On 2008-01-06, Joseph Gwinn wrote:
In article ,
Paul wrote:
[ ... ]
BXA is the correct size for this machine, and the Phase II I have has
been more than adequate even though it's the (GASP) dreaded piston
version. It works just fine, if you just have to have the wedge style
go for it but don't be afraid of the piston type. I've used a genuine
Aloris 'D' size and it was quite nice, this on a much larger lathe than
mine, I also have some experience with an 'A' size wedge type (I don't
know what brand) and found it to be somewhat lacking. I'm pretty sure
it was not an Aloris but which import I couldn't say.
All reports point to BXA as the correct size. Given the small price
differential between Aloris and the knockoffs,
That differential can be a lot larger if you luck into a sale
price on the Phase-II toolposts. (Unless you discover that they no
longer offer sale prices on the wedge style.
I'm leaning towards
genuine Aloris, but had not really thought about piston versus wedge.
I guess the piston approach is more-or-less equivalent in mechanical
solidity to the Dickson, despite the differences in mechanical setup,
and the Dickson is also reported to be adequate.
I believe the Dickson to be more rigid than the piston style
toolposts.
The wedge style pulls the dovetail holder into firm contact with
the wings of the dovetail on the toolpost, thus giving a fairly wide
base.
The Dickson style toolpost pulls (via the T-slot and cam-driven
T-bolt) the widely separated V-ways into firm contact, giving similar
support.
The piston style, however, pushes the holder *away* from the
toolpost, so the only firm contact is on the angled part of the
dovetail, and the center where the piston presses. The "wings" are
separated by a gap between the holder and the toolpost. To my mind,
this leaves a little more give possible.
Also -- a second thing to beware of with the piston style. If
there is no tool holder on either dovetail, the locking lever can rotate
a full 360 degrees, making it possible for the ball handle to come into
interference with the moving jaws of the chuck. I have read (here) of
it resulting in the ball handle being turned into shrapnel. Even aside
from this -- the angle at which the handle locks up the holder shifts by
90 degrees when you move from the turning station to the facing/boring
station.
All in all -- I am much happier with the Wedge style, though at
the time I did not know of the lock-up lever angle changes.
DoN gave me some good advice back when I got the Phase II which is to
replace the tool bit clamp setscrews with a decent USA brand. I bought a
box of 100 Holochrome brand and replaced them all. The original ones
were certainly of lesser quality and prone to stripping or splitting the
socket.
Yes. Steel and tempering quality seems to be a weakness in all Chinese
and Indian machine-tool products.
I'll be replacing all the clamp screws on the Dickson-style toolpost
holders that came with the lathe, probably with Holochrome. I gather
that the Holochrome cap screws have been adequate on your Phase II
holders.
They have in mine. FWIW, I wound up putting in imperial screws
instead of the metric ones. It *is* possible to re-thread them -- but
those holders are hard. The advantage to re-threading them is that I
use the same T-handled Allen wrench for both the Aloris and the Phase-II
holders. The Phase-II screws are 8mm, and the Aloris 5/16" (very close
in diameter), and the thread pitch is pretty close, so you don't have
much work to do until you are near the bottom of the threads in the
holder. I used a HSS gun tap for the purpose, and then replaced it with
a new and sharp one. Don't try it with a carbon steel one -- you will
almost certainly break that in the holders. :-)
I've made a couple of tool holders over time, the knurled thumb
nut is available from MSC, but I made a batch of my own. The jamb nuts
I purchased. I used imperial size fasteners for the homemade ones.
The lathe came to me with the familiar four position tool post, and was
adequate, just not convenient. The wedge post is for sure better.
I also got a 4-side screwclamp holder, but with no attachment hardware
whatsoever. Who knows what it was to fit, as it seems a bit undersize
for the lathe.
Just make another T-nut and tap it for a center post of the
proper diameter. I've got one -- which came from a 13" Jet, and which I
used for the very short time it took to get the Phase-II set. (Yes, it
was on sale at the time.)
Enjoy,
DoN.
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