Subject: Re: Lathe Parting (Cut-off) Tool

From: "John R. Johnson" <[email-masked]>
Date: Wed, 4 Dec 1996 11:17:54 -0600

On Mon, 2 Dec 1996, Charles Stroom wrote:

> In article <[email-masked]>,
> Roger Peterson  <[email-masked]> wrote:
> >
> >Really recommend that everyone consider an Aloris/Dorian/Armstrong
> >gib-type tool post before going to the trouble of installing a
> >rear-mounted system.  ALL of your lathe work will be much easier and a
> >better quality finish.
> >
> >Roger...
> >
> >
> 
> Would somebody be so kind to point to somewhere where I can see
> a picture/drawing of an "Aloris/Dorian/Armstrong gib-type tool
> post".
> Thanks,
> 
In the December MSC sales catalog.  They have their Phase I Piston
tool post sets on sale about 30% off the normal price.  

John

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From: [email-masked] (James Wilkins)
Date: Wed, 04 Dec 1996 12:57:15 -0400

> It also helps (a lot) to have some form of coolant in the cut.  On
> CNC, that's easy, but on the manual, I just drip Tap Magic (Original)
> or Cool Tool II into the cut as it is cutting.  It is also important
> to keep a constant feed.  

>>>>> The best way is to USE the power feed (if available). <<<<

I pound this into our employees, who seem to be afraid to
> use power feed for cut off, but it really works better than trying to
> hand feed.
> 
> Scott Logan

Just to add another cutoff tool data point, I've been getting good results
on stainless with the Enco / Swiss type toolholder, the one with a 40
position vertically splined column. They aren't worth the ~600 list price
but my set cost $50 second hand. Apparently they are unwanted orphans.

-- 
James Wilkins
The Mitre Corp.
Bedford, MA

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From: [email-masked] (Jens)
Date: Wed, 04 Dec 1996 08:35:25 -0800

[email-masked] (Scott Logan) wrote:

>I've heard that that type is actually far superior to the Aloris type
>and its clones.  Not sure why, in fact, I've never even looked at one
>closely.

I've looked at them from afar ....longingly

One thing that drives me nuts with a standard Aloris type post is the
fact that the base has to be re-aligned a lot.
Let's say you want to cut threads - you set your compound to 28
degrees but then you need to loosen the toolpost, re-align and (if you
are picky) indicate it. This seems a great big waste of time to me. I
would rather be able to set up the post once and forget about it ...
then just move the holder over a few notches.

I guess since they are fixed notches getting an angle exact could be a
problem. Also, if you want to make a tool holder, that kind of a
holder would be very difficult to build.

Jens

PS.: Never used one of those fancy splined holders so take my opinion
with several grains of salt.

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From: [email-masked] (Charles Stroom)
Date: Thu, 5 Dec 1996 13:36:27 GMT

In article <[email-masked]>,
Kevin Meier  <[email-masked]> wrote:
>Charles Stroom wrote:
>If you don't have an aversion to downloading 2Mb movies, there is
>a fairly good .mpg of one of these posts being installed on a lathe
>and a tool-holder installed on the post at:
>
>  http://www.nmis.org/EducationTraining/machineshop/05/l_toolpost.mpg
>
>But, again, this is 2 Megabytes, so don't expect it to pop right up
>unless you have a blindingly fast link.
>
>	Kevin Meier

like a charm!  40 secs to download, a good video and thanks for the
very useful http address.  It is really great.

-- 
Charles Stroom, ESTEC/YCV

[email-masked]
European Space Technology Centre, Noordwijk, the Netherlands

---

From: [email-masked] (Charles Stroom)
Date: Tue, 3 Dec 1996 16:40:34 GMT

In article <[email-masked]>,
Jens <[email-masked]> wrote:
>[email-masked] (Charles Stroom) wrote:
>
>Any tool supplier will carry these (or their clones).
>MSC is one supplier of course but even a local (to you) supplier
>should know what it is or have them listed in their catalog.
>Jens

Sure about that?  Aloris etc. exports to Europe?  But some kind souls
sent me a picture and now I do know what it is and yes, I have
seen them (but different manufacturers:-)

Cheers,

[email-masked]

---

From: Abrasha <[email-masked]>
Date: Sat, 07 Dec 1996 01:06:42 -0800

> very useful http address.  It is really great.

40 SECONDS!  What kind of connection do you have. A cable modem, because even ISDN 
doesn't do that file in 40 seconds.  I'm jealous!

Abrasha (ook Nederlander, maar woonachtig in San Francisco sinds 1977)
http://www.abrasha.com

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From: [email-masked] (Peter Drumm)
Date: 7 Dec 1996 13:56:06 GMT

In message <[email-masked]> -
[email-masked] Dec 1996 17:53:33 GMT writes:
:->Works for me. It is actually a lot harder to describe than it is to do.
:->
:->Peter
:->Still screwing around in the shop.
:->

Sounds like it works, but I still think my method is simpler. I keep
the compund at 29d, unless I'm turning some odd angle. I made a tool
holder years ago that holds an indexable turning tool on one side, and
a indexable threading tool on the other. All I have to do is rotate
the holder 180d and start threading :)

[email-masked] <http://www.dwave.net/~pdrumm>
Using OS/2 Warp 4!
Wausau, WI. 44d 58m 00s N x 89d 36m 45s W
All opinions are mine alone, you go get your own!

---

From: Kevin Meier <[email-masked]>
Date: Thu, 05 Dec 1996 15:25:21 -0500

> very useful http address.  It is really great.

I probably should have also mentioned that this is a part of a whole
series, which has a lot of good "getting started" kinds of instructions
for a bunch of different machines.  The root URL is:

http://me.mit.edu/2.70/machine/outline.html

You probably have already found all of this, but maybe there is
someone who has not yet seen it.

	Kevin Meier

---

From: [email-masked] (Jim Hanrahan)
Date: Fri, 6 Dec 1996 15:39:49 GMT

In article <[email-masked]> [email-masked] (Scott Logan) writes:

> It is also importantto keep a constant feed.  The best way is to USE the 
> power feed (if available).  I pound this into our employees, who seem to be 
> afraid touse power feed for cut off, but it really works better than trying 
> to hand feed.

I second the use of power feed for cut off, works great; takes some nerve.

--------------------------------------------------------------
  Jim Hanrahan, PE, CP-IA         Naval Surface Warfare Center
  [email-masked]      Annapolis, Maryland, USA

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From: [email-masked] (James Wilkins)
Date: Fri, 06 Dec 1996 13:23:47 -0400

> holder would be very difficult to build.

The only advantage I've found is that it is easy to adjust the angle of
hand-ground HSS bits in forged toolholders to both turn and face. The base
still gets realigned a lot. I'll have to try moving the compound 27
degrees (3 notches) for threading. The BIG disadvantage is that
toolholders are about $100 and hard to find second hand. 

The toolholder geometry isn't too hard to duplicate. If the holder blank
is set up to rotate around what would be the axis of the post, using an
angle plate on a vertical rotary table, the grooves can be milled with a
single point vee tool in a boring bar.

-- 
James Wilkins
The Mitre Corp.
Bedford, MA

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From: [email-masked] (Charles Stroom)
Date: Mon, 2 Dec 1996 10:59:48 GMT

[email-masked]

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From: [email-masked] (Scott Logan)
Date: Thu, 05 Dec 1996 01:01:04 GMT

On Wed, 04 Dec 1996 12:57:15 -0400, [email-masked] (James Wilkins)

Scott Logan
[email-masked]
www.loganact.com

---

From: [email-masked]
Date: 6 Dec 1996 17:53:33 GMT

In article <[email-masked]>, [email-masked] (Jens)

>then just move the holder over a few notches.

Seemed like a good idea to me too.

About that 28 degrees. I have seen mention of doing tis but I was taught
(103 years ago) to cut threads differently.

1. Leave the compound where it normally is but set its hand wheel to zero
with the backlash taken up in the direction of cutting towards the chuck.

2. Get your calculator and divide the pitch by 2.

3. Move the cutter up to the work so that it jusr barely marks the turning
shaft to be threaded.

4. Remember the hand wheel setting on the cross slide.

5. Pull to the right of the shaft and advance the cutter for the first
pass.

6. Cut it.

7. Go back to the right of the work for the next pass.

8. Advance the cross slide for the next cut and *also* advance the
compound by about a 0.001" not important, just enough to give clearance on
the right side of the tool during the cut.

9. Cut it.

10. Repeat 7-9 until you are about 0.001 or 0.002 prior to full depth of
cut. *Warning* as you advance the compound for each subsequent cut *do
not* exceed the total travel you calculated in step 2. Advancing the
compound is only to give clearance on the right side of the tool.
Sometimes you may only need to adjust it forward for every second pass.

11. Rewind the compound to the original setting, taking up any backlash as
needed.

12. Move the crosslide in the last 0.001 or 0.002 and make your final cut.
This will cut on both sides of the tool and clean up.

Works for me. It is actually a lot harder to describe than it is to do.

Peter
Still screwing around in the shop.

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From: [email-masked] (Jens)
Date: Thu, 05 Dec 1996 23:56:14 -0800

[email-masked] wrote:

<snip>

>It is actually a lot harder to describe than it is to do.

It took me several reads to figure out what the heck you are doing but
eventually the lights came on ...... seems like a lot more efford to
do though.

Jens

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From: Paul Pierce <[email-masked]>
Date: Fri, 06 Dec 1996 20:06:09 -0700

Jim Hanrahan wrote:
> > It is also importantto keep a constant feed. .....

Mike Hovda (went into T&D in 1950 when I went into electrician's
apprenticeship) told me:
1.  Razor sharp tool.
2.  On center.
3.  Power feed.
He could really make the parting tool sing...  While I about
filled my britches....  Nerve is right---.  I still stand back
a bit when I try it but when I remember what Mike said seems
like luck is with me.
-- 
Paul in AJ AZ  NRA Endowment Member

Checkout the Metal Web News at:
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http://www.ten.k12.tn.us/~wgray

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From: [email-masked]
Date: 7 Dec 1996 05:52:17 GMT

>eventually the lights came on ...... seems like a lot more efford to

Nope, actually easier than turning the compound and resetting it. Well for
me it is anyway, may not be for everyone. You can take much heavier cuts
too and get done in half the time.

Peter