In article ,
Daniel A. Mitchell wrote:
ATP* wrote:
"Jaggy Taggy" wrote in message
...
On my recently acquired Reed & Prentice lathe is an old style tool holder
(lamp post style??) which really sucks.
But the alternative, get a modern stable setup, is a bewildering task.
There
are many styles and a large swing in prices.
My lathe is a 12"
[ ... ]
You'll probably be happy with the cheaper Enco kit, which goes on sale at a
substantial savings periodically.
[ ... ]
I've had good luck with the wedge type Phase-II toolpost. The wedge
posts are a bit more expensive than the piston type, and a bit more
rigid, all else being equal. Phase-II makes both types. The toolholders
are the same for either type. That said, many are happy with the piston
posts for occasional or lighter work.
For a 12" lathe you'd likely want the '200' series (aka; "BX' series) size.
I agree with both choices -- as they match the ones which I made
for my 12x24" Clausing -- 200 series Phase-II (same as BXA size for
Aloris and some other brands, whose tool holders you can also use with
the Phase-II toolpost).
My considerations we
1) The AXA/Series 200 size was at its maximum range on a 12" lathe
so I figured that the next size up would be under less stress
on heavy cuts.
2) The Design of the wedge style pulls the holder against the
flats on either side of the dovetail, producing a more rigid
lock-up than the piston style, which pushes the holder *away*
from the body of the toolpost, producing lock-up only on the
angled sides of the dovetail, allowing for a bit more flex.
I later discovered another reason for preferring the wedge
style. That is that the angle through which the locking lever swings on
a wedge style is limited, while it shifts about 90 degrees towards the
chuck when you shift from the turning (side) dovetail to the
boring/facing dovetail (side towards the length of the workpiece). And
when there is no tool holder on the toolpost, it is free to turn a full
360 degrees, which can bring the handle into contact with the spinning
chuck. At least one poster here in the past encountered this very
phenomenon, resulting in the plastic ball grip on the end of the locking
lever turning into shrapnel when hit by the chuck's jaws.
Note that once you have used the quick-change toolpost, you will
not want to go back to the lantern style for most things -- nor will you
want to go to a turret toolpost. The reason for this is that each tool
gets its own toolholder, which has an adjustment nut which can be
locked in position so every time you drop the tool holder onto the
toolpost and lock it, it will be at the same height. Even when you are
not in a hurry, you may be reluctant to change tools to a more
appropriate one if you have to stop the spindle and re-adjust the height
of the tool. (The same reasoning applies to a quick-change gearbox for
threading and turning when contrasted to a change gears style, where you
must get your hands rather messy changing the gear train to get the
proper feed rate. (You *will* have to change to get the proper pitch
for cutting threads, which may make you postpone learning to cut
threads.)
With a lantern style, you have to tweak the height of the
cutting edge each time you replace it.
With a turret style toolpost, you have to place a stack of shims
under the tool's shank to bring the edge up to the proper height. This
is not too bad for a production run, where you load the turret with the
tools you need for that project, and rotate to bring up the next one as
you finish one part of the task. There, the time for the setup to
height can be swallowed in time saved in the actual production -- even
over a quick-change toolpost. But for the kind of work which you
suggest you will be doing, the quick-change toolpost will make life
easier and your time in the shop more productive, and thus probably more
satisfying.
The other style which you mentioned, the KDK -- if it is the one
which I am thinking of -- is *very* nice, but *very* expensive,
especially in this country. It allows you to drop on the tools at 15
degree increments, so if you like to cut with angled tools, this would
be the one for you. But the price may discourage you from getting
enough of the tool holders to cover all of your tools, so you lose time
swapping tools in tool holders and having to re-adjust the height.
This is where the Aloris/Phase-II style really wins. There are
lots of makers of the tool holders, and they interchange between the
different brands (except in some cases with piston-style posts, where
the depth of the dovetail is too great, since the piston *has* to press
on the bottom of the dovetail, so the depth of the dovetail is more
critical. With the wedge style, the dovetail on the toolpost increases
in width to lock the holder to the post.
I hope that this helps,
DoN.
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