[TheForge] RE: Spinning

[Bob Ehrenberger]

Frosty,

What I have is an old engine lathe (circa 1920's or 30's).  I did a complete
cleaning on it when I got it and didn't find a make. For a tool rest I move
the cradle out of the way and put the tail stock in front of it. (I couldn't
get the cradle locked down tight enough to take the force of the spinning
tools).  For the tool holder frame I took a couple of pieces of heavy bar
stock (3/4 x 2"). I clamp them over the ways like the tail stock.  I made a
tool holder that slides over the top bar, it is a tight fit so it will slide
when there is no side force on it but locks in place when using the tools.
On the tool holder I have a bar 1 x 1 x 10  with a series of holes which I
put pins in to push against.

As the piece progresses it's easy to slide the holder in closer as the
material moves in over the form. When I need to move up the piece I just
move the pin into the next hole on the bar. I don't actually have to move
the main holder frame except when changing forms.

For my live center I got a broken drill bit that had a MT #2 shank, which
fits my tail stock. I took the MT shank and welded a piece of round bar
stock to it and bored a hole down the center. On the end I welded a heavy
flat washer. For the part that spins I got a rod the same size as the hole
bored in the round bar and welded a large flat washer to one end. This was
all designed to match the bearings that I had which consisted of a flat disk
with a series of roller bearings, kind of looks like a clutch disk.  With
the disk are two hardened washers for the bearings to use as races.  (the
bearings and races came out of an automotive AC compresser).  When
assembeling I slide the bearings and races over the smaller rod and slide it
into the hole bored in the larger rod connected to the MT shank. It spins
very smooth with moderate pressure but drags under heavy load.

The live centers I've seen in the books tend to be based on having a
hardened shaft riding on a single ball bearing at the bottom of a hole.

While I'm telling all I might as well talk about my forms.  I lucked into a
bunch of wooden forms from a tool collector that got them at an auction
along with something that he wanted.  He was using them for fire wood so
hard telling how many he had already distroyed before I got to him. He just
gave them to me since I was buying a bunch of other tools from him, and he
didn't want them. The classic way to attach forms to the head stock is to
either screw them to a face plate or bore and thread the form to screw
directlly onto the head stock.  I didn't do this. I have a large pipe flange
screwed to the back of the form with a short piece of pipe. I then clamp the
pipe into my 4 jaw chuck. This lets me center it on the tail stock by
adjusting the chuck.

Hope this helps, as you can see I don't do anything the usual way, but
usually figure out a way to make it work.

Robert Ehrenberger
Shelbyville, Mo.

+++ Original Message: +++
From: "Jerry Frost" <frosty@customcpu.com>
Subject: Re: [TheForge] RE: Spinning, was roses
Date: Sat, 3 Jan 2004 01:38:51 -0900

What kind of lathe do you have?

I plan on turning a live center to replace the live center (pointed) on my
machine lathe. Not knowing your setup makes it hard to make suggestions.
However <grin> I improvised a live center for the old Craftsman wood lathe I
have by turning one from wood and gluing it to the live center (pointed)
that came with the lathe.

The tailstock on the wood lathe isn't strong enough for a good friction hold
on a blank so I wiped the contact face of the wooden live center mod with
silicone calking. After it dries it's grippy enough the blank doesn't slip,
provided it isn't too large or heavy gage.

Frosty