularly abrupt the momentum of
the chuck and workpiece (usually a heavy bowl blank) will cause it to
unthread when the spindle stops. Normally the braking is setup to give
quicker stops and to also avoid unscrewing the work.

I got a bad catch the other day and stopped the spindle and my outboard
handwheel turned off the spindle. I usually just put it on hand tight and I
run with the drive belt a bit on the loose side which was enough to allow
the spindle to quickly stop.
Billh

wrote in message
ups.com...
Maybe I shouldn't have gotten the L/R thread on my adaptor (from what I
see here-- Ron) & I wouldn't have to be worrying-- Does the RH thd
have a counterbore (recess) ? I was thinking-- "maybe I'll use it on
the outboard side for sanding" & ordered the L/R adaptor instead of the
RH adaptor-- Many tks for all the responses-- Can't wait to turn the
lid for my new urn on it (glue dry tomorrow)
PH