left hand boring bar
mikec
cutting edge is acceptable. Anybody got a lead on where I can buy one
of these?
Thanks
Mike
Will be in LV for Christmas (steve?)
Buerste
"mikec" <mcru...@gmail.com> wrote in message
news:b6b1d7cd-fd59-4a27...@z3g2000prd.googlegroups.com...
Why? Explain the job and you might get a better idea how to do it.
Karl Townsend
>> looking for a left hand boring bar; C6 or m42 tip , small radius
>> cutting edge is acceptable. Anybody got a lead on where I can buy one
>> of these?
...
> Why? Explain the job and you might get a better idea how to do it.
The only thing i could think of is left hand inside threading, but he's not
looking for a thread tool. But it got me thinking, I don't know how to cut a
left hand thread on my manual lathe anyway. How is this done?
Glenn Lyford
> looking for a thread tool.
Boring a hole with a bridgeport in back gear? Except you can reverse
the rotation on the motor. Double chuck CNC lathe, and he needs
tooling for the finish operations in the 2nd chuck?
> But it got me thinking, I don't know how to cut a
> left hand thread on my manual lathe anyway. How is this done?
Simply put, spindle running forwards, thread away from the headstock;
or thread towards the headstock with the spindle in reverse. Note
that you'll have to change the relief on the cutting tool to
compensate.
--Glenn Lyford
Lloyd E. Sponenburgh
4918-824a-0...@a32g2000yqm.googlegroups.com:
> Note
> that you'll have to change the relief on the cutting tool to
> compensate.
>
yeah... quite some large amount, too, if you're running in reverse...
almost like running the tool upside-down. (no... wait... it IS upside-
down!) <G>
LLoyd
Mark Rand
You'll need one if you put it in the side hole of a boring head :-)
Mark Rand
RTFM
mikec
> On Thu, 17 Dec 2009 05:46:13 -0600, "Karl Townsend"
>
EXACTLY!!! That is what I'm doing.......very large hole.
Robert Nichols
In article <a68ab4ed-e2ce-4cd0...@g4g2000pri.googlegroups.com>,
mikec <mcru...@gmail.com> wrote:
:On Dec 17, 10:28=A0am, Mark Rand <ra...@internettie.co.uk> wrote:
:> On Thu, 17 Dec 2009 05:46:13 -0600, "Karl Townsend"
:>
:> <karltownsend....@embarqmail.com> wrote:
:>
:> >>> looking for a left hand boring bar; C6 or m42 tip , small radius
:> >>> cutting edge is acceptable. Anybody got a lead on where I can buy one
:> >>> of these?
:> >...
:> >> Why? =A0Explain the job and you might get a better idea how to do it.
:>
:> >The only thing i could think of is left hand inside threading, but he's =
:not
:> >looking for a thread tool. But it got me thinking, I don't know how to c=
:ut a
:> >left hand thread on my manual lathe anyway. How is this done?
:>
:> You'll need one if you put it in the side hole of a boring head :-)
:>
:> Mark Rand
:> RTFM
:
:EXACTLY!!! That is what I'm doing.......very large hole.
Your mill can't run its spindle in reverse?????????????
--
Bob Nichols AT comcast.net I am "RNichols42"
David Billington
can't run them in reverse unless you take special precautions to stop
them coming undone.
Buerste
We never had any of them fancy "Store-Bought" tools when I was young. We
made boring bars by drilling a hole in a steel bar. I have some that the
hole is drilled at a 45 deg angle and some perpendicular. A HHS tool bit
fits in the hole and is held with a set screw.
Robert Nichols
David Billington <d...@djbillington.freeserve.co.uk> wrote:
:Robert Nichols wrote:
:>
:> Your mill can't run its spindle in reverse?????????????
:>
:>
:Many of the boring heads use a threaded fitment to the arbor so you
:can't run them in reverse unless you take special precautions to stop
:them coming undone.
Ahh yes, that would be a problem. My boring head has an integral
shank, so I didn't consider that factor.
mikec
<SEE_SIGNAT...@localhost.localdomain.invalid> wrote:
> In article <4b2b8f2c$0$2485$db0fe...@news.zen.co.uk>,
So I bought a solid carbide bit....$56 (OUCH!) Should get here monday
via ups.
Jim Wilkins
> > :Many of the boring heads use a threaded fitment to the arbor so you
> > :can't run them in reverse unless you take special precautions to stop
> > :them coming undone.
It's called "Loctite", works well and releases when heated.
I simply screwed the head on tight. The boring bar will break before
it can apply as much torque as a big wrench
> So I bought a solid carbide bit....$56 (OUCH!) Should get here monday
> via ups.-
You know, the extra stiffness of solid carbide isn't necessary when
you cut with the end of the bar. A little deflection won't change the
diameter of the hole.
You can regrind the end of a right hand boring bit. The lost shank
clearance generally doesn't matter for the side hole of a boring head.
jsw
mikec
Maybe I'll try this next time.......don't think I want to take a
chance of breaking my $56 bit!
> So I bought a solid carbide bit....$56 (OUCH!) Should get here monday
> via ups.-
You know, the extra stiffness of solid carbide isn't necessary when
you cut with the end of the bar. A little deflection won't change the
diameter of the hole.
Not very concerned with that tight of tolerances so not worried about
any deflection but I could not locate a carbide tipped bar....any
suggestions as to where I could get one?
You can regrind the end of a right hand boring bit. The lost shank
clearance generally doesn't matter for the side hole of a boring
head.
How would you do this on a carbide tipped bar? I might think about
trying that next.
Thanks
Mike