DoN. Nichols wrote:
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.

We have several similar toolposts in our shop at work. There are
several different makers, all pretty much to the same plan. For the most
part, the toolholders interchange between posts of a similar size.

Any markings?

If I remember, I'll check the names on the ones we have. Made in
Italy, IIRC. Definately not Dixon, but of that design.

Cheers
Trevor Jones