Brian Lawson wrote:
Hey Ron,

The Dicksons have another unique feature, in that they "lock' the
height adjust at the same time they lock the tool-holder. Dorians and
Phase II and all the others depend on your dropping the tool holder
onto the post and that it contacts the height-adjust plate atop the
tool-post correctly.


I think that is not quite correct, both the Dickson and Bison (Dickson
copy) toolholders I have are fitted with a threaded stud into the top of
the toolholder, the height adjustment knob screws onto this stud and
into the top of the knob is threaded a square headed set screw. The
height adjustment knob can be locked at the desired height by tightening
the set screw against the top of the stud. The locking cam pulls the
tophat plunger in to pull the toolholder to the toolpost and at the top
of the cam is a shelf that the height adjustment knob rests on.

Take care.

Brian Lawson,
Bothwell, Ontario.
XXXXXXXXXXXXXXXXX

On Tue, 20 May 2008 13:10:44 -0500, "Ron Moore"
wrote:


Don,
I'll bet you're right on the way the "pistons" work. I was wondering how
the pressure was working but you're way makes sense. Now if I can just
figure out what to do with it. Maybe mount a Unimat on it for stability.
Thanks again,
Ron


"DoN. Nichols" wrote in message
...

On 2008-05-19, Ron Moore wrote:

Found at the Guthrie tool swapmeet this weekend, a very large three
piston
(one per side) square tool post.

Are you sure that these are *pistons* to press? In my
experience, they are T-bolt heads to pull the holder towards the
toolpost. The post has two male 'V's per side (mine has only two sides,
not the three that yours has) and is smaller on an Emco-Maier
Compact-5/CNC lathe. The male 'V's on the toolpost fit into two female
'V's in the holders, and there is a vertical T-slot in between the two
female 'V's to accept the heads of what you are calling pistons.

Unlike the usual piston style toolposts, this locks up with
greater rigidity because it pulls two widely separated support surface
pairs together.

For my 12x24" Clausing, I have the wedge style toolpost, and for
the Compact-5/CNC I have the Dickson style (mine branded EMCO), and
consider both to be quite rigid. The one inconvenience to the Dickson
style in my opinion is that it needs a special wrench to be moved from
cam to cam to lock the different tool holder stations.


Crawford collets are noted on the tag.
About 4" tall and 5" square.

Not sure about the Crawford collets, but the Dickson toolposts
are from England, and one size (smaller than what you appear to have) is
common on the Myford lathes.


Anyone know anything about these guys? One
HECK of a doorstop.

You have what I know about them above.

Enjoy,
DoN.

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