This isn't my auction, but I have some of these tool holders:
http://cgi.ebay.com/ws/eBayISAPI.dll...omMakeTra ck=
true

I'm thinking that if I can get the post that these are meant for it would
serve well on my 12" Harrison.

But I can't seem to find a source for these in Canada or the States.

For that matter, I don't even know if they are called Colchester quick
change.

Can anyone confirm the ID or point me to where they sell them?

Thanks for the help.

DOC

Buy my junk! http://www3.sympatico.ca/doc/robotone/for-sale.html

I have a Colchester Master 13" lathe, it came with a post and 9
holders, I think these are known as Dickson toolposts in the UK

http://www.crawford-collets.co.uk/pr...qctoolpost.htm

This was the first pic I found, hope it helps.

Yes. That's a help. Thanks.

A little more digging on the Dickson name and I came up with
the UK lathes site and this info:
http://www.lathes.co.uk/latheparts/page13.html

And I have located some places that sell these but all of them
are in England.

The prices so far seem to be about the 100 pound
range. And shipping prolly expensive as well.

Humm.... Thinking maybe another project here! :-)

DOC

"shedfull" wrote in message
oups.com...
I have a Colchester Master 13" lathe, it came with a post and 9
holders, I think these are known as Dickson toolposts in the UK

http://www.crawford-collets.co.uk/pr...qctoolpost.htm

This was the first pic I found, hope it helps.

Before I got my master I was thinking of making a QCTP,

got some ideas here,

http://homepage.ntlworld.com/v.ford/gt.htm


also,

http://homepage.mac.com/bhagenbuch/m...es/freeby.html

try,

http://www.gadgetbuilder.com/ToolHolders.html#Tangent

Food for thought ?

Lee

In article .com,
shedfull wrote:
Before I got my master I was thinking of making a QCTP,

got some ideas here,

http://homepage.ntlworld.com/v.ford/gt.htm


also,

http://homepage.mac.com/bhagenbuch/m...es/freeby.html

try,

http://www.gadgetbuilder.com/ToolHolders.html#Tangent

Food for thought ?

Well -- as far as I can tell, he already has the toolpost and
some holders, and wants to get more holders.

What he has is akin to the QCTP on my Emco-Maier Compact-5/CNC,
though his is almost certainly larger, since the Compact-5 is a 5" swing
machine.

It is an excellent design, as the "piston" on it (whose head
fits into a T-slot in the holders) *pulls* the holders firmly into contact
with the inverted V rails on the older. In this, it is more similar to
the Aloris wedge style QCTP than to the piston style ones made by some
of the clone makers, where the piston pushes the holder out to where it
is only making firm contact at the sides of the dovetail and the point
of contact of the piston.

However, it has two cams, one for each piston, and you need to
move the L-shaped wrench from one to the other when switching from
turning to boring/facing positions.

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

I actually have 4 of the holders.

And being the "optimistic engineer" type, I'm thinking that
all I have to do now is make up the toolpost! :-)

One thing I can't quite figure out though is how those pistons
are secured on some sort of cam inside the block.

Regards,
DOC





"DoN. Nichols" wrote in message
...
In article .com,
shedfull wrote:
Before I got my master I was thinking of making a QCTP,

got some ideas here,

http://homepage.ntlworld.com/v.ford/gt.htm


also,

http://homepage.mac.com/bhagenbuch/m...es/freeby.html

try,

http://www.gadgetbuilder.com/ToolHolders.html#Tangent

Food for thought ?

Well -- as far as I can tell, he already has the toolpost and
some holders, and wants to get more holders.

What he has is akin to the QCTP on my Emco-Maier Compact-5/CNC,
though his is almost certainly larger, since the Compact-5 is a 5" swing
machine.

It is an excellent design, as the "piston" on it (whose head
fits into a T-slot in the holders) *pulls* the holders firmly into contact
with the inverted V rails on the older. In this, it is more similar to
the Aloris wedge style QCTP than to the piston style ones made by some
of the clone makers, where the piston pushes the holder out to where it
is only making firm contact at the sides of the dovetail and the point
of contact of the piston.

However, it has two cams, one for each piston, and you need to
move the L-shaped wrench from one to the other when switching from
turning to boring/facing positions.

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

In article ,
DOC wrote:
I actually have 4 of the holders.

And being the "optimistic engineer" type, I'm thinking that
all I have to do now is make up the toolpost! :-)

One thing I can't quite figure out though is how those pistons
are secured on some sort of cam inside the block.

That part is easy.

1) The pistons have a hole large enough to drop the cam rod
through.

2) There is a hole the full diameter of the cam rod which
intersects the hole for the T-headed pistons.

3) The pistons are slid into the hole, with a spring behind them.

4) The cam rod (which has a hex head) has an eccentric surface
turned at the right height to engage the hole in the piston.
The maximum height of the cam is level with the OD of the cam
rod. Everything else is below that height.

5) The piston is pushed in and the cam rod is then dropped through
the hole in the piston.

6) When released, you can then turn the cam rod, and withdraw or
extend the piston.


The real trick is generating the inverse 'V's at the proper
spacing. That would be easier to do with a horizontal spindle mill and
a custom set of cutters stacked onto a single arbor. I see five
cutters. A wide slab cutter to take out the space between the 'V's, and
two pairs of angled cutters, facing each other to form the 'V's.

Enjoy,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

Been meaning to thank Don for the nice explanation of how
this thing works. Kind of a break out diagram in words! :-)

Meanwhile, I have been busy scrounging and managed to
come up with a somewhat BROKEN example of the toolpost
I now plan to build.

It's the right size, an S2, so it makes figuring measurements
dead easy.

Couple pics show the post itself and the cam just as Don
described in one of his posts.
http://www3.sympatico.ca/doc/dickson1.jpg
http://www3.sympatico.ca/doc/dickson2.jpg

If you are wondering, this is not an original Dickson but
a copy that was made by a tech school in Toronto.

That probably explains why two of the three holes for the cam
are completely broken off.

Even still, I figure that someone must have put an awful
LOT of torque on the cams in order to wreck up the block
that badly.

Don also commented on how you might want to mill out this
shape and suggested multi cutters on a horizontal mill.

I am lucky enough to have some large V blocks, so my
plan is to use a my vertical mill and mill the critical
V surfaces by mounting the block like so:
http://www3.sympatico.ca/doc/dickson3.jpg

The fun continues.

DOC

Buy my junk! http://www3.sympatico.ca/doc/robotone/for-sale.html










"DOC" wrote in message
. ..
I actually have 4 of the holders.

And being the "optimistic engineer" type, I'm thinking that
all I have to do now is make up the toolpost! :-)

One thing I can't quite figure out though is how those pistons
are secured on some sort of cam inside the block.

Regards,
DOC





"DoN. Nichols" wrote in message
...
In article .com,
shedfull wrote:
Before I got my master I was thinking of making a QCTP,

got some ideas here,

http://homepage.ntlworld.com/v.ford/gt.htm


also,

http://homepage.mac.com/bhagenbuch/m...es/freeby.html

try,

http://www.gadgetbuilder.com/ToolHolders.html#Tangent

Food for thought ?

Well -- as far as I can tell, he already has the toolpost and
some holders, and wants to get more holders.

What he has is akin to the QCTP on my Emco-Maier Compact-5/CNC,
though his is almost certainly larger, since the Compact-5 is a 5" swing
machine.

It is an excellent design, as the "piston" on it (whose head
fits into a T-slot in the holders) *pulls* the holders firmly into
contact
with the inverted V rails on the older. In this, it is more similar to
the Aloris wedge style QCTP than to the piston style ones made by some
of the clone makers, where the piston pushes the holder out to where it
is only making firm contact at the sides of the dovetail and the point
of contact of the piston.

However, it has two cams, one for each piston, and you need to
move the L-shaped wrench from one to the other when switching from
turning to boring/facing positions.

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

In article ,
DOC wrote:
Been meaning to thank Don for the nice explanation of how
this thing works. Kind of a break out diagram in words! :-)

You're welcome.

Meanwhile, I have been busy scrounging and managed to
come up with a somewhat BROKEN example of the toolpost
I now plan to build.

It's the right size, an S2, so it makes figuring measurements
dead easy.

Couple pics show the post itself and the cam just as Don
described in one of his posts.
http://www3.sympatico.ca/doc/dickson1.jpg
http://www3.sympatico.ca/doc/dickson2.jpg

Ouch!

If you are wondering, this is not an original Dickson but
a copy that was made by a tech school in Toronto.

And it has *three* tool mounting faces, instead of the two which
have been on all that I have seen.

That probably explains why two of the three holes for the cam
are completely broken off.

I wonder whether it was over-hardened (not tempered enough)?

Even still, I figure that someone must have put an awful
LOT of torque on the cams in order to wreck up the block
that badly.

Yep -- *twice* at least. How big a cheater pipe did they use --
and *why*?

Don also commented on how you might want to mill out this
shape and suggested multi cutters on a horizontal mill.

I am lucky enough to have some large V blocks, so my
plan is to use a my vertical mill and mill the critical
V surfaces by mounting the block like so:
http://www3.sympatico.ca/doc/dickson3.jpg

That looks as though it will work. Remember that you only need
two faces, one for turning and one for boring/facing. I'm not sure what
the other station might be used for. Perhaps turning near the end of a
skinny workpiece supported by a fat live center?

The fun continues.

Indeed.

Good Luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

In article ,
DOC wrote:

"DoN. Nichols" wrote in message
...
...

If you are wondering, this is not an original Dickson but
a copy that was made by a tech school in Toronto.

And it has *three* tool mounting faces, instead of the two which
have been on all that I have seen.

The uk.lathes site shows the post with three faces.

Interesting.

Other than the number of sides, does yours fit the "spec"
that they show?
http://www.lathes.co.uk/latheparts/page13.html

Well ... without going downstairs and actually *measuring*, I
think that mine is pretty close to the "S00" size. It has only the two
sets of dovetails, at 90 degrees to each other, and does *not* have the
hole for the pin (which would be rather nice to have, actually).

The dimensions *may* be different, depending on whether Emco
makes this one themselves, or buys them from Dickson.

The dimensions look rather strange for metric units, so I
converted the 'L' dimension to imperial units, and I come up with
2.2441", which is pretty close to 2.25". I wonder whether these were
designed before the metric takeover in the UK?

The "B" diameter for the "S0" converts to 0.8748 -- pretty close
to 0.875" (7/8"), so I suspect so.

If mine turns out to be actually made to even mm dimensions, we
can assume that it was made by Emco-Maier (or a subcontractor) using the
basic design of the Dickson toolposts.

[ ... ]

Even still, I figure that someone must have put an awful
LOT of torque on the cams in order to wreck up the block
that badly.

Yep -- *twice* at least. How big a cheater pipe did they use --
and *why*?

Sometimes, when students are involved, asking why doesn't get
you any useful information. :-)

I'm sure that some of them, at least, could not answer the
question -- even if they tried. :-)

http://www3.sympatico.ca/doc/dickson3.jpg

That looks as though it will work. Remember that you only need
two faces, one for turning and one for boring/facing. I'm not sure what
the other station might be used for. Perhaps turning near the end of a
skinny workpiece supported by a fat live center?

AFAIK, you can mount three tool holders at the same time. So you could do
something like one each for facing, turning & boring.

Not much point to that with a quick-change toolpost such as this
is. You only *need* the two sets of ways. Normally, you just mount the
toolpost square to the chuck face and the spindle axis, and drop on a
tool holder in either the turning or the boring/facing station. Even
the Aloris for larger machines has only two dovetails -- at least any
that *I* have seen.

Now -- I could see using the center station as the turning one,
and the two others as boring/facing for larger or smaller sizes, if the
cross-slide does not have enough travel. (My Compact-5/CNC has two
tapped holes for placing the toolpost either for work close to the
center of the spindle, or for larger work (which probably won't clear
the cross-slide, so it has to be short, anyway. :-)

Or one of those could be knurling. I learned that the hole that you see
in the post on the fourth side is there so that you can drop a pin down
it. The pin fits into a hole in the toolpost or a block that is secured
in the toolpost.

You mean a block secured to the compound (if fitted) or the
cross-slide?

That way the post is not likely to rotate off square when
you are doing the standard knurling operation.

But you are thinking in turns of rotating it, as you do with a
turret toolpost. That is a *very* inefficient way to use a
quick-change toolpost, because you waste time getting the angle adjusted
right each time you loosen it to turn it. (Unless you have a full set
of index holes for the pin drilled around a raised center which ensures
that the center of rotation would remain fixed.

Generally, if I need an angled cutting edge, I have a different
tool in another holder which provides the tool edge at the desired
angle. I almost *never* loosen and rotate the toolpost. (It takes too
long to get it set *properly* again.)

Enjoy,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---