Joseph Gwinn wrote:
In article ,
David Billington wrote:


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
[light] 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.


There are dings from clamping without wiping the chips away as well. Th
think this toolpost and holders set has seen *lots* of use, and abuse.
I'm sure that a number of crashes are in that history.



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.


That's my impression as well, and Aloris gets glowing reports.



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.


Put a straightedge on the outside surface of the T-shaped plate. It
ought to be flat. On mine, it was quite obviously out of flat, the arms
of the T being bent up, and the metal that bears on the toolholder
visibly upset. I doubt that replacement parts are available for mine,
which appears to have outlived its maker. Time to start over.

Joe Gwinn

Just done that and all 8 T pieces seem to be flat and the holders
undamaged in the clamping area. One T piece closest to the chuck has
obviously met it on occasion as it has some evidence of an arc worn
slightly into the surface but otherwise OK. The T piece I crashed is
flat even though that incident broke a small part off the flange at the
top of the eccentric pin. The spare parts included 2 T pieces, both
flat, one complete eccentric shaft, and the bit of eccentric shaft that
fits in the T piece, both ends having been broken off.

Shame you're in the US and the holders are in a state from what you said
before. The Dickson holders always seems to fetch good money in the UK
on ebay. Luckily having had the Toolmex version and then bought the
Harrison with a Dickson and holders I now have 5 which will take 22mm
height tool and a couple of ones to take round or square to about 17mm.
I haven't found a use for the Morse taper holder yet. That allows me to
keep the commonly used tools set-up with a couple over to set-up with
other tools as required.

Anyway good luck on your choice of a new toolpost and let us know how it
goes.