Joseph Gwinn wrote:
It is the toolpost mechanism that's bent, allowing the toolholders to
unseat. Specifically, two of the three T-shaped plates that pull the
toolholder down onto the ways was visibly bent, preventing full clamping
of the holder to the post. The T-plate in the least-used position is
unbent. No wonder the holders became unseated under cutting force. The
"bolt" does not appear to be bent.

I figured this out 5 minutes after running the lathe with the new
overhead fluorescent lamp operating. Before installing the light
fixture, I really couldn't see that well, and didn't realize how much I
was missing. The toolholder was always unseating, but not enough to be
seen before, but enough to cause all manner of machining problems. The
fixture was $40 from Home Despot.

I have pretty much given up on the Dickson-style toolpost that came with
the lathe. It's just too beaten and worn and damaged to be worth
fixing, although the attempt has been educational. I have ordered the
smallest Aloris BXA set.

Joe Gwinn

If only tools could talk that toolpost probably has some nasty tales to
tell by the sound of its condition. My 2nd hand Dickson has no problems
that I am aware of. I have crashed the Toolmex Dickson copy once and
unseated the tool holder but apart from breaking part of the flange that
sets the height at the top of the clamping eccentric no other damage
seems to have occurred. From the sound of the state it does sound like a
better option is to replace it as I expect the spares might cost a
significant part of a new replacement of a design more common in the US.
Thinking about it my Harrison did come with a couple of spare parts for
the Dickson post, I expect these were old worn parts, not really looked
at them much as they live in the storage compartment and as the toolpost
has always worked as expected I haven't bothered to examine them.