On 2007-12-31, Joseph Gwinn wrote:
In article ,
"DoN. Nichols" wrote:
On 2007-12-30, Joseph Gwinn wrote:
[ ... ]
"Dickenson style" implies multiple makers. What are likely names?
Maybe Myford has a favorite maker?
AFIK, Myford uses genuine Dickenson (or is it Dickensen or some
other variant)?.
It turns out to be "Dickson", according to David Billington of the UK:
"The correct spelling is "Dickson", pic on the right here
As I saw a few articles past the one to which I replied. :-)
http://www.pratt-burnerd.co.uk/specialchucks_7.asp . I have a genuine
Dickson and a Toolmex made one and the holders are interchangeable."
And the current problem is that the site currently has their
catalogs down for updating (presumably for the new year), and they want
me to register to be notified of the update. I tend not to register at
sites unless I *really* need the information. :-)
The interesting thing about the illustration (which I had to
turn on Flash to view -- I hate things like that, too) is that it shows
a version with *three* tool stations, not just two at 90 degree
intervals like mine.
What *I* have is labeled with an EMCO tag, with no clues
whether it was made by someone else. I have seen a set of the same size
[ ... ]
Emco also made a different version where the T-slot in the
holders is off center, and a T-headed bolt runs through the block
(clearing the center bolt) with a nut on the opposite side to lock the
tool holder down. I've never seen these except in the service manual
for the Compact-5/CNC.
So, Emco is another possible source.
Note that is *Emco* -- not *Enco*. Emco is the Austrian maker
of lathes and milling machines which made my little 5" CNC lathe. They
used to make a matching manual lathe, but no longer do so.
[ ... ]
The one I have appears to be intended to mount on a cylindrical post
with a smaller cylindrical screw clamping it down. There is a sliding
pin with a rounded nose that is intended to engage location holes at
various angles in a plate that is not in evidence, to prevent rotation.
There is no taper.
O.K. There was no index detent on this one -- but the taper at
the bottom would lock it firmly once clamped down.
Probably the taper is used in a later version. It would be tough to
make the pin-in-hole version completely rigid, so I assume that one also
torques the central bolt down tight. Actually, the purpose of the pin
is probably to prevent annoying rotation while torquing down. Tapers
lock almost immediately, making rotation less of a problem.
The pin is almost certainly not intended to lock it in position,
but just to be an indicator to tell you when you have rotated it
sufficiently to cut the bevel which you want.
I tend to keep mine oriented so one side is parallel to the
workpiece axis and the other parallel to the chuck face. If I want a
bevel, I switch toolholders to one with an insert at the desired angle.
This assures that it is properly set up to hold threading insert tools
in the right position -- unless I've had to change the angle of the
compound -- such as for switching between standard threading or Acme
threading (or potentially Whitworth threading, if I ever do that), or
switching from right-hand threading to left-hand threading or back. In
those cases, I need to re-orient the BXA holder on my compound on the
12x24" Clausing. For the Compact-5/CNC with the Dickson style toolpost,
there is never any need to change the angle of the toolpost, as all
angled cuts are handled by the CNC itself -- including threading infeed.
I don't think this toolpost came with the lathe, as it is cobbled to the
lathe.
Note that when you get a new post -- even from Aloris -- unless
you have paid extra for the mounting plate to be specifically machined
for your lathe (in which case you will need to feed them information
about the lathe's T-slot), you will receive a blank mounting plate,
which you will need to mill to the proper dimensions for *your* T-slot.
Usually, this simply requires changing something like this:
/ /
/ /
+----------------------------------------+
| |
| | /
| |/
+----------------------------------------+
to something like this:
/ / / / / /
/ / / / / /
/ +------------------+ / / /
/ | |/ / /
+----------+ +----------+ /
| |/
+----------------------------------------+
So it will slide into the T-slot, leaving the height of the center just
a little below the top of the compound when it is pulled up as tight as
it can be. There is a pre-tapped hole in the center of the plate which
accepts the mounting rod on the toolpost.
Understood. It is not a common style in the US. I would not
bother using it for long -- but instead keep an eye out for an Aloris
style wedge in BXA size given the size of your machine. (I use BXA on
my 12x24" and am quite happy with it. And you even have a better chance
on eBay going for BXA than for AXA, because more of the hobby users are
going for the AXA size. :-)
I'll keep an eye out for BXA posts and holders. What's a reasonable
price?
There *is* no reasonable price in my opinion (as a retired
hobbyist on a fixed income) -- especially for a genuine Aloris. As a
result, I have a set of Phase-II wedge style which I got when they were
on sale (Series 200, which is the same size as the Aloris BXA series).
I've added to that extra holders which are Phase-II (always purchase new
American-made setscrews for holding the tool shanks, as the sockets in
the supplied ones tend to split out when you crank down on them). I've
also obtained Genuine Aloris holders from eBay and other used sources,
and purchased two specifically new -- because I could never find them in
an eBay auction which closed any lower than 10% under the new price in
MSC's catalog. :-) Those two are the BXA-16N (which mounts two
triangular carbide inserts -- one for turning and one for facing -- on
opposite ends of the holder), and an extended reach one (whose number I
forget, but you can find them in the MSC catalog) which is particularly
nice when threading, as it allows me to reach in with a threading tool
with proper support without hitting the live center with the toolpost.
Note that AXA size holds up to 1/2" shank tools, while the BXA
holds up to 5/8" shank tools -- and that extra 1/8" does make a
difference in rigidity.
I've also picked up some interesting Aloris only tools,
including a very nice knurling tool in which the knurls are held in two
arms which move on a vertical dovetail, with a leadscrew coupling them
with a left-hand thread for one and a right-hand thread for the other,
so they maintain the centering on the axis (once initially set), while
you adjust the spacing for the size of the workpiece being knurled. The
knurls apply to the top and bottom instead of having to be pressed in
with the cross-slide, so the load forces on the machine are much less
than with the common "bump" style knurlers -- which are often supplied
as part of an Aloris or Aloris-style kit. Those are mostly useful for
facing, using the half-toolholder in the other end. :-)
Enjoy,
DoN.
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