Subject: Re: question - Lathe tool height

From: Max Elorza <[email-masked]>
Date: 18 May 1996 00:54:56 GMT

You might try a KDK tool holder.  It has a holder base with seperate  
holders for your different tool bits.  Each holder has a seperate height 
adjustment.  I recently bought a new lathe that came with a turret style 
tool post.  I am getting a KDK for my lathe.  It seems idiotic to me that 
the majority of tool holders do not have height adjustment.  You would 
think that with all the money you spend on a lathe, you would get a tool 
holder that doesn't require shimming.

---

From: Walt Slominski <[email-masked]>
Date: Fri, 17 May 1996 14:42:34 GMT

I am new to metalworking - The Southbend book indicates that the tool point
should be at the center of the work that is being turned.
The four way tool post on my 9x20 Jet does not have a height adj. and the 1/2"
square tool is a little below center. Should I shim the tool to the correct
hieght?
Also the tool holder cannot be tilted - the book shows most cutters at an
angle to the work.

The tools I am using are 1/2" square carbide tipped (80 degree point and
square tip).

How about some recomended reading.

Thanks, Walt

---

From: [email-masked] (Jonathan M. Elson)
Date: 20 May 1996 21:26:18 GMT

Steve Wellcome ([email-masked]) wrote:
: Yes, you'll probably need to shim the height.  Get some .010",
: 005", and .002" feeler gauge stock and keep a few pieces of 
: each around; then you can easily build up any height without 
: much difficulty.  (In theory I suppose you might need some 
: 001" stock to get it within .001" of center, but I strongly
: suspect .002" is close enough!)

: You don't need the angled tool holders; the old "Armstrong"
: style tool holders have a built-in 10 degree angle, but in fact
: I think you're better off without it. If you need that angle on
: the toolbit, grind it.  In fact, there are some Armstrong tool
: holders designed for carbide that don't have that angle built
: into them.

The angle (positive rake) is desirable for aluminum.

: Incidently, I think you would be better off using high-speed
: steel for most things instead of carbide.  A small lathe simply
: isn't rigid enough to take advantage of carbide.  HSS is much
: more suitable, and works fine.

The lathe is often not the problem, it's that awful 'lantern' style
toolpost.  The cup washer, slider, (sometimes a shim) and tool holder
are a MASSIVELY flexible contraption.  Also, the armstrong-style holders
force you to keep the toolpost far away from the cutting edge, increasing
overhang and the moment arm on the compound.  This makes it very NON-rigid.
I changed from a lantern toolpost to an aloris copy some years ago, and
was astounded at the difference!  I have only had the lantern back on the
lathe twice in 5 years to use a specially formed tool bit.  Otherwise,
the quick-change stays on all the time.  Boring with a boring bar is 
difficult enough without adding any more flex to the lathe.

---

From: [email-masked] (Jonathan M. Elson)
Date: 19 May 1996 04:53:13 GMT

Max Elorza ([email-masked]) wrote:
: You might try a KDK tool holder.  It has a holder base with seperate  
: holders for your different tool bits.  Each holder has a seperate height 
: adjustment.  I recently bought a new lathe that came with a turret style 
: tool post.  I am getting a KDK for my lathe.  It seems idiotic to me that 
: the majority of tool holders do not have height adjustment.  You would 
: think that with all the money you spend on a lathe, you would get a tool 
: holder that doesn't require shimming.

I have a Phase II dovetail-type toolpost, a knockoff of the Aloris.  It is
a bit expensive, but I'll never go back.  It has a thumbwheel for vertical
adjustment, with a jam nut to lock the thumbwheel once you have it set
the way you want.  You can set the various tool holders, and then switch
back and forth from, say, turning tool to cutoff tool to boring bar, and
each tool keeps its setting.  Really nice.  you can see these in nearly
any machinist's supply catalog, ie. Enco, MSC, etc.

I use a combination of brazed carbide bits and indexable carbide holders.

---

From: Steve Wellcome <[email-masked]>
Date: 20 May 1996 12:37:03 GMT

Yes, you'll probably need to shim the height.  Get some .010",
005", and .002" feeler gauge stock and keep a few pieces of 
each around; then you can easily build up any height without 
much difficulty.  (In theory I suppose you might need some 
001" stock to get it within .001" of center, but I strongly
suspect .002" is close enough!)

You don't need the angled tool holders; the old "Armstrong"
style tool holders have a built-in 10 degree angle, but in fact
I think you're better off without it. If you need that angle on
the toolbit, grind it.  In fact, there are some Armstrong tool
holders designed for carbide that don't have that angle built
into them.

Incidently, I think you would be better off using high-speed
steel for most things instead of carbide.  A small lathe simply
isn't rigid enough to take advantage of carbide.  HSS is much
more suitable, and works fine.

Recommended reading: you've got the South Bend book.  I also
like "The Amateur's Lathe," by L.H.Sparey.  It's a British book,
but available from many of the "usual" hobby suppliers.

---

From: [email-masked] (Michael Edelman)
Date: 20 May 1996 19:26:18 GMT

Walt Slominski ([email-masked]) wrote:

: I am new to metalworking - The Southbend book indicates that the tool point
: should be at the center of the work that is being turned.
: The four way tool post on my 9x20 Jet does not have a height adj. and the 1/2"
: square tool is a little below center. Should I shim the tool to the correct
: hieght?

You can, yes.

: Also the tool holder cannot be tilted - the book shows most cutters at an
: angle to the work.

: The tools I am using are 1/2" square carbide tipped (80 degree point and
: square tip).

These tools are probably designed to run at 90 degrees to the work.

: How about some recomended reading.

South Bend's old "How To Run A Lathe" (reprints available from Lindsay;
originals available in every used bookstore I've ever been in!), plus
Guy Lautard's "Machinist's Bedside Reader", vol. 1,2 and 3.

--mike