In article ,
"DoN. Nichols" wrote:

On 2008-02-25, David Billington wrote:
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.

Hmm ... why not examine the wrench. I suspect that you will
discover that there are dings on the handle from someone using a
"cheater pipe" on it. A pity, because they are otherwise good
toolposts and holders.

The wrench that came to me is pristine - no evidence of abuse. But see
below.


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.

Yes -- with the Phase-II being not too bad as cheap
replacements, especially if you replace the setscrews in the holders
with "Made in USA" ones. (Good European ones would be good too, but
unlikely to show up at the usual vendors here.) I got my set of screws
from MSC - a full box of 100, and have never needed to go beyond the
original replacement.

This seems to be universal. It will be a few years before Chindia
figures out how to make good steel.


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.

[ ... ]

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.

I suspect that the failure of the ones Joe has came from the use
of a cheater pipe on the eccentric wrench. (Hmm ... I wonder whether
the same was done with *your* broken eccentric?

That was probably not the reason, which is far simpler: The toolpost is
too small for the lathe. When I got it, the toolpost was spaced above
the cross slide by two pieces of 0.250" hot rolled steel, and this left
the toolpost too low. When I made a spacer, I used 0.75" thick CRS, and
even so it wasn't quite thick enough.

The aloris BXA is basically a cube 70mm on a side, versus 45mm high by
70mm square for the Dickson.

What I suspect happened is that people (probably the weld shop folk) had
the holder way too high in the toolpost, with half of the holder
sticking up above the toolpost, and a crash forced the holder out of the
toolpost, bending the T-plates in the process. What should have
happened instead is that tool should have snapped off, without damage to
the toolpost and holder. But the cockamamie setup generated lots of
leverage, so the toolpost lost the encounter.

The Aloris certainly seems robust enough to break a toolbit or bar.


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.

I've used the Morse taper holder (for BXA, not for Dickson) for
holding a drill chuck for power drilling through a workpiece at lager
sizes like 1", or for holding a Morse taper mount cut knurling tool for
experimentation. I've got the Morse taper to cylinder socket for the
turret for serious use, of course.

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

Indeed so.

It arrived today. What a difference. More later.

Joe Gwinn