Hi Dennis,
Thanks for all the information.? The
odd thing about my collets is that they seem to be .004 - .005
undersized from the advertised dimensions for thread diameter and
shaft diameter.? That said, I don't see how that could account for
the complete lack of thread engagement.? I'll try to send it back.
Thanks again,
Peter
On 3/1/25 2:48 PM, Dennis Turk via
groups.io wrote:
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One other thing I forgot.? The end gear on the end
of the spindle is also special as it has an extended sleeve that
supports the lever operated closer to the end of the spindle.?
The lathe in the picture was originally a pedal powered lathe
that I found in California.? It was missing many things
including the pedal setup as well as the tail stock?and compound
slide.? What remained was in almost like all new condition and
as I had the missing parts I was able to complete the lathe.? I
also used a cast iron pedestal?for mounting it as it
originally?had a Lot 6 lathe secured to it. The chip tray is
original to the pedal?lathe. The last picture is of how the
lathe was displayed at my business building along with 29 other
restored lathes, shapers and drill presses. After selling my
business in ;2019 all these display machines had to be removed
and most of them are now in storage at my home.? Anybody need a
lathe got lots of them:-))))
On Sat, Mar 1, 2025 at
11:40?AM Dennis Turk via <dennisturk448=
[email protected]>
wrote:
Some additional information.? A lever operated
collet closer had to be ordered when purchasing a Dalton
lathe.? The casting that supports the end door hinge for a
lever operated collet closer lathe is totally different that
what most have.? The casting has to support the end of the
lever collet handle.? Also the casting that covers?to pupper
part of the spindle?is also special to a lever operated
collet closer as it has to have the two pins that
support?the tilt up collet closer guard.
On Sat, Mar 1, 2025 at
11:35?AM Dennis Turk via
<dennisturk448=
[email protected]>
wrote:
Hi Peter
I have Dalton as well as SB and Hardinge 3C
collets.? They only vary a couple of thousands?in
outside?thread diameter but that is not the critical
dimension.? The?pitch diameter?of the thread? is what
counts, not the outside diameter.? If your collets
slide in and out of the threaded end of the draw tube
this is very odd.? It may indicate that the thread in
the draw tube is totally?worn out as I have seen this
on a couple of SB draw tubes.? Especially?on the lever
operated collet closer as they can exert way more
force than a hand wheel draw bar. As to lever operated
Dalton draw bar setups they are very rare.? I have one
for a Lot 6 and Dalton 9 inch but do not have one for
the smaller lathe.? I only know of one that is owned
by a guy near Chicago and he loaned it to me when we
exhibited?at the NAMEs model engineering show in
2016.? Ralph also has many other Dalton accessories we
only see in catalogs. Pictures attached were taken
when Ralph loans?me his lever operated collet closer.?
Just some information guys.
Well...
I've got a problem.? I ordered a 3C Collet Draw Bar
from Ebay
that is a bit longer than the Dalton draw bar I have.?
I chose to do
this because I didn't want to butcher the Dalton draw
bar for more
extension.
I received the draw bar but when I went to screw in
the Dalton collet it
just slid right in. No thread engagement at all.? I
looked up 3C collet
dimensions and as you would expect there are more than
one dimension
documents that don't appear to match.
South Bend collet dimensions for a #3 collet which is
claimed to be
compatible with 3-C collets shows an overall length of
2 7/16 which
matches my Dalton collet.? The diameter of the collet
shaft is .6495 on
the chart and my Dalton collet diameter is .645, a
difference of .0045.?
The thread length on the chart for a 3-C is .750 and
the Dalton collet
thread length is .600.? The thread diameter on the
South Bend chart is
.642 which is very close to the Dalton collet thread
diameter.
The inside diameter of the draw bar where threaded is
.654 which allows
my Dalton collets to slide in and out.
Before I ask to return this draw bar I want to make
sure that it is not
3-C as advertised.? I can't find a thread diameter on
the SB chart that
matches it so it may be a metric draw bar.
I was under the impression that 3-C was a hard
standard but if mistaken
please set me straight.
I want to make sure that I am correct before I ask to
a return the draw bar.
Thanks,
Peter